EPA 430/K94/029
MONTREAL PROTOCOL
ON SUBSTANCES THAT DEPLETE
THE OZONE LAYER
UNEP
1994 Report of the
Methyl Bromide
Technical Options Committee
1995 Assessment
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UNEP
1994 Report of the
! Methyl Bromide
Technical Options Committee
i
1995 Assessment
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Montreal Protocol
On Substances that Deplete the Ozone Layer
UNEP
1994 Report of the
Methyl Bromide Technical Options Committee
1995 Assessment
The text of this report is composed in Times Roman.
Co-ordination:
Composition and Layout:
Reprinting:
Date:
Jonathan Banks (Chair MBTOC)
Michelle Koran
UNEP Nairobi, Ozone Secretariat
30 November 1994
No copyright involved
Printed hi Kenya; 1994.
ISBN No. 92-807-1448-1
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1994 Report of the
Methyl Bromide
Technical Options Committee
for the
1995 Assessment
of the
U N E P
MONTREAL PROTOCOL
ON SUBSTANCES THAT DEPLETE
THE OZONE LAYER
pursuant to
Article 6
of the Montreal Protocol;
Decision IV/13 (1993)
by the Parties to the Montreal Protocol
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Disclaimer
The United Nations Environment Programme (UNEP), ihe Technology and Economics
Assessment Panel co-chairs and members, the Technical and Economics Options Committees
chairs and members and the companies and organisations that employ them do not endorse the
performance, worker safety, or environmental acceptability of any of the technical options
discussed. Every industrial operation requires consideration of worker safety and proper disposal
of contaminants and waste products. Moreover, as work continues -including additional toxiciiy
testing and evaluation- more information on health, environmental and safety effects of
alternatives and replacements will become available for use in selecting among the options
discussed in this document.
UNEP, the Technology and Economics Assessment Panel co-chairs and members, ;and the
Technical and Economics Options Committees chairs and members, in furnishing or distributing
this information, do not make any warranty or representation, either express or implied, with
respect to the accuracy, completeness or utility; nor do they assume any liability of any land
whatsoever resulting from the use or reliance upon, any information, material, or procedure
contained herein, including but not limited to any claims regarding health, safety, environmental
effects or fate, efficacy, or performance, made by the source of information.
Mention of any company, association, or product in this document is for information purposes
only and does not constitute a recommendation of any such company, association, or product,
either express or implied by UNEP, the Technology and Economics Assessment Panel co-chairs
and members, and the Technical and Economics Options Committees chairs and members or the
companies or organisations that employ them.
Acknowledgement
The UNEP Methyl Bromide Technical Options Committee acknowledges with thanks, die
outstanding contributions from all of the individuals and organisations who provided technical
support to committee members.
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1
EXECUTIVE SUMMARY
1. Committee Mandate
!
The Methyl Bromide Technical Options Committee (MBTOC) was established by the Parties to
the Protocol to review technical issues concerning methyl bromide, the material listed in Annex
E of the Protocol.
MBTOC, and this report in particular, address the technical availability of chemical and non-
chemical alternatives for the current uses of methyl bromide, apart from its use as a chemical
feedstock. It covers the methodologies to control emissions of methyl bromide into the
atmosphere, potential for recovery, reclamation and recycling and the issues of special
relevance to Parties operating under Article 5. It also provides an estimate of emissions to the
atmosphere from present uses.
The Committee currently consists of 68 members, with representation from 23 countries
drawn from a wide range of expertise and interests associated with methyl bromide, including
scientists, end users, manufacturers, NGOs, and government representatives from Parties
including 8 from Article 5 countries. j
I
2. Existing uses of methyl bromide i
Methyl bromide is principally used as a fumigant, controlling a wide spectrum of pests,
including pathogens, insects and nematodes. It has sufficient phytotoxicity to control many
weeds and seeds in soils.
It has features which make it a versatile and convenient material with a wide range of
applications. In particular, it is quite penetrative, usually effective at low concentrations and
leaves residues which have generally been found acceptable. Its action is usually sufficiently
fast and it airs rapidly enough from treated systems to cause relatively litde disruption to
commerce or crop production.
Methyl bromide is normally supplied and transported as a liquid in pressurised cylinders but at
ambient temperature and pressure, the material is a gas. These containers are typically cylinders
of about 10 to 200 kg in content, though there is also trade in larger containers and also small
pressurised disposable steel cans typically of 0.5 to 1 kg capacity eac h. Methyl bromide is
normally used directly from these cylinders or containers, but may sometimes be transferred to
smaller units.
Of the 1992 global sale of methyl bromide of 75,625 tonnes, 3.2% v/as used as a feedstock for
chemical synthesis. It is estimated that the remainder was used for soil treatment (76%),
fumigation of durables (13%), fumigation of perishables (8.6%), and fumigation of structures
and transportation (3.0%). The proportions for 1991, the base year, are similar to those for
1992. The Committee noted that, in the absence of controls, some developing countries expect
to expand uses of methyl bromide substantially. Global consumption,, excluding feedstock
uses, has increased about 3700 tonnes per year since 1984. ;
Although methyl bromide is clearly a most useful tool in specific instances, there are a number
of issues not related to the ozone depletion, which have led countries to impose restrictions on
its use. Concerns include toxicity to humans and associated operator safety and public health,
and residues. In some countries, pollution of surface and ground water by methyl bromide and
derived bromide ion is also of concern.
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3. Emissions from, methyl bromide use, and their reduction, including
recovery
•
Estimates of the proportion of methyl bromide released into the atmosphere vary widely.
Emissions occur inadvertantly through leakage and permeation during treatment and
intentionally while venting at the end of treatments. The quantity of methyl bromide emitted
from a treatment varies on an individual case basis as a result of the use pattern, the condition
and nature of the fumigated materials, the degree of seal of the enclosure, and local
environmental conditions. Methyl bromide is a reactive material: it is incorrect to equate
production with emissions as at least part of methyl bromide applied is converted in use to non-
volatile materials. i
Under current usage patterns, the proportions of applied methyl bromide emitted eventually to
atmosphere globally were estimated by MBTOC to be 30 - 85%, 51 - 88%, 85 - 95% and 90 -
95% of applied dosage for soil, durables, perishables and structural treatments, respectively.
These figures, weighted for proportion of use and particular treatments, correspond to a range
of 46 - 81% overall emission from agricultural and related uses (34,000 - 59,000 tonnes, based
on 1992 sales data).
Available containment techniques for decreasing methyl bromide leakage are in limited use
worldwide. Lack of adoption is constrained particularly by poor dissemination of information
and perceived or real increases in costs and logistical problems. A high degree of containment
is a prerequisite for efficient recovery of the used methyl bromide.
Better sealing of enclosures and the use of less permeable sheeting were identified as an
immediately applicable, technically proven means of reducing emissions from soil, durable
commodity and structural fumigations, with the largest improvement coming from soil
fumigation. These measures, combined with longer exposure times, may permit reduced
dosage levels while still achieving the required degree of pest control. Many facilities used for
fumigating perishables, particularly for quarantine, already have a high standard of
gastightness, leading to very low leakage rates (often less than 2% of dosage).
There is active research into the development of recovery and recycling equipment for methyl
bromide. A few special examples of recovery equipment are in use and it is anticipated that
prototype systems capable of recycling recaptured gas for some use areas will be evaluated by
the end of 1995. Most development work is directed at recovery from enclosures used-for
structure or commodity fumigation (about 22% of global non-feedstock production). Some
preliminary work on recovery for soil fumigation is in progress.
It is unlikely that significant demand from developing countries can be met with recycled
material. There is, however, potential for some recycling in some specialised applications,
including in Article 5 countries, when commodities, notably perishables, are treated in gastight
chambers.
Most of the potential recovery and recycling systems are complex and may be expensive to
install compared with the cost of the fumigation facility itself. Some systems would have high
running costs associated with energy requirements. Many would require a level of technical
competence to operate that would not normally be found at many fumigation facilities.
If recovery is to be recognised as an acceptable method of reducing methyl bromide emissions
to the atmosphere, it will be necessary to set specifications on aspects of fumigation, such as
equipment efficiency and tolerable levels for emission.
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4.
Alternatives to methyl bromide
There is no single alternative to methyl bromide in all of its wide ranges of uses. However,
technically, alternatives do already exist for a number of current applications.
A number of potential alternative chemicals have been identified. They include fumigants and
non-fumigants. However, the environment and health considerations, which may limit the use of
any pesticide, including methyl bromide, need to be taken into account when selecting alternatives.
Furthermore, it is very likely that regulatory restrictions on use of agrochernicals will increase,
resulting in higher costs of use and increasing inconvenience. Additionally, costs of achieving full
commercial registration of unregistered materials are high, and the process is slow. It was noted
that there are specific constraints on rapid implementation of some alternatives associated with the
time taken to gain registration and regulatory acceptance of some procedures. The problem is
particularly acute in some cases relating to treatment of exports to meet quarantine standards
where extensive trials and protracted bilateral negotiations may be required.
Many of the alternatives identified by MBTOC were of the 'not-in-kind' type. In a number of
cases a rational combination of procedures, including non-chemical measures, can be used to avoid
creating the circumstances where methyl bromide is currently regarded as in-eplaceable. This
approach, known as Integrated Pest Management (IPM), utilises pest monitoring techniques,
establishment of pest injury thresholds, and a mix of tactics selected to prevent or manage pest
problems. Emphasis is placed on producing a marketable crop using sale, environmentally sound
and cost-effective procedures. Chemical intervention, at present possibly including use of methyl
bromide, is employed only on the basis of need rather than by routine. The ability to design IPM
depends on a thorough knowledge of the pest or disease complex to be controlled.
In general, the effect on production and profitability will vary widely and may lead to increases,
or decreases, depending on local circumstances. In the only instance of methyl bromide phaseout
for soil fumigation throughout a country (the Netherlands) it is reported that adoption of some
alternatives have increased yields in specific crops.
i f
MBTOC estimates that by using known technology it is technically possible for Parties operating
under Article 2 to significantly reduce usage of methyl bromide. Estimates of the magnitude of the
reduction and its time scale varied widely amongst MBTOC members. Opinions ranged from a
reduction of 50% feasible by 1998, to decreases of only a few percent by 2001. Reductions should
be achievable through a combination of implementing alternatives and use of better containment
technology, together with longer exposure times and lower dosages for methyl bromide treatment,
particularly in soil fumigation. Achievement of such reductions may entail use of some
alternatives which may have potential to cause adverse environmental and health effects. Some
alternatives, notably those leading to residues in products, while technically effective, may not be
acceptable to regulatory authorities, markets or end users.
MBTOC did not identify a technically feasible alternative, either currently available or at an
advanced stage of development, for less than 10% of 1991 methyl bromide use. These include
control of some soilbome viruses and other pathogens and some quarantine procedures.
MBTOC assumed that the most energy intensive alternative to methyl bromide was use of steam
heating for soil treatment. The indirect Global Warming Potential of methyl bromide, in terms of
COj produced, with energy required supplied electrically, was 20 kg CO2 per tonne for
synthesis and vaporisation. Using equivalent energy sources, steaming at 4 - 7 m3 per m2
and methyl bromide at 25 - 100 g per m2 were equivalent to 1200 - 2100 and 5 - 20 g
CO2 per m2. The atmospheric lifetimes of all gaseous potential alternatives to methyl
bromide were too short to give appreciable direct GWP. ;
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4.1. Alternatives on a sector basis
4.1.1
Soils
On a global basis, the largest single use of methyl bromide is as a soil fumigant (about 75% of
non-feedstock uses). It is used as a pieplant soil fumigant to maintain or enhance crop
productivity in locations where a broad complex of soilborne pests, including diseases, limit
economic production of certain crops, and particularly where they are repeatedly grown on the
same land. Methyl bromide has been successfully used under a wide variety of cropping
systems. The major current categories of use include some nursery crops, vegetables, fruits,
ornamentals and tobacco.
Soil fumigation with methyl bromide has been successfully replaced in diverse areas by
methods and techniques that have been available for many years, by adapting or modifying
them to suit local requirements. None of the specific alternative methods discussed, except
steam, when used alone, have the broad spectrum of activity, efficacy or consistency of methyl
bromide. For some situations there may not be existing alternatives for methyl bromide. The
development of a comparable agricultural system without the use of methyl bromide, in many
cases, may require the integration of multiple alternative techniques (IPM). A commitment to
research and technology transfer will be required to achieve a similar spectrum of efficacy and
reliability, and adoption by growers. '
An IPM approach to managing pests and diseases will be needed in order to avoid future
environmental problems associated with soilborne pest control. Each individual tactic in an IPM
strategy may have constraints, but the package of approaches can often be tailored to specific
sites and situations to provide effective pest management. In this context, constraints should be
viewed as indicating research gaps. Research to overcome these constraints needs to focus not
only on biophysical systems, but also socio-economic and political parameters, and generation
of registration data.
s
A number.of non-chemical alternatives are currently in use and other potential alternatives are
under investigation. These are not equally effective for all pests, cropping systems or locations
and may have a narrow spectrum of activity. Non-chemical alternatives include;
• Cultural practices such as crop rotation, planting time, artificial plant growth substrates,
deep ploughing, flooding/water management, fallowing, cover crops, living mulches,
fertilization/plant nutrition, and plant breeding and grafting.
• Biological control and organic amendments
• Physical methods such as soil solarization, steam treatments, superheated ;or hot water
treatments and wavelength-selective plastic mulches.
i »
Non-chemical alternatives generally do not require extensive regulatory approval.
There are a number of available and potential replacement fumigants, including
methyUsothiocyanate (MTTC), compounds which generate MTTC, and halogenated
hydrocarbons. Mixtures of soil fumigants may provide a spectrum of control approaching that
of methyl bromide. These combination products may represent the most efficacious short-term
alternatives to methyl bromide in certain situations, provided they are acceptable to regulatory
agencies.
Control of individual soilborne pests and diseases approximating that of methyl bromide may
be achieved in some cases through the use of combinations of non-fumigant materials (e.g.
nematicides, fungicides, herbicides and insecticides).
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There are additional chemicals which would require further research to determine their potential
as alternatives for methyl bromide. Some were previously used with vsirying degrees of
success (e.g. anhydrous ammonia, formaldehyde, carbon bisulphide, inorganic azides).
Renewed interest and research may lead to re-establishment of some of these pesticides.
4.1.2
Durables
Durables include dry agricultural and forestry products, such as cereal grains, dried fruits and
nuts, timber and artifacts. Approximately 13% of non-feedstock global production of methyl
bromide is used for disinfestation of durable commodities. Generally, methyl bromide is not
widely used on durables but a few economically important industries have a tradition of use of
methyl bromide fumigation as their principal means of pest control. These include the dried
fruit and nut industry, some major importers and exporters of cereal grains, and export trade in
unsawn timber. Methyl bromide is particularly useful where a rapid treatment is needed, such
as at import or prior to shipment, and for quarantine purposes. It is effective down to low
commodity temperatures (5°C). I
There are potential or existing alternatives for most uses of methyl bromide on durable
commodities. However, there is no general in-kind replacement All alternatives will require
some changes in practice. Of the alternatives, only phosphine is extensively used, principally
for cereals and legumes. Insect resistance to phosphine is an emerging problem, particularly in
developing countries, but resistant pests can, at present, be controlled using currently used
phosphine-based technology. i
Some alternatives are already in industrial use for some classes of durable. Those identified
include other fumigants, controlled and modified atmospheres, contact insecticides, physical
methods and biological control methods. Many are limited in particular circumstances by speed
of action, regulatory constraints, temperature, consumer acceptance, and lack of research data.
4.1.3
Perishables
Perishable commodities include fresh fruits and vegetables, cut flowers, ornamental plants,
fresh root crops and bulbs. Methyl bromide fumigation is the predominant treatment when
disinfestation is required for perishable commodities, using about 8.6% of global non-
feedstock methyl bromide production, with about half of that for disinfestation of fruit for
quarantine purposes. A minor quantity of methyl bromide, less than 0.2% of global use, is
used to help prevent the spread of pests within countries.
Alternative treatments to methyl bromide include pest-free zones, inspection, physical removal,
the systems approach; and disinfestation based on chemical treatments, coldstorage, heat,
controlled and modified atmospheres, irradiation and a combination of these treatments.
Although these are approved for disinfestation of specific commodilies, very few are in use
relative to the number of different commodities treated with methyl bromide. Their widespread
application is limited in some cases by their commodity and pest specificity. There are also very
few examples of alternative treatments developed for commodities routinely treated with methyl
bromide because few people recognised the need to develop them until now.
For each alternative, MBTOC identified a number of specific approvals in various countries.
For example, heat treatments are approved for 6 applications, chemical fumigants for 5, cold
treatments for nine, pest-free zones for four, and irradiation for two, Currently, there are no
existing alternatives, meeting quarantine standards, for five groups of economically important
exports: apples and pears infested with codling moth; stonefruit infested with codling moth;
grapes potentially infested with a certain mite (from Chile to the USA); berryfruit infested with
various insects; and certain root vegetables where soil is not removed.
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Some promising alternatives require further research to determine their suitability for control of
pests in specific commodities. MBTOC identified twelve potential alternative treatments.
MBTOC noted that there are constraints on use of chemical treatments for disinfestation of
perishables and that they have very limited application. They are difficult to apply, have a
narrow pest spectrum of activity, can damage many commodities, and are not approved for use
in some countries. Many consumers have indicated preference for foods with less or without
chemical residues, provided they are of good quality and value.
Perishable commodities absorb relatively little methyl bromide, leaving 85 - 95% available for
recovery. Many perishable commodity fumigations are carried out using well-sealed solid-wall
facilities, that restrict leakage. There is thus opportunity for efficient recovering and recycling.
Where alternatives are not feasible for quarantine treatments, minimising methyl bromide
released using recapture technology could be used to maintain national and international trade in
perishables.
4.1.4 Structures and transportation vehicles
Treatment of structures and transport vehicles uses about 3.0% of global non-feedstock methyl
bromide production.
Fumigation is used as a structural pest management technique on either an entire structure or a
significant portion of a structure. It is utilized whenever the infestation is so widespread that
localized treatments may result in reinfestation or when the infestation is within the walls or
other inaccessible areas.
Structures that are fumigated are classified as food production and storage facilities (mills, food
processing, distribution warehouses); nonfood facilities (dwellings, museums), and transport
vehicles (trucks, ships, aircraft, railcars).
Pest management in these facilities is best achieved through IPM procedures. These may
include periodic full site treatments. Reduction or elimination of the use of methyl bromide can
be accomplished with IPM programs in some situations, including some full site treatments.
Structural IPM relies on good construction and maintenance with modification, where required,
to remove pest harbourages, and sanitation to remove pests and their food sources. Pest
detection serves as a quality assurance for the pest management program, and indicator of need
for treatment.
There are significant opportunities to reduce methyl bromide dosage through better containment
and monitoring, and combining methyl bromide with carbon dioxide.
Presently, there is no single substitute fumigant for methyl bromide for all treatments of
structures against pest infestation. Phosphine and hydrogen cyanide are alternative fumigants
in some situations, including full site treatments. Sulphuryl fluoride is used as a direct
substitute for methyl bromide to eradicate wood destroying insects in some countries, Non-
fumigant pesticides and non-chemical methods are also being used as local treatments. Heat
treatment is probably the most useful non-chemical fullsite technique. Other alternative pest
management strategies incorporate the use of non-fumigant pesticides and non-chemical
procedures.
Transport vehicles pose particularly difficult pest management problems because they often
contain sensitive equipment, innumerable harborages and it is economically difficult to keep
them out of operation for more than a brief period. Furthermore, methyl bromide is the only
fumigant currently allowed for quarantine treatments on ships in many countries. Presently
there are no established alternatives to methyl bromide for rapid rodent and insect elimination
aboard aircraft.
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5.
Concerns relating to Article 5 countries
Developing countries cuirently use about 18% of methyl bromide produced globally for
agricultural and related uses. The main uses are for soil fumigation (about 70% of total) and
disinfestation of durables (about 20%).
Soil fumigation is mainly carried out in Article 5 countries for pest and disease control in the
production of certain high value cash crops (e.g., tobacco, cut flowers, strawberries,
vegetables). It is used particularly for fumigation of nursery and seed beds. Methyl bromide is
not used during production of staple foodstuffs. Where used on durables, the main application
is the protection of local stocks of food grains and for disinfestation of imported and exported
cereal grains. Some perishables, important to particular economies, are fumigated on export to
developed countries.
Alternatives to methyl bromide in developing countries and potential constraints on their use are
the same as in developed countries, but some chemical treatments, not permitted in some
developed countries, may still be acceptable. Application is generally further constrained by the
social conditions, level of infrastructure and other conditions typical of many Article 5
countries.
At present there is no single in-kind alternative for all uses of methyl bromide in developing
countries. For some quarantine applications (e.g. certain berryfruit infested with thrips or
aphids, certain unwashed root vegetables infested with soil pests) there are currently no
technically feasible alternatives.
It may be possible to use alternative treatments and/or production methods, including IPM
strategies, to substitute for most of the pest control uses of methyl bromide. However, the
varied and special conditions in Article 5 countries require that the alternatives be appropriately
adapted to the climatic conditions, particular cropping techniques, resource availability and
specific target pests. Different alternatives will have to be used for different crops, commodities
and situations. This is likely to involve significant effort to select appropriate: alternatives,
adaptive research, field testing, technology transfer, user education, institutional capacity
building and training, among other factors. It is critical that those Article 5 countries which
utilize methyl bromide receive technical and financial assistance to introduce or adapt alternative
materials and methods to manage the pests currently controlled by methyl bromide.
The Committee noted that the specified incremental costs eligible for funding under the
Multilateral Fund and items on the indicative list may need revision in order ito accommodate
the special needs associated with methyl bromide, if phaseout is considered.
Potential trade restrictions relating to methyl bromide use are of great concern to those Article 5
countries dependent on certain exports now produced with the aid of methyl bromide. Such
restrictions, which could be applied by developed, importing countries and regions, as a result
of their own or international restrictions on methyl bromide, are seen as an issue of substantial
importance. They could nullify the effect of any grace period.
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Montreal Protocol on Substances that Deplete the Ozone Layer
UNEP 1994 Report of the Methyl Bromide Technical Options
Committee
December 1994
Contents
! Page No.
Executive Summary l
1. Committee mandate „ . 1
2. Existing uses of methyl bromide , 1
3. Emissions from methyl bromide use, and their reduction, including recovery... 2
4. Alternatives to methyl bromide 3
i
4.1 Alternatives on a sector basis . ( 4
4.1.1 Soils 4
4.1.2 Durables 5
4.1.3 Perishables 5
4.1.4 Structures and transportation vehicles 6
5, Concerns relating to Article 5 countries 7
Contents : 8
Methyl Bromide Technical Options Committee - composition and
organisation at 1 December 1994 > 24
Glossary 27
1.0 INTRODUCTION 28
1.1 References 30
Annex 1.1 - Decisions taken by the Parties at the fourth (Copenhagen) meeting
relevant to methyl bromide and MBTOC , 31
2.0 CURRENT APPLICATIONS OF METHYL BROMIDE...... 35
2.1 General scope of use 35
2.2 Supply of methyl bromide 37
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2.3 Application methods , 37
2.3.1 Soil fumigation 37
2.3.1.1 Manual application , 37
2.3.1.2 Mechanised injection 38
2.3.2 Application to commodities and structures.! 38
2.4 Global quantities of methyl bromide used 39
2.5 Technical and legislative limitations to methyl bromide use... 43
i
2.5.1 Technical limitations 43
2.5.2 Legislative limitations :........ 43
2.6 References ., 44
3.0 EMISSIONS, EMISSION REDUCTION AND RECLAMATION,
RECOVERY AND RECYCLING OF METHYL BROMIDE 45
Executive Summary 45
3.1 Definitions ; 45
3.2 Emissions of methyl bromide from treatments ; '. 46
3.3 Global warming potential and alternatives 49
3.4 Opportunities for methyl bromide emission i 50
3.5 Containment J 51
3.5.1 Soil fumigation i 51
3.5.2 Structural and commodity fumigation 52
3.6 Recovery 53
3.6.1 Activated carbon 53
.
3.6.2 Condensation/activated carbon | 54
3.6.3 Absorption into reactive liquids 54
j
3.6.4 Adsorption onto zeolite.... •...., 55
3.6.5 Techniques under development '< 55
3.7 Reclamation and Recycling j 56
3.7.1 Condensation/activated carbon 56
3.7.2 Activated carbon 56
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1 0
3.7.3 Zeolite 57
3.8 Constraints 57
3.9 References 57
Annex 3.1 - Calculation of % emission of methyl bromide from treatments using
the mass balance approach 60
1. Derivation of formula 60
2. Calculation of emission of methyl bromide from bulk and
bag stack treatments of grain 60
3. Calculation of methyl bromide emissions from treatment
of dried fruits and nuts 61
3.1 Dried fruits 61
3.2 Nuts 62
4. Calculation of methyl bromide emissions from treatment of
perishables 62
4.1 Nectarines 62
5. Sample calculations for emissions of methyl bromide resulting
from fumigation of timber (logs) in the hold of a ship prior to
import into Japan (data source: A. Tateya, MAFF, Japan) 62
4.0 ALTERNATIVES TO METHYL BROMIDE 64
4.1 Alternatives for soil treatment 64
Executive Summary 64
4.1.1 Introduction ;...„ 67
4.1.2 Existing uses of methyl bromide 68
4.1.2.1 Application of methyl bromide „ 68
4.1.3 Training and worker protection 69
4.1.4 Soil pest management strategies.. 69
4.1.4.1 Monitoring and pest detection 70
4.1.5 Soil pest management alternatives to methyl bromide 70
4.1.5.1 Non-chemical methods 70
4.1.5.1.1 Organic amendments 70
4.1.5.1.2 Biological control 71
4.1.5.1.3 Cultural practices 73
4.1.5.1.4 Plant breeding and grafting 75
* 4.1.5.1.5 Physical methods 76
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11
4.1.6
4.1.5.1.6 Research priorities for non-chemical
alternatives 7g
4.1.5.2 Chemical methods 79
4.1.5.2.1 Fumigants 79
4.1.5.2.2 Non-fumigants ....."........81
4.1.5.2.3 Chemical alternatives which require
further development 81
4.1.5.2.4 Research priorities for chemical
alternatives 33
Emission reduction 33
Reduced dosage 33
Plastic soil covers ........... ...84
Improving application techniques ."34
4.1.6.1
4.1.6.2
4.1.6.3
4.1.6.4 Reducing leakage during greenhouse fumigation.........!84
4.1.6.5 Use of diffusion enhancing co-fumigants 85
4.1.6.6 Reduced frequency of application .............S5
4.1.6.7 Research priorities for reduced emissions..................!85
4.1.7 Research priorities g5
4.1.8 Transfer of knowledge and training in improvements 86
4.1.9 Uses without known alternatives gg
4.1.10 Constraints j 87
4.1.10.1 Environmental.., g7
4.1.10.2 Logistical -".".:.!.".....!!!.".!!!!.""... 87
4.1.10.3 Health, safety and environment 88
4.1.10.4 Biotic ' '" gg
4.1.10.5 Informational .?....!..."!......".. 88
4.1.10.6 Economic \ .'."...*.....' 89
4.1.10.7 Sociological/psychological [.."................. 89
4.1.11 General conclusions [ gg
4.1.12 References i 90
Case history 4.1.1: Methyl bromide reduction and elimination in
horticultural production in Italy 99
Case history 4.1.2: Forest tree nurseries in the People's Republic of China.. 102
Case history 4.1.3: Alternatives in forest tree nurseries in the USA
(Pacific Northwest) and Western Canada 104
Case history 4.1.4: Use of alternatives in vineyards in California, USA 106
Case history 4.1.5: Replacement of methyl bromide use in horticultural
nurseries, Ohio JQO
Case history 4.1.6: Organic strawberries in California... 109
Annex 4.1.1 - Methyl bromide soil fumigation use survey.
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12
Annex 412- Soilborne pathogens, nematodes, arthropods, and weeds
controlled by soil fumigation with methyl bromide in various countries
or regions of the world • 12°
Annex 4.1.3 - Sample toxicological data for chemical alternatives to
methyl bromide for soil treatment - • 122
Annex 4 1.4 - Discussion on potential use rate reductions on methyl
bromide conducted at MBTOC Bordeaux meeting and through subsequent
communications among members of the Soil fumigation subcommittee 124
4.2 Alternatives for treatment of durables 132
•tV)
Executive summary ? i0*.
4.2.1 Introduction • ; 133
4.2.2 Existing uses of methyl bromide 134
4.2.2.1 Targetpests
4.2.2.2 Types of fumigation enclosure
4.2.3 General description of alternatives , 136
4.2.3.1 Fumigants and other gases ••••• 136
4.2.3.1.1 Phosphine •
4.2.3.1.2 Hydrogen cyanide •
4.2.3.1.3 Ethylformate 138
4.2.3.1.4 Carbon bisulphide 138
4.2.3.1.5 Carbonyl sulphide J38
4.2.3.1.6 Ozone W^* ' Ill
4.2.3.1.7 Methyl isothiocyanate (MTTC) 138
4.2.3.1.8 Sulphuryl fluoride }3«
4.2.3.1.9 Ethyleneoxide '13*
4.2.3.1.10 Controlled and modified atmospheres 139
4.2.3.2 Contact insecticides 14°
4.2.3.2.1 Organophosphorus compounds 141
4.2.3.2.2 Synthetic pyrethroids 141
4.2.3.2.3 Botanicals 142
4.2.3.2.4 Insect growth regulators (IGRs) 142
4.2.3.2.5 Inertdusts • 142
4.2.3.3 Physical control methods 143
4.2.3.3.1 Cold treatments }43
4.2.3.3.2 Heattreatment , 144
4.2.3.3.3 Irradiation J44
4.2.3.3.4 Physical removal (sanitation) 145
4,2.3.4 Biological methods. 145
4.2.3.4.1 Biological control with predaceous
insects or parasitoids
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13
4.2.3.4.2 Insect pathogens as microbial
control agents , 146
4.2.3.4.3 Pheromones ,1 146
4.2.4 Alternatives to methyl bromide in stored cereal grains
and similar commodities 147
4.2.4.1 Commodities and pests 147
4.2.4.2 Scope of the problem 14g
4.2.4.3 Existing substitutes for cereal grain and
similar commodities 149
4.2.4.3.1 Phosphine 149
4.2.4.3.2 Controlled atmospheres (CA) 150
4.2.4.3.3 Grain protectants 150
4.2.4.3.4 Physical control methods.... 151
4.2.4.3.4.1 Gamma ray or accelerated
electron irradiation 151
4.2.4.3.4.2 Heat treatment 151
4.2.4.3.4.3 Cold treatments 152
4.2.4.3.5 Biological control methods 152
4.2.4.3.5.1 Biological control with
predaceous insects or
parasites... 152
4.2.4.3.5.2 Insect pathogens of
microbial origin 152
4.2.4.3.5.3 Pheromones 152
4.2.5 Substitutes in dried fruit and nuts 153
4.2.5.1 Definition of commodities and pests 153
4.2.5.2 Scope of the problem 156
4.2.5.3 Existing substitutes 157
4.2.5.3.1 Phosphine 157
4.2.5.4 Other fumigants and gases 157
4.2.5.4.1 Hydrogen cyanide 157
4.2.5.4.2 Ethyl formate 153
4.2.5.5 Controlled atmospheres 153
4.2.5.6 Contact insecticides and inert dusts 158
4.2.5.7 Physical methods 159
4.2.5.7.1 Irradiation 159
4.2.5.7.2 Optimised hot and cold treatments 159
4.2.5.8 Biological methods i 159
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14
4.2.5.9 Others :•— 160
4.2.5.9.1 Packaging and containerisation 160
4.2.5.9.2 Detection, sorting, certification 160
4.2.5.9.3 Engineering.... 160
4.2.5.9.4 Genetic engineering 160
4.2.5.9.5 Combination of processes - IPM systems.. 160
4.2.6 Beverage crops •••••161
4.2.6.1 Definition of commodities and pests 161
4.2.6.2 Scope of the problem 161
4.2.6.3 Existing substitutes 162
4.2.6.3.1 Phosphine 162
4.2.6.4 Other fumigants and gases .•;—•• 162
4.2.6.4.1 Hydrogen cyanide 162
4.2.6.4.2 Controlled and modified atmospheres. 162
4.2.6.5 Contact insecticides 162
4.2.6.6 Physical methods 162
4.2.6.6.1 Irradiation 162
4.2.6.6.2 Temperature control 163
4.2.7 Herbs and spices • 163
4.2.7.1 Definition of commodities and pests 163
4.2.7.2 Scope of the problem 164
4.2.7.3 Existing substitutes • 164
4.2.7.3.1 Phosphine ; 164
4.2.7.4 Other fumigants and gases 164
4.2.7.4.1 Ethyleneoxide 164
4.2.7.4.2 Controlled and modified atmospheres 165
4.2.7.5 Contact insecticides 165
4.2.7.6 Physical control methods 165
4.2.7.6.1 Irradiation , 165
4.2.7.6.2 Heat and cold treatments 165
4.2.8 Tobacco : 165
4.2.8.1 Definition of commodities and pests.... 165
4.2.8.2 Scope of the problem 166
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15
4.2.8.3 Existing substitutes 166
4.2.8.3.1 Phosphine 166
!
4.2.8.4 Contact insecticides 166
4.2.8.5 Physical control methods 166
4.2.8.5.1 Irradiation 166
4.2.8.5.2 Heat and cold treatment 167
4.2.9 Artefacts 167
4.2.9.1 Definition of commodities and pests 167
4.2.9.2 Scope of the problem 168
4.2.9.3 Existing substitutes „ 168
4.2.9.3.1 Phosphine -.. 168
4.2.9.4 Other fumigants and gases 168
4.2.9.4.1 Controlled/modified atmospheres 168
4.2.9.5 Contact insecticides 168
4.2.9.6 Physical methods i 168
4.2.9.6.1 Irradiation .. 168
4.2.9.6.2 Heat and cold treatment ,i 169
4.2.10 Logs, timber, bark and wood products , 169
4.2.10.1 Insect control 1 169
4.2.10.1.1 Definition of commodities and pests 169
4.2.10.1.2 Scope of the problem 170
4.2.10.1.3 Existing substitutes ,; 170
4.2.10.1.3.1 Phosphine 171
4.2.10.1.3.2 Sulphuryl fluoride 171
4.2.10.1.3.3 Contact insecticides 171
4.2.10.1.4 Physical control methods...;! 171
4.2.10.1.4.1 Irradiation 171
4.2.10.1.4.2 Other methods 171
4.2.10.2 Control of fungi 1 172
4.2.10.2.1 Target pests • 172
4.2.10.2.2 Contact fungicides
('Wood preservatives1).....; 172
4.2.10.2.2.1 Bifluorides 172
4.2.10.2.3 Physical control methods 172
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16
4.2.10.2.3.1 Heat treatment 172
4.2.11 Seeds for planting 172
4.2.11.1 Scope of the problem 172
4.2.11.2 Existing substitutes 174
4.2.11.2,1 Phosphine .' 174
4.2.11.3 Chemical soaking and fumigation 174
4.2.11.4 Physical control methods 174
4.2.11.4.1 Cleaning 174
4.2.11.4.2 Hot water treatment 174
\
4.2.12 Dried fish, meat and seafood 174
4.2.12.1 Definition of commodities and pests 174
4.2.12.2 Scope of the problem 175
4.2.12.3 Existing substitutes , 175
4.2.12.3.1 Phosphine 175
i
4.2.12.4 Contact insecticides 175
4.2.12.5 Physcial control methods 175
4.2.12.5.1 Irradiation... 175
4.2.13 Reducing emissions '. 176
4.2.14 Transfer of knowledge and training in improvements and
alternatives •> i. •••• 177
4.2.15 Research priorities 177
4.2.16 Uses without known alternatives , 179
4.2.17 Constraints 179
4.2.17.1 Consumer acceptance and registration of chemicals 179
4.2.17.2 Technical aspects 179
4.2.17.3 Quarantine 180
i '
4.2.18 References 180
Case history 4.2.1: Rice irradiation in Indonesia 194
Annex 4.2.1 - Minimum exposure periods (days) required for control of all
stages of the stored product pests listed, based on a phosphine concentration
of 1.0 g m-3 t 196
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17 j
Annex 4.2.2 - Sample lexicological data on pesticides used: for treating
durable commodities and structures , 197
Annex 4.2.3 - Estimates of the minimum cf-product (g h nr3) of methyl
bromide for a 99.9 per cent kill of various stages of a numter of insect
species at 10,15,25 and 30°C and 70 per cent RH. (Heseltine
and Thompson, 1974) 201
Annex 4.2.4 - Methyl bromide dosage table. European Plant
Protection Organization (1993). 202
i
4.3 Alternatives for treatment of perishables 203
Executive summary j.... 203
4.3.1 Introduction [ 206
i
4.3.2 Existing uses of methyl bromide i 207
]
4.3.3 Characteristics of potential alternatives 1 208
4.3.3.1 Preharvest practices and inspection procedures 208
4.3.3.1.1 Cultural practices leading to
pest reduction 208
4.3.3.1.2 Pest-free zones and periods 209
4.3.3.1.3 Inspection and certification 209
4.3.3.2 Postharvest treatments j 210
4.3.3.2.1 Non-chemical alternatives 210
4.3.3.2.1.1 Cold treatment 210
4.3.3.2.1.2 Heat treatment 210
4.3.3.2.1.3 _'_ Controlled atmosphere... 211
4.3.3.2.1.4 Modified atmosphere 211
4.3.3.2.1.5 Irradiation 212
4.3.3.2.1.6 Microwaves 212
4.3.3.2.1.7 Physical removal 212
4.3.3.2.1.8 Combination treatments.. 212
4.3.3.2.2 Chemical alternatives i..... 213
4.3.3.2.2.1 Fumigation 213
4.3.3.2.2.2 Chemical dips..... 213
4.3.3.2.3 Constraints to acceptance of
alternatives 213
4.3.4 Suitability of alternatives for controlling pests on each group
of commodities 214
4.3.4.1 Apples and pears .1 214
. 4.3.4.2 Stonefruit ! ",',\". 215
4.3.4.3 Citrus 216
4.3.4.4 Grapes 1 217
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18
4.3.4.5 Berryfruit 217
4.3.4.6 Rootcrops • 218
4.3.4.7 Vegetables 218
4.3.4.8 Cucurbits 219
4.3.4.9 Tropical fruit 220
43.4.10 Cut flowers and ornamentals 221
4.3.4.11 Bulbs 222
4.3.5 Summary table of existing and potential alternatives to methyl
bromide for disinfestation •• 222
4.3.5.1 Cultural Practices (Systems Approach,
Multiple Pest Decrement 222
4.3.5.2 Pest-free Zones and Periods 223
4.3.5.3 Inspection and Certification 223
4.3.5.4 Cold Treatment .' 223
4.3.5.5 Heat Treatments 224
4.3.5.6 Controlled Atmospheres 224
4.3.5.7 Modified Atmospheres 224
4.3.5.8 Irradiation • 225
4.3.5.9 Microwaves • 225
4.3.5.10 Physical Removal of Pests 225
4.3.5.11 Combined Treatments • 225
4.3.5.12 Fumigation 226
4.3.5.13 ChemicalDips ; • 226
4.3.6 Commodities without approved quarantine alternatives
to methyl bromide 226
4.3.7 Opportunities to reduce emissions 227
4.3.8 Research priorities r 227
4.3.8.1 Developing countries 227
4.3.8.2 Developed countries 228
4.3.9 Transfer of knowledge, and training in improvements
and alternatives • 228
4.3.10 Developing country issues • • 228
4.3.11 References - • 229
Case history 4.3.1: Heat disinfestation treatments for payaya in Hawaii 236
Annex 4.3.1 - List of countries that were sent forms to determine the
postharvest use of methyl bromide on perishable commodities 238
Annex 4.3.2 - Forms sent to government organisations within each
country to determine the postharvest use of methyl bromide on
perishable commodities 239
Annex 4.3.3 - Perishable commodities treated with methyl bromide,
at least on some occasions, for disinfestation and pest control 247
Annex 4.3.4 - Examples of fumigation of imports as a condition of entry.... 253
Annex 4.3.5 - Examples of fumigation of exports as a condition of entry 256
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19
Annex 4.3.6 - Examples of fumigation for shipment i
within the same country I 259
4.4 Alternatives for treatment of structures and transportation 260
Executive Summary 260
i
4.4.1 Introduction 1 261
4.4.2 Existing uses of methyl bromide in structural fumigation 264
4.4.2.1 Pests other than wood destroying insects 264
4.4.2.2 Wood destroying insects 265
4.4.2.3 Transport vehicles 265
4.4.3 Substitutes and alternatives to methyl bromide 1... 266
4.4.3.1 Substitutes and alterantives for pests other
than wood destroying insects 266
4.4.3.1.1 Fumigants !..... ..268
4.4.3.1.2 Controlled atmospheres '....„ 269
4.4.3.1.3 Combinations ..269
4.4.3.1.4 Nonfumigantpesticides 269
4.4.3.1.5 Nonchemical treatments.,, 270
i
4.4.3.2 Substitutes and alternatives for wood
destroying insects L... ..271
4.4.3.2.1 Fumigants 272
4.4.3.2.2 Nonfumigant pesticides ..273
4.4.3.2.3 Nonchemical .:.... 274
4.4.3.3 Ships, aircraft and other transport vehicles 274
4.4.3.3.1 Ships 1... 274
4.4.3.3.2 Aircraft 275
4.4.3.3.3 Other vehicles (freight trucks,
railcars, etc.) 275
4.4.4 Containment/methods for reducing current methyl bromide use..... 275
4.4.4.1 Improved containment 275
4.4.4.2 Methyl bromide and carbon dioxide 276
4.4.4.3 Volume displacement technologies 276
4.4.5 Transfer of knowledge and training 276
4.4.6 Research requirements 276
. 4.4.6.1 Emission reduction for methyl bromide 276
4.4.6.2 Substitutes and alternatives 277
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20
4.4.7 Uses without alternatives 277
4.4.8 Feasible reduction in methyl bromide use 277
4.4.9 Constraints 278
4.4.10 Developing country issues 278
4.4.11 References 280
Case history 4.4.1: Heat treatment of flour mill and cleaning house 281
Case history 4.4.2: Moth control in flour mills using mass trapping,
mating disruption and attracticide method 282
Case history 4.4.3: Fumigation of three stave churches in Norway,
August - September 1984 283
i
5.0 DEVELOPING COUNTRY ISSUES 284
Executive Summary 284
5.1 Introduction ; 284
5.2 Methyl bromide use in Article 5 countries....... 285
5.3 Soil fumigation 289
5.3.1 Progress on development and adoption of alternatives
to methyl bromide use in soil fumigation 290
5.4 Fumigation of durables 290
5.4.1 Progress on development and adoption of alternatives
to methyl bromide in durable commodity pest
control.... 291
5.5 Fumigation of perishables 291
5.5.1 Progress on development and adoption of alternatives
to methyl bromide in perishable fumigation... 292
5.6 Structural fumigation 292
5.6.1 Progress on development and adoption of alternatives
to methyl bromide for structural fumigation 292
5.7 Recycling, recovery and reclamation 293
5.8 Replacement of methyl bromide , 293
5.9 Conclusion .....: 293
Appendix: UNEP Methyl Bromide Technical Options Committee address list
as at 1 December 1994 295
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21
LIST OF TABLES
Page No.
2.1
2.2
2.3
3.1
3.2
3.3
3.4
3.5
3.6
4.1.1
4,1.2
4.1.3
4.1.4
4.1.5
4.1.6
4.1.7
4.2.1
4.2.2
Global sales of methyl bromide (tonnes) by use sector (China, India
and former USSR not included) ................................ . 35
Sales of methyl bromide by region, including chemical feedstock,
but excluding China, India and former USSR ..................... ................. 41
Global methyl bromide usage (tonnes, 1992) by sector. ........................... 42
Estimated usage of methyl bromide and emissions to atmosphere
for different categories of fumigation ....................... ........ .................. . 43
Half-life and % methyl bromide remaining in soil (laboratory studies)
after 3 and 7 days. Calculated from data reviewed in Visser and
Linders (1992) [[[ . 49
Relative global warming calculations for methyl bromide and! steam
sterilisation as an alternative soil treatment ........................ .............. 50
Emissions from a methyl bromide fumigation of greenhouse soil using
two different covers (from de Heer et al. 1981)..... ...... ,; ............ T. 51
Examples of pressure test standards for gastightness of some fumigation
enclosures and treated structures ........................................ 52
Fumigation of cereal grains on import into Japan (1992 data) with
calculated emissions of methyl bromide based on bromide ion residue
levels in commodity after treatment Data source: A. Tateya,
MAFF, Japan [[[ _ . 6j
Production yields and costs for forest tree nurseries in the PRC. ............... 103
Comparison of conventional and organic strawberry production
in California, USA ...... . ........................... ...f. ............... 110
Responses to MBTOC survey on methyl bromide use as soil fumigant ....... 112
MBTOC survey results. Methyl bromide use as soil fumigant by
country and use sector ........................................... ......
Dosage reduction in lOyears (by 2004) ....... . ................. .................. 125
Feasible reductions in methyl bromide soil fumigant use ........... ............. 127
Dosage reduction in 10 years .................................... ...... ............. 131
The basic differences between contact insecticides and fumigants . ............. 141
Examples of cereal and legume crops which may be fumigated with
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22
4.2.4 Varieties of nuts and fruits sometimes treated with methyl bromide 153
4.2.5 Target pests of dried fruits and nuts i 155
426 World production of main dried fruits and nut crops. 3 year average
(1990/91 - 1992/93) r 156
4.2.7 Target pests in beverage crops 161
4.2.8 Herbs and spices sometimes disinfested with methyl bromide -, 163
4.2.9 Some target pests in herbs and spices ;. 164
4.2.10 Target pests in tobacco and related products , 166
4.2.11 Some common pests>of artefacts made of wood, skin, feathers,
wool and other organic materials 167
4.2.12 Targetinsectpepsin logs, timber and bark products 170
4.2.13 Some nematodes transmitted by seeds 173
4.2.14 Common pests in dried fish, meat and seafood -— 17:5
4.2.15 Minimum exposure periods (days) required for control of all stages
of the stored product pests listed, based on a phosphine concentration
of 1.0 g nr3. This dosage is as recommended for good conditions and
the dosage applied will usually need to be increased considerably in ;
leaky situations (EPPO, 1984) 196
4.2.16 Estimates of the minimum cr-product (g h nr3) of methyl bromide
for a 99.9 per cent kill of various stages of a number of insect species
at 10,15,25 and 30°C and 70 per cent RH. (Heseltine
and Thompson, 1974) '. 201
4.2.17 Methyl bromide dosage table. European Plant Protection
Organization (1993) -202
4.3.1 List of countries that were sent forms to determine the postharvest
use of methyl bromide on perishable commodities , 238
4.3.2 Examples of fumigation of imports as a condition of entry 253
4.3.3 Examples of fumigation of exports as a condition of entry 256
f
4.3.4 Examples of fumigation for shipment within the same country 259
4.4.1 Methyl bromide usage for structural pest control. Global estimate
for 1992 : 263
4.4.2 Estimates for feasible reductions in structural uses of methyl bromide
by 1998 and 2003 279
5.1 Consumption of methyl bromide by some Article 5 countries (1992).. i. 286
5.2 Consumption of methyl bromide (t) in developing countries in
three regions (1992) -288
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23
LIST OF FIGURES
2. 1 Total global sales of methyl bromide (excluding China, India and
former USSR) on an annual basis for the period 1984 to 1992 excluding
feedstock uses ................................................ ........................... 40
4. 1 . 1 Global methyl bromide use for soil fumigation - by country 1992
MBTOC survey data .......................................... .' ......... ]
4.1.2 Global use of methyl bromide (excluding USA) for soil fumigation
- by use category. 1992. MBTOC survey data ........... ......................... 117
4. 1 .3 Use of methyl bromide in USA in 1992 for soil fumigation
- by use category. MBTOC survey data ............................................ 118
4. 1 .4 Global use of methyl bromide for soil fumigation - by major crop.
Minor uses not included. 1992. MBTOC survey data ................. . .......... 118
4. 1 .5 Global use of methyl bromide for soil fumigation (excluding USA)
- for major crops only. 1992. MBTOC survey data ......... , .................... 119
4.1.6 Use of methyl bromide for soil fumigation in USA - msijor crops only
1992. MBTOC survey data. ................................ ......... ..... .. ........ 119
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24
Methyl Bromide Technical Options Committee -
composition and organisation at 1 December 1994
Chair
Jonathan Banks
Vice Chair and Chair of
'Soils' subcommittee
Affiliation .
CSIRO
Rodrigo Rodriguez-Kabana Auburn University
Subcommittee chairs and
co-chairs
Country
Australia
USA
Chair - 'Reclamation,
Recovery and Recycling'
Don Smith
Co-chair 'Soils'
subcommittee
YaacovKatan
Chairs - 'Durables'
subcommittee
Bishu Chakrabarti
Patrick Ducom
Chairs - 'Perishables'
subcommittee
Thomas A. Batchelor
AkioTateya
Chair - 'Structural*
subcommittee
Richard Kramer (alternate:
Vem Walter)
Chair - 'Developing
countries' subcommittee
Industrial Research Limited
Hebrew University
Central Science Laboratory
Ministere de 1'Agriculture et de la Peche
ENZA New Zealand (International)
Agricultural Chemicals Inspection Station
MAFF
National Pest Control Association
New Zealand
Israel
UK
France
New Zealand
Japan
USA
David Okioga
Kenya Agricultural Research Institute
Kenya
-------
Committee Members
Joel arap-Lelei
Mohd. Azmi Ab Rahim
Antonio Bello
Barry Blair (alternate:
John Shepherd)
Richard Bruno (alternate:
Ed Ruckert)
Adrian Carter
Vicent Cebolla
Chamlong Chettanachitara
Patricia Clary
Jorge Corona
Miguel Costilla
Jennifer Curtis
Tom Duafala (alternate:
Dean Storkan)
Joe Eger
Juan Francisco Fernandez
Michael Graber
Avi Grinstein
Doug Gubler
ThorkilE.Hallas
Toshihiro Kajiwara
Laurent Lenoir
Maria Ludovica Gullino
Michelle Marcotte
Melanie Miller
Takamitsu Muraoka
Maria Nolan
Joe Noling
Henk Nuyten
Gary Obenauf (alternate:
Frank Mosebar)
Mary O'Brien
William Olkowski
(alternate: Sheila Daar)
Sergio Oxman
Santiago Pocino
Michael Host Rasmussen
(alternate: Mr J. Jacobsen)
A. Nathan Reed
Christoph Reichmuth
Ralph Ross
Tsuneo Sakurai
John Sansone
Colin Smith
Don Smith
Michael Spiegelstein (alternate:
David Shapiro)
Morkel Steyn
Robert Suber
Robert Taylor
25
Embassy of Kenya, Netherlands
Ministry of Agriculture
Centre de Ciencias Medioambientales
Tobacco Research Board
i
Sun Diamond Growers of California
Agriculture Canada
Institute Valenciana de Investigaciones
Department of Agriculture
Californians for Alternatives to Toxics
Canacintra
Agro-Industrial Obispo Colombres
Natural Resources Defense Council
TriCal ;
DowElanco |
Ministerio de Agricultura !
Ministry of the Environment i
Laboratory for Pesticide Application
University of California \
Danish Technological Institute \
Japan Plant Protection Association
UCB SA
University of Turin
Nordion international Inc. '
Sustainable Agriculture Alliance i
Sanko Chemical Co. Ltd. !
Department of the Environment i
University of Florida
Experimental Garden Breda \
Agricultural Research Consulting !
Pesticide Action Network, North America
Regional Center
Bio-Integral Resource Center
The World Bank '
FMC For6t S.A. i
Danish EPA
Stemilt Growers Inc.
Federal Biological Research Centre for
Agriculture and Forestry
U.S.A. Department of Agriculture i
Teijin Chemicals Ltd. !
SCC Products i
Rentokil Ltd.
Industrial Research Limited
Bromine Compounds Ltd.
Department of National Health and Population
Development
RJR Nabisco !
Natural Resources Institute
Kenya
Malaysia
Spain
Zimbabwe
USA
Canada
Spain
Thailand
USA -
Mexico
Argentina
USA
USA
USA
Chile
Israel
Israel
USA
Denmark
Japan
Belgium
Italy
Canada
UK
Japan
UK
USA
Netherlands
USA
USA
USA
USA
Spain
Denmark
USA
Germany
USA
Japan
USA
UK
New Zealand
Israel
South Africa
USA
UK
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26
Committee Members
(cont.)
Bill Thomas (alternate:
Janet Andersen)
Gary Thompson
Torn Tidow
Patrick Vail
loop van Haasteren
Etienne van Wambeke
Kenneth Vick
Chris Watson
Robert Webb
Rene Weber (alternate:
David MacAlister)
James Wells
WangWenliang
Frank Westerlund
U.S.A. EPA
Quaker Oats
BASF
USDA-ARS
Ministry of Housing, Physical Planning and
Environment
Katholieke Universiteit Leuven
U.S.A. Department of Agriculture
IGROX Ltd.
Driscoll Strawberry Associates Inc.
Great Lakes Chemical Corporation
California Environmental Protection Agency
Zhejiang Chemical Industry Research
Institute
California Strawberry Commission
USA
IUSA
• Germany
USA
Netherlands
Belgium
USA
UK
USA
USA
I USA
China
:USA
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27
Glossary
The following abbreviations and acronyms are used commonly throughout this report:
1,3-D
Bt
CA
CO2
cf-product
EDB
EPPO
HCN
IPM
MA
MBTOC
MeBr
MTTC
NGO
TEAP
1,3-dichloropropene '
Bacillus thuringiensis, a microorganism which produces insecticidal toxins
Controlled atmospheres. Storage of pest control atmospheres with a set
combination of the atmospheric gases, oxygen, nitrogen and carbon dioxide
(CC>2). Strictly, a controlled atmosphere is one where the composition,
typically low in oxygen, is regulated by some meams (see also MA), such as
by adding gas continuously or from time to time to the system.
Carbon dioxide
The value obtained by multiplying the concentration of a fumigant (c) by the
time of exposure (f). Under varying concentrations the cf-product is given by
the integral of c over time. Used as a measure of exposure of pests to
fumigants.
Ethylene dibromide |
European Plant Protection Organisation i
Hydrogen cyanide i
Integrated Pest Management systems. A rational combination of measures
designed to provide optimum control of pests. Usually associated with use of
non-chemical as well as chemical measures.
in which the
processes
with gases such as
by further addition of
Modified Atmospheres. Storage or pest control atmospheres
normal content of oxygen, nitrogen and CC>2 is changed by natural
such as respiration, sometimes with an initial purge
nitrogen or CX>2, but not controlled within set limits
gas.
Methyl Bromide Technical Options Committee.
Methyl Bromide
Methyl isothiocyanate
Nongovernmental Organisation
Technology and Economics Assessment Panel.
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28
1.0 INTRODUCTION
Methyl bromide was listed as an ozone-depleting substance by the Fourth Meeting pf the
Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer in Copenhagen in
November 1992. At that time no date for phase out of methyl bromide use
(production/consumption) was set although the annual consumption by signatories to the
Protocol was limited to 1991 levels by 1995. Exemptions were made for Article 5 countries and
for methyl bromide used in preshipment and quarantine treatments. Details of the Decisions
relevant to methyl bromide made by the Parties at the Copenhagen meeting are given in
Annex 1.1.
There are several sources of atmospheric methyl bromide. Some of these result from release of
manufactured methyl bromide into the atmosphere, some result inadvertently from the activities
of humans, while others originate entirely from natural sources. Estimates of the relative
contribution of the different sources is given in the 1994 Report of the Science Panel. The main
anthropogenic, and thus controllable, contribution to the atmospheric methyl bromide load
results from use of manufactured gas as a fumigant.
This report is produced in response to Decision IV/23 of the Copenhagen meeting, which
called, inter alia, for a technical assessment pf the alternatives to current uses of methyl
bromide, their economic feasibility, their suitability for developing countries and their potential
for global wanning.
There are two main uses of methyl bromide which fall under this Decision: as a fumigant and as
a chemical feedstock. The use of methyl bromide as a fire extinguisher is now discontinued.
This report is restricted to a detailed technical assessment of methyl bromide as a fumigant
Economic feasibility of the alternatives has been considered by the Economics Options
Committee of the Technology and Economics Assessment Panel. Use of methyl bromide as a
chemical feedstock is exempted from control under the Montreal Protocol as it is used as an
intermediate in chemical synthesis in fully contained systems and results in only minor and
inadvertent emissions.
Methyl bromide is widely used as a fumigant in agriculture and pest control in structures,
stored commodities and quarantine treatments. It is active against a diverse variety of organisms
at low concentration, including mammals and many insects, mites, nematodes, fungi, weeds,
bacteria and viruses. The broad spectrum of activity and ease of application of the material have
led to its use as the treatment of choice in a number of situations. Several agricultural
production systems involving intensive production of high value crops have become dependent
on use of methyl bromide. Production of high value export crops in some Articled countries,
notably tobacco, some cut flowers, and some vegetables and fruit may also use methyl bromide
for pest, weed and pathogen control.
In this report a general summary of the use of methyl bromide fumigant is given. This is
followed, first by discussion of recapture/recycling and emission reduction technology, then by
discussion of specific alternatives and practices under four categories, corresponding to the
main areas of application of methyl bromide. These are: ,
• as a soil fumigant
• as a fumigant for durable commodities
• as a fumigant for perishable commodities
• as a fumigant for structures in a broad sense, including buildings and transport vehicles
and containers.
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29
Finally, concerns of Article 5 countries are discussed in relation to use of methyl bromide
Darners to adoption of alternatives, and implications of possible phaseout of the material. '
An important use of methyl bromide, for both developing and developed countries, is for
presnipment and quarantine treatments. Methyl bromide may be particularly difficult to replace
in such situations despite the availability of apparently technically feasible alternatives, as its
use may be specified by bilateral agreement Establishment of alternatives mav reauire
extensive demonstration trials and negotiation..
Almost all treatments of perishable commodities, typically fruit and vegetables come under the
categories of preshipment and quarantine treatment as defined. They are for the purposes of
control of pests which do not normally multiply on the commodity after harvest fa Contrast
much of the use of methyl bromide on durables, notably in Article 5 countries, is to control
pests that can complete their life cycle on the commodity in storage. Treatments are often to
prevent damage to the commodity, not primarily to restrict the spread of pests.
Case histories showing application of particular alternative technologies are given where there
are no adequate published references. These provide evidence that particular proposed
alternatives work in practice. The Committee assumed that a technology demonstrated or in use
in one region of the world would be applicable in another unless then; were obvious technical
2SSK0 f° K^ (ug- Veiy different climate>- However, it was noted that frequently
SS ^f • "F***** bamers to *<> adoption of a technically feasible altemative^fa many
cases, the principal impediment to rapid adoption of an alternative will be regulatory, as the
ctTo?cS
™Sy? °n rathyl bromide use were conducted by MBTOC in an attempt to determine the
particular usesof the fumigant and what was the consumption of methyl bromide in particular
applications. These surveys were conducted through questionnaires sent to ministries
concerned with agriculture and the environment in various Parties to the Protocol. Results are
given in this Report
ufl0m. ^preliminary UNEP assessment report on methyl bromide
K -A Th*B1have b.een ^eral meetings apart from those of MBTOC held to discuss
foS SoT^65' ?roceedingos^nd other Publicatio:ns are available from some of
; ? ; ClVer0l° 7 aL' 1993; Hallas' et al:' 1994> which Provide further
fromkle n P aspects of alternative technologies and the current role of methyl
A workshop was recently held in Orlando, Florida (November, 1994) to discuss methyl
bromide and alternatives/The toxicology of methyl bromide has been recently reviewed in
depth (Anon., in press). There have also been a number of economic studies which have
included discussion of some technical aspects of methyl bromide use and alternatives These
are under review by the Economics Option Committee of TEAP.
. w^ this Rep0rt brouSht toSe*er exPerts« government
nominees, industry NGOs and other interested individuals from a broad range of disciplines
and backgrounds At 1 November 1994, MBTOC had 68 members from 23 countries
including » Article 5 countries. In the course of creating and debating this report, MBTOC met
five times (April 1993, The Hague, The Netherlands; July 1993, NaLbi/Harare
KenyayZimbabwe; October 1993, Washington, United States of America; March' 1994
Santiago, Chile; and August 1994, Bordeaux, France). This international group considered the
practice of fumigation across all applications, rather than concentrating on particular
subdisciphnes, such as soil fumigation or disinfestation of perishables. This has highlighted
JJT1? t(5?T5 d«fici?"cies' ^ven in the b«dy of the report and, in particular, drawn Stention
to the lack of effective information transfer on fumigation technology and alternatives thereto
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30
One outcome of the work of the Committee has been to emphasise the large range of
alternatives available for many situations in which methyl bromide is currently used.
1.1
References
Anonymous. 1992. Proceedings of the international workshop on >
bromide for soil fumigation, U.N. Environment Programme, 19-21 October 1992,
Rotterdam; 22-23 October 1992, Rome/Latina. 325 p.
Anonymous. 1993. Methyl bromide substitutes and alternatives. A research agenda for the
1990's. United States Department of Agriculture, 28 p.
Anonymous. In press. Environmental Health Criteria for Methyl Bromide. PCS/EHC/94.
International Programme on Chemical Safety. UNEP/ILO/WHO.
Civerolo, E.L., Narang, S.K, Ross, R., Vick, K.W. and Greczy, L. edj. 19S3. Alternatives
to methyl bromide: assessment of research needs and priorities. Proceedings from the
USDA Workshop on Alternatives to Methyl Bromide. 29 June -1 July, 19V3,
Arlington, Va., 80 p.
Hallas, T.E., Gyldenkaerne, S., Nehr Rassmussen, A. and Jakobsen, J-1993. Methyl
bromide in the Nordic Countries - Current Uses and Alternatives. The Nordic Council,
Stockholm, 51p.
i
United Nations Environment Programme, 1992. Methyl bromide: its atmospheric science,
technology, and economics. Nairobi, Kenya, United Nations Headquarters, Ozone
Secretariat, 41 p.
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31
Annex 1.1
Decisions taken by the Parties at the fourth (Copenhagen) meeting relevant to
methyl bromide and MBTOC
Annex XV
i
RESOLUTION ADOPTED BY THE PARTIES TO THE MONTREAL PROTOCOL
ON SUBSTANCES THAT DEPLETE THE OZONE LAYER
Methyl bromide
The Parties to the Montreal Protocol on Substances
the Ozone Layer
that Deplete
Resolve in the light of serious environmental concerns raised in the
scientific assessment, to make every effort to reduce emissions of and to
recover, recycle and reclaim, methyl bromide. They look forward to
receiving the full evaluations to be carried out by the UNEP Scientific
Assessment Panel and the Technology and Economic Assessment Panel, with a
view to deciding on the basis of these evaluations no.later than at their
Seventh Meeting, in 1995, a general control scheme for methyl bromide, as
appropriate, including concrete targets beginning, for Parties not
operating under paragraph 1 of Article 5, with, for example a 25 per cent
reduction as a first step, at the latest by the year 2000, and a possible
phase-out date. |
I. Articie 2H: Methyl Bromide
The foLlov.'ir.g Articlo shall be Inserted after Article 2C- of ths ?^-ctocol:
Article 2H: Methyl Bromide ;
Each Party shall ensure that for ths twelve-month period commencing
en 1 January 199S, and in each twelve-month period thereafter, its
calculated lev-si of -ortsumption of the controlled substance in Annex E
does not exceed, annually, its calculated level of cbnsumpticn in 1991.
Each Party producing the substance shall, for the same periods, ensure
that its calculate-i level of production of the substance does not exceed,
annually, its Calculated level of production in 1991. However, in order
to satisfy the basic domestic needs of the Parties operating under
paragraph 1 of Article 5, its calculated level of production may exceed
that limit by up to ten per cent of its calculated level of production in
1991. The calculated levels of consumption and production under this
Article shall not. include the amounts used by the Party for quarantine
and pre-shipment applications.
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32
4.
Decision IV/13.- Assessment panels
To note with appreciation the work done by the Panels for Ozone
Scientific Assessment, Environmental Effects Assessment, and
Technology and Economic Assessment in their reports of NovembPT-
December 1991; wuuer-
To request the- Technology and Economic Assessment Panel and its
Technical and Economic Options Committees to report annually to
the Open-ended Working Group of the Parties to the Montreal
Protocol the technical progress in reducing the use and
emissions of controlled substances and assess the use of
alternatives, particularly their direct and indirect global-
warming effects; yj.u"«n
To request the three assessment panels to update their reports
and submit them to the Secretariat by 30 November 1994 for
tepM^r«*l?h b£ ^ °Pen-ended Working Group and by the Seventh
Meeting of the Parties to the Montreal Protocol. These
assessments should cover all major facets discussed in the 1991
assessments with enhanced emphasis on methyl bromide. The
scientific assessment should also include an evaluation of the
impact of sub-sonic aircraft on ozone;
To encourage the panels to meet once a year to enable the co-
chairpersons of the panels to bring to the notice of the
meetings of the Parties to the Montreal Protocol, through the
Secretariat, any significant developments which, in their
opinion, deserve such notice;
1.
2.
Decision IV)'23. Methyl bromide
» thS Scientific Assessment Panel and the Technology and
wth A
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33
Decision IV/24. Recovery, reclamation and
recycling of controlled substances
To annul decision i/12 H of the First Meeting of the Parties, which
reads "Imports and exports of bulk used controlled substances
should be treated and recorded in the same manner as virgin
controlled substances and included in the calculation of the
Party's consumption limits";
Not to take into account, for calculating consumption, the import
and export of recycled and used controlled substances (except when
calculating the base year consumption under paragraph 1 of Article
5 of the Protocol), provided that data on such imports and exports
are subject to reporting under Article 7;
To agree to the following clarifications of the terms '"recovery"
"recycling" and "reclamation":
(a) Recovery: The collection and storage of controlled
substances from machinery, equipment, containment vessels, etc.,
during servicing or prior to disposal;
(b) Recycling: The re-use of a recovered controlled
substance following a basic cleaning process such as filtering and
drying. For refrigerants, recycling normally involves recharge
back into equipment it often occurs "on-site";
(c) Reclamation: The re-processing and upgrading of a
recovered controlled substance through such mechanisms as
filtering, drying, distillation and chemical treatment in order to
restore the substance to a specified standard of performance. It
often involves processing "off-site" at a central facility;
To urge all the Parties to take all practicable measures to prevent
releases of controlled substances into the atmosphere, including,
inter alia: • y
(a) To recover controlled substances in Annex A, Annex B
and Annex C of the Protocol, for purposes of recycling, reclamation
or destruction, that are contained in the following equipment
during servicing and maintenance as well as prior to ecruipment
dismantling or disposal:
(i) Stationary commercial and industrial refrigeration and
air conditioning equipment;
(ii.) Mobile refrigeration and mobile air-conditioning
equipment;
(iii) Fire protection systems; \
(iv) Cleaning machinery containing solvents;
(b) To minimize refrigerant leakage from commercial and
industrial air-conditioning and refrigeration systems during
manufacture, installation, operation and servicing;
(c) To destroy unneeded ozone-depleting substances where
economically feasible and environmentally appropriate to do so;
To urge the Parties to adopt appropriate policies for export of the
recycled and used substances to Parties operating under paragraph 1
of Article 5 of the Protocol, so -as to avoid any adverse impact on
the industries of the importing Parties, either through an
excessive supply at low prices which might introduces unnecessary
new uses or harm the local industries, or through an inadequate
supply which might harm the user industries;
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34
6. To request the Scientific Assessment Panel to study and report, by
31 March 1994 at the latest, through the Secretariat, on the impact
on the ozone layer of continued use of recycled controlled
substances and of the utilization or non-utilization of available
environmentally sound alternatives/substitutes and to request the
Open-ended Working Group of the Parties to consider the report and
to submit their recommendations to the Sixth Meeting of the
Parties;
To request the Technology and Economic Assessment Panel to review
and report, by 31 March 1994 at the latest, through the
Secretariat, on: ;
(a) The technologies for recovery,
and leakage control;
reclamation, recycling
(b) The quantities available for economically feasible
recycling and the demand for recycled substances by all Parties;
(c) The scope for meeting the basic domestic needs of the
Parties operating under paragraph 1 of Article 5 of the Protocol
through recycled substances;
(d) The modalities to promote the widest possible use of
alternatives/substitutes with a view to increasing their usage and
release their reclaimed substances to Parties operating under
paragraph 1 of Article 5 of the Protocol; and
(e) Other relevant issues and to recommend policies, with
respect to recovery, reclamation and recycling, keeping in mind the
effective implementation of the Montreal Protocol;
To request the Open-Ended Working Group of the Parties to the
Protocol to consider the reports of the Scientific Assessment Panel
and the Technology and Economic Assessment Panel and any
recommendations in this regard made by the Executive Committee and
submit their recommendations to the Sixth Meeting of the Parties,
in 1994; ;
.
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35
2.0 CURRENT APPLICATIONS OF METHYL
BROMIDE
2.1 General scope of use !
Methyl bromide is used as a fumigant against a wide spectrum of pests, including pathogens
(fungi, bacteria and soil-borne viruses), insects, mites, nematodes and rodents. These pests
may be in soil, in durable or perishable commodities or in structureiS and transportation
vehicles.
It has some features which make it a versatile and convenient material for many applications In
particular, it is quite penetrative, thus reaching pests in soil, commodities and structures often at
a considerable distance from the application point of the fumigant and inaccessible to many
other control measures (e.g. contact insecticides, fungicides of low volatility). Also, it is active
against most pests at low concentrations, though there is a broad range of susceptibility and
dosage schedules need to be adjusted accordingly. Exposures typically range from an hour up
to 2 days with concentrations ranging from 10 to 150 g nr3 for commodities and some days
with application rates of 20 to 100 g nr2 for soils. Exposure periods and concentrations used
typically are varied within these ranges depending on system under treatment, target pest and
quarantine, contractual and other specifications and regulations.
Global sales of methyl bromide, excluding China, India and former USSR, for major use
sector, are given in Table. 2.1. Many of the diverse uses of methyl bromide individually
consume only small quantities of methyl bromide annually. Despite their low consumption
many of these applications are currently of considerable importance with regard to quarantine or
to particular industries. There are relatively few major uses of methyl bromide. However, the
multitude of uses makes overall consideration of methyl bromide, as a fumigant, complex and
also makes simple consideration of alternatives impossible.
Surveys were carried out by MBTOC to determine the proportion of methyl bromide used in
particular applications within those sectors. Results of those surveys are given in detail in the
sections of this report dealing specifically with sectors of application (Sections 4.1,4.2, 4.3,
4.4). Major uses in 1992 with annual consumption of more than 900 tonnes per annum were-
In soil
as a preplant treatment against insect, nematode and fungal pests
and for weed control in production of cut flowers, strawberries,
tobacco, curcurbits, tomatoes and peppers;
as a replant treatment for deciduous fruit trees against 'replant
disease';
as a treatment of seed beds principally against fungi for production
of seedlings, notably tobacco;
as a treatment to ensure production of pest-firee propagation stock,
e.g. strawberry runners.
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36
Table 2.1 Global sales of methyl bromide (tonnes) by use sector (China, India and former
USSR not included).
Year
1984
1985
1986
1987
1988
1989
1990
1991
1992
SoU
30,408
33,976
36,090
41,349'
45,131
47,542
51,306
55,079
57,407
Post Harvest
9,001
7,533
8,332
8,708
8,028
8,919
8,411
10,290
9,564
Structural
1,285
1,274
1,030
1,763
i,9ia
2,083
1,740
860
902
Residential/
Commercial
881
983
999
1,160
1V73T
1,530
1,494
957
1,062
Chemical
Intermediates
3,997
4,507 ,
4,004
2,710
3,804
2,496 ,
3,693
4,071
2,648
Total
Sales
45,572
48,273
50,455
55,690
60,610
62,570
66,644
71,257
71,583
Data source: Methyl Bromide Global Coalition (1994)
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37
In durables
In perishables
In structures
as a treatment against insect pests far cereal grain and similar
commodities in storage to restrict damage to ithe commodity;
as a treatment for cereal grain and similar commodities at point of
import or export as quarantine, phytosanitary or contractual measures;
to control pests of dried fruit and nuts in storage and trade;
as a quarantine measure for treatment of expc«ed or imported timber
principally against insects and some fungal pests.
as a ptytosanitaiy or quarantine treatment against insect pests in
many fresh fruit and vegetables in export trade.
as a treatment for flour mills and similar premises against established
insect infestations; j
as a fumigant, principally against termites, in domestic premises;
as a treatment of ships and freight containers, either empty or
containing durable cargo, against rodents and ins«ect pests, often as a
quarantine or contractual measure.
2.2
Supply of methyl bromide
from
countries.
has a boiling point of 4°C. It is normally supplied and transported as a liquid
iM, Th • i OT C^S- Typicallythe cylinders used range in size from 10 kg to
ity. There is also trade in larger cylinders of up to 18 t capacity and in small
MX, f^jS CanS' |yPlca|1y <*f 0.4 - 1 kg capacity. Methyl bromide is usually applied
7™i- !
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When applied from small steel cans of less than 1 kg capacity, the methyl bromide is not
normaS vaporised, but discharged directly from the can under its own pressure using a special
opener. This can be done so as to release methyl bromide under the plastic cover without
damage to the cover.
Methyl bromide is supplied as a mixture containing 2% chloropicrin (added as a warming
agent) when used for manual application.
2312 Mechanised injection. In this method, MeBr from cylinders is applied by
infecting the fumigant to a depth of 20 -25 cm into the soil, the treated area being
simultaneously sealed by plastic sheeting (shallow injection). The process is normally earned
out as a broad-acre fumigation where one sheet is glued to the previous one. However, some
application is done under strips of plastic, with the edges of the strips buned by the machinery
in the soil. !
Another system of mechanised injection is deep placement (approx. 80 cm) of the fumigant
without covering the area with plastic sheets. The deep injection of MeBr is earned out mainly
prior to planting and replanting in deciduous orchards, vineyards and other plantations, mainly
in U.S.A.
Mechanised injection is carried out with outdoor fumigation only, and is the dominant method
in U.S.A. It is also used in some European countries, Israel, Australia and South Africa.
A variety of mixtures of MeBr and chloropicrin are used in this type of fumigation. In many
situations a 2% chloropicrin in methyl bromide mixture is used, but under certain conditions,
30 - 50% chloropicrin may be included in the formulation.
Crops mentioned above under manual application are relevant to this method as well.
2.3.2 Application to commodities and structures
Methyl bromide is typically applied direct from the cylinder through a narrow bore application
line (or series of lines) culminating in an atomising jet or series of jets which are designed to
enhance the speed of vaporisation of the fumigant. The rate at which the liquid fumigant
becomes a vapour is largely dependent on the ambient air temperature. These lines and jets are-
laid out either on the commodity, or throughout the structure to try to ensure;an even
distribution of fumigant. Alternatively, the methyl bromide is passed through a vaponser (heat
exchanger) which vaporises the fumigant before it is applied through suitably perforated
distribution pipes, again laid out in such a way as to facilitate good distnbutton.
The dose of methyl bromide is calculated according to label, contractual, or legislative (e.g.
quarantine) requirements. Then the required dose, taking into account the volume of space and
weight of commodity, is applied by weighing the cylinder of liquid methyl bromide and
allowing the required dose to be released.
In the case of commodities, this will vary from gastight purpose built fumigation chambers
(portable and fixed) to very poorly sealed bagged stacks. In between these extremes, are ship s
holds (sometimes very gas tight, but not always), freight containers (often not very gas tight),
and well sealed bagged stacks with laminated sheeting (can be very gas tight).
In the case of structures, the gastightness varies from aircraft (sometimes very gastight) ship's
holds, modern food factories and mills (can be very gastight) to older buddings such *s many
flour mills (often not very gastight and, in many cases, impossible to make more than partially
gastight).
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39
Normally, in all these situations, fumigation is carried out for a pre-determined period to try to
ensure that the gas has had sufficient time to penetrate to the target organism, and that the ct-
product needed to eradicate all stages of the pest life cycle has been achieved in the most
difficult-to-penetrate part of the enclosure under treatment.
Technology exists to enable the cf-product to be monitored during the fumigation, and much
lower doses can be Utilised in many cases to achieve the same results, as with unmonitored
treatments. The concentration must be measured in critical areas of the treatment enclosure, e.g
in the centre of the commodity bulk. This technology is not widely used, however, as it is
normally cheaper to use more methyl bromide than to involve the use of the technology.
In structures (buildings, ships, aircraft, etc.) the same principles and application techniques
apply, but the cf-product must be calculated in the floors, walls, machinery, etc. where deep
seated and inaccessible infestation is the target, and which is normally the reason for using
methyl bromide. Again, accurate monitoring, lower doses, but with the ability to add more
fumigant, is increasingly becoming more widely used, rather than the still widely practiced
method of over dosing to try to guarantee success.
In most countries, commodity and structural treatments are carried out with 100% methyl
bromide formulations, superseding the formulation containing 2% chloropicrin, which is still in
use in some regions. /
2.4 Global quantities of methyl bromide used
Global sales of methyl bromide for the period 1984 -1992 by year and region are given in
Table 2.2. This data was supplied by the Methyl Bromide Global Coalition (1994) and does not
include production in China, India and former USSR. These are estimated for 1992 to be 1000
40 and 30001, respectively (Wang, W., S. Rajenderan, G.A. Zakladnoi, pers. comm.) giving '
a total global production and sale of 75,6251 and an estimated usage of 72,9751 for soil,
commodity and structural fumigation.
Figure 2.1 shows the trend in global methyl bromide sales (excluding China, India and former
USSR) for fumigation of soil, commodities and structures from 1984 - 1992. The figures
show an approximately linear increase over this period at a rate of about 37001 per year.
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40
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41
Table 22 Sales of methyl bromide by region, including chemical feedstock, but excluding
China, India and former USSR
Year
1984
1985
1986
1987
1988
1989
1990
1991
1992
North
America
t9,659
20,062
20,410
23,004
24,848
26,083
28,101
30,909
29,466
South
America
1,389
1,503
1,774
1,820
2,058
1,701
1,621
2,068
2,300
Europe
11,364
14,414
13,870
15,359
17,478
16,952
19,119
17,447
18,521
North
Africa
183
45
380
385
277
618
432
1,058
1,363
Africa
1,595
1,975
2,205
1,751
. 1,582
2,075
1,838
2,093
1,697
Asia
10,687
9,743
11,278
12,816
13,555
14,386
14,605
16,843
16,944
Australasia
704
531
538
555
812
755
928
842
1,294
Total
Sales
45,572
48,273
50,455
55,690
60,610
62,570
66,644
71,260
71,585
Data source: Methyl Bromide Global Coalition (1994) |
Note: |
i
Statistical regions comprised:
North America
Antigua and Barbuda, Bahamas, Barbados, Belize, Bermuda, Qanada, Colombia,
Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Grenada, Guatemala,
Haiti, Honduras, Mexico, Nicaragua, Panama, St. Kitts and Nevis, St. Lucia, St.
Vincent & Grenadines, Trinidad and Tobago, and United States of America.
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guayaitia, Netherlands Antilles,
Paraguay, Peru, Suriname, Uruguay and Venezuela.
Europe
European Economic Community (E.E.C.): Belgium, Denmark, France, Germany,
Greece, Ireland, Italy, Luxembourg, The Netherlands, Portugal, Spain and United
Kingdom.
Other European Countries: Albania, Austria, Bosnia and Herzegovina, Bulgaria,
Czechoslovakia (Czech Republic and Slovakia), Finland, Hungary, Iceland,
Liechtenstein, Malta, Norway, Poland, Romania, Slovenia, Sweden and Switzerland.
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42
North Africa* Western and North Eastern Africa
Algeria, Benin, Burkina Faso, Cape Verde, Chad, Cote d'lvoire, Djibouti, Egypt,
Ethiopia, Gambia, Ghana, Guinea, Guinea-Bissau, Kuwait, Liberia, Libya, Mali,
Mauritania, Morocco, Niger, Nigeria, Qatar, Saudi Arabia, Senegal, Sierra Leone,
Sudan, Togo, Tunisia, United Arab Emirates and Yemen (Republic of).
Africa, Central and Southern Africa ;
Angola, Botswana, Burundi, Cameroon, Central African Republic, Comoros,
Congo, Equatorial Guinea, Gabon, Kenya, Lesotho, Madagascar, Malawi,
Mauritius, Mozambique, Namibia, Reunion, Seychelles, Somalia, South Africa,
Swaziland, Uganda, Zaire, Zambia and Zimbabwe.
Asia
Afghanistan, Bahrain, Bangladesh, Belarus, China, Cyprus, India, Indonesia, Iran,
Iraq, Israel, Hong Kong, Japan, Jordan, Korea (Republic of), Lebanon, Maldives,
Mongolia, Nepal, Philippines, Russian Federation and former countries of USSR,
Singapore, Sri Lanka, Syria, Taiwan, Thailand, Turkey and Vietnam.
Australasia ;
Australia, Fiji, French Polynesia, Kiribati, Micronesia, Nauru, New Zealand, Papua
New Guinea, Solomon Islands, Tonga, Tuvalu, Vanuatu and Western Samoa.
Certain countries were reclassified to different regions between the 1984 and 1992 reports.
A separate set of data was obtained on global consumption of methyl bromide in
1992 through the MBTOC surveys carried out by the various MBTOC sector
subcommittees. The figures obtained differ slightly from the data in Table 2.2, as shown
in Table 2.3. . :
Table 2.3 Global methyl bromide usage (tonnes, 1992) by sector
Sector
Soils
Durables
Perishables
Structural
China/India/former USSR
Totals
Table 2.2 data
57,407
9,564
a
1,964
4,040
72,975
Survey data
50,913
9,855
6,537
3,736
b
71,041
" Tonnage for perishables included with durables as 'post-harvest' use. I
* Table 2.2 data adjusted to include production tonnage for China, India and former USSR. Included in
survey data as estimates of 3001 for structural and remainder for durable treatment.
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43
The figures given in Table 2.3 differ from the two data sources, both in total and by sector. The
discrepancy in total, with the survey showing l,934t less than the sales data, is ascribable to
incomplete reporting, double counting (some data in more than one category) inventory changes
(i.e. annual production does not necessarily equate to consumption in any one year and
uncertainties in some estimates). The differences by sector may reflect reporting of methyl
bromide in different sectors in the two data sets in addition to inventory changes. Survey data
obtained by MBTOC may be expected to underreport consumption globally because of lack of
response from some users.
Further study is required to reconcile these figures fully. For the purposes of this report, the data
presented in Table 2.2 is taken to be correct, but the proportions of use as shown in the MBTOC
surveys are used where needed to scale within sector use. ;
2.5 Technical and legislative limitations to methyl bromide use
2.5.1 Technical limitations i
Although methyl bromide is well recognised as being a most useful fumigant, there are a number
of technical factors which restrict its application. Not only have these tended to limit its field of
application, apart from direct economic considerations, but some have also led to legislative and
other restrictions, independently of its detrimental effect on the ozone layer.
Methyl bromide can have adverse effects on a number of commodities, causing taint and odours.
These are listed in Bond (1984). It also has substantial phytotoxicity. This makes it an effective
weedicide in soil treatments, but can limit its usefulness in treatment of growing plants and
perishables against pests, sometimes resulting in reduced storage life (e.g. of cut flowers) or
preference for alternatives.
Treatments with methyl bromide result in production of bromide ion residue. These may
accumulate to excessive levels in commodities that are fumigated several times and have been a
cause for concern in ground water in some European countries. Production of these residues is
discussed in detail in later sections of this report.
A major limitation to methyl bromide use is its toxicity to humans. Many countries restrict the
actual application of methyl bromide to trained, licenced fumigators and "may specify appropriate
safety equipment and airing times for removal of residual gas after treatments. Additionally, there
may be stringent controls on allowable concentrations in workspaces and in the environment
around fumigations. The toxicity to humans has recently been reviewed in detail (Anon., in press).
2.5.2 Legislative limitations ;
A number of countries have current or projected legal restrictions on the use of methyl bromide.
Some of these are in response to its status as an ozone-depleting substance, but others, such as in
the Netherlands, were put in place in response to concerns over local environmental contamination
mainly related to methyl bromide in air and to bromide in surface water.
The 1994 TEAP Report contains a summary of legislative controls on methyl bromide in various
countries. Since that report, the EU, Italy, Canada, Sweden and Denmark have all increased their
present or future restrictions on methyl bromide. i
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44
The European Union has adopted a new Council Regulation (EC) No 3093/94 on substances that
deplete ftVozone layer, in force from 23 December 1994, which introduces a 25% cut m the
portion and supply of methyl bromide based on 1991 levels from 1 January 1998 with an
exemption for quarantine and preshipment. Canada has adopted a similar position. Article 15 of
the EU Council Regulation on ODS also requires all precautionary measures practicably to be
taken to prevent emissions of methyl bromide resulting from leakage from 3 months after the
regulation becomes effective. Denmark is to phase out the major use area of methyl bromide
(soil/tomatoes) by 1 January 1996 (about 70% of total use) and the remaining use areas by 1
January 1998 without exemptions for preshipment and quarantine (Ministry of the Environment
Statutory Order No. 478, June 1994). The Nordic Environmental Strategy, adopted by the nordic
countries is for phaseout of Methyl Bromide by 1 January 1998, with exemption for preshipment
and quarantine uses. In Italy, a phaseout date of 1 January 1999 has been set with exemptions in
exceptional circumstances (Italian Law 594/93). However, this law is not currently in force.
The Netherlands has now completed its phaseout of use of methyl bromide for soil fumigation
with very restricted uses still permitted for some commodity treatments.
2.6 References
Anonymous. In press. Environmental Health Criteria for Methyl Bromide. PCS/EHC/94.
International Programme on Chemical Safety. UNEP/ILO/WHO.
Bond, E. J. 1984. Manual of fumigation for insect control. FAO Plant Production and Protection
Paper No. 54, FAO, Rome, 432 p.
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45
3.0 EMISSIONS, EMISSION REDUCTION AND
RECLAMATION, RECOVERY AND
RECYCLING OF METHYL BROMIDE
Executive Summary i
Estimates of the proportion of the applied methyl bromide released into the atmosphere
from fumigation vary widely. Emissions occur inadvertantly through leakage and
permeation during treatment and intentionally while venting at the end of treatments. The
quantity of methyl bromide emitted from a treatment varies on an individual case basis as
a result of the use pattern, the condition and nature of the fumigated materials, the degree
of seal of the enclosure, and local environmental conditions. Methyl bromide is a reactive
material: it is incorrect to equate production with emissions as at leasit part of methyl
bromide applied is converted in use to non-volatile materials.
Under current usage patterns, the proportions of applied methyl bromide emitted
eventually to atmosphere globally were estimated by MBTOC to be 30 - 85%, 51 - 88%.
85 - 95% and 90 - 95% of applied dosage for soil, durables, perishables and structural
treatments, respectively. These figures, weighted for proportion of use arid particular
treatments, correspond to a range of 46 - 81% overall emission from agricultural and
related uses (34,000 - 59,000 tonnes, based on 1992 sales data). ,
MBTOC assumed that the most energy intensive alternative to methyl bromide was use of
steam heating for soil treatment. The indirect Global Warming Potential of methyl
bromide, in terms of CO2 produced, with energy required supplied electrically, was 20 kg
CO2 per tonne for synthesis and vaporisation. Using equivalent energy sources, steaming
at 4 - 7 m3 per m2 and methyl bromide at 25 - 100 g per m2 were equivalent to 1200 -
2100 and 5 - 20 g CO2 per m2. The atmospheric lifetimes of all gaseous potential
alternatives to methyl bromide were too short to give appreciable direct GWP.
There are well developed containment technologies for decreasing the rate of leakage of
methyl bromide from fumigation of soil, structures and commodities. These techniques are
only in limited use worldwide, with their lack of adoption constrained particularly by poor
dissemination of information and perceived or real increases in costs and increased logistic
problems. Better containment is essential before recovery of the used methyl bromide can
be considered.
Better sealing of enclosures and the use of less permeable sheeting was identified as an
immediately applicable, technically proven means of substantially reducing emissions from
soil, durable commodity and structural fumigation treatments, with the largest
improvement coming from soil fumigation. Better containment and/or longer exposure
times can lead to reduced dosage levels to achieve the required degree of control. These
changes in application techniques are estimated to be able to reduce emissions
substantially for the soils, durables and structural sectors respectively. M'any facilities
used for fumigating perishables already have a high standard of gastightness, but there is
scope for improvement in others.
There is active research into the development of recovery and recycling plant for methyl
bromide. There are a few special examples of recovery plant already in use and it is
anticipated that prototype plant capable of recycling recaptured gas will be evaluated by
the end of 1995. Some may eventually be suitable for recovery from soil fumigations, but
most are directed at recovery from enclosures used for structure or commodity fumigation
(currently around 10% of global use). ;
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46
It is unlikely that significant demand from Article 5 countries can be met with recycled material.
There is, however, potential for recycling, including in developing countries, in some
specialised applications, notably treatment of perishables in gastight chambers.
Most of the potential recovery and recycling technologies are complex in nature and expensive
to install compared with the cost of the fumigation facility itself. Some systems would have
high running costs associated with energy requirements. Many would require a level of
technical competence to operate that would not normally be found at many fumigation facilities.
It will be necessary to set specifications on equipment efficiency and tolerable levels of
emission if recovery is to be recognised as an acceptable method of reducing methyl bromide
emissions to the atmosphere. |
3.1
Definitions
The following terms are used throughout this section and where appropriate are consistent with
the definitions used in the Montreal Protocol documents.
Containment:
Recovery:
Recycling:
Reclamation:
Destruction:
Securing the fumigation site so that inadvertent leakage from the
treatment area does not occur during the actual fumigation treatment
The collection and storage of methyl bromide from fumigation
operations.
The re-use of methyl bromide following a basic recovery and cleaning
process. Normally this would only involve 'on-site' processing.
The re-processing and upgrading of recovered methyl bromide by more
complex physical or chemical treatments. Often this would involve
storage for subsequent re-use, either on-site or at other sites.
The chemical or physical destruction of methyl bromide recovered from
fumigation operations.
3.2
Emissions of methyl bromide from .treatments
In normal use, methyl bromide may be vented intentionally from a treatment at the end of the
exposure period, it maybe lost inadvertently through leakage and permeation during the
exposure period, and it may be lost through desorption of sorbed material subsequent to the
fumigation. Overall, the sum of the quantity of methyl bromide emitted from these processes
will constitute the emission to atmosphere, unless recapture systems are in place.
A proportion of any applied dosage of methyl bromide reacts with the treated material (e.g.
soil, grain, fruit) or associated structures and packing material. The end product of this reaction
is typically non-volatile bromide ion, various methylated products and carbon dioxide. These
have not been identified as ozone depletors. The proportion of non-volatile bromide residue
formed as a result of a treatment is a direct measure of the proportion of the applied methyl
bromide not emitted to atmosphere. The proportion emitted is found by difference. This 'mass
balance' approach is typically used to estimate quantities of methyl bromide released to
atmosphere from a treatment It gives a conservative estimate and is simple to use as bromide
ion tends to be easily detected and quantified. An allowance has to be made for natural bromide
ion already present prior to treatment
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47
An alternative approach, is to observe the quantities emitted directly. This is experimentally
difficult as it relies on quantification of a number of fluxes of gas and may miss some important
ones. The approach tends to underestimate the emissions, but is often used in soil fumigation
studies.
The proportion of applied methyl bromide converted to fixed residues, and thus not released to
atmosphere, varies widely with the particular treatment situation. It is influenced, inter alia, by
the degree of containment (sealing, permeability of the enclosure), and temperature, moisture
content and reactivity of the treated material. With soil fumigation, the mode of application, e.g.
'hot gas', deep injection, is also a major factor since it influences the contact time between die
methyl bromide and substrate, and thus the opportunity for varying degrees of reaction and
dispersion within the soil before loss from the system.
There is remarkably little firm quantitative field data available on production of bromide ion or
other measures of loss of methyl bromide from particular systems. For the purposes of this
Report, MBTOC has relied on some particular data for specific situations and estimates
provided by MBTOC members. Ranges of estimates have been given. These are used to
encompass both the true variability to be expected with different sites, techniques and
situations, and the range of opinions expressed by experts within MBTOC. An approximation
of the quantity of methyl bromide lost to atmosphere has been made by integrating this
information over the total usage of methyl bromide (Table 3.1).
Table 3.1 includes estimates for emissions from four types of application to soils. The variation
given in two of these is wide and reflects the range of data available to MBTOC experts. It is
not possible to provide a weighting of figures within these ranges to give a precise average
emission as the distribution of emissions over the global range of practice is not estimatable,
because of lack of good data on the subject. However, it may well be that the true value differs
substantially from average value of range quoted. i
The potential range of emissions can be estimated from laboratory sorption (decomposition)
studies with various soils. Table 3.2 shows a range of values of residual methyl bromide
calculated on the basis of the stated half life for 3 and 7 day exposures, corresponding to
medium and prolonged exposure periods in practice. It can be seen that the ranges given in
Table 3.1 fall within the variation in rate of reaction in Table 3.2. Arvieu (1983) gives a similar
range of reactivity. i
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48
Table 3.1 Estimated usage of methyl bromide and emissions to atmosphere for different
categories of fumigation
The following table shows the amounts of methyl bromide used and the estimated percentage
emitted to the atmosphere for each of the major categories of use.
Type of
fumigation
and commodity
Amount used
(t) (% of global
non-feedstock
usage)
Estimated emissions
(t) (%)
Notes
Enclosed Space
(Durables)
Grains, etc. 4601
Nuts 236
Dried Fruit 236
Timber . 4782
Subtotal 9855 12.96%
Enclosed Space
(Perishables) 6537 8.59%
Enclosed Space
(Structural) 2264 2.98%
Soil Fumigation
Soil injection - 31000
shallow with
tarp
Soil injection - 2296
deep with tarp
Vaporised gas 22963
with tarp
Soil injection - 1148
deep without
tarp
Subtotal 57407 75.47%
Total agricultural
usage 76063
2347 - 3221
120
205
4208
6880 - 7754
5556 - 6210
2038-2151
10230 - 24800
689
11481 -19518
918
21022 - 45925
35229 - 61773
51 - 70
51
187
88
70-79
85-95
90-95
33-80
130
40-85
80
37-80
46-81
ajb
a
a
a
d
d
d
64
Mean emission
over all categories
a Calculations supporting these figures given in Annex 3.1.
b Higher emission rate estimated from residue data for bag stacks by MBTOC (Annex 3.1).
c Values estimated by MBTOC. Calculations consistent with higher figure given in Annex 3.1.
d Range of values estimated by individual MBTOC members on basis of experience and
published studies.
e Low value consistent with emissions from reactive soils estimated by MBTOC, high value
from data in Yagi et al., (1993) corrected by Cicerone, R.J. (pers. cornm.).
/ MBTOC recognises that the true value of emissions may differ substantially from this mean.
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49
Table 3.2 Half-ltfeand % methyl bromide remaining in soil (laboratory studies) after 3 and
7 days. Calculated from data reviewed in Visser and Linders n Q
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50
Tflh1e 1 3 shows comparative energy costing for some methyl bromide and steam .
Jeatoente of Si SS suggeste an increased relative global warming potential using
steam as an alternative.
Table 3.3 Relative global warming calculations for methyl bromide and steam
sterilisation as an alternative soil treatment
BS'cflcuSons: energy supplied by electricity and direct GWP of methyl bromide may
be neglected.
m Methyl bromide fumigation (hot gas method):
v ' - energy for synthesis 774 MJ t
energy for vaporisation 306 MJ t
TOTAL 1080 MJ t"
For a power station generation efficiency of 33.5%:
energy required = 3223 MJ t"'
At an emission of 0.0618 kg C02 per MJ = . 203 kg CO2t-'
At application rates of 25 - 100 g m-2, energy equivalent = 5 - 20 g C02 m2
(2) Steam sterilisation under sheets or using negative pressure systems:
steam consumption 4"7m3,ml,T ,
total energy equivalent 6.4 - 11.2 MJ m-2
For a power station generation efficiency of 33.5%:
energy required = 19 - 33 MJ nr2
At an emission equivalent of 0.0618 kg CO2 per MJ = 1200 - 2100 g CO2 nr2
Data sources: Methyl Bromide Global Coalition and MBTOC ;
•
3.4 Opportunities for Methyl Bromide Emission
During any fumigation operation there are three distinct opportunities for methyl bromide
to be emitted to the atmosphere.
By leakage during the actual fumigation treatment. This is undesirable from the
fumigation point of view because it reduces the effectiveness of the treatment
as well as having worker safety implications.
During venting of the fumigation space immediately afterfumigation or removal of
the cover sheets when a deliberate discharge to the atmosphere take place.
Following treatment when the treated soil, commodity or structure slowly emits
« any adsorbed methyl bromide.
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51
For most fumigation operations venting following fumigation results in the largest discharge.
Emission of adsorbed methyl bromide is the next largest followed by leakage, although this is
very commodity and site dependent The first and to some extent the third type can be
controlled or reduced by better containment of the fumigation site. The second can only be
controlled by recovery followed, if possible, by recycling or reclamation or by destruction.
Possibilities for emission reduction in soil, durable and perishable, treatments are further
discussed in Sections 4.1.7, 4.2.13 and 4.3.7, respectively.
3.5 Containment ., !
i
3.5.1 Soil Fumigation
Emissions to the atmosphere from soil fumigation can be reduced by using sheeting with a
lower permeability and by improving the techniques used for sealing: the edges of the sheeting.
At present there are no objective test methods to determine the degress of seal achieved for
methyl bromide treatments carried out under sheets for soil fumigation. Leakage control is
effected by burying the edges of the fumigation sheets in the soil, but the: reliability of this
process varies widely with the conditions under which the fumigations are carried out, with the
skills of the operator, the degree of quality control exercised and the intactness of the sheeting
used. Research is in progress to limit permeation losses by employing thicker polyethylene
sheets or laminated sheets incorporating other materials. There are many publications on the
influence of less permeable sheeting on emissions. Table 3.4 gives some typical experimental
results showing improved gasholding as a result of using less permeable sheets.
Table 3.4 Emissions from a methyl bromide fumigation of greenhouse soil using two
different covers (from de Heer el al., 1981).
Saranex
LDPE
Exposure time (days) % emitted
Airing time (days) % emitted during airing
Total % emitted
Remaining in soil
Transformed by reaction
5
20
2
48
68
. 5
56
2
22
78
c. 20 c. 10
c. 10 c. 10
Further data on emission reduction from soil fumigations through containment and priorities for
further research are given in Section 4.1.7. ,
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52
i
3.5.2 Structural and Commodity Fumigation I
Some level of containment is necessary to achieve effective fumigation. Increased containment,
through improved gas tightness, and increasing the duration of the fumigation treatment can in
many cases enable lower doses to be used, thereby reducing emissions to the atmosphere. A
large proportion of the durable and perishable commodities are fumigated in temporary
enclosures such as under tarpaulins. The remainder are treated in fixed enclosures such as
freight containers and purpose built fumigation chambers. A minimum cf-product must be
achieved to ensure effective fumigation. By improving the degree of gas tightness of the
enclosure, lower initial doses can be used and the need for top up doses prevented. A move to
more gastight or permanent enclosures, especially those equipped with circulation fans would
make recovery of methyl bromide for subsequent recycling or destruction more feasible.
In a few countries there are standards of gastightness for various structures and enclosures
which are treated with methyl bromide. These are applied to ensure leakage from fumigation is
reduced so that methyl bromide concentrations are maintained at a level necessary for an
effective treatment or for environmental or human health reasons. Table 3.5 shows standards
for several countries.
Table 3.5 Examples of pressure test standards for gastightness of some fumigation
enclosures and treated structures
Structure Country Typical Fuller Time
pressure empty
range (Pa)
Reference-
Bag stacks
under sheets
Farm storage
bins
Flour mills,
churches
Freight
containers
Fumigation
chambers
Silo bins
Silo bins
Storage sheds
Indonesia
Australia
Germany
Australia
USA
Japan
Australia
Australia
-200
250-
to-100
125
10-5
200-
500-
5000
1000
200-
100
50
-2000
-500
100
full
empty
empty
empty
empty
empty
full
full
• > 10 min
>5min
>4 sec
> 10 sec
>30 sec
> 20 min
>5min
>5 min
Nataredja and
Hodges, 1990
Chantler, 1984
Reichmuth, 1993
Banks, 1988
USDA-APHIS, 1976
Takeda etal, 1980
Banks, 1984a
Banks, H.J.
(pers. comm.)
Direct emission of methyl bromide by leakage can be very significant Permanent (non-flexible)
structures achieving the highest standards shown in Table 3.5 can be expected to lose gas at a
rate of up to 5% per day (Banks and Annis, 1984) although flexible (but well sealed)
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53
enclosures created by using low-permeability plastic sheeting, such as are used for carbon
dioxide fumigation of rice stacks in Indonesia lose gas at less than half that rate (Annis et al.,
1984). After introducing very low, but measurable levels of leakage, such as that specified for
flour mills in Germany, ventilation rates of several air changes per day can still occur, (two
changes per day results in 86% loss by leakage).
There are techniques available for the durable sealing of buildings, such as grain stores, silos
and mills, to achieve a high level of gastightness (Newman, 1990). These have been used
successfully on very large structures (eg 250,000 tonne capacity grain storage sheds at
Kwinana, Western Australia (Ripp, 1984), but their use is not widespread. Using a patented
process, methyl bromide can also be released by heating the carbon bed electrically
(Stankiewicz and Schreiner, 1993). These processes are often more effective than sheeting of
structures with plastic or various temporary measures often used to prepare structures for
methyl bromide treatment. Doubts are often expressed about whether increased gas tightness or
sealing of complex structures such as flour mills is possible. However in several parts of the
world, achievement of significant levels of sealing in such structures is being achieved
(Reichmuth, 1993).
Emission reduction for treatments of durables through containment is further discussed in
Section 4.2.13.
3.6
Recovery
A number of techniques have been proposed or investigated for their potential to recover or
capture methyl bromide from fumigation operations. Depending on the technique used,
recovery would lead to the methyl bromide either being emitted to the atmosphere at some later
stage, being recycled within the fumigation facility or being destroyed. For technical or
economic reasons only three recovery techniques are currently or have been in commercial use
at the time of writing this report. These are adsorption onto activated carbon, condensation and
absorption into reactive liquids. Several others.are being actively researched. If containment
and recovery are to be specified as the means of reducing methyl bromide entering the
atmosphere, it will be necessary to define the maximum permissible quantity or concentration
that may be emitted. This will allow specification of efficiencies required for recapture
equipment
3.6.1
Activated Carbon
Activated carbon can adsorb relatively large amounts (up to 10 - 30% by weight depending on
activated carbon type and conditions) of methyl bromide. It is widely used throughout the
world to remove trace amounts of organic contaminants from gas streams. For fumigation
operations, a vessel containing activated carbon is installed in the gas vent line. At the end of
the fumigation treatment, the gas mixture containing methyl bromide and air is passed through
the activated carbon onto which the methyl bromide is adsorbed. The proportion retained on the
activated carbon depends mainly on the amount of free activated carbon available and the rate at
which it adsorbs depends on the concentration in the gas stream, gas flow rate, activated carbon
characteristics and temperature. At low loadings recovery rates of cloise to 100% are achievable.
However, for most systems, some methyl bromide will be emitted to the atmosphere.
Eventually the adsorption capacity of the activated carbon is reached zmd it needs to be
regenerated or disposed of. Regeneration can be achieved by passing hot gas over the activated
carbon and could be the basis of a reclamation process (see Section 3.7.2). Alternatively, the
activated carbon and methyl bromide can be incinerated in a specialised facility. However
concerns about emissions of toxic chemicals may prevent this from being a viable option in
some areas.
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54
Although there has been much research into the potential use of activated carbon with methyl
bromide, there are only a few known commercial fumigation installations worldwide which
have or have had activated carbon beds installed to recover methyl bromide. There was a
30 m3 chamber in Belgium which is no longer in use. There are five 30 m3 chambers in the
Netherlands (one transportable) each with a 70 kg filter of activated carbon. Fumigation at 30 g
m-3 is carried out and a 40 - 50% recovery is achieved. The activated carbon lasts for
40 fumigation operations and the spent carbon containing the adsorbed methyl bromide is
incinerated in a special incineration facility. There is also a 30 m3 chamber in Thailand fitted
with a 72 kg bed of activated carbon. The chamber is used for fumigating asparagus and green
okra exported to Japan. The system is capable of reducing methyl bromide concentrations in the
vented gas to 5 ppm within 30 minutes. The fully absorbed activated carbon is disposed of in a
sanitary land-fill. Italy is reported to require activated carbon scrubbing systems on fumigation
installations to reduce the potential hazard to workers and the public. It has not been possible to
verify whether they are in use and whether this includes non-chamber fumigation.
An activated carbon system has also been developed by Rentokil UK for use with their
fumigation bubble, a well sealed plastic tent enclosure used for fumigation of small structures.
A 10 kg activated carbon bed which can hold up to 1.5 kg methyl bromide (equivalent to
5 fumigations) is used. Regeneration of the activated carbon is achieved by blowing hot air
through the beds. This results in direct emission to the atmosphere. However, its use was
intended only to prevent emissions that might endanger people in the immediate vicinity of the
fumigation operation not as a means of emission prevention.
i
Although activated carbon systems provide the most immediate potential for reducing methyl
bromide emissions, they have usually only been considered for very small facilities where
commodities or structures are fumigated and where, for reasons of protecting the immediate
surroundings, very low concentrations of methyl bromide are permitted. Very large activated
carbon beds containing tonnage quantities of carbon would be required for the fumigation of
large structures or enclosures such as mills, grain silos or tarpaulin fumigation. However, in
October 1994 trials were carried out in a mill in Germany using activated carbon to recover and
recycle methyl bromide. Further information on this plant is given in Section 3.7.2. In all
situations, once the activated carbon has been fully loaded it will be necessary to remove the
carbon for disposal or regeneration in an appropriate manner. While this is by no means
impossible, there are regulatory implications associated with the transportation and storage of
toxic materials.
3.6.2
Condensation/activated carbon
A system is in operation in California, USA which uses a method of condensation to recover
methyl bromide followed by removal of residual trace quantities with an activated carbon bed.
This plant directly recycles the methyl bromide and is more fully described in Section 3.7.1.
3.6.3 Absorption into reactive liquids
Amines typically react with methyl bromide to give methylated non-volatile products. A system
based on organic amines and alkali for removing residual methyl bromide from fumigated
28 m3 freight containers in Russia has been described (Rozvaga and Bakhishev, 1982). No
information was available to MBTOC on whether this system is in current use. See
Section 3.6.5 for additional information on this technique. Mordkovich etal., (1985) have also
described a technique using aqueous sodium sulphite as a neutraliser and a mixture of ethylene
diamine and sodium carbonate as an adsorbent Again, it is not known whether these
techniques have achieved general use.
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55
3.6.4 Adsorption onto zeolite
Processes based on the use of zeolite adsorbents to remove CFCs from vented air streams are
in commercial use. Work is well advanced on the development of this process for methyl
bromide, both for recovery and for recycling (Nagji and Veljovic, 1994a). Although zeolites
are more expensive than activated carbon, they have high adsorptive capacity, particularly at
low concentrations. They can be manufactured to very narrow pore size distribution tolerances
for specific applications and it may be possible to avoid any potential problems of
contamination of the recovered methyl bromide with other volatile compounds by utilising the
selective sorption that is conferred by a particular pore size range. Pilot scale demonstration
trials of the process were carried out in July 1994 to demonstrate the technical feasibility of the
technique. Recovery in excess of 90% was achieved (Nagji and Veljovic, 1994b). Analysis of
the recycled methyl bromide from cherry fumigation showed no other volatile compounds from
the fruit were released. However, these tests need to be confirmed over a large number of
adsorption/desorption cycles. The Port of San Diego Authority have announced a decision to
install, in early 1995, a full size prototype plant based on adsorption of zeolite to reduce methyl
bromide emissions from a 2,100 m3 quarantine chamber. i
3.6.5 Techniques under development
• Improved solid absorbants i
Research in Japan has led to the development of a new adsorbent, MBAC, which is a
mixture of activated carbon and special substances (amines) which has a greater
• adsorptive capacity for methyl bromide than activated carbon alone. This material can be
produced as sheets and introduced into packaging to recover the slowly desorbing
methyl bromide from fumigated commodities and also has potential to recover some
methyl bromide from soil fumigations. The Japan Methyl Bromide Industries
Association is currently conducting evaluation tests (Muraoka T., pers. comm.). There
are no details yet on techniques for disposing of the contaminated adsorbent.
• Separation by refrigeration and condensation j
Because of the low methyl bromide concentration in vented gases and its low boiling
point this option has been considered too complex and expensive for recovery of methyl
bromide from fumigation operations, although it is used to recover methyl bromide at
installations where pure methyl bromide is dispensed from bulk containers into smaller
ones for direct use.
,
• Absorption into a liquid (gas/liquid scrubbing)
Research was carried out in the 1970s into a technique of liquid scrubbing to remove
methyl bromide from fumigation operations (Anon., 1976a). The process was
developed and tested on timber fumigation under stacks and consisted of equipment to
circulate methyl bromide and air from the fumigation enclosure tlirough a tank of
aqueous monoethanolamine (50%) and back to the fumigation tent. The process
achieved 70% reduction in methyl bromide concentrations, but was slow taking 40 - 60
minutes to achieve this level of reduction. The size of the necessary equipment for full
scale operation and the difficulties of handling the contaminated liquid material have
prevented its further commercial development.
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3.7
56
Ozone treatment/activated carbon
A system is under development in California, USA to use ozonation to directly destroy
methyl bromide in the vented gas stream from a chamber fumigation operation. The
treated vent gas would then be passed through an activated carbon bed to further
remove further unreacted methyl bromide. This process has been tested on a pilot scale
and a full scale plant with a target recovery of 90% is expected to be installed soon. The
process will produce activated carbon contaminated with methyl bromide breakdown
products. At this stage it is not known if these will present disposal difficulties.
Direct combustion and catalytic destruction
Research was also carried out in Japan in the 1970s into a direct combustion method
and a catalytic cracking method for destroying methyl bromide in the vent gas stream
from chamber fumigations (Anon., 1976b). Large pilot plants were built to test the
techniques, but neither method proceeded to full size installation. The processes were
effective at reducing the concentration in vent gas streams down to ppm levels but were
not further developed because of the high cost, their unsuitability for stock fumigations
(i e. not transportable), concerns about the use of direct heat when methyl bromide can
(under very restricted conditions) form an explosive mixture with air and the difficulties
of handling the products of destruction (HBr and Br2).
Reclamation and recycling
3.7.1 Condensation/activated carbon
There is a facility where methyl bromide is now reclaimed and recycled using a
condensation/activated carbon process. This facility, located in Los Angeles, has two vacuum
chambers which were retrofitted with a recovery/recycle plant At the cornpleuon,ot each
fumigation operation, the remaining methyl bromide is diluted by the addition of air from a
single airwastu This diluted mixture is then drawn through vessels where liquid nitrogen cools
and condenses most of the methyl bromide. The remaining methyl bromide and air is passed
through an activated carbon bed where most of the remaining methyl bromide is adsorbed.
Periodically the activated carbon bed is isolated and undergoes a pressure swing idesorption.
The plant is designed to recover 98% of the methyl bromide available for capture. The process
is computer compiled. The plant was installed in late 1993, but because the fumigation
chambers have not been in steady operation since then has only gone through approximately
30 recovery cycles. The capital cost and operating costs are not available, nor are figures tor
the effectiveness of operation.
3.7.2 Activated carbon.
It is technically possible to recycle methyl bromide adsorbed on activated carbon by heating the
carbon, traditionally by passing hot air over it or altering the pressure (temperature and pressure
swing adsorption). Circulating air strips the desorbed methyl bromide from the activated carbon
and the mixture can potentially be reintroduced into the fumigation chamber. The methyl
bromide is reclaimed as a high concentration mixture in air suitable for direct reuse as a
fumigant, but some topping up will be necessary to compensate for system losses sc> as to
achieve a^satisfaa(W fumigation concentration. Pilot scale studies have demonstrated the
SSSiKf Sa process (Smith, 1992) with up to 95% of the recoveraWe methyl
Sdebeing available for direct reuse. The technique has not yet been demonstrated on
commodity fumigation where the build up of other gas phase impurities, if any, may beof
concern both from product quality and regulatory view points. In Germany, a mill hasbeen
equiped with a recycle system based on temperature swing adsorption on activated carbon
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57
j
(Stankiewicz and Schreiner, 1993). This transportable recycle system has some extra features
in that it has an enrichment step to obtain high concentration and also condensation. This
reduces the size and transportation effort and enables high concentrations during the recycle
desorption even when the concentration in the extracted air at the end of the recovery is low.
For some configurations, nitrogen will be used as the desorption gas to avoid potential
explosive methyl bromide and air mixtures.
This technique could also be used for soil fumigation operations (open field or glasshouse with
sheeting). In this case desorption with recycling is achieved by a combination
temperature/pressure swing adsorption could be carried out using heating by direct electrical
resistance. This avoids the use of excessive diluting air. Both these ]proc«ss steps have already
been successfully used to recover CFC-11 and for cleaning exhaust air from soil clean-up to
remove volatile organic compounds (VOCs) from soil (Schreiner, H., pers. comm.). The
prototype plant for recovery of methyl bromide from mill fumigation operations was
commissioned in September 1994. The mill has a volume of 35,000 m3. A recovery of 97% of
methyl bromide remaining after fumigation was achieved. Of this, 93.5% was available for
recycling.
3.7.3
Zeolite
The recovery process based on the use of a zeolite adsorbent described in Section 3.6.4 above
shows equal promise. Recycling rates in excess of 96% of that recovered have been achieved in
preliminary trials (Nagji and Veljovic, 1994b).
3.8
Constraints
Most of the recovery technologies mentioned in Section 3.7 and all the recycling technologies
described in Section 3.7 are complex in nature. They are likely to be relatively expensive to
install compared with the cost of the fumigation facility itself and in some instances may be
more expensive. Some systems would have high operating costs associated with the energy
needed. Many would require a level of technical competence to operate that would not normally
be found at many fumigation facilities.
3.9
References
Annis, P.C., Banks, HJ. and Sukardi. 1984. Insect control in stacks of bagged rice using
carbon dioxide treatment and an experimental PVC-membrane enclosure. CSIRO
(Aust) Division of Entomology Technical Paper No. 22, 38p.
Anonymous. 1976a. Methyl bromide neutralization system by chemical method Methyl
Bromide Research Society (Japan). Report No. 3, 8-16.
Anonymous. 1976b. Methyl bromide neutralization system by combustion method and catalytic
cracking method. Methyl Bromide Research Society (Japan). Report No. 3,24-30.
Arvieu, J.C. 1983. Some physio-chemical aspects of methyl bromide behaviour in soil Acta
Horticulturae 152,267-274.
Banks, HJ. 1984. Assessment of sealant systems for treatment of concrete grain storage bins
to permit their use with fumigants or controlled atmospheres: laboratory and full scale
tests. Canberra, CSIRO Division of Entomology, 38 p.
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58
Banks, HJ. and Annis, P.C. 1984. Importance of processes of natural ventilation to
fumigation and controlled atmosphere storage. In: Ripp, B.E., et al., eds, Controlled
. Atmosphere and Fumigation in Grain Storages. Amsterdam, Elsevier, 299-323.
Banks, HJ. 1988. Disinfestation of durable foodstuffs in ISO containers using carbon
dioxide. In: Ferrar, P., ed, Transport of Fresh Fruit and Vegetables, ACIAR Proceedings
No. 23, 45-54. :
Chantler, D. 1984. The adoption of silo sealing by Western Australian farmers. In: Ripp, B.E.,
et a/., eds, Controlled Atmosphere and Fumigation of Grain Storages: Elsevier,
Amsterdam, 683-705.
De Heer, H., Hamaker, P. and Tuinstra, L.G.M.T. 1981. Report on an optimization study
after the use of the fumigant methyl bromide in horticulture. Report 10B, Wageningen.
i
Hinsch, R.T., Harris, CM., Hartsell, P.L. and Tebet, J.C. 1992. Fresh nectarine quality and
methyl bromide residues after in-package quarantine treatments. HortScience, 27,1288-
1291. :
Mordkovich, Y.B., Menshikov, N.S. and Luzan, N.K. 1985. Modern means and methods of
plant product fumigation in the USSR. Bulletin OEPP/EPPO Bulletin, 15,5-7.
Nagji, M. and Veljovic, V.M. 1994a. Molecular sieve adsorption technology and recycling for
capturing methyl bromide. Halzone Technologies Inc. Report, 16 February 1994.
Nagji, M. and Veljovic, V.M. 1994b. Bromosorb adsorption technology for capturing and
recycling methyl bromide. Annual International Research Conference on Methyl Bromide
Alternatives and Emission Reductions, November 1994, Orlando, Florida.
Nataredja, Y.C. and Hodges, R J. 1990. Commercial experience of sealed storage of bag
stacks in Indonesia. In: Champ, B.R., Highley, E. and Banks, HJ., eds., Fumigation
and Controlled Atmosphere Storage of Grain, ACIAR Proceedings No. 25,197-202.
Newman, CJJE. 1990. Specification and design of enclosures for gas treatment. In: Champ,
B.R., Highley, E. and Banks, H J., eds.,,Fumigation and Controlled Atmosphere
Storage of Grain, ACIAR Proceedings No. 25,108-130.
Reichmuth, C. 1993. Drucktest zur Bestimmung der BegasungsfShigkeit von Gebauden,
Kammem oder abgeplanten Giitem bei der Schadlingsbekampfung. Biolgische
Bundesanstalt fiir Land- und Forstwirschaft, Merkblatt Nr 71, September 1993.
Ripp, B.E. 1984. Modification of a very large grain store for controlled atmosphere use. In:
Ripp, B JB., et al., eds, Controlled Atmosphere and Fumigation in Grain Storages:
Elsevier, Amsterdam, 281-292.
Rozvaga, R.I. and Bakhishev, G.N. 1982. Adsorbants of methyl bromide. In: Mordkovich,
Ya. B., ed., Disinfestation of Plant Products against Quarantine and other Dangerous
Pests. Moscow, All-Union Scientific Technical Institute for Quarantine arid Plant
Protection, 58-60. ;
Stankiewicz, Z. and Schreiner, H. 1993. Temperature-vacuum process for die desorption of
activated charcoal. Transactions of the Institute of Chemical Engineering, Vol 71, Part B,
134-140.
Schreiner, H. 1994. New desorption processes for high efficiency air cleaning. The 1994
IChemE Research Event, 1994, London, 371-373.
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59 !
I
Smith, D.K.W. 1992. Presentation to international workshop on alternatives and substitutes to
methyl bromide. Washington DC. 16-18 June 1992. Information based on Confidential
DSIR Report IPD/TSC/6004, April 1982.
Takeda, H., Yoshida, T. and Nonaka, M. 1980. Seal-O-Silo system (method for restoring
airtightness of reinforced concrete silos used for storage of cereals). In: Shejbal, J., ed.,
Controlled Atmosphere Storage of Grains. Amsterdam, Elsevier, 517-528.
USDA-APHIS. 1976. Plant protection and quarantine treatment manual. Section IV. Treatment
facilities. Part 2. Atmosphere fumigation chambers - construction and performance
standards - fittings for pressure-leakage test and fumigant concentration sampling.
Revised January, 1976. 4 p.
i
Visser, J.T. and Linders, J. 1992. Methyl bromide Adviesrapport 91/670104/011. National
Institute of Public Health and Environmental Protection, Netherlands, 35 p.
Yagi, K., Williams, J., Wang, N.Y. and Cicerone, RJ. 1993. Agricultural soil fumigation as
a source of atmospheric methyl bromide. Proceedings of the Natural Academy of
Science, USA, 90, 8420-8423.
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Annex 3.1
Calculation of % emission of methyl bromide from treatments using the mass
balance approach
1 . Derivation of formula
• Consider an enclosure containing product at density, p, in t nr3 with an applied dosage
ofC0gnr3MeBr.
• If all the methyl bromide is converted into bromide, the resulting residue (X) will be:
X = £4 xO.SSgf1 (ppmw/w)
P
(0.85 factor converts MeBr to Br - by mass)
If the actual residue is x g fl, then the percentage not converted, and assumed to be
emitted to atmosphere is given by:
• (1)
2. Calculation of emission of methyl bromide from bulk and bag stack
treatments of grain
The average emissions from bulk grain treatments under recirculatory treatment with methyl
bromide on import into Japan were calculated according to Equation (1) and used to give an
estimate of emissions from bulk grain fumigation generally (Table 3.6).
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61
Table 3.6 Fumigation of cereal grains on import into Japan (1992 data) with calculated
emissions of methyl bromide based on bromide ion residue levels in commodity after treatment
Data source: A. Tateya, MAFF, Japan
Wheat
Buckwheat
Maize
Other grains
Totals
Quantity fumigated Methyl bromide Estimated
(t) applied (kg) quantity
MeBr
residue leve
(mg kg-1)
910,597
21,403
11,056,507
2,616,647
14,605,154
55,996 20
1,316 50
679,903 30
Equivalent
methyl
bromide
1 residue (kg)
18,212
1,070
331,695
160,907 33 i 86,349
898,122 - j 437,326
Remitted0
67.5
18.7
51.2
46.3
51.3
a Calculated as 100(l-(methyl bromide residue/methyl bromide applied))
Typical residues of bromide in bag stack treatments of cereal grain an; in the 5 -10 g r1 region
per application. Actual residues will vary substantially with proficiency of the treatment and the
nature and state of the commodity. For the purposes of this Report, the following were
assumed: product density of 0.7 t nr3, dosage of 24 g rrr3 methyl bromide and residue of
8.5 g f1 bromide (MBTOC estimates).
On the basis of equation (1), calculated emission: 70%.
3.
3.1
Calculation of methyl bromide emissions from treatment of dried
fruits and nuts
Dried fruits
In a typical fumigation, product density is 0.371 nr3. For a dosage of 24 g irr3 over 24h plus
24h a typical residue is 5 g f1 bromide ion with 4 g r1 'organic' bromide, i.e. undesorbed
methyl bromide. Assuming 60% of the organic bromide reacts to give bromide ion while 40%
is desorbed as methyl bromide, expected residue from the treatment is 7.4 g f1 (MBTOC
estimates).
On the basis of equation (1), this is equivalent to a total release of 87% and a release of 68%
after the initial 24 h of airing.
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62
3.2
Nuts
In a typical fumigation, product density is 0.341 nv3. For a dosage of 56 g nr3, over 24h plus
24h aeration, a typical residue is 40 g r1 bromide ion plus 48 g r1 organic bromide. Assuming
60% of the organic bromide reacts and 40% desorbs on further airing, total expected residue
from the treatment is 69 g r1 (MBTOC estimates).
On the basis of equation (1) this is equivalent to a total release of 51% and a release of 36%
after the initial 24h of airing.
4. Calculation of methyl bromide emissions from treatment;of
perishables I
4.1 Nectarines
A fumigation of nectarines (Hinsch et a/., 1992) at a product density of 0.181 nr3 and at a
dosage rate of 48 g nv3 methyl bromide over 2h resulted in a bromide residue of about 6 g f1
with a natural level of <2 g r1.
On the basis of 4 g r1 residue, equation (1) gives an emission of 98%.
Figures of 85 - 95% emissions from perishables were adopted by the Committee since typical
fumigations are likely to be performed at higher product density and with more reactive
product, both tending to lower emission percentage. The March 1994 TEAP report gives lower
estimates of emissions for perishables, but these figures do not take into account slow
desorption of sorbed material and only give recoverable methyl bromide (i.e. free space
concentration) at the end of the fumigation period.
5.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
Sample calculations for emissions of methyl bromide resulting from
fumigation of timber (logs) in the hold of a ship prior to import into
Japan (data source: A. Tateya, MAFF, Japan)
Volume of hold . 7,508m3
Volume of logs 4,085m3
Space volume [(1) - (2)] 3,423 m3
Dosage 25.0 gm-3
Total dose [(!)* (4)1 187-7kS
Observed final gas concentration 31.7 g m-3
Gas in free space at end of treatment [(6) * (3)] 108.5 kg
Therefore, gas vented at the end of fumigation as % of total dose, assuming
no desorption:
* 100 = 57.8%
(5)
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63
(9) Methyl bromide residue in the timber.
(9.1) Timber weight at apparent specific gravity of 0.9 1 nr3 [(2) * 0.9]
= 3676 1
(9.2) On the basis of inorganic bromide residue of 5 g r1 produced in the timber,
weight of residual inorganic bromide is: ••
3676 * 5 = 18,380g
(9.3) Converting this to equivalent methyl bromide on basis of molecular weights.
Methyl bromide lost = 18.380 * 9_5_
1000 80
= 21.8 kg
(10) Thus, the total emission of methyl bromide is given by:
(5) - (9.3) = 187.7 - 21.8 = 165.9 kg
(11) Total % emission of methyl bromide fumigation from timber in this
case:
*100 = 165.9*100 = 88.4%
(5) 187.7
Data from nine holds (2 ships) gave about 88% emission of applied; methyl bromide on the
basis of the same method of calculation. Treatment at approx. 23°C and 25 g nv3 application
rate.
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64
4.0 ALTERNATIVES TO METHYL BROMIDE
4.1 Alternatives for soil treatment
Executive Summary
On a global basis, the major use of methyl bromide is as a preplant soil fumigant to enhance
crop productivity in locations where a broad complex of soilborne pests, including plant
pathogenic fungi, bacteria, viruses, nematodes, arthropods and weeds, otherwise limit
economic production of certain crops. However, methyl bromide is a toxic fiimigaht of
environmental concern which has been used successfully under a wide variety of conditions
and cropping systems.
Soil fumigation with methyl bromide has been successfully replaced in some areas by methods
and techniques that have been available for many years but that have been adapted 6r modified
to suit local requirements. Alternatives used in such systems, as well as potential alternatives
used or under study in other crops, are discussed in this report. None of the specific alternative
methods discussed here, used alone, have the broad spectrum of activity, efficacy or
consistency of methyl bromide. For some situations there may not be adequate alternatives for
methyl bromide. The development of a comparable agricultural system without the use of
methyl bromide, in many cases, will require the integration of multiple alternative technologies
and extensive research to achieve a similar spectrum of efficacy and reliability.
To implement alternatives to methyl bromide, an integrated pest management (IPM) strategy
will be required. IPM utilises pest monitoring techniques, establishment of pest injury levels,
and a mix of strategies and tactics to prevent or manage pest problems in an environmentally
sound and cost-effective manner. This approach tomanaging pests is needed to avoid future
environmental problems associated with soilborne pest control.
Non-chemical alternatives to methyl bromide
Cultural practices are alternatives to methyl bromide but are not equally effective for all
pests, cropping systems, or locations. A significant commitment to applied research and
technology transfer programs will be needed to take full advantage of cultural practices in
alternative cropping systems.
• Artificial plant growth substrates such as rock wool, allow culturing of crops
without soil fumigation. Use of substrates is technically and economically feasible in
greenhouses and in open fields, under suitable climatic and economic conditions. This
technique has completely replaced methyl bromide in greenhouse culture in The Netherlands.
• Crop rotations of non pest-susceptible cultivated plants with agronomic and
horticultural crops are effective in controlling many soilborne pests on crops in various parts of
the world. It is possible to increase pest suppressiveness by including within rotations plants,
such as oilseed rape, that are inhibitory to some plant pests. Limitations to this alternative are
availability of land, persistent pest inoculum, appropriate rotational crops, equipment,
expertise, and socio-economical considerations. Research on and implementation of alternatives
to methyl bromide must address these factors in addition to the technical options.
• Timing of planting to coincide with low pest density and/or environmental
conditions unsuited to activity of soil pests can be used to prevent pest damage. Use of this
technique may be limited in crops with inflexible marketing and production windows.
• Deep ploughing can reduce pathogen inoculum through burial of pathogens and
stimulation of microbial antagonists.
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65
• Flooding/water management can be used to control some soilborne pests in
suitable areas. K
^ A involves taking land out of production to deny pests the host or substrate
needed for survival. It is a common technique in many parts of the world, but its use is limited
in areas wi th high land values, shortages of agricultural land or when pests can survive
prolonged fallow periods.
nrf t, u™PS fe non-ooMnwrcial plantings of various plant s]3ecies which are grown
and toned back into the soil as green or dry residues. Their decomposition stimulates activity
of micro-organisms antagonistic to soilborne plant pests. Cover crops must be designed into
the cropping system so that they do not compete with the commercial crop.
* -,u FertIJisation and Ptent nutrition manipulations can reduce or suppress some
soilborne pathogens and nematodes by stimulating antagonistic microorganisms, increasing
resistance of host plants, or other mechanisms. 5
• Living mulches such as miniature brassicas or clovers grown with the main crop can
suppress weeds and reduce insect pests without reducing yields in some cropping systems.
n,,mh- P!rant b™edin8 and g/afting. Cultivars resistant or tolerant to single or limited
number of specific pathogens (and races) are available for many crop specie?. In most cases
new cumvars can be developed through plant breeding techniques to address specific pest
' ™ breedm§ 1S a permanent component of crop production but it is currently very
d7el°P ™ltlvars ^stant to several pathogens. Frequently the planting of a cultivi
*£*??* T*** °f £StS results in increased ^age from peste to which it is
« ™ ^g °? suscePtible a™"*1 or Perennial crops on resistant rootstocks is possible
tor some crop species. In some cases, grafting techniques can economically and efficiently
permit production without the need for soil fumigation. "cuiucauy
°- " antaS°nisfi.c' Predatory or proactive organism to control
a target pest(s). There are cropping systems which have successfully used biological control
agents. Generally, the spectrum of activity and host specificity of biocontrol agents is very
n™W ri Cy V3?eS "nd^dSwent cultural conditions. A limited number of commercial
preparations are currently available, and more are undergoing field trials.
H a™endme"ts such as composts, sewage, by-products from agriculture, forest and
food industries may be used to control certain soilborne pests in various crops Their
18^ ^ dependent on reliable ^^^ of raw materials for conversion
Physical methods
• Soil solarisation, the covering of moist soil with clear plastic to increase soil
temperature to lethal levels, provides opportunities for control of some soil pests. Solarisation
is effective when suitable environmental conditions prevail. Its pest control efficacy can be
improved by integrating it with other pest-control strategies.
• Steam is as effective as methyl bromide for control of soilborne pests. Energy costs
capital investments, and some specific soil types are limitations.
• Superheated or hot water may have the potential for control of weeds, soilborne
pathogens and arthropods but their use is limited.
• Wavelength-selective plastic mulches provide the dual benefits of excluding
photosynthetic lightwaves, thus preventing weed germination, while allowing heat-generating
lightwaves to reach the soil; thus enhancing plant growth. These mulches are in use in many
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66
annual row crops, and transition to their use should be feasible in methyl bromide-treated crops
such as tomatoes and strawberries where other types of plastic mulches are already a
component of the cropping system.
• Other physical methods based on the use of microwave irradiation technologies and
low temperatures may have potential for development of management techniques designed for
specific pests and production systems. Considerable research will be needed to explore these
alternatives to determine their potential.
Chemical alternatives
A number of potential alternative chemicals have been identified. They include fumigants and
non-fumigants; However, many of them are under study for their potential to cause negative
health effects as well as environmental contamination. It is very likely that regulatory
restrictions on use of agrochemicals will increase, and chemical treatments against agricultural
pests will be problematic and involve additional time and expenditures.
Available fumigant chemicals ,
Methylisothiocyanate (MITC) and compounds which generate MITC are highly
effective for control of some soil pests. The compounds are highly dependent on soil
preparation and moisture for activation and uniform distribution.
• Halogenated hydrocarbons have been used successfully for the production of
crops under the same cultural conditions in which methyl bromide is now used. However, the
movement of these compounds is slower than that of methyl bromide, requiring longer aeration
and dissipation times following soil fumigation. For field applications, halogenated ;
hydrocarbons can be applied with few modifications using the same equipment that is used lor
methyl bromide. For pests on which they are effective, their performance is relatively
consistent.
Mixtures. Mixtures of soil fumigants may provide a spectrum of control approaching
that of methyl bromide. These combination products may represent the most efficacious short-
term alternatives to methyl bromide. A constraint for preformulated mixtures is the lack of data
for registration purposes.
Non-fumigant chemicals
Control of individual soilborne pests approximating that of methyl bromide may be achieved in
some cases through the use of combinations of non-fumigani: materials (e.g. nemattcides,
fungicides, herbicides and insecticides).
Several non-fumigant chemicals have been detected in ground water under certain conditions
and/or have health and safety limitations.
Non-fumigant alternatives are especially problematic due to the ability of many soU pests to
develop resistance or the potential of microflora to decompose these compounds. Their
regulatory status, health and environmental effects may limit their use and availability.
Other chemicals
There are additional chemicals which require further research to determine their useias
alternatives for methyl bromide. Some were previously used with varying degrees of success
(e.g., anhydrous ammonia, formaldehyde, carbon bisulphide, inorganic azides). Renewed
interest and research may lead to re-establishment of some of these pesticides as viable tools.
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67
Emission reductions
For an immediate reduction in atmospheric emissions of methyl bromide, plastic films with
improved barrier properties to permit reduced application rates without: loss in pest control
efficacy can be used. Currently these films are available in many countries but they are more
expensive than conventional polyethylene film.
Improvements in application technology and reduced application frequency result in immediate
reductions of methyl bromide emissions.
'
i
Constraints !
Since there is no single substitute for methyl bromide, multiple IPM strategies and tactics, used
simultaneously are required. Each strategy or tactic may have constraints, but the package of
approaches can be tailored to specific sites and situations to provide effective pest management
under many conditions. In this context, constraints are viewed as indicating research gaps and
should receive priority attention. Research to overcome constraints should focus not only on
agricultural and ecological considerations, but also socio-economic and political parameters.
The methods for overcoming the constraints are discussed.
Research agenda |
The primary goal of the research agenda is to develop least-toxic alternative methods and
cropping systems that are both cost-effective and environmentally sound. Existing and potential
alternatives are identified in this report Most will require applied research to adapt them to
specific agronomic, regulatory, market, and other conditions in various locations.
Research emphasis in the short term (2-5 years) should be placed on documenting existing
alternatives and on technology transfer.
Long-term research (5+ years) should emphasise multi-disciplinary efforts to develop
integrated pest management methods and cropping systems suited to local ecosystems.
4.1.1
Introduction
Crops grown in soil are susceptible to soilbome pathogens (fungi, viruses and bacteria),
nematodes, arthropods and weeds. Cultural practices such as crop rotation, organic
amendments, and soil fallow are ancient methods which have been, and still are, used with
varying degrees of success to deal with these problems. However, because the evolution of
intensive production systems has led to an increase in damage from soil pests, more effective
and/or reliable integrated pest management techniques are required.
Current management systems include use of biological agents and cultural practices, physical
methods, fumigants, non-fumigants. Soil fumigation with methyl broraddej which has been
used since the 1940s, can be viewed as a disinfestation technique - a method for treatment of a
wide spectrum of soil pests prior to planting (Martin and Woodcock, 1983). Because of its
physical and chemical properties, methyl bromide is used in many geographical regions of the
world encompassing many soil types and climates. The widespread use of this fumigant has
been encouraged by its simple application systems and technology. The major advantages of •
methyl bromide use can be summarised as: 1. rapid and consistent action; 2. the spectrum of
activity against soil pests is wider than any other known soil treatment except steam; 3. no
known pest resistance in the field; 4. very effective at penetrating soil; 5. can be used in soils
with a wider range of moisture contents and temperatures than some other chemical treatments;
6. dissipates quickly after treatment; 7. unlike other fumigants, methyl broimde is an effective
viricide. However, there are a number of disadvantages which have restricted its use (Anon.,
1980, in press; Canton et al, 1983; Hamaker et al, 1983; de Heer et at, 1986; Wegman et al,
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68
1981,1983; van Wambcke etal., 1992; United Nations Environment Programme, 1991,1992;
Yagi et al.t 1993) and the major ones are: 1. high tpxicity and volatility make protective
measures for workers critical; 2. reduces soil biodiversity; 3. bromide residues are formed in
the soil which may be problematic in some crops and for some countries; 4. air pollution in
neighbouring areas; 5. water contamination may occur in areas with high water tables; 6.
disposal problems of plastics used to contain the fumigant during treatments; 7. classified as an
ozone-depletor.
4.1.2 Existing uses of methyl bromide
i
Major uses: Annex 4.1.1 summarises data on worldwide use of methyl bromide as a soil
fumigant MBTOC received information on soil fumigation uses for 48 countries, representing
approximately 89 percent of global methyl bromide soil use. The information used was based
on responses to a survey distributed to signatory countries to the Protocol, and industry
estimates. Of the countries which responded, those responsible for the greatest use of methyl
bromide as a soil fumigant include the United States, Italy, Japan, Spain, Israel, France,
Brazil, Turkey and Greece. Soil fumigation with methyl bromide is greatest by volume for the
following crops: tomatoes, strawberries, cucurbits, nursery crops, peppers, tobacco, replant
vineyards and orchards, and flowers.
Significant pest species. The broad spectrum of activities of methyl bromide against pests
does not permit exhaustive enumeration of all species and countries in which the compound is
used. Annex 4.1.2 presents a list of the main pest species which are controlled by methyl
bromide. The Annex contains data pertaining to countries and areas of the world where methyl
bromide is used for soil fumigation.
4.1.2.1 Application of methyl bromide
The high vapour pressure of methyl bromide makes necessary the use of some barrier to
prevent its rapid dissipation from soil into the atmosphere following application (Kolbezen et
aL, 1974; Munnecke and van Gundy, 1979; Rodriguez-Ka'bana et al, 1977). This is done
mainly by the use of plastic covers or less commonly by deep injection into the soil (Rodriguez-
Ka'bana et al., 1987b) followed by compacting the upper soil layer using a roller and/or "water
sealing", i.e., wetting surface layer of the soil to reduce escape into the atmosphere.
When plastic covers are used, methyl bromide is injected into the upper soil layers, through
hollow shanks prior to covering, or is distributed under the plastic as pressurised gas by a
manifold pipe system to assure uniform distribution. There are also other methods of applying
methyl bromide that do not use mechanical means of application. For example, cans containing
methyl bromide can be placed below plastic covers and then punctured or the gas can be
dispensed through a tube inserted at various locations through the cover. The latter practices
can result in greater emissions to the atmosphere if not properly covered and sealed.
In replant operations in California and other U.S.A. states, methyl bromide is injected into soil
through hollow shanks to depths of 20-70 cm followed immediately by covering, with plastic or
by compaction of the soil surface.
Movement and distribution of methyl bromide in the soil is by gravity and diffusion (methyl
bromide vapour is three times heavier than air) (Munnecke and van Gundy, 1979). Good soil
preparation is essential for optimal distribution of the vapour through the soil. The soil should
be free of large clods, undecomposed plant residues or other materials that hinder its movement
and penetration. Soil moisture should ideally be kept at approximately 70% of field capacity.
Pre-irrigation is recommended to enhance germination of weed seeds. Soil temperatures should
be above 7°C.
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Studies in the United States and western Europe indicate that from 20 to 85% of the methyl
bromide applied to soil could be released to the atmosphere (Bakker, 1993; de Heer et al,
1983; Hamaker et al., 1983). The amount emitted depends on the method of application and
skills of the applicator, type and quality of sealing, sealing period, dosage, soil preparation,
soil type, soil moisture, air movement, and temperature (Cuany and Arvieu, 1983; de Heer et
al., 1983; van Wambeke, 1983,1989b; van Wambeke et al., 1974).
4.1.3 Training and worker protection j
Because of methyl bromide's toxicity and its physical and chemical properties, avoidance of
exposure requires comprehensive training. Workers must be aware of regulations in their
country and equipped to follow handling requirements for protection. This will help reduce
accidental release and exposure during applications. In North America, Japan, and Europe,
workers are usually trained and regulated, but in some developing countries, methyl bromide's
use is unregulated or regulations are not enforced. Safe methyl bromide handling requires
development of adequate government regulations and investment in comprehensive worker
training (see discussion for current uses of methyl bromide).
4.1.4 Soil pest management strategies
Key elements in considering alternatives to methyl bromide are: (a) the need for extensive
research to document existing alternatives and expand the knowledge base on new alternatives;
(b) an extensive program to transfer technology to growers, extension agents, pest control
consultants; (c) a commitment from policy makers to create or strengthen the institutional
support systems crucial to this effort. This is particularly important since there is a greater body
of experience on the use of methyl bromide than on alternatives which makes its replacement
difficult
Methyl bromide is successfully used in the production of propagation material, e.g. bulbs and
seedlings in nurseries, to assure pest free material and avoid dissemination of pests into non-
infested lands. In such cases, methyl bromide should be replaced by highly effective methods
to assure similar level of efficacy in pest control and prevent spread of pests to new areas.
Additionally perennial crops (trees and vines) as compared to annual crops are planted in the
same location for many years, they are deep rooted with most pest problems occurring deeper
in the soil, and the breeding cycles for the pests have generally longer time frames than those of
annual crops. It is therefore essential that propagation materials for perennials be as clean and
free of pests as possible.
Alternatives to methyl bromide may be based on the use of other chemicals or on non-chemical
methods. It is not anticipated that any single chemical or non-chemical treatment listed here will
alone substitute for methyl bromide. However, in most cases, a combination of these methods,
tailored to specific crops, sites, and other variables, can be, and in some cases are being used in
place of methyl bromide (see Case histories 4.1.1 - 4.1.6). For example, in the decade 1981 to
1991, The Netherlands and Germany completely eliminated use of methyl bromide in soil
fumigation (Anon., 1992; Mus and Huygen, 1992). This was accomplished by employing an
integration of non-chemical alternatives such as improved steam sterilisation techniques,
artificial and natural growth substrates, resistant plant species, crop rotation, and chemical
substitutes such as metham-sodium, dazomet, and 1,3-dichloropropene (Anon., 1992).
One strategy for eliminating methyl bromide use against soil-dwelling pests is to utilise
Integrated Pest Management (EPM) approach for crop protection (Franco et al., 1993; Pimentel,
1981). IPM programs utilise pest monitoring techniques to detect pesl: presence and determine
economic thresholds that warrant treatment. When treatment is needed, a mix of strategies and
tactics is used to prevent and manage pest problems in an environmentally sound and cost
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effective manner. This approach to managing soil pests is needed to avoid future environmental
problems associated with management of soils pests.
4.1.4.1. Monitoring and pest detection. Because of the broad spectrum activity of methyl
bromide, the pest complexes which impact crop production in the absence of methyl bromide
are sometimes unknown or poorly understood. The first component of an IPM program is to
identify pests and natural enemies. The next step is to monitor populations of these organisms.
From these data a pest "injury level" or "economic threshold" can be established. Treatment,
using a combination of controls, occurs only when pest numbers threaten to reach the injury
level. It is possible, however, to have pests not detected by monitoring to increase to levels
during crop growth that cause significant crop loss.
A number of commercial techniques exist to facilitate accurate monitoring of some soil-dwelling
pests (insects, mites, nematodes, pathogens, viruses, and weeds). These include ELISA
(Enzyme-linked Immuno Sorbent Assay) tests for detecting soil pathogenic fungi, viruses, and
phytoparasitic nematodes; a variety of traps and surfactant drenches to detect insect and mites;
and seed sampling to detect weeds. More widespread use of such monitoring methods will
pinpoint more precisely if and when pest populations are at levels requiring treatment, reduce
unnecessary treatments of any type, and increase use of spot treatments rather than broad-scale
applications over entire crops. These monitoring and economic threshold systems are well
developed for some key insect, mite and nematode pests, but are either non-existent or at an
early stage of development for some plant pathogens. Further research is necessary to develop
and improve comparable monitoring and economic thresholds for plant pathogens. Research is
also necessary to determine the presence and importance of natural enemies.
4.1.5 Soil pest management alternatives to methyl bromide
Because of its versatility, there is no single alternative chemical treatment or combination of
treatments that can substitute methyl bromide in all its many uses in soil fumigation. It is
possible however, to consider alternative chemicals and crop production methods that can
substitute methyl bromide to a large degree in many situations (Anon., 1993a, 1993b).
4.1.5.1 Non-chemical methods.
These include methods for treating soil that do not rely on the use of pesticides to suppress
plant pathogens, phytonematodes, arthropods, or weeds; and methods of culturing plants in
non-soil substrates. Among these are: the use of organic amendments, biological control
agents, various cultural practices, plant breeding, grafting, and physical methods.
4.1.5.1.1 Organic amendments. The addition of organic matter to soil to improve fertility and
manage pests and diseases is a practice almost as old as agriculture. A wide variety of materials
has been tested as amendments to soil to manage nematodes, soilbome phytopathogenic fungi,
and weeds. These include livestock manures, waste products from paper and forest industries
(e.g. newsprint, paper mill digests, wood, etc.), oil cakes and pomaces, materials from
seafood and fisheries operations (e.g. shells from shrimp and other crustaceans), sewage and
other municipal wastes, as well as numerous by-products from agricultural, food and other
industries, and allelopathic residues from plants (Hoitink, 1988; Mian, 1982; Rodriguez-
Ka"bana, 1986; Rodrfguez-Ka"bana et al, 1987; Stirling, 1991). The efficacy of organic
amendments against nematodes and other soilborne pathogens is dependent on chemical
composition and physical properties which determine the type of microorganisms involved in
their decomposition in soil. High nitrogen materials which generate nematicidal ammonia in
soil, e.g. urea and guanidines, have been studied as amendments to soil for the management of
nematodes and other plant pathogens (Canullo, 1991; Canullo et a/., 1992; Ghian, 1990). The
addition of chitin or chitinous materials to soil not only generates ammonia but also results in
stimulation of the activities of chitinolytic microflora in soil (Culbreath, 1985; Godoy et al,
1983; Rodriguez-Kdbana et a/.,1983,1989,1990). Many chitinolytic microorganisms are
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effective in the destruction of nematode eggs and mycelia of some phytopathogenic fungi.
There is a large body of knowledge on the use of organic amendments for the management of
soilborne pathogens (Cook and Baker, 1983; Hoitink, 1988). The possibilities for development
of treatments to suppress phytonematodes and other soilbome pathogens are as varied as the
types of "waste" raw materials available to prepare the amendments (Rodriguez-Kabana and
Milch, 1991). A number of commercial products are available but iare limited in efficacy.
Successful organic amendments generally require large amounts of materials to be added to soil
(> 501 ha-1). Consequently, their use is localised, limited by the availability of raw material and
transportation costs. Nevertheless, these treatments can contribute to management of soilborne
pests particularly when combined with other alternatives. For example, combining organic
amendments to soil with solarisation (solar heating of soil under clear plastic cover) has been
studied and offers considerable potential to increase efficacy of the amendments against
pathogens and reduce amounts of material needed per hectare (Ramirez-Villapuda and
Munnecke, 1988; Gamliel and Stapleton, 1993).
Certain plants contain allelopathic toxins that when released to soil through leaching, or
biodegradation after incorporation in soil, inhibit the growth of competing weeds and
pathogens. These properties have led to use of allelopathic residues from some plants such as
annual rye (Secale cereale), and certain Brassica spp. or used as intercrops in orchards and as
rotational or intercrops in annual grains and vegetables to impede weed growth. This is an area
of active research and implementation in a number of countries (Anon., 1991; Baukloh, 1976;
Franco etal., 1993; Schlang, 1985,1989; Schmidt, 1983; Thurston etal., 1994; van Wambeke
et al, 1988).
Some substrates, used mostly in floriculture, may have suppressive effects on soil pests.
When hardwood bark, composted or not, is used, improved plant growth is generally
observed, especially in potted plants. Suppressiveness and improved plant vigour in such bark
substrates result from the physical characteristics of bark compost and higher levels of
antagonistic microorganisms supported by these composts. Bark composts show good
antagonistic activity against Phytopkthora spp., Pythium spp., Rhizoctonia solani and several
formae speciales of Fusarium oxysporum. Such composts can be directly used for potted crops
or can be used as sources for microbial antagonists to induce Suppressiveness in conducive
substrates (Hoitink, 1988).
A major problem in the use of organic amendments is the variability in composition of materials
used for preparation of the amendments (Stirling, 1991). Nitrogen content of poultry litter, for
example, can vary greatly depending on storage conditions, humidity, temperature, etc. The
standardisation of composition of amendments, i.e. quality control, is an area needing
development of appropriate methodology. Some organic amendments have the potential to
accumulate deleterious compounds and increase the inoculum level of some soil pathogens
(Cook and Baker, 1983; Rodrfguez-Ka"bana, 1986).
CONCLUSIONS. Alternatives to methyl bromide are currently available for specific
problems and more may be developed using organic amendments. The spectrum of activity of
the amendments, formulations, and rates to be used will depend on raw materials available for
preparation of the amendments. This approach to control of phytonematodes and other
soilborne plant pathogens will be necessarily localised and dependent on reliable sources of raw
material for conversion into useful formulations. With this method,, success in one area on
certain specific pathogens does not necessarily mean that the same solution will supply the
same results to the same specific pathogens in another area. Amendments can also be
formulated to provide essential plant nutrients to serve as fertilisers that stimulate activities of
soil microflora antagonistic to nematodes and other plant pathogens.
4.1.5.1.2 Biological control. Soilbome plant pests exist in soil in equilibrium with other
components of the soil biota. There is a great deal of literature available describing many types
and species of organisms antagonistic to plant pathogens (Belarmino etal., 1994; Surges,
1981; Cook and Baker, 1983; Ferrera Cerrato and Quintero Lizaola, 1993; Gomes Cameiro
and Belarmino, 1994; Hornby, 1988; Jairajpuri etal., 1990; Mukerji and Garg, 1986;
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Rodrfguez-Kdbana, 1991; Rodriguez-Kdbana and Canullo, 1992a, 1992b; Stirling, 1991).
Research on the possibility of utilising antagonists to control plant pathogens has been going on
for more than a century. Most of these studies are phenomenological in nature, providing
descriptions of organisms or cases where a given pathogen was "controlled" by an organism.
There are also descriptions of numerous attempts at utilizing soil microorgnisms for control of
soilbome plant pathogens. However, to date there have been very few successes. The number
of commercially available products whose mode of action is based on the introduction of
biocontrol agents into soil is limited to less than six. Innate to the utilisation of biocontrol
agents is the specificity of their activity. A given antagonistic fungus or bacterium,; for example,
will serve to control only a pathogen or a reduced number of pathogens. The introduction and
establishment of an organism in soil requires that the organism be placed in an "unbccupied
ecological niche" or that it be added in colonised substrate in large amounts
(t ha'l) to overwhelm competing indigenous organisms.
Soils suppressive to several soilborne pathogens (i.e. several formae speciales of
F. oxysporum, R. solani, Pythiwn ultimum, Phytophthora spp., Thielaviopsis basicola, etc.)
have been described in different areas (Cook and Baker, 1983; Parker et al, 1985; Rodriguez-
K£bana and Calvet, 1994). Soilborne diseases do not occur or are less severe in such soils.
Antagonists isolated from suppressive soils and responsible for suppressiveness can be
successfully used to control soilbome pathogens. Some preparations of such antagonists are
now registered. In the future, use of antagonistic Fusarium spp.. and/or fluorescent
Pseudomonads, active against several formae speciales of F. oxysporum (f.sp. dianthi, f.sp.
lycopersici, f.sp. cyclaminis, f.sp. melonis, f.sp. basilicum) may permit control of Fusarium
wilts and other diseases. Also, use of Trichoderma spp. as seed dressing or soil treatment may
provide better opportunities for control of damping-off and root rots caused by Phytophthora
spp., Pythium spp., and R. solani (Cole and Zvenyika, 1988). However, in the case of
antagonists, the spectrum of activity is generally limited. Moreover, often their activity
significantly varies in different soils and, more generally, under different environmental and
cultural conditions.
Plant growth promoting rhizobacteria. Another approach to biological control is the
utilisation of rhizobacteria, i.e., bacterial species that develop in and around the roots of plants
(Keel et al., 1990; Kloepper et al., 1988). Many rhizobacteria are antagonistic to pathogens and
more importantly, can colonise the roots and establish a "biological shield" to delay invasion of
the roots by nematodes and other pathogens. This concept implies a broadening of the spectrum
of activity, since presumably occupation of the roots by rhizobacteria could prevent attacks
from several pathogens. Many rhizobacteria can be introduced into soil in seed coverings or
coatings. Following seed germination the bacteria will develop with the seedling roots and offer
protection to die plant at its most critical early growth stages. There are now several
rhizobacteria products in the market that have been successfully tested under field conditions. A
beneficial side-effect of treatments with rhizobacteria is the frequently observed stimulation of
plant growth; the terms Plant Growth Promoting Rhizobacteria (PGPR) or Plant Health
Promoting Rhizobacteria (PHPR) refer to this phenomenon (Suslow, 1982). !
Mycorrhizae. With few exceptions, all plant roots in nature develop in close association with
specialised fungi forming a complex, the mycorrhizae (Ferrera Cerrato and Quintero Lizaola,
1993; Mosse, 1973; Perrin, 1991). Some mycorrhizae grow only on the surface and outer
layers (ectomycorrhizae); others penetrate deeper into the root (endomycorrhizae). The type of
mycorrhizae formed depends on the species of plant and fungi. There is a certain degree of
specialisation in these plant-fungus systems. Most conifers, for example, have typical
ectomycorrhizae. These root-fungus associations are for the most part beneficial in that they
result in root proliferation and consequent increase in nutrient adsorptive root surface. This
permits the plant to survive and thrive in environments where nutrients are limiting or are
difficult to extract. In soils where nutrients are not limited, mycorrhizae may adversely affect
plant health. There is also evidence that plants with mycorrhizae are more resistant to some
soilbome diseases (Calvet et a/., 1993; Chet, 1987). There are commercial produces available to
inoculate plants with mycorrhizae (Rodriguez-Kabana and Calvet, 1994; Vozzo, 1971). A great
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deal of research is going on now to determine how best to exploit the beneficial effects of
mycorrhizae to protect plants. This is particularly important since soil disinfestation with methyl
bromide and other "broad-spectrum agents" has often been reported to eliminate mycorrhizal
fungi from soil or to retard development with detrimental effects on some crops growing in the
disinfected soil (Rodrfguez-Ka'bana and Curl, 1980; Schenck, 1982).
Endophytes. Most plant species have a variety of endophytic microorganisms that develop in
them which may be beneficial or detrimental to the plant or animals feeding upon the plant
(Cook and Baker, 1983). The use of non-pathogenic endophytes to control or prevent plant
diseases is a recent development in biological control. The possibility exists of using seed
treatment to introduce selected antagonistic endophytes into plants. Successful introduction of
endophytic antagonists in crops could remove one of the main disadvantages of biocontrol
agents - their dependency on specific environmental conditions. The plant offers a protected
environment for the endophyte. This makes it possible to have the same organism in a plant in
as wide environmental conditions as are suitable for the plant species. Field research with
cucumbers has shown that endophyte-inoculated plants are resistant against a variety of plant
pathogens and had higher yields than cucumber plants raised conventionally (Ryder et al.,
1994). The mechanism(s) underlying the resistance of the endophyte-plant system against
pathogens is not well understood. There is evidence that the endophyte in the plant triggers a
broad spectrum defence response of the plant against pathogens.
CONCLUSIONS. Biological control of soilborne pests has been developed for various
cropping systems and in some cases have been in use for many years. However, the spectrum
of efficacy is generally limited to one, or a small number of pests. It is in use in greenhouse
culture in some countries, but the efficacy significantly varies under different cultural and
environmental conditions. It is unlikely that adequate substitutions for methyl bromide infield
applications will be developed solely from biological control methodologies in the near
(< 5 years) future. Biological control of soilborne pests is a research field much under-
financed. Research should be encouraged and supported to develop new biological control
products and, most importantly, to provide a broader understanding of the general ecology of
the soil microbiota. This knowledge is essential for development of these alternatives to methyl
bromide. It must be stressed that, when available, most biocontrol agents, due to their narrow
spectrum of activity, are only able to solve very specific problems.
The use of beneficial endophytic microorganisms and mycorrhizae fungi to protect plants
against pathogens could be a solution to the problems of environmental specificity and narrow
spectrum of activity encountered with other biocontrol agents..Research on this approach to
biological control is still very preliminary. It is not possible to determine at present when
efficacious products may become commercially available. Some biological control agents are
commercially available for specific pests and situations.
4.1.5.1.3 Cultural practices. Crop production systems have been designed to suppress
soilborne pests (Bello etal, 1994; Johnson, 1982; Rodriguez-Kabana and Canullo, 1992b;
Tnyedi and Barker, 1986). The use of appropriate cropping systems lias led to sustained
agricultural production for centuries in many parts of the world. It can be stated that for many
pest problems, a cropping system can be developed to manage the problem(s).
Among the many cultural practices within production systems that offer alternatives to methyl
bromide for the management of soilborne pests are: crop rotations, planting time strategies,
deep ploughing, flooding, fallow, cover crops, intercropping, green manures, fertilisation and
plant growth substrates.
Crop rotations. Crop rotations can be an effective method for suppressing damage by
soilborne pests. The literature on the subject is extensive and there are several reviews available
(Cook and Baker, 1983; Rodriguez-Kdbana and Canullo, 1992a, 1992b). Very effective
rotations of non-host plants with agronomic and horticultural crops have been described for
control of soilborne pests in many parts of the world.
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It is possible to increase the suppressiveness of crop rotations on pathogens by including in
cropping systems plants that are antagonistic to pathogens. Oilseed rape, for example, produces
methyl isothiocyanate and related mustard oils which are fungicidal and nematicidal;: these
plants have been used in rotations to control several soilbome phytopathogenic fungi, cyst and
root-knot nematodes in sugarbeet, potatoes, and other crops (Anon., 1991; Baukloh, 1976;
Schlang, 1985,1989; Schmidt, 1983). Crop rotation systems that include forage or pasture
crops can also be very effective and profitable in that they introduce livestock production into
the rotation system. The inclusion of disease resistant (or tolerant) cultivars, when available,
within cropping systems can be a very effective way of managing pest problems without use of
methyl bromide (Rodriguez-Kdbana and Canullp, 1992b; Weaver and Rodriguez-K£bana,
1992). Limitations to this alternative are availability of land, persistent pest inoculum,
appropriate rotational crops, equipment, expertise, and socio-economical considerations.
Planting time. Knowledge of population dynamics of plant pathogens sometimes suggests
development of cultivars for planting in time intervals when pathogen inoculum is low and/or
environmental conditions are not conducive to disease development. The efficacy of this
approach was demonstrated in Georgia, U.S.A., where damage from root-knot nematodes was
maintained at low levels through a combination of crop rotation and early planting to avoid
periods optimal for nematode development (Heald, 1987; Johnson, 1982; Trivedi and Barker,
1986). Use of this technique may be limited in crops with inflexible marketing and production
windows.
Deep ploughing can reduce pathogen inoculum through burial of reproductive structures and
stimulation of microbial activity by decomposition of crop debris. Numbers of sclerptia of
Sclerotium rolfsii in soil can be reduced significantly by deep burial - this operation has long
been practiced in the production of peanut (Arachis hypogaea) and other crops in the southern
U.S.A. to reduce the incidence of southern blight (Punja, 1985).
Flooding and water management. Where water is abundant and available, water
and van Aartrijk, 1992). Flooding was effective in the control of Verticillium wilt of cotton
(Cook and Baker, 1983; Pullman and DeVay, 1981) but was only partially useful for the
management of Panama disease of bananas (F. oxysporum f. sp. cubensis) (Stover, 1962). It
is particularly effective when organic matter is incorporated into soil prior to flooding.
Anaerobic microbial activity can result in the production of metabolites toxic to many soilborne
pests (Cook and Baker, 1983).
Fallowing. The practice of fallowing (taking land out of production) can be useful in reducing
the impact of certain plant pests through denial of host and/or substrate for growth (Cook and
Baker, 1983; Johnson, 1982; Trivedi and Barker, 1986). This practice may not be particularly
reliable as many pathogens can survive prolonged fallow periods (e.g. Verticillium 15+ years,
Olpidium 30+ years). There are numerous production systems throughout the world that
include fallowing as part of a pest management program. Successful fallowing must avoid
weeds that may serve as hosts or reservoirs for pathogens. It is for this reason that weed
control, by herbicides or repeated cultivations, must be achieved. It is a common technique in
many parts of the world, but its use is limited in areas with high land values, shortages of
agricultural land or when pests can survive prolonged fallow periods.
Cover crops. Cover cropping is a very common practice consisting of planting a non-
commercial crop which at a given level of maturity is turned back into the soil as green or dry
residues. For example in Florida, winter vegetable production may be preceded by summer
cover cropping with sorghum (Sorghum bicolor), sudan grass (Sorghum sp.), American
jointvetch (Aeschynomene americana) or hairy indigo (Indigofera hirsuta). This practice has
been beneficial in reducing damage from phytonematodes and other soilbome pathogens in the
following winter vegetable crops (McSorley el al, 1994; Rhoades, 1983). Cover crops must
be designed into the cropping system so that they do not compete with the commercial crop.
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A living mulch is a cover crop that is grown simultaneously with the main crop in a reduced
tillage system. Living mulches can suppress weeds and reduce insect pests 'without reducing
yields (Thurston et al., 1994). Soil-dwelling and foliar insect numbers can also be kept below
injury levels by the mulch. This may be due to confusing or repelling pest insects because of
changes in reflected light produced by the mulch; attraction of natural enemies to the mulch
which serves as habitat and alternative food source; loss of crop visibility to insects due to loss
of contrast between bare soil and crop plant.
Fertilisation and plant nutrition. It is generally recognised that the maintenance of an
adequate and balanced plant nutrition may reduce the impact of soilborne pests. The type of
fertilisation used can affect pathogen and disease development. Phytonematodes, for example,
are sometimes adversely affected by the use of urea or ammoniacal nitrogen sources (Franco et
al., 1993). As was discussed under organic amendments, this is directly related to microbial
activity in soils. Ammoniacal nitrogen sources (e.g. ammonia, ammonium carbonate and
ammonium bicarbonate) can reduce damage from S. rolfsii in carrots and other crops (Punja,
1985). Enhanced calcium nutrition through application of lime (calcium carljonate), or
landplaster (calcium sulfate) can reduce pod rot (Pythium myriotylwn, Rhizoctonia solani,
Fusariwn spp.) in peanut (Pattee and Young, 1982). In some cases, only a change in pH is
required to cause reductions in some soil pests (Cook and Baker, 1983), These examples serve
to demonstrate that a great deal can be done to reduce disease through appropriate management
of fertilisers, nutrition, and soil pH.
Plant growth substrates. Artificial plant growth substrates allow culturing without soil
fumigation. Substrates such as rock wool, tuff stone, clay granules, and flexible polyurethane
foam blocks allow the plant root to absorb nutrients and water (Anon., 11992). Specialised
farming systems with these substrates have demonstrated the technical and economic feasibility
of totally eliminating use of methyl bromide in greenhouses and raised beds and, under good
climatic circumstances, in open field (Anon., 1992). However, these specialised systems
require adequately trained personnel. Substrates need to be disinfected between crops to avoid
build-up of pathogen populations (Gamliel et al., 1989; Sneh et al., 1983). The disposal of
certain substrates may involve environmental problems. However, some of these materials can
be recycled or used to improve soil structure (Anon., 1992; Rockwool/Grodan, 1994). In most
cases, the investments necessary for the substrate technique restrict its use to high value-crops
that are treated with methyl bromide.
In areas where volcanic pumice is available, production systems have been developed based on
the heat absorbance and retention properties of the pumice. Pumices are utilised to heat the
underlying soil and eliminate plant pathogens (Bello et al., 1991,1993),
CONCLUSION. Cultural practices such as crop rotation, fallowing, cover crops, deep
plowing, and others can be used to augment production systems suppressive of some plant
pests. Prerequisite for the utilisation of these practices is, first of all, availability of land (for
crop rotation), and abundance of water (for flooding) and also a good understanding of pests'
dynamics and the general ecology in specific production fields. It is possible to develop pest-
suppressive cropping systems within specific localities and reduce or eliminate use of methyl
bromide. Information necessary for development and implementation of these systems is not
available for most areas but may be obtained within five years or more. A major consideration
with the crop rotation approach is that farmers may be forced to rely upon relatively few
profitable crops (or even a single crop) with which they have experience rather than on a variety
of crops, a prerequisite for development of effective crop rotations. The use of plant growth
substrates has demonstrated the technical and economic feasibility of totally eliminating the use
of methyl bromide in greenhouses in The Netherlands. This technology may be feasible in
similar situations in other countries.
4.1.5.1.4 Plant breeding and grafting. The selection and development of crop cultivars
resistant or tolerant to pests is as old as agriculture. Systematic, scientific plant breeding, begun
almost a century ago, has yielded crop cultivars resistant to many soilborne pests. There are,
for most crop species today, varieties resistant (or tolerant) to root-knot nernatodes or to
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phytopathogenic fungi in genera such as Phytophthora, Fusarium, Vertidllium, and
Sclerotinia. New resistant varieties to individual pests can be developed for some crops at a rate
of one every 5-15 years depending on crop species and existing research commitment. Recent
discovery that certain genes are turned on by root-knot nematodes (Meloidogyne spp.) offers
hope for expediting development of resistant plant material (Opperman et a/., 1994). There are
however, limitations to what can be done through plant breeding even with up-to-date
molecular techniques. It is very difficult to develop cultivars resistant to several pathogens.
Most fields are infested with a multiplicity of major and minor plant pathogens. Frequently, the
planting of a cultivar resistant to only a limited number of pathogens results in increased
severity of disease caused by pathogens to which the cultivar is susceptible. Even for a single
pathogen, cultivars may be resistant to a narrow spectrum of races within the pathogen's
genome. This again can result in the appearance of "new races" through selection by the use of
resistant cultivars. Resistant cultivars may not have desirable agronomic and marketable
characteristics. Also, the instability of resistance genes in unfavourable environmental
conditions, e.g. high soil temperature, may limit the efficacy of resistant plants (Trudgill,
1991). It is, however, possible to utilise resistant cultivars judiciously within a cropping
system (Weaver and Rodrfguez-Ka'bana, 1992). For example, alternate plantings of resistant
and susceptible soybean cultivars have been used to prevent "race shifts" in fields infested with
the cyst nematode, Heterodera glycines (Riggs and Wrather, 1992). Resistant cultivars can be
integrated within crop rotation systems to enhance pathogen suppression by the systems (Cook
and Baker, 1983; Trivedi and Barker, 1986).
Grafting of susceptible plants onto pathogen-resistant rootstock is an old method used in the
production of fruit and nuts. More recently, efficient grafting techniques have been developed
for annual crops, e.g. cucurbits, tomato, eggplants, to permit production of these crops without
the need for fumigation. Tomato can be grafted onto Solatium torvum rootstock to obviate
damage from root-knot nematodes and bacterial wilt (Pseudomonas spp.). Similarly, melons or
cucumbers can be grafted onto wild melon or pumpkin rootstock to avoid problems caused by
Fusarium wilt pathogens (G6mez, 1993). Grafting may permit quick response to market
demands.
CONCLUSIONS. Cultivars resistant or tolerant to single or limited number of specific
pathogens (and races) are available for many crop species. In most cases new cultivars can be
developed through plant breeding techniques to address specific pest problems. Plant breeding
should be viewed as a permanent component of crop production but it is currently very difficult
to develop cultivars resistant to several pathogens. Frequently the planting of a cultivar resistant
to a limited number of pests results in increased damage from pests to which it is susceptible.
Grafting of susceptible annual or perennial crops on resistant rootstocks is possible for some
crop species. In some cases, grafting techniques can economically and efficiently permit
production without the need for soil fumigation.
4.1.5.1.5 Physical methods. Physical control of soilborne pests include such techniques as
steam, solarisation, and wavelength-selective plastics. The only practical methods for
sterilisation of soil are those based on the use of heat Dry heat and steam treatments have been
used for more than a century to treat soils.
Steam. Under the appropriate conditions, soil pasteurisation with steam at temperatures of
70 - 80°C is as effective as methyl bromide (Anon., 1992; Runia, 1983). Soil pasteurisation is
aimed at reducing pathogen inoculum while retaining a significant portion of the soil microflora
as a "biological shield" against re-infestation by undesirable microorganisms. Sterilisation of
soil (>80°C) can result in a "biological vacuum" where any microorganism, including
pathogens, can re-colonize the sterilised soil. In addition, prolonged treatment of soils at high
temperatures (80 - 120°C) can result in destruction of soil structure and release of phytotoxic
materials from soil organic matter. There is also evidence that heavy metals, e.g. manganese,
are released by high temperature treatments with ensuing phytotoxic effects. There are
however, methods available to use steam efficaciously with no phytotoxic after-effects.
Steaming with or without negative pressure has replaced soil fumigation with methyl bromide
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in The Netherlands (Anon., 1992; Runia, 1983). At present, these steaming processes are used
mostly in greenhouse operations in several countries.
Solarisation is of relatively recent development (Katan and DeVay, 1991) and consists of the
treatment of soil with solar heat by covering the soil surface with thin, transparent plastic
(mostly polyethylene) sheets for prolonged periods (Grinstein and Hetzrpni, 1991). It is a form
of pasteurisation in that it does not result in the sterilisation of soil. Solarisation was shown to
be successful for management of many soilborne pathogens and other pests. Pest inoculum,
including resting structures, in moist soil covered with plastic for four or more weeks can be
significantly reduced or eliminated. This results not only in reduced disease incidence in the
subsequent crops but also in significant yield increases. The mode of action of Solarisation
treatments is still under study. Increased soil temperature is essential for reducing soil inoculum
but there are other important effects derived from microbial activity. There is good evidence for
stimulation of beneficial microorganisms by Solarisation in addition to thermal killing.
Solarisation is most successful in dry climates with low number of cloudy days and intense
solar heat. It is used by farmers in Greece, Israel, Italy, Spain and other places with similar
Mediterranean type climates. Its value in areas of high rainfall, significant cloudiness, or wide
fluctuations in daily temperatures is questionable (Grinstein and Heteroni, 1991). Solarisation
can be used in cooler climates by using closed plastic houses or greenhouses. This technique
has been developed in northern Italy and it is used in Japan in over 2200 hectares of
strawberry, eggplant, tomato, and cucumber (Horiuchi, 1991; Katan and DeVay, 1991).
Solarisation may require treatment periods of 4 - 8 weeks, so that it may not be useful where
such prolonged periods without crops are not available. The possibility of using Solarisation
while the crops are still in the ground has been demonstrated in almond, olive and pistachio
groves and on cherry tomatoes. Solarisation has had mixed results in controlling
phytonematodes. While it is effective for control of some ectoparastic and migratory
endoparasites (Ditylenchus spp., Pratylenchus spp.) results obtained with endoparasitic root-
knot nematodes (Meloidogyne spp.) have, in most cases, not been satisfactory (Heald, 1987).
Soil Solarisation does not effectively control certain weeds (e.g., nutsedge [Cyperus spp.]) and
some deeply located fungal pathogens in the soil such as Armillaria spp. A serious problem in
Solarisation technology as with methyl bromide application, is the disposal of polyethylene
sheets after treatment. Although a great deal of effort has been devoted to the recycling of these
plastics, the problem is serious in some areas.
The combination of Solarisation with other alternatives such as organic amendments and
pesticides applied at reduced dosages has been successful for controlling nematodes and other
soilborne pests (Afekera/., 1991; Ben-Yephet et al, 1988; Gamliel and Stapleton, 1993).
These combination treatments may: 1) shorten the time needed for Solarisation, 2) increase the
efficacy and consistency of Solarisation against pathogens and broaden its spectrum of activity
to include phytonematodes, and 3) allow its use in cooler conditions.
Wavelength-selective plastic mulch. Wavelength-selective plastic mulches are used to
heat the soil but prevent weed growth by excluding photosynthesising light waves from
reaching the soil (Hyplast1, Hoogstraten, Belgium). They are also used in vegetable and berry
production to prevent damage from various root maggots by serving as a barrier to adult insects
that lay eggs at the base of host plants, or larvae that drop to the soil to complete their lifecycle.
Flaming/superheated water. The use of heat is one of the oldest weed control methods
known to agriculture. While primitive agriculturists used fire, contemporary growers use heat
technology in the form of hand-held or tractor-driven "flamers" or superheated water sprayers
fuelled by propane or other petroleum products. These implements are used to control weeds in
orchards, cotton, vegetables, and many other crops. Large and small- scale commercial flaming
equipment is available in most countries. The technology for superheated water application is a
recent development and commercially available in New Zealand and the U.S.A. In many cases,
thermal manipulations of habitat via hot water dips have also been successfully used within
regulatory plant certification programs to control nematodes in infesttsd plant material (Heald,
1987).
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Low temperatures to suppress nematodes. Thermophilous species of nematodes are
susceptible to low temperatures. In greenhouse systems, soil temperatures below 20°C can be
used for the management of some species of root-knot nematodes. The utility of using low
temperatures to control phytopathogenic nematode species merits research attention (Bello,
1994; Fernandez et al, 1993).
Irradiation and microwave technologies for treatment of soils. Other physical
methods, based on the use of irradiation microwaves and radio frequency heating, may have
potential for managing particularly specific pests in specific systems. Irradiation technologies
pertain particularly to the treatment of containerized or potting soils as well as nursery pots,
mats and other reusable items, but not to broad acre applications. The commercial irradiation of
nursery pots, seedling containers and mats for disinfestation and disinfection have assisted the
glasshouse industry in Netherlands to discontinue use of methyl bromide; the recycling of these
containers has resulted in less solid waste generated for landfills. While some research has been
conducted on the irradiation of potting soils, further research on this is required to determine
the potential of this alternative.
Numerous laboratory studies have indicated the potential for heat treatments applied with
microwaves and radio frequency radiation in pest disinfestation of growing substrates and
soils. Although there may be a potential for treating small quantities of substrate (e.g., bagged
potting soil), more information is required on the feasibility of this approach on a larger scale
(van Wambeke, 1987; van Wambeke et al, 1983,1984; Vela et al, 1976).
CONCLUSION. Under the appropriate conditions, soil pasteurisation with steam is as
effective as methyl bromide. New technologies for application of steam to soil under negative
pressure replaced soil fumigation with methyl bromide in greenhouse cultures in The
Netherlands and this technology may be applicable in some other countries. Soil solarisation
may offer an alternative to methyl bromide in areas with long periods of low cloudiness and
intense solar heating. Solarisation is now used by producers in many parts of the world either
alone, or more often in combination with another agent such as organic amendments or low
dosages of pesticides. Also solarisation methods may be improved to extend the value of these
treatments into other areas with more research and development. Wavelength-selective plastic
mulches, superheated water, low temperatures, and microwave technologies may also have
some usefulness with more research. A disadvantage of methods which requires the burning
of fossil fuels for the production of heat is their potential impact on global warming (but see
Section 3.3).
4.1.5.1.6 Research priorities for non-chemical alternatives
Short term (five years or less) :
1. Incorporate existing knowledge and methods of non-chemical controls into crop
production systems as an alternative to the use of methyl bromide.
2. Develop effective methods of transferring existing knowledge and experiences on
alternatives between different regions and countries.
Long term (more than five years)
1. Long term basic research is necessary to develop an understanding of soil ecology as it
relates to the etiology, pathogenicity, epidemiology and suppression of arthropod pests,
nematodes, diseases and weeds in the development of crop management systems.
Research results should be continuously integrated into crop management systems.
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79
Investigate effects of cultural control methods such as organic soil amendments and crop
rotation on pathogen and soilborne biotic populations in relation to crop production.
Methods for production of amendments and application techniques need to be developed
to reduce inconsistency or variability in degree of pest control obtained with amendments
to soil.
Investigate factors related to root protection by root-influencing organisms such as
rhizobacleria, mycorrhizae, and endophytic microorganisms. Methods need to be
developed which enhance root protection organisms in a variety of soil types.
Determine efficacy of potential biological control organisms ilnd methods of use.
Evaluate and develop germplasm and cultivars for resistance or tolerance to major
soilborne pathogens for major crops affected by loss of methyl bromide.
4.1.5.2 Chemical methods
Chemical compounds that can be considered as alternatives for methyl bromide may be
classified according to their availability to the market. There are compounds that are currently
available in agriculture; others will require additional research and registration before they can
be utilised by producers (Martin and Woodcock, 1983; Thomson, 1989). One of the
considerations in evaluating chemical alternatives is the fact that methyl, bromide is an effective
vincide, a property that is lacking or has not been reported for other chemical alternatives.
The relative toxicity and safety of chemical alternatives to methyl bromide is an important
consideration. Annex 4.1.3 presents a sample summary of relevant lexicological information
available for chemical alternatives considered in this report. Additional information is presented
for some of the chemicals in the text Classification of acute toxicity is based on OECD
(Organization for Economic Cooperation and Development) guidelines and carcinogenicity
according to IARC (International Agency for Research on Cancer) guidelines.
4.1.5.2.1 Fumigants. A fumigant is a chemical which, under typical field conditions, exists
as a gas or is converted into a gas, in sufficient concentration to be lethal to pest organisms.
Distribution of fumigants through soil is principally in the gas or vapour phase. Fumigants
typically can be expected to show biological activity at a place remote from the point of
application. By contrast, a non-fumigant is a chemical that is toxic i:o pests as a solid or liquid.
Their movement through soil is usually by solution in water or other mechanisms not involving
a gas or vapour phase.
Methyl isothiocyanate (MUC). This compound has been effective for the control of
arthropods, some weeds and soilborne pathogens, principally fungi and a limited number of
plant parasitic nematode species (Rodriguez-Ka'bana et a/., 1977). It is mostly used in
combinations with 1,3-dichloropropene (1,3-D) which enhances the nematicidal activity. It is a
liquid and is injected into the soil. Problems with product stability jind corrosion have limited
the use and distribution of this compound. The lexicological profile of MTTC (toxic, skin and
eye irritant, sensitiser) may be a technical constraint to its use as an (alternative. MTTC has the
physical characteristics indicating iis potential to contaminate ground water, however,
monitoring has not revealed groundwater contamination.
MITC Generators. These are compounds or iheir formulations which, when incorporated
into moist soil, decompose to produce methyl isothiocyanate. The spectrum of activity of MTTC
generators is similar to MITC (Rodriguez-Ka'bana etal, 1977). These materials have been
commercially available for 40 years. Inconsistent results have been reported with these
materials because uniform distribution of formulated produci and release of MITC in ihe soil
are highly dependent upon application method, adequate soil moisture, lemperaiure, pH, and
the effectiveness of ihe soil surface sealing meihod (e.g. waterseal, covering wilh plastic or
compaction).
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Metam-sodium. Metam-sodium is formulated as a liquid and may be applied to the
soil by either injection, drip or sprinkler irrigation, or sprayed on the soil surface prior to
tilling. The toxicological profile of metam-spdium (mildly toxic, eye irritant, teratogen,
genotoxin) may be a technical constraint to its use as an alternative.
Dazomet. Dazomet is formulated as a granule and is incorporated into the soil
generally by roto-tilling (Anon., 1989). Although dazomet is a MTTC generator, it produces
other breakdown products such as carbon bisulphide and formaldehyde. Persistence in soil of
MTTC or breakdown products is influenced by temperature and moisture, which, if sub-optimal
such as cool and wet, often require longer waiting periods before planting to prevent crop
phytotoxicity. The main breakdown products of dazomet are MTTC and formaldehyde.
i
Conclusions. These compounds are immediately available and effective for control of certain
pests, but successful treatment with them is strongly dependent on ideal application conditions.
Phytotoxicity can be an important post-treatment effect.
i
Halogenated hydrocarbons. 1,3-dichloropropene (1,3-D). This material is an
effective nematicide but it has limited fungicidal and herbicidal activity (Johnson1 and
Feldmesser, 1987; Rodriguez-Kdbana et al., 1977). It is formulated as a liquid and injected into
the soil followed by some method of soil sealing. The toxicological profile of 1,3-D (toxic,
skin and eye irritant, sensitiser, genotoxin, suspected carcinogen) may be a technical constraint
to its use as an alternative.
1,3-D has been found to contaminate groundwater only in areas of porous soils and high water
tables.
Chloropicrin (trichloronitromethane). This material is highly effective for the
control of soilbome pathogens and some arthropods (Wilhelm et al., 1974; Wilhelm and
Westerlund, 1994). It is a weak nematicide and herbicide. Chloropicrin is a liquid and is
injected into the soil followed by covering with plastic. In the absence of nematodes, improved
growth and yield responses with Chloropicrin are similar or superior to methyl bromide alone.
It is known to enrich the soil with fungi and bacteria which are antagonistic to many plant
pathogens. Chloropicrin alone diffuses well through the soil, but it is usually used in
combination with methyl bromide at various percentages for the added control of weeds and
nematodes (Wilhelm etal., 1974). The toxicological profile of Chloropicrin (toxic, skin and eye
irritant, sensitiser, teratogen, genotoxin) may be a technical constraint to its use as an
alternative.
Ethylene dibromide (EDB). This material is an effective nematicide with activity
against some arthropods (Johnson and Feldmesser, 1987; Rodriguez-Kabana etal, 1977). It is
a liquid and is injected into the soil. The toxicological profile of EDB (toxic, skin and eye
irritant, reproductive toxin, genotoxin, carcinogen) may be a technical constraint to its use as an
alternative. Its use was banned in some countries because of groundwater contamination and
carcinogenic effects.
CONCLUSIONS. Halogenated hydrocarbons can be applied with few modifications using
the same equipment that is used for methyl bromide. However, because the vapor pressure of
these materials is less than that of methyl bromide, their movement in soil is more limited.
These compounds have been used successfully for the production of crops under the same
cultural conditions in which methyl bromide is now used (Overman and Jones, 1984). For
pests on which halogenated hydrocarbons are effective, their performance is relatively
consistent. Aeration and dissipation from soil following fumigation with these compounds is
slower than with methyl bromide, requiring longer waiting periods before planting.
Mixtures of fumigants. Mixtures of soil fumigants may provide a spectrum of soil pest
control approaching that of methyl bromide (Overman and Jones, 1984). For example, Vorlex
(40% 1,3-dichloropropene and 20% MTTC) and Telone C-17 (77.9% 1,3-dichlorpropene and
16.5% Chloropicrin) have been used for many years on a variety of crops in North America
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(Rodriguez-Kdbana etal., 1977; Thomson, 1989). Included arc crops in the same areas where
methyl bromide is used These combination products may represent the most efficacious short
term alternatives to methyl bromide. Other combination products, such as EDB plus MTTC or
chlpropicrin have also been used for many years. Preformulated mixtures must be tested and
registered. The use of non-preformulated combination treatments may raise; health and
environmental concerns.
4.1.5.2.2 Non-fumigants. Control of weeds, insects, nematodes, and soilborne pathogens
approximating the control found with methyl bromide may be achieved; in some cases through
the use of combinations of available non-fumigant materials (such as herbicides, fungicides,
nematicides and insecticides). These chemicals may also be combined with other fumigants or
non-chemical approaches. Some of these combinations are used commercially and are effective
m many production systems. However, the full spectrum of activity for most of these
combinations is not well understood and requires additional research. A comprehensive listing
and description of these non-fumigant chemical alternatives, and their possible combinations is
available in crop protection manuals (Thomson, 1989). All non-fumigant nematicides are
organophosphates or carbamates and therefore are highly acutely toxic neu rotoxins
(cholinesterase inhibitors) (Johnson and Feldmesser, 1987). Several non-fumigant pesticides
have been detected in groundwater under certain conditions, and have health and safety
limitations.
i
AVAILABLE CHEMICALS - CONCLUSIONS
None of the available chemical alternatives alone offer the broad spectrum disinfestation
attributes of methyl bromide. It may be possible to achieve similar results from combinations of
fumigants, non-fumigants, and non-chemical alternatives. Further research on application
techniques, in some cases, may enhance the activity of various alternative fumigants Non-
fumigant alternatives are especially problematic due to the ability of many soil pests to develop
resistance or the potential of soil microflora to decompose these chemicals. In addition,
environmental and health considerations may limit the use of any pesticide.
4.1.5.2.3 Chemical alternatives which require further development
Formaldehyde. Formaldehyde may be applied as a liquid solution or can be generated in soil
after application of granular paraformaldehyde (Rodriguez-Ka'bana et aL, 1977; Johnson and
Feldmesser, 1987; Thomson, 1989). It does not require covering with plastic but water sealing
or equivalent is necessary. This compound is primarily a bactericide with limited activity
against ectoparasitic nematodes and some fungi. Early use of this material was limited because
of phytotoxicity problems. Recently, new formulations with reduced phytotoxicity have been
developed which may offer possibilities as a soil fumigant. The waiting period following
treatment is highly temperature dependent. No information is available regarding its potential to
contaminate groundwater. The lexicological profile of formaldehyde (toxic, skin and eye
irritant, reproductive toxin, genotoxin, carcinogen) may be a technical constraint to its use as an
alternative.
i
i
Carbon bisulphide (CS2). CS2 is a liquid that is injected into soil. No covering is
required. It was formerly used for its insecticidal properties but it has limited fungicidal and
nematicidal activity (Rodnguez-Kdbana etal., 1977; Thomson, 1989). Also, because of
phytotoxicity, carbon bisulphide, like formaldehyde, may require long (> 2 weeks) waiting
periods before soil can be planted. It is flammable and explosive. The lexicological profile of
carbon bisulphide (harmful, skin and eye irritant, reproductive toxin, teratogen, carcinogen)
may be a technical constraint to its use as an alternative.
Sodium tetrathiocarbonate is a water soluble salt formulated in stabilised concentrated
aqueous solutions which can be applied to soil. Decomposition of this material releases CS2
(Young, 1990). Data available on field efficacy are very limited but suggest variable fungicidal
and nematicidal properties. No lexicological data were available.
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These materials do not show much promise as adequate alternatives to methyl bromide at this
time. '
Dichloro-isopropyl ether. This compound is available in liquid and granular formulations
(Thomson, 1989). It is marketed in Japan for nematode control in fruits, vegetables and
tobacco, but it has shown variable activity in other countries. The toxicological profile of
dichlonMSOpropyl ether (toxic, skin and eye irritant, suspected carcinogen) may be a technical
constraint to its use as an alternative.
Anhydrous ammonia (NH3). Anhydrous ammonia is a gas at standard atmospheric
pressure. It is sold in pressurised containers for use as a fertiliser. Ammonia is injected into the
soil and no covering is necessary. It has a broad spectrum of activity against soilborne pests
(Punja, 1985; Rodrfguez-Kdbanaef a/., 1981,1982). Its high solubility in water (pH
dependent) and retention in clay and soil organic matter impede its diffusion and movement
through soil. This may account for the variable results obtained when used against soilborne
pests. Ammonia is inexpensive and methodology may be developed to make its use practical.
The toxicological profile of anhydrous ammonia (toxic, skin and eye irritant) may be a technical
constraint to its use as an alternative.
Sulphur dioxide (SO2). SO2 is a gas that has been considered for soil treatment of plant
pathogens; however, there is very little information on its efficacy or non-target effects in soil
(Rodrfguez-Kdbana et al., 1977). Sulphur dioxide is inexpensive and methodology may be
developed to make its use practical. The toxicological profile of sulphur dioxide (toxic, skin
and eye irritant, reproductive toxin, genotoxin, suspected carcinogen) may be a technical
constraint to its use as an alternative. It is an atmospheric pollutant and its concentration in the
atmosphere is closely monitored in many countries.
Bromine-containing compounds. Propargyl bromide (- 3-bromo-l-prppyne) was used as
an additive to enhance the fungicidal properties of methyl bromide-chloropicrin mixtures for the
control of soiborne pests and reduce the amount of methyl bromide and chloropicrin (Rhode, et
al., 1980). Trizone, a combination of 30% chlroropicrin, 61% methyl bromide, and 9%
propargyl bromide was manufactured by Dow Chemical but was discontinued in 1968.
Propargyl bromide was formulated as a gel for application to soil without covering; however, it
resulted in high bromide residues, a fact which contributed to discontinuation of its
development as a soil fumigant (van Wambeke et al., 1986).
Bromonitromethane is a broad spectrum, very reactive fumigant. It is a liquid at standard
pressure and temperature. The potential of this compound as a soil fumigant was recognised
recently (Rodriguez-Kdbana et. al., 1991). It is an irritant and lachrimatory material but no
other data are available on its toxicity. The toxicological profile of propargyl bromide and
bromonitromethane (skin and eye irritants) may be a technical constraint to their use as
alternatives.
Inorganic azides - These materials are solids and can be formulated as granules or liquids.
When added to soils they release hydrazoic acid (HN3) which escapes to the atmosphere or is
converted to nitrate in soil. Azides applied to soil demonstrated broad spectrum activity against
weeds and soilborne phytopathogenic fungi, but higher rates are required for nematode control
(Kclley and Rodrfguez-Kdbana, 1979a; Rodriguez-KSbana et al., 1972; van Wambeke et al.,
1984,1985; van Wambeke and van den Abeele, 1983). Application rate reductions are
possible with covering. Microbiological studies of soil treated with NaN3 for several years
indicated enrichment of treated soils with a group of fungi antagonistic to many soilbome
phytopathogenic fungi (Kelley and Rodriguez-K^bana, 1975,1979b, 1981). A serious
limitation to the use of NaN3 or KN3 is the possibility of formation of explosive azides when
these salts come in contact with copper or lead, e.g. during storage or transportation.
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Others - Research on the nematicidal and microbiocidal properties of some volatile, naturally
occurring compounds has shown promise for development of new soil treatments for the
management of nematodes and other soilborne plant pathogens (Soler-Seirratosa, 1993).
Furfuraldehyde, for example, has been shown to be effective for the management of nematodes
and some phytopathogenic fungi (Rodriguez-Kabana et a/., 1993; Rodriguez-Kabana and
Walters, 1992). Addition of this volatile material to soil enhances populations of fungi and
bacteria that are known antagonists of many plant pathogens.
CONCLUSION | •
Some of the materials listed as "requiring further research" were previously used with varying
degrees of success, but interest in the research and use of these declined after the introduction
of new technologies, including methyl bromide. Renewed interest and research using more
sophisticated application equipment and formulation techniques may lead to re-establishment of
these pesticides as viable tools. Additional research on toxicology, ecatoxr.city and residues will
be needed for regulatory purposes for some of these pesticides.
4.1.5.2.4 Research priorities for chemical alternatives
Short term (5 years or less)
1. Evaluate the effects of individual chemical alternatives on pest control, yield, quality,
environmental, health and safety impacts and cost-benefit ratios.
2. Evaluate combinations of chemical alternatives for soil treatment (e.g. 1,3-
dichloropropene + chloropicrin or 1,3-dichloropropene + MITC).
3. Evaluate combinations of chemicals with non-chemical alternatives (e.g. soil fumigants +
solarisation).
4. Evaluate use parameters for chemical alternatives that are consistent with D?M strategies
and methodologies.
5. Improve application equipment and chemical use patterns.
Long term (more than 5 years)
1. Screening of naturally occurring and synthesised chemicals for activity against soil pests.
4.1.6
Emission reduction
The inclusion of methyl bromide in the Montreal Protocol is due to its emissions to the
atmosphere and consequent effect on the ozone layer. Implementation of existing technology
and research and development of new technology may significantly reduce emissions while
maintaining the efficacy of methyl bromide.
4.1.6.1 Reduced dosage
i
In current practice, dosages of methyl bromide applied to treated fields are often higher than
needed for control. This practice is considered necessary to compensate for the wide range of
conditions under which fumigations occur (e.g. variations in pest susceptibility, soil type,
moisture, temperature, land preparation, and application techniques). Although some
information is available on the minimum dosage needed for pest control under various
combinations of these conditions, more data are needed to reduce dosage and consequently
emissions of methyl bromide; this includes information on the minimum practical concentration
and exposure period for efficacy under typical field conditions (McKenry and Thomason,
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1976; Munnecke and van Gundy, 1979). The first step in this process is to generate laboratory
and field data on the time required for acceptable control of specific soilbome pests under a
given temperature and concentration (Munnecke and Lindgren, 1954). If temperature is held
constant then, within certain limits, the time required for control is inversely related to
concentration. If the concentration is doubled then exposure time is cut by half. This can be
expressed as a cr-product These ct values can be used to determine the minimum dosage of
methyl bromide for field applications at a given field temperature. It is necessary in all cases to
confirm with actual field study the predictions made with cr-based models.
4.1.6.2 Plastic soil covers
There are many types of plastic films used in the soil fumigation process (Bakker, 1993; de
Heer et al, 1983; Hamaker, 1983). The barrier properties of these plastic films can vary
considerably based on plastic composition, windspeed, temperature, and film thickness (Basile
et al, 1986; De Heer et al., 1983; van Wambeke, 1989b). For example, high density
polyethylene films tend to provide a greater barrier to methyl bromide than low density
polyethylene (LDPE) films. Also for monolayer films, there is a direct correlation between film
thickness and permeability to methyl bromide, as film thickness increases, so permeability
decreases. A number of new covers are available that are significantly less permeable to methyl
bromide than LDPE (van Wambeke, 1983,1989a, 1989b). Generally these films are more
expensive and can be more difficult to handle in the field (Bakker, 1993).
Under suitable climatic conditions (no air movement, low temperature) high barrier films offer
the advantages of permitting a significant reduction in dosage while maintaining the ct values
needed for effective control. This is possible because less methyl bromide is lost to the
atmosphere while the plastic cover is in place. The right combination of reduced dosage along
with longer fumigation periods will also result in effective ct values. Longer covering has the
additional advantage of allowing for opportunities for greater degradation of methyl bromide in
the soil profile and thus further reducing the amount emitted to the atmosphere. Degradation is
due to reaction with soil organic matter and some mineral constituents as well as other reaction
pathways such as hydrolysis (De Heer- et al., 1983). Additionally emissions can be reduced by
taking more care in sealing edges, sealing overlaps and by repairing mechanical damage to the
cover. Following these measures, it is anticipated that emission reductions of 30% or higher
can be attained. In cases where the application is not purely mechanical, the success of using
new plastics greatly depends on the skill of the operator and the degree of quality control
exercised.
4.1.6.3 Improving application techniques ;
Traditionally methyl bromide has been applied to soil by direct injection or by surface
application under plastic covers (Rodrfguez-Kabana etal., 1977). Better application systems
need to be developed which will result in a more uniform distribution of the gas in the soil
profile and reduce the loss of gas during the application process (Kolbezen et al., 1974;
McKenry and Thomason, 1976; Rhode et al, 1980; van Wambeke, 1989a, 1989b, 1992).
Two examples of processes which could accomplish this goal are systems which allow for
deeper injection of the fumigant and systems which reduce the number of injection shanks.
Both deeper injection and fewer shank tracks reduce the emission rate of fumigant from the soil
surface, without compromising the dosage required for effective control.
4.1.6.4 Reducing leakage during greenhouse fumigation
Keeping ventilation in greenhouses as low as possible during the cover period is important for
reducing emissions. From experiments it was concluded that air movement inside of the
greenhouse as a result of ventilation (opening of windows and doors) is probably the most
important factor influencing the leakage of methyl bromide from underneath the plastic covers
(Bakker, 1993; de Heer et al, 1983; van Wambeke et al, 1986).
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4.1.6.5 Use of diffusion enhancing co-fumigants
Reduced application rates can be used when using diffusion enhancing co-fumigants with
methyl bromide under improved plastic covers (van Wambeke, 1983; van Wambeke et al
™.f?™- Cf ^fV™^* d° not necessarily show pesticidal properties by themselves. The
co-fumigant must have a gas density comparable to methyl bromide and it should be
competitive in adsorption to soil particles. This results in a longer availability of effective
methyl bromide concentrations but may result in less adsorption and decomposition of the
chemical. Research in this area is in the preliminary stages;
4.1.6.6 Reduced frequency of application 1
Depending upon the crop/pest combination, the frequency of methyl bromide applications mav
be reduced or, if possible, the chemical may be used in rotation with alternative conn-ol
measures. This approach wiU require additional information and research regarding the
interest"1 economic threshol<*s of the various pests, when known, upon the crop(s) of
4.1.6.7 Research priorities for reduced emissions I
Short term (5 years or less) I
1.
2.
3.
4.
Develop plastics with improved handling, barrier and disposal properties.
Quantify the relationship between ct values and efficacy.
Improve application methodologies.
the«fficacy
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3. Improve methods of monitoring and defining economic thresholds that will enhance the
development of a cultural systems approach based on IPM programs.
4. Develop methods to produce pest-free propagation materials inoculated with beneficial
microorganisms to minimise the need for alternative treatment methods.
5. Evaluate existing and proposed chemical and non-chemical alternatives and the
application technology required to maximise their utility and reduce emissions.
i
• The emphasis in the short term (2-5 years) should include studies on appropriate
timing of application, determination of minimum efficacious rates, and the integration of
existing alternatives into an IPM strategy. As much as possible, currently existing programs
and expertise should be utilised and supported.
• The emphasis in the long term (5+ years) should include the development 'of
cultural/crop systems, which maximise non-chemical control strategies and maximise the
efficacy of the required crop protection chemicals. t
6. Evaluate the modification of the soil environment by chemical fumigants, crop residues,
and botanical extracts on the ecology and the resulting recolonisation of theisoil by
beneficial microorganisms. >
7. Develop emission reduction with the development of plastics with improved handling,
barrier and disposal properties, quantify the relationship between cr-values and efficacy,
improve application methodologies, evaluate the efficacy of combining reduced methyl
bromide application rates with other methods such as solarisation, cultural practices, and
beneficial organisms; develop methodologies to reduce the frequency of applications.
4.1.8 Transfer of knowledge and training in improvements
Information and research on many of the non-chemical methods and chemical alternatives to
methyl bromide for each cropping system is incomplete or non-existent. Additionally, the use
of improved technology and application methods for reduced emissions from soil fumigation
(i.e. the use of high barrier plastic covers, and reduced dosages) is the most expedient means
for rapidly decreasing methyl bromide emissions to the atmosphere.
As new information on alternatives and emission reduction becomes available, systems to
transfer this knowledge must be implemented. The most likely avenue would be through
'agricultural specialists representing government agencies and NGOs, UN organisations,
institutes of higher education and product distributors. These individuals and organisations
need to be equipped to inform the end users of appropriate alternative methods and improved
application technologies through the use of publications, training seminars and field
demonstrations. In some countries the infrastructure for transferring this information may not
be well established.
4.1.9 Uses without known alternatives •
The problems associated with soil fumigation with methyl bromide are so complex that this
section, although applicable to other methyl bromide uses, is beyond the scope of this Sub-
Committee. Often the situations for which there are no known replacements are localised
because of marketing and/or environmental conditions; what is an irreplaceable use of methyl
bromide in one area may not be the case in another.
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4.1,10
Constraints
Since there is no single substitute for methyl bromide, multiple IPM strategies and tactics, used
simultaneously are required. Each strategy or tactic may have constraints, but the package of
approaches can be tailored to specific sites and situations and provide effective pest
management under many conditions. In this context, constraints are viewed as indicating
research gaps and should receive priority attention. Research to overcome constraints should
focus not only on biophysical systems, but also on socio-economic parameters. Changes in
socio-economic context can reduce constraints on technical options.
Other options for overcoming constraints include: (1) strong incentive programs (e.g., IPM
transition insurance, cost-sharing on implementing IPM alternatives to methyl bromide, tax
incentives, etc.); (2) accelerated technology transfer programs emphasising farmer-to-farmer
communication, on-farm demonstrations, and technical support on alternatives.
4.1.10.1 Environmental !
I
i
Crops grown in soils treated with methyl bromide are cultivated worldwide, from the tropics to
the subfrigid zone, and in areas with high to low rainfall. In these same areas, production also
occurs in greenhouses with dissimilar environmental conditions and pest complexes.
The diversity of production is probably the single most significant constraint to replacing
methyl bromide. Certain alternatives are only effective in specific regions. For example, where
water supplies are scarce, the use of flooding is not practicable. Soil solarisation is not effective
in areas with high rainfall, significant cloudiness and fluctuation in daily temperature. Steaming
has limitations when used in heavy soils where special techniques, e.g. use of negative
pressure, are necessary to obtain satisfactory pest control.
An alternative strategy which can be effectively used in greenhouse or field in one region may
not be transferable to another due to a change in environmental conditions (e.g., temperature,
rainfall, humidity, soil type, topography, etc.). Additionally, the global incidence and severity
of soilborne pests is determined by environmental conditions.
4.1.10.2 Logistical j
Land availability is limited and land values are high in many of the areas of intense methyl
bromide use. Thus, continuous production of one or a few relatively high value crops may be
required to obtain adequate profitability. The use of cultural practices which remove land from
production for extended periods of time (fallowing, cover crops, solarisation, flooding) may
not be practical in these areas. In addition, alternative pest control strategies which require
longer soil preparation times or extended pfeplanting intervals will be difficult to implement
under these conditions.
Market considerations are critical in determining planting times for many crops utilising methyl
bromide fumigation. Alternative pest control strategies that impact on planting time may not be
applicable for these crops. For example, planting during times of low pest inoculum may result
in crop maturity at a time when the returns on that crop are unprofitable.
Labour is an important component in the production of crops fumigated with methyl bromide
and may be limited during periods of peak production activity such as; planting and harvesting.
Adequate labour may not be available to implement some alternative control practices. For
example, increased labour may be required for alternatives based on combination treatments.
The adoption of alternative strategies will require the development and acquisition of specialised
equipment and new patterns for the use of equipment.
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4.1.10.3 Health, safety and environment
Agrochemicals are regulated by government agencies and are sold and used by special permits
and other specific label requirements. On a global basis there is no uniformity in regulatory
requirements which include toxicology, ecotoxicology, environmental fate, aquatic toxicity,
residues and others. A constraint to the adoption of a chemical alternative is the possible
absence of registration for many uses.
t
Many existing agrochemicals are under scrutiny for their ability to causes wide array of
potential health effects (e.g., reproductive toxicology, carcinogenicity and neurotoxicity).
Additional studies are required for environmental issues like metabolism, residues, ground
water and soil contamination and emissions to air. Annex 4.1.3 shows that some alternative
chemicals to methyl bromide are listed as suspect carcinogens, mutagens, or reproductive
toxins by international agencies e.g., the International Agency for Cancer Research (IARC).
It is very likely that regulatory restrictions on use of chemicals will increase, and chemical
treatments against agricultural pests will be problematic and will involve additional time and
expenditures.
A constraint to the use of some non-chemical alternatives may also involve health, regulatory or
environmental concerns.
4.1.10.4 Biotic
Breeding cultivars resistant to soilborne pests is a keystone for pest management systems.
However, the use of this approach has definite limitations. Most cultivars are resistant to an
individual pest or a limited spectrum of pest species and races. Use of these cultivars may result
in changes in community structure or genetic composition of pests. New pest species and races
may appear in response to repeated use of individual resistant cultivars. For some crops,
development of multi-pest resistant cultivars is currently not feasible. There is a lack of
correlation between what can be achieved through breeding for resistance and the number of
pests present in soils. For some pest complexes (e.g. fungi x nematodes x insects x viruses)
there are no cultivars available resistant to the complex, even though there are cultivars resistant
to individual pest components of the complex. Cultivars with a limited resistance spectrum can
be used rationally as components of pest management systems. To use these cultivars, accurate
information on the biology, dynamics, and general ecology of pests must be available which is
not always the case. Alternation between resistant and susceptible cultivars can prevent many of
the problems of species and race shifts arising from the use of resistant cultivars. Breeding for
horizontal or field resistance (multi-gene based) should be encouraged when possible to
overcome these problems. Currently most breeding programs are not oriented towards
horizontal or field resistance.
Biological control agents are generally highly adapted to specific hosts, target organisms, and
environments. Small variations in any of these parameters may reduce or eliminate efficacy.
4.1.10.5 Informational
It would appear that many new alternative strategies for soil pest control will need to be
developed and successfully implemented on a broad scale commercial agricultural basis to
replace the pest control and crop production attributes of methyl bromide (Anon., 1993a,
1993b). Some of these alternative approaches have not been intensively studied and additional
research will be required to characterise and maximise pest specific efficacy, crop production
consistency, and geographical transferability. Although many different alternative strategies are
currently under study, most have not been developed to allow immediate transfer and adoption
to growers, at least without inherent risks.
To overcome these informational voids or constraints, new information will need to become
available. New multidisciplinary research and extension programs will therefore need to be
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developed to consider a diversity of crops, environments, production systems and pest
complexes. New systems for information organisation and archives to ensure rapid retrieval
and dissemination will also likely be required. New educational programs and special training
seminars for crop care consultants, farm-employed pest managers andfor growers will have to
be conducted to ensure and expedite information transfer. Finally, and most importantly, to
provide this information, adequate funds, equipment, and personnel to support information and
technology transfer activities will need to become available.
4.1.10.6 Economic
The primary consideration is to ensure that the alternative system enables ihe fanners to
produce a crop which is profitable without additional risks.
For most cases, information necessary for risk assessment of the transition to alternative
production systems is not available. For example, the effect of these alternative systems on
such factors as availability of capital, and marketing opportunities are unknown, thus financing
by the traditional agricultural funding sources is problematic.
4.1.10.7 Sociological/psychological
Reluctance to change is a common human trait For many growers and others facing loss of
methyl bromide, this trait is reinforced by fear of potential economic losses, lack of knowledge
about or experience with alternatives, and lack of an extensive research base or technology
transfer infrastructure to turn to for assistance.
In some cases, adoption of alternatives will occur without major disruptions to the system. In
other cases, major paradigm shifts in cropping systems and marketing arrangements will be
needed, and growers will have to undergo major changes and incur significant risks to stay
profitable.
4.1.11 General conclusions
Soil fumigation with methyl bromide has been successfully replaced in some areas by means of
methods and techniques that have been available for many years but that have been adapted or
modified to suit local requirements. Additional research is needed to develop treatments that
could eventually eliminate it in other areas. Because the degree of current dependency on
methyl bromide varies greatly around the world, some regions may be able to substitute methyl
bromide quicker than others and in some areas it is likely that it will not be possible to
economically replace methyl bromide at all. In these areas it is also necessary to consider that
crop systems dependent on methyl bromide may be moved to areas or other countries where
such dependency does not exist or where it can be significantly reduced. These production
shifts could cause serious hardship given the existing cultural and sociological considerations
associated with agricultural production and consumption.
While there are many methods and materials that offer possibilities for replacement of methyl
bromide, there is no single alternative available for immediate use by producers. Alternatives to
methyl bromide will develop in direct response to financial investment in research needed to
"ready" the alternatives for use by producers. The level of research investment required will be
larger in some areas than in others. The speed with which methyl bromide can be replaced will
vary according to the investment in research made by nations in areas where it is presently
used. It is essential that research on alternatives (chemical, non-chemical and integrated
systems) be performed thoroughly and in a wide range of climatic and geographical locations.
This is essential to avoid substitution of methyl bromide by fumigation or treatment with other
chemicals, or by other methods, which may be more damaging to human health and the
environment than methyl bromide.
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4.1.12 References
Afek, U., Menge, J. A. and Johnson, E. L. V. 1991. Interaction among mycorrhizae, soil
solarization, metalaxyl and plants in the field. Plant Disease, 75,665-671.
Anonymous. 1980. Methyl bromide, policy document on phasing out the use of methyl
bromide. Parliament of The Netherlands, Lower House Session 1980-1981,16400,
Chapter XIV, No. 50.
Anonymous. 1989. Basamid-Granules. Limburgerhof, Germany, BASF Aktiengesellschaft.
Ill p.
Anonymous. 1991. Biologische Nematoden Bekampfung. Hannover, Germany, Staaten-
Union GmbH, 57 p.
Anonymous. 1992. Proceedings of the international workshop on alternatives to methyl
bromide for soil fumigation. U. N. Environment Programme. 19-21 October 1992,
Rotterdam; 22-23 October 1992, Rome/Latina.
Anonymous. 1993a. Alternatives to methyl bromide: assessment of research needs and
priorities. Proceedings from the USDA Workshop on Alternatives to Methyl Bromide.
29 June -1 July, 1993, Arlington, Va., 80 p.
Anonymous. 1993b. Methyl bromide substitutes and alternatives. A research agenda for the
1990's. United States Department of Agriculture, 28 p.
Anonymous. In press. Environmental Health Criteria for Methyl Bromide. PCS/EHC/94.
International Programme on Chemical Safety. UNEP/ILO/WHO.
Bakker, D. J. 1993. A review of Dutch studies over the period 1981-1992. TNO Report IMW
R 93/309.
Basile, M., Lamberti, R, Melillo, V. A. and Basile, A. C. 1986. Influenza del metodo di
somministrazione e della qualita della copertura suU'efficacia del bromurp di metile nei
confronti di nematodi "Longidoridae" e sulle concentrazioni di bromuro inorganico nel
terreno. Rivista della Ortoflorofrutticoltura Italiana, 70,193-203.
Baukloh, H. 1976. Untersuchungen ziir Wirtspflanzeneignung der Kruziferen gegeniiber dem
Riibennematoden Heterpdera schachtii Schmidt, unter besonderer Berucksichtigung der
Resistenzzuchtung. Universitat Gottingen, Dissertation.
Belarmino, L. C., Gomes Cameiro, R. M. D. and Puignau, J. P., eds. 1994. Control
bioldgico en el cono sur. EMBRAPA/CPACT, Pelotas, RS, Brasil. 149 p.
Bello, A., Escuer, M. and Arias, M. 1994. Nematological problems, production systems and
Mediterranean environments. Bulletin OEPP/EPPO Bulletin, in press.
Bello, A., Gonzalez, J. A., Bun, M., Dominguez, J., Lopez Cepero, J., Rodriguez, C. M.
and Tello, J. 1993. Interns agroecoldgico de la solarisacidn de un substrate de pumitas
en Canarias. Actas del Xn Congreso Latinoamericano de la Ciencia del Suelo, 1608-
1615.
Bello, A., Gonzalez, J. A., Korayem, A. M. and Gowen, S. R. l994.Meloidogynejavanica
management on bananas in the Canary islands. Nematropica, in press.
-------
91
Bello, A., Rodriguez, C. M., L<5pez Cepero, J. and Gonzalez, J. A. 1991. Sistemas
productivos y nematodos del suelo en cultivos de papas sobre puniitas. Comunicaciones
de la XVII Reunidn Nacional de Suelos. Islas Canarias, Universidad de La Laguna,
153-163.
Ben-Yephet, J., Melero-Vera, M. and DeVay, J. E. 1988. Interaction of soil solarization and
metham-sodium in the destruction of Verticillium dahlias and Fusarium oxysporum f,
sp. vasinfectum. Crop Protection, 7, 327-331.
Surges, H. D., ed. 1981. Microbial control of pests and plant diseases 1970-1980. New York,
Academic Press, 949 p.
Calvet, C., Pera, J. and Barea, J. M. 1993. Growth response of marigold (Tagetes ?-ecta L.)
to inoculation with Glomus mosseae, Trichoderma aurecviride and Pythiwn ultimum in
a peat-perlite mixture. Plant and Soil, 148,1-6.
Canton, J. H., Wester, P. W. and Mathyssen-Spiekman, E. A. M. 1983. Study on the toxicity
of sodium bromide to different fresh water organisms. Food and Chemical Toxicology,
21, 369-378.
Canullo, G. H. 1991. Use of slow-release N amendments and furfural to control Sclerotiwn
rolfsii: studies on changes in populations of microorganisms. Auburn University,
Ph.D. Thesis, 119 p.
Canullo, G. H., Rodriguez-Kdbana, R. and Kloepper, J. W. 1992. Changes in populations of
microorganisms associated with the application of soil amendments to control
Sclerotium rolfsii Sacc. Plant and Soil, 144,59-66.
Chet, I. 1987. Innovative approaches to plant disease control. New York, John Wiley and
Sons, 372 p.
Chian, Ru-Ju. 1990. Inorganic nitrogen compounds as amendments to soil for nematode
control. Auburn University, 143 p.
Cole, J. S. and Zvenyika, Z. 1988. Integrated.control of Rhizoctonia solani and Fusarium
solani in tobacco transplants with Trichoderma harzianum and triadimenol. Plant
Pathology, 37, 271-277.
Cook, R. J. and Baker, K. F. 1983. The nature and practice of biological control of plant
pathogens. St. Paul, American Phytopathological Society, 539 p.
Cuany, A. and Arvieu, J. C. 1983. Distribution patterns and nematocidal activity of methyl
bromide in various soil conditions and methods of application. Acta Horticulturae, 152,
277-237.
Culbreath, A. K. 1985. Studies on the use of chitin soil amendments for control of root-knot
nematodes. Auburn University. 96 p.
de Heer, H., Hamaker, Ph., Tuinstra, L. G. and van der Burg, A. 1983. Use of gas-tight
plastic films during fumigation of glasshouse soils with methyl bromide. I. Significance
of permeation and leakage for the emission into the outside air. Acta Horticulturae, 152,
109-125.
de Heer, H., Hamaker, Ph., Tuinstra, L. G.-and van der Burg, A. 1986. Leaching of methyl
bromide and bromide ions into surface water after fumigation of glasshouse soils. In:
Effects of land use on fresh waters: agriculture, forestry, mineral exploitation,
urbanisation. London, Water Research Center, Ellis Horwood Limited, 194-201.
-------
92
Fernandez, C., Pinochet, J. and Felipe, A. 1993. Influence of temperature on the expression of
resistance in six Primus rootstocks infected with Meloidogyne incognita. Nematrobica
23, 195-202.
Ferrera Cerratp, R. and Quintero Lizaola, R., eds. 1993. Agroecologfa, sostenibilidad y
cducaci6n. Montecillo, Mexico, Colegio de Postgraduados.
Franco, J., Gonzales, A. and Matos, A. 1993. Manejo integrado del nematodo quiste de la
papa. Cochabamaba, Bolivia, Programa de investigacidn dela papa (PROINPA).
Gamliel, A., Katan, J., Chen.Y. and Grinstein, A. 1989. Solarization for the recycling of
container media. Acta Horticulturae, 255,181-188.
Gamliel, A. and Stapleton, J. J. 1993. Effect of chicken compost or ammonium phosphate and
solarization on pathogen control, rhizosphere microorganisms, and lettuce growth
Plant Disease, 77, 886-891.
Godoy, G., Rodrfguez-Ksibana, R., Shelby, R. A. and Morgan-Jones, G. 1983. Chitin
amendments for control of Meloidogyne arenaria in infested soil. II. Effects on
microbial population. Nematropica, 13,63-74.
Gdmez, A. M. 1993. El injertp herbaceo como metodo altemativo de control de enfermedades
teluricas y sus aplicaciones agronomicas. Spain, Universidad Politecnica de Valencia,
Doctoral Thesis, 494 p.
Gomes Cameiro, R. M. D. and Belarmino, L. C., eds. 1994.4° Simpdsio de Controle
Bioldgico. Anais: Conferencia e Mesas Redondas. Gramado, 15-20 May, 1994
Pelotas, RS, Brasil, EMBRAPA/CPACT.
Grinstein, A. andHetzroni, A. 1991. The technology of soil solarization. In: Katan, J. and
DeVay, J. E., eds. Soil Solarization. Boca Raton, Florida, CRC Press, 159-170.
Hamaker, Ph., de Heer, H. and van der Burg, A. 1983. Use of gastight plastic films during
fumigation of glasshouses with methyl bromide. II. Effects on the bromide-ion mass
balance for a polder district. Acta Horticulturae, 152,127-135.
Heald, C. M. 1987. Classical nematode management practices. In: Veech, J. A. and Dickson,
D. W., eds., Vistas on Nematology. Hyatsville, MD., Society of Nematologists, 100-
104.
Hoitink, H. A. J. 1988. Basis for the control of soilborne plant pathogens with composts.
Annual Review of Phytopathology, 24,93-114.
Hollis, J. P. and Rodriguez-Kdbana, R. 1966. Rapid kill of nematodes in flooded soil.
Phytopathology, 56, 1015-1019.
Horiuchi, S. 1991. Soil solarization in Japan. In: Katan, J. and DeVay, J.E. eds., Soil
Solarization, CRC Press, 216-225.
Hornby, D., ed. 1988. Biological control of soil-borne plant pathogens. Wallineford, Oxon,
CAB International, 479 p.
Jairajpuri, M. S., Alam, M. M. and Ahmad, L 1990. Nematode biocontrol. Delhi, India, CBS
Publishers, 152 p.
-------
93
Johnson, A. W. 1982. Managing nematode populations in crop production. In: Nematology in
the Southern Region of the United States, Southern Cooperative Service Bulletin, 276,
193-203. ,
Johnson, A. W. and Feldmesser, J. 1987. Nematicides - A historical review. In: Veech, J. A.
and D. W. Dickson, eds., Vistas on Nematology. Hyatsville, Maryland, Society of
Nematologists, 448-454.
!
Katan, J. and DeVay, J. E. 1991. Soil solarization. Boca Raton, Florida, CRC Press, 267 p.
Keel, C., Koller, B. and Defago, G., eds. 1990. Plant growth-promoting rhizobacteria:
progress and prospects. Second International Workshop on PGPR, Interlaken,
Switzerland, 418 p.
Kelley, W. D. and Rodriguez-K^bana, R. 1975. Effects of potassium azide on soil microbial
populations and soil enzymatic activities. Canadian Journal of Microbiology, 21,565-
Kelley, W. D. and Rodriguez-Ka'bana, R. 1979a. Nematicidal activity of sodium azide.
Nematropica, 8,49-51.
Kelley, W. D. and Rodriguez-Kabana, R. 1979b. Effects of sodium azide: and methyl bromide
on soil bacterial populations, enzymatic studies, and other biological variables. Pesticide
Science, 10, 207-215.
Kelley, W. D. and Rodrfguez-Ka'bana, R. 1981. Effects of annual applications of sodium azide
on soil fungal populations with emphasis on Trichoderma spp. Pesticide Science, 12,
235-244.
Kloepper, J., Lifshitz, R. and Schroth, M. N. 1988. Pseudomonas inoculants to benefit plant
production. ISI Adas of Science: Animal and.Plant Sciences, 60-65.
Kolbezen, M. J., Munnecke, D. E., Wilbur, W. D., Stolzy, L.. H.,. Abu-El-Haj,. F. J. and
Szuszkiewics, T. E. 1974. Factors that affect deep penetration, of ddl soils by methyl
bromide. Hilgardia, 42,465-492.
Martin, H. and Woodcock, D. 1983. The scientific principles of crop protection: London,
Edward Arnold Ltd., 486 p.
McKenry, M. and Thomason, I. J. 1976. Dosage values obtained following pre-plant
fumigation for perennials. H. Using special methods of applying methyl bromide and
1,3-dichloropropene nematicides. Pesticide Science, 7,535-544.
McSorley, R., Dickson, D. W., de Brito, J. A., Hewlett, T. E. and Frederick, J. J. 1994.
Effects of tropical rotation crops on Meloidogyne arenaria population densities and
vegetable yields in microplots. Journal of Nematology, 26,175-181.
Mian, I. H. 1982. Organic amendments of soil for control of plant-parasitic nematodes.
Auburn University, 101 p.
Mosse, B. 1973. Advances in the study of vesicular-arbuscular mycoirhija. Annual Review of
Phytopathology, 11, 171-196.
Mukerji, K. G. and Garg, K. L., eds. 1986. Biocontrol of plant diseases. Boca Raton,
Florida, CRC Press, volumes 1 & 2.
-------
94
Muller, P. J. and van Aartrijk, J. 1992. Flooding reduces the soil populations of the stem
nematode Ditylenchus dipsaci in sandy soils. Netherlands, Bulb Research Centre,
Lisse.
Muller, P. J., van Beers, Th. and de Rooy, M. 1992. Flooding, a non chemical soil treatment
to control the root-lesion nematode Pratylenchus penetrans. Netherlands, Bulb Research
Centre, Lisse.
Munnecke, D. E. and Lindgren, D. L. 1954. Chemical measurements of methyl bromide
concentration in relation to kill of fungi and nematodes in nursery soil. Phytopathology,
44,605-606. • V **
Munnecke, D. E. and van Gundy, S. D. 1979. Movement of fumigants in soil, dosage
response and differential effects. Annual Review of Phytopathology, 17, 405-429.
Mus, A. and Huygen, C. 1992. Methyl bromide: a notice on the Dutch environment situation
and policy. Hague, Ministry of Housing, Physical Planning and the Environment, 13 p.
Overman, A. J. and Jones, J.P. 1984. Soil fumigants for control of nematodes, Fusarium wilt,
and Fusarium crown rot on tomato. Proceedings of the Florida State Horticultural
Society, 97, 194-197.
Opperman, C. H., Taylor, C. G. and Conkling, M. A. 1994. Root-knot nematode-directed
expression of a plant root-specific gene. Science, 263,221-223.
Parker, C. A., Rovira, A. D., Moore, K. J., Wong, P. T. W. and Kollmorgen, J. F., eds.
1985. Ecology and management of soilbome plant pathogens. St. Paul, Minnesota,
American Phytopathological Society, 358 p.
Pattee, H. E. and Young, C. T. 1982. Peanut science and technology. Yoakum, Texas,
American Peanut Research and Education Society, 825 p.
Perrin, R. 1991. Mycorrhizes et protection phytosanitaire. In: Strullu, D.G., ed., Les
mycorrhizes des arbres et plantes cultivees. Paris, Technique et Documentation
Lavoisier, 93-130.
Pimentel, D., ed. 1981. CRC Handbook of Pest Management in Agriculture. Vols. I, U. Boca
Raton, Florida, CRC Press.
Pullman, G. S. and DeVay, J. E. 1981. Effect of flooding and padding rice culture on the
survival of Verticilliiun dahliae and incidence of Verticillium wilt in cotton.
Phytopathology, 71,1285-1289.
Punja, Z. K. 1985. The biology, ecology and control of Sclerotiiim rolfsii. Annual Review of
Phytopathology, 23, 97-127.
Ramfrez-Villapuda, J. and Munnecke, D. E. 1988. Effect of solar heating and soil amendments
of cruciferous residues on Fusarium oxysporwn f. sp. conglutinans and other
organisms. Phytopathology, 78,289-295.
Rhoades, H. L. 1983. Effects of cover crops and fallowing on populations of Belonolaimus
longicaudatus and Meloidogyne incognita and subsequent crop yields. Nematropica,
JL.JI V"lO*
Rhode, W. A., Johns_on, A. W., White, L. V., McAllister, D. L. and Glaze, N. C. 1980.
Dispersion, dissipation, and efficacy of methyl bromide-chloropicrin gas vs gel
formulations on nematodes and weeds in Tifton sandy loam. Journal of Nematoloev
12,39-44. &y
-------
95
Riggs, R. D. and Wrather, J. A. eds., 1992. Biology and Management of the Soybean Cyst
Nematode. St. Paul, Minnesota, APS Press, 186 p.
Rockwool/Grodan. 1994. Recycling. P. O. Box 1160, 6040 KD Roermorid, The Netherlands,
Rockwood/Grodan.
Rodriguez-Kabana, R. 1986. Organic and inorganic nitrogen amendments to soil as nematode
suppressants. Journal of Nematology,18, 129-135.
Rodriguez-Kabana, R. 1991. Control biologico de nematodes parasitos de plantas.
Nematropica, 21,111-122.
Rodriguez-Kabana, R., Backman, P. A. and Curl, E. A. 1977. Control of seed and soilbome
plant diseases. In: Siegel, M. R. and Sisler, H. D., eds. Antifungal Compounds. New
York, Marcel Dekker, Vol. 1,117-161.
Rodriguez-Ka'bana, R., Backman, P. A., Ivey, H. and Farrar, L. L. 1972. Effect of post-
emergence application of potassium azide on nematode populations and development of
Sclerotiwn rolfsii in a peanut field. Plant Disease Reporter, 56, 362-367.
Rodriguez-Kabana, R., Boube, D. and Young, R. W. 1989. Chitinous materials from blue
crab for control of root-knot nematode. I. Effect of urea and enzymatic studies.
Nematropica, 19,53-74.
Rodrfguez-Ka'bana, R., Boube, D. and Young, R. W. 1990. Chitinous materials from blue
crab for control of root-knot nematode. II. Effect of soybean meal. Nematropica, 20,
153-168.
Rodriguez-Kabana, R. and Calvet, C. 1994. Capacidad del suelo para conlrolar enfermedades
de.origen eddfico. Fitopatologia Brasileira, 19,129-138.
Rodriguez-Kabana, R. and Canullo, G. H. 1992a. Protecci6n vegetal en un sistema de
production estable. Fitopatologfa Brasileira, 17,13-17.
Rodriguez-Ka'bana, R. and Canullo, G. H. 1992b. Cropping systems for the management of
phytonematodes. Phytoparasitica, 20,211-224.
Rodriguez-Ka'bana, R. and Curl, E. A. 1980. Nontarget effects of pesticides on soilborne
pathogens and disease. Annual Review of Phytopathology, 18,, 311-332.
Rodriguez-Kabana, R., Godoy, G., Morgan-Jones, G. and Shelby, R. A. 1983. The
determination of soil chitinase activity: conditions for assay and ecological studies. Plant
and Soil, 75, 95-106. \
Rodriguez-Ka'bana, R. and Hollis, J. P. 1965. Biological control of nematodes in rice fields:
role of hydrogen sulfide. Science, 148,524-526.
Rodriguez-Kabana, R., King, P. S. and Pope, M. H. 1981. Combinations of anhydrous
ammonia and ethylene dibromide for control of nematodes parasitic of soybeans.
Nematropica, 11,27-41.
Rodrfguez-Kdbana, R., Kloepper, J. W., Weaver, C. F. and Robertson, D. G. 1993. Control
of plant parasitic nematodes with furfural - a naturally occurring fumigant
Nematropica, 23, 63-73. i
Rodriguez-Kabana, R. and Milch, R. 1991. Composition for biological control of plant
pathogenic nematodes. U.S.A. Patent No. 5057141.
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96
Rodrfguez-Kiibana, R., Morgan-Jones, G. and Chet, 1.1987a. Biological control of
nematodes: soil amendments and microbial antagonists. Plant and Soil, 100,237-247.
Rodrfguez-Ka'bana, R., Robertson, D. G. and King, P. S. 1987b. Comparison of methyl
bromide and other nematicides for control of nematodes in peanut Annals of Anou'ed
Nematology, 1, 56-58.
Rodrfguez-Kdbana, R., Shelby, R. A., King, P. S. and Pope, M. H. 1982. Combinations of
anhydrous ammonia and 1,3-dichloropropene for control of root-knot nematodes in
soybean. Nematropica, 12, 61-69.
Rodrfguez-Ka'bana, R., Smith, R. and Thomberg, S. 1991. Method for treatment of
nematodes in soil using bromonitromethane. U.S.A. Patent No. 5013762.
Rodrfguez-Kiibana, R. and Walters, G. 1992. Method for treatment of nematodes in soil using
furfural. U.S.A. Patent No. 5084477.
Runia, W. T. 1983. A recent development in steam sterilisation. Acta Horticulturae, 152,195
Ryder, M. H., Stephens, P. M. and Bowen, G. D., eds. 1994. Improving plant productivity
with rfnzosphere bacteria. Proceedings Third International Workshop on Plant Growth-
Promoting Rhizobacteria, 7-11 May, 1994. Glen Osmond, South Australia, CSIRO
Division of Soils, 288 p.
Schenck, N. C, ed. 1982. Methods and principles of mycorrhizal research. St Paul
Minnesota, APS Press, 244 p.
Schlang, J. 1985. Resistenzverhalten verschiedener Olretichsorten gegenuber Heterodera
schachtii. Gesunde Pflanzen, 37,233-235.
Schlang J. 1989. Zur biologischen Bekampfung des Weissen Rubensystennematoden
(Heterodera schachtii) dutch resistente Zwischenfriichte. Die Zuckerriibe, 38,224-227.
Schmidt, J. 1983. Zur Wirkung "resistenter" Olrettichsorten auf die Riibennemtoden-
Population. Die Zuckerriibe, 32,169-172.
Sneh, B., Katan, J. and Abdulraziq, A. 1983. Chemical control of soilborne pathogens in tuff
medium for strawberry cultivation. Pesticide Science, 14,199-202.
Soler-Serratosa, A. 1993. Naturally occurring allelopathic compounds for control of plant-
parasitic nematodes. Auburn University, MS. Thesis, 195 p.
Stirling, G. R. 1991. Biological control of plant parasitic nematodes: progress, problems and
prospects. Wallingford, Oxon, CAB International, 282 p.
Stover, R. H. 1962. Fusarial wilt (Panama disease) of bananas and other Musa species.
Commonwealth Mycological Institute Phytopathology Paper 4,1 -117.
Suslow, T. V. 1982. Role of root-colonizing bacteria on plant-growth. In: Mount, M.S. &
Lacey; G.H., eds., Phytopathogenic Prokaryotes. New York, Academic Press, 187-
Thomson, W. T. 1989. Agricultural Chemicals. Fresno, California, Thomson Publications,
288 p.
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97
Thurston, H. D., Smith, M, Abawi, G. and Kearl, S., eds. 1994. Slash/mulch: how farmers
use it and what researchers know about it. Ithaca, N.Y., Cornell Institute for Food,
Agriculture and Development (CHFAS), Cornell University, 302 p.
Trivedi, P. C. and Barker, K. R. 1986. Management of nematodes by cultural practices.
Nematropica, 16,213-236.
Trudgill, D. L. 1991. Resistance to and tolerance of plant parasitic nematodes in plants. Annual
Review of Phytopathology, 29,167-192.
United Nations Environment Programme. 1992. Methyl bromide: its atmospheric science,
technology, and economics. Nairobi, Kenya, United Nations Headquarters, Ozone
Secretariat, 41 p.
Van Wambeke, E. 1983. Efficiency increase of methyl bromide soil fumigation by admixture
with methyl bromide or ameliorated tarps. Acta Horticulturae, 152,137-141.
Van Wambeke, E. 1987. Alternative chemical and physical methods for soil disinfestatipn by
methyl bromide. Proceedings FAO-INRA European Workshop on methyl bromide as
soil fumigant related problems and alternative solutions, 20-21 November, 1986,
Avignon, France.
i
Van Wambeke, E. 1989a. Behaviour of fumigants and their degradation products in soil:
consequences and solutions. Acta Horticulturae, 255,347-359.
Van Wambeke, E. 1989b. Soil mulching for chemical soil disinfestation: possibilities and
evolutions. Acta Horticulturae, 255,243-254.
Van Wambeke, E. 1992. Effects and fate of soil fumigants in the soil, atmospherical and
aquatic environment. Parasitica, 48,43-50.
Van Wambeke, E., Buset, N., Vanachter, A. and van Assche, C. 1988. Methylisothiocyanate
residues in crops and how to avoid them. Mededelingen van de Rijksfaculteit
Landbouwwetenschappen te Gent, 53,1511-1517.
Van Wambeke, E., De Coninck, S., Descheemaeker, F. and Vanachter, A. 1984. Sodium
azide for the control of soil borne tomato pathogens. .Mededelingen van de Rijksfaculteit
Landbouwwetenschappen te Gent, 49,373-381.
Van Wambeke, E., Vanachter, A. and van Assche, C. 1974. Some factors affecting bromide
residues in soil and plant. Mededelingen van de Rijksfaculteit I^andbouwwetenschappen
teGent, 39, 1311-1324.
Van Wambeke, E., Vanachter, A. and van Assche, C. 1985. Fungicidal treatments with azides.
BCPC Monograph 31, B6, 253-256.
Van Wambeke, E., van Assche, C. and Vanachter, A. 1992. Long term risks or benefits from
soil fumigant use?. Mededelingen van de Rijksfaculteit Landbouwwetenschappen te
Gent, 57, 1261-1267.
Van Wambeke, E., van Cauwenbergh, M., Vanachter, A. and van Assche, C. 1986. Diffusion
of candidate methyl bromide co-fumigants through soil and plastic foils. Mededelingen
van de Rijksfaculteit Landbouwwetenschappen te Gent, 51,185-190.
Van Wambeke, E. and van den Abeele, D. 1983. The potential use of azides in horticulture.
Acta Horticulturae, 152,147-154.
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Van Wambeke, E., Wijsmans, J. and d'Hertefelt, P. 1983. Possibilities in microwave
application for growing substrate disinfestation. Acta Horticulturae, 152,209-217.
Vela, G. R., Wu, J. F. and Smith, D. 1976. Effect of 2450 MHz microwave radiation on some
soil microorganisms in situ. Soil Science, 121,44-51.
Vozzo, J. A. 1971. Field inoculations with mycorrhizal fungi. In: Hacskaylo, E., ed.,
Mycorrhizae. Washington, D.C., U.S.A. Government Printing Office, 187-196.
Weaver, D. B. and Rodrfguez-Ka'bana, R. 1992. Disease management in soybean: use of
cultural techniques and genetic resistance. In: Copping, L.G., ed., Pest management in
soybeans. Essex, England, Elsevier, 214-223.
Wegman, R. C. C, Greve, P. A., de Heer, H. and Hamaker, P. 1981. Methyl bromide and
bromide-ion in drainage water after leaching of glasshouse soils. Water, Air and Soil
Pollution, 16, 3.
Wegman, R. C. C., Hamaker, Ph. and de Heer, H. 1983. Bromide-ion balance of a polder
district with large scale use of methyl bromide for soil fumigation. Food and Chemical
Toxicology, 21(4), 361-367.
Wilhelm, S., Storkan, R. C. and Wilhelm, J. M. 1974. Preplant soil fumigation with methyl
bromide-chloropicrin mixtures for control of soil-borne diseases of strawberries - A
summary of fifteen years of development. Agriculture and Environment, 1,227-236.
Wilhelm, S. and Westerlund, F. V. 1994. Chloropicrin - soil fumigant. Watsonville, CA,
California Strawberry Commission, 30 p.
Yagi, K., Williams, J., Wang, N. Y. and Cicerone, R. J. 1993. Agricultural soil fumigation as
a source of atmospheric methyl bromide. Proceedings of the National Academy of
Sciences of the U.S.A., 90, 8420-8423.
Young, D. C. 1990. GY-81, a new concept in soil fumigation. Proceedings Brighton Crop
Protection Conference - Pests and Diseases, 19-22 November, Brighton, 79-85.
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I
Case history 4.1.1: Methyl bromide reduction and elimination in horticultural
production in Italy
i
Crops: Fruits, Vegetables, Flowers, Plants0
Pests: Soil-borne diseases, especially those caused by the Rhizoctonia,
Phytophthora, Pythium, Fusariwn, and Thielaviopsis1*.
Geographic areas:
Region 1: Lake Bracciano Area (Bracciano, Trcvignano and AnguiUara municipalities);
Region 2: Emilia-Romagna region0;
Region 3: Emilia-Romagna Cooperatives
Region 1: Lake Bracciano |
Alternatives: Chemical products, steam, solarisation, crop rotation, intercropping and
biological control.
Until 1983, methyl bromide was heavily used in fields and greenhouses surrounding Lake
Bracciano, located in Bracciano, Trevignano and Anguillara municipalities, in the province of
Rome. The area is intensively cultivated, especially near the lake shore in Trevignano
municipality where vegetables are grown in plastic greenhouses. This region is in central Italy.
General climatic information includes an average rainfall each year of 749 L/m2, an average of
2491 hours of sunshine each year with 56 percent of the days being cloudy. Latitude and
longitude are approximately 41 and 12 degrees, respectively. Average height above sea level is
125 metersd.
A prohibition was placed on the use of methyl bromide in this area, by Regional Ordinance
(No. 288,3rd August 1983), because of concerns about contamination of the water carried
from lake Bracciano to the city of Rome.
Lazio Region gave funds to farmers to compensate the main costs of applied treatments; the
first alternative applied was steam sterilisation. Ersal (a Regional body for agriculture
development) purchased steam machinery and organised soil treatment in the area.
Steam treatments were considered too expensive and in order to find a tetter alternative to
steam, ENEA (the Italian Commission of Innovation Technology, Energy and Environment)
and A.G.E.R. (an agricultural advice cooperative) conducted a research program over several
years, to study the feasibility of soil solarisation in the Bracciano lake area. The research was
carried out on 14 horticultural farms, comprising 2.8 hectares of greenhouses (out of a total of
12 hectares in the zone), and 9.2 hectares of open fields.
a General information about crop production, specifically the number of cropping cycles per
year, was not available.
" Although the authors were not available to provide specific species names, typical
horticultural pest species are included.
c General climatic information was not available.
d Rudolf, Willie., World-Climates: With Tables of Climatic Data and Practical Suggestions,
Wissenschaftliche Verlagsgesellschaft: 1981.
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Serialisation involves laying plastic film on the soil to enhance the sun's heat and kill certain soil
organisms. The researchers found that solarisation had an important impact in inhibiting weeds
and fungi, but was not sufficiently effective as a nematicide. However, good results were
obtained by combining solarisation with Integrated Pest Management, including the use of
organic substances and compost, agronomic techniques, and selected and targeted use of low
toxicity pesticides.
The combination of solarisation with other cultural techniques has given very positive technical
results. Yield has not been reduced, and in some cases yield has increased. The combined
method has been so successful that it will be applied to other parts of the Lazio region. The
method received a favourable reaction from local farmers, from the perspectives of economics,
environmental protection, and health protection.
Solarisation is most effective in the Southern Regions of Italy (where methyl bromide is used
heavily at present). In these Regions, it is common agricultural practice to suspend cultivation
for about one month during the wannest period, so effective solarisation treatment is feasible.
But for many crops, solarisation is likely to be more effective if it is combined with other
cultural practices.
Cost and yield implications: The cost of the combined solarisatipn/EPM method is very %
low compared to methyl bromide use or steam. Cost of solarisation in the Bracciano lake area
is about 800,000 - 900,000 liras per hectare (around US$ 550-600).
Region 2: Emilia-Romagna regional program
Alternatives: Reducing methyl bromide applications by 50 percent.
The Agricultural Regional Authorities in this region have promoted several regional programs
to control the use of pesticides since the 1970s. The most recent Integrated Production
Regional Program involved 20 percent of fruit growers and seven percent of vineyard growers
by 1991. The program prescribes a code of production (the Integrated Crop Management Code
of Production) which specifies the technical methods to be used. The Code limits the use of
methyl bromide to one fumigation in every two years. As a result, growers on at least 20,000
hectares have reduced the use of methyl bromide by 50 percent.
Cost and yield implications: The price of each methyl bromide fumigation in the
Emilia-Romagna area is 6 million liras per hectare (about US$3,700). Limiting the frequency
of fumigations has saved farmers considerable expenditure.
Estimation of methyl bromide being replaced: The Emilia-Romagna region uses
considerable quantities of methyl bromide (6701 in 1990). Twenty percent of fruit growers
and 7 percent of vineyard growers comprising a total of 20,000 hectares of agricultural land
have reduced methyl bromide use 50 percent
Region 3: Emilia-Romagna Cooperatives
Alternatives: Strip fumigation with methyl bromide only on land intended for planting.
Several fanners' cooperatives in the Emilia-Romagna region have developed the Regional
Program further. The APO cooperative has adopted a technique that allows a greater reduction
in methyl bromide use, by fumigating soil only on the strip of land where plants will be
planted.
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Estimation of methyl bromide being replaced: This technique is applied to almost
100 hectares of strawberries. The technique uses 60 percent of the amount of methyl bromide
used for an entire field.
Cost and yield implications: Taking account of the biannual treatment, the total reduction
in methyl bromide use has been 70 percent, according to the cooperative's technical advisers.
The results of cutting methyl bromide were monitored, and the cooperative found there were no
losses in yield, and that the cost savings were quite high.
Documentation: Dr. L. Cori+ and Prof. L. Triolo*, " Review of Cases of Methyl Bromide
Reduction and Elimination in Italy," January 1994, unpublished paper.
(+COSPE, Bologna; *Biotechnology and Agriculture Sector, Technology Innovation
Department, ENEA, Rome).
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Case history 4.1.2: Forest tree nurseries in the People's Republic of China
Crop
Forest nurseries. The most abundantly produced trees are Pinus (22 species), Picea (19 spp.),
Larix (10 spp.), Cunninghamia lanceolata (Chinese fir), Populus spp., Salix spp., Ulmus spp.
Pests
Numerous fungi, including Rhizoctonia solani, Pythium spp., Fusariwn spp., Macrophomina
phaseolina, Sclerotium rolfsii, andRosellinia necatrix; bacteria, including Agrobacterium
tumefaciens; nematodes, including Meloidogyne spp.; and insects, including Otiorrhynchus
spp. (root weevils), Agrotis spp., Paria spp. (rootworms), Pantomorus cervinus, Euxoa spp.
Gryllotalpa spp. (mole cricket).
Geographic area
Seedlings are grown in nurseries throughout China. In North China, primarily temperate
species are grown, especially Populus spp. (poplars and aspens), Salix spp. (willows), Ulmus
spp. (elms), and Pinus tabulaeformis. In South China, primarily sub-tropical species are
grown, especially Cunninghamia lanceolata (Chinese fir), Pinus massoniana (Massonia pine),
and numerous species of sub-tropical hardwoods.
Alternatives
The People's Republic of China uses no methyl bromide in the production of tree seedlings for
forestry. A combination of methods is used as part of an IPM strategy.
Crop rotation and fallowing, burning, soil serialisation, and repeated ploughing and raking of
the soil are all used to reduce pest levels before seedlings are planted.
Seed treatments are used to disinfest seeds prior to planting. Treatments include formalin,
sodium hypochlorite (bleach), potassium permanganate, hot water, and a botanical extract from
Stellaria chamaejasme.
The following botanicals are used especially to reduce damping off fungi and soil-borne
insects:
Melia azadarach, Aleurites fordii (tung), Camellia sasangua, Rhododendron molle, Polygonum
nodosum, Tripterygiwn wilfordii, Daphne genkwa, and rotenone.
Beneficial micro-organisms also are widely used. They are applied to both seeds and to
seedling roots during transplanting. Most commonly used are Arthrobotrys oligospora (for
control of root knot nematodes), Trichoderma harzianum, Bacillus cereus, and Actinomyces
5406.
Comments
Each year some 204,000,000 seedlings are grown to plant approximately 6 million ha. The
total area used for forest nurseries is about 241,200 ha, but because crop rotation is practiced
only about one-half of this area is planted with seedlings at any one time. Of the total area,
42,800 ha are state nurseries, 85,300 ha are collectively owned, and 113,100 ha are privately
owned.
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Typical production yields and costs are described in Table 4.1.1:
Table 4.1.1 Production Yields and Costs for Forest Tree Nurseries in the PRC
Species
Production
Cseedlines / hectare!
i Costs
gjSS/hal
Cunninghamia lanceolate
(Chinese fir)
cuttings
seedlings
Piwts tabulaeformis
(Chinese Pine)
one year
two year
Populus spp. (Poplar)
cutting
1,200,000 to 1,350,000
1,800,000
2,250,000 to 2,400,000
1,125,000 to 1,350,000
60,000 or 150,000
$445 to 500
$445 to 500
$500
$500
$1420
Documentation: i
Cheng, Wan Jun, et al, editors. 1981. The Silviculture of Main Chinese Trees. China
Forestry Publishing House, Beijing. 1342 pp. [In Chinese].
Personal communications with Momei Chen, Professor of Forest Pathologist (retired), Chinese
Academy of Forestry, Beijing, People's Republic of China; and Anghe Zhang,
Professor of Forest Management (retired), Chinese Academy of Forestry, Beijing,
People's Republic of China.
Scientific and Technological Information Center, Ministry of Forestry, China. 1991.
Development of Forestry Science and Technology in China. China Science and
Technology Press, Beijing. 205pp.
Wang, Yung Zhang, Momei Chen, et al. eds. 1982. The Forest Diseases of China. China
Forestry Publishing House, Beijing. 254pp. [In Chinese].
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Case history 4.1.3: Alternatives in forest tree nurseries in the USA
(Pacific Northwest) and Western Canada
Crop
Forest nurseries. The most abundantly produced species are Ponderosa pine (Pinus
ponderosd), Scots pine (Pinus sylvestris), Colorado spnice (Picea pungens), and Douglas fir
(Pseudotsuga menziesii)
Pest
1 **
Weeds, and plant-pathogenic fungi in the genera Pythium, Fusarium, Phytophthora^ and
Rhizoctonia.
Geographic area
Forest nurseries of the northwestern USA and adjacent Canada.
Alternative
Soil fumigation with dazomet (Basamid®), or metam sodium.
Campbell and Kelsas found seedling growth and survival were as good after pre-plant
fumigation with dazomet or metam-sodium as with methyl bromide-chloropicrin mixtures.
Furthermore, seedlings grown in dazomet treated soil showed greater uniformity of height and
diameter than with the other fumigants.
Scholtes describes use of dazomet as a replacement for methyl bromide/chloropicrin fumigation
at the nursery he manages. Douglas fir is the primary species grown on 213 acres of seedling
production land. The nursery produces approximately 21 million seedlings annually. Methyl
bromide was used starting in 1978, but use was greatly reduced starting in the mid-1980s due
to concerns about increasing regulations on methyl bromide, difficulties with disposal of plastic
tarps, and poor contractor safety and performance. Dazomet has proved quite satisfactory, the
only limitation being phytotoxicity to Western White Pine caused by the containment of
vapours during periods of climatic thermal inversions. The problem has been avoided by
planting Western White Pine upwind from the treatment sites, and by using large buffer zones
around these sensitive seedlings.
Alspach describes the success of dazomet for soil fumigation at a nursery in Canada. Trials
began in 1963, and the material is currently in routine use. This nursery produces 7 to 10
million trees annually and ships seedlings to clients throughout the Canadian prairies, primarily
in Manitoba and Saskatchewan.
Similarly, McElroy describes studies on the successful use of both dazomet and metam-sodium
at three nurseries over a three year period in the mid-1980s. He concludes that both materials
gave control equivalent to methyl bromide-chloropicrin.
Economic data for these production systems not available. However, according to Scholtes,
USDA Forest Service Nurseries are required to be self-supporting, including paying
government labour rates which are considerably higher than those paid in the private sector.
Who now uses the alternative?
Several forest nurseries operated by the United States Department of Agriculture Forest Service
and Agriculture Canada.
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105
Comments
Researchers and forest nursery managers have found dazomet and metam-sodium to be
effective alternatives to fumigation with methyl bromide/chloropicrin. Cost of applying
dazomet and metam-sodium are considered to be equal to or less than methyl bromide-
chloropicrin.
Documentation: i
Oral presentations, published in Scholtes (1989).
Alspach, L.K. 1989. Dazomet use for seedbed fumigation at the PFRA Shelterbelt Centre,
Indian Head, Saskatchewan. General Technical Report RM-184, Rocky Mountain
Forest and Range Experiment Station, United States Department of Agriculture Forest
Service, Fort Collins, Colorado, USA. 40-42.
Campbell, S.J., and B.R. Kelpsas. 1988. Comparison of three soil fumigants in a bareroot
conifer nursery. Tree Planters' Notes (USDA Forest Service, Washington, D.C.),
39(4): 16-22.
McElroy, F.D. 1986. Use of metam-sodium and dazomet fumigants. General Technical
Report RM-137, Rocky Mountain Forest and Range Experiment Station, United States
Department of Agriculture Forest Service, Fort Collins, Colorado, USA, 139-146.
.Scholtes, J.R. 1989. Soil fumigation at J. Herbert Stone Nursery. General Technical Report
RM-184, Rocky Mountain Forest and Range Experiment Station, United States
Department of Agriculture Forest Service, Fort Collins, Colorado, USA, 35-37.
Scholtes, J.R. 1994. Personal communication.
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Case history 4.1.4: Use of alternatives in vineyards in California, USA
Crop
Grapes (Vitas vimfera)
Pest
Numerous soil-borne pests, including weeds, nematodes, fungi (especially oak root fungus
Armillaria mellea), and insects (especially the root aphid Phylloxera),
Geographic area
All of the grape growing areas of California. California is one of the premier wine regions of
the world.
Alternatives
A number of control measures are used, including cover crops (especially cereal rye, alfalfa,
and Sesbania), rootstocks resistant to Phylloxera and nematodes, application of composts and
manures to encourage beneficial soil microorganisms, monitoring to identify areas of the
vineyard in need of particular treatments, subsoil plowing and ripping, fallow and rotation
periods prior to replanting grapes. In addition, some growers feel fumigation is unnecessary at
some sites despite presence of pest populations at varying levels.
Who now uses the alternative?
Many wine grape growers in California, including some of the largest and best known in the
world, have areas that are not fumigated. Growers include such well-known producers as
Frey, Fetzer and Gallo, as well as smaller growers. Grapes from these vineyards are used to
produce wines of all qualities, including some of the finest wines from the region.
Comments
As of 1992, there were 137,085 ha of wine grapes grown in California. White soil fumigation
.is commonly practiced in some California vineyards, it is by no means universally practiced.
The number of acres fumigated with methyl bromide vary widely depending on a number of
factors including crop and pest history, region of the state, grower preference, etc. In 1992, of
the 3,096 acres of winegrapes planted, only 41% (1,264 acres) were fumigated with methyl
bromide. Data on yields and other economic parameters are proprietary and were not made
available.
Documentation
Interviews with vineyard owners and managers, and crop consultants associated with
vineyards in California:
Fetzer Vineyards, Hopland
Frey Vineyards, Mendocino County
Greg Cpleman, Gallo Vineyards
Phil Phillips, Area IPM Advisor, Cooperative Extension, Ventura County
Sahatdgian Farms, Madera
Soghomonian Vineyards, Fresno
-------
107
California Agricultural Statistics Service. 1992. California Grape Acreage 1992. California
Dept. Food and Agriculture, Sacramento, CA.
DepL of Pesticide Regulation. 1993. Annual Pesticide Use Report 1992. California EPA,
Sacramento, CA.
-------
108
Case history 4.1.5: Replacement of methyl bromide use in
horticultural nurseries, Ohio
Crop
Horticultural and vegetable nursery plants.
Pest
Soil-borne diseases, especially those caused by the fungi Rhizoctonia, Phytophthora, Pythium,
Fusarium, andThieloviopsis.
Geographic area
Ohio, US A
Alternative
Composted hardwood barks as a potting soil amendment.
Who now uses the alternative?
Widely practiced by nursery growers in Ohio on crops as varied as chysanthemums, Christmas
trees, cut flowers, and vegetables. Some of these operations are among the largest of their kind
in the USA. The combination of antifungal substances in young bark compost, and biocontrol
organisms in mature bark composts, effectively control soil pathogens.
Comments
Starting in the 1970s, the use of compost replaced virtually all uses of methyl bromide in the
Ohio nursery industry. In contrast, nursery growers in California use more than 9001 of .
methyl bromide annually.
Documentation
Hoitink, ELAJ., and G.A. Kuter. 1985. Effect of composts in container media on diseases
caused by soilbome plant pathogens. Acta Horticulturae, 172,191-197.
Hoitink, H.A. 1994. Ohio State University, Wooster, OH 44691, USA. Personal
communication.
Moore, L.W. 1983. Composted bark, chrysanthemums, and Christmas trees. Plant Disease,
67, 706.
-------
109
Case history 4.1.6: Organic strawberries in California
Crop
-
Strawberry (Fragaria x ananassd) \
|
Pests I
Numerous other soil-borne pests, including fungi (especially Verticillium dahlias,
Phytophthora fragariae, Phytophthora spp., Pythium spp.), nematodes (especially root
knot nematodes in the genus Meloidogyne), weeds, and the complex responsible for black
root rot disease.
i
Geographic area !
Coastal California, which produces some of the largest yields in the world.
Alternative
Each year, roughly 2,000 t of methyl bromide are used on California strawberries. This
accounts for 3% of the world's total use of methyl bromide.
Organic strawberry growers in California do not use methyl bromide as a pre-plant soil
fumigant (although they do use transplants grown in soil treated \yith methyl bromide and
chloropicrin). They control weeds and reduce losses to soil borne diseases using a
combination of methods including cover crops, crop rotation, and acceptance of lower
yields in return for higher prices at the supermarket.
Who now uses the alternative? •
In California, twenty-two organic farms currently produce strawberries without methyl
bromide. Most consider their operations profitable. One of the best documented is
Swanton Berry Farms, on California's central coast near Santa Cruz.
Comments
Yields in organic production are about 65% that of conventional production. However,
currently, organic strawberries sell for approximately twice the price of conventional
berries, and this offsets the lower yield. Fruit quality is considered quite good, although
organic fruit may be slightly smaller. The growers who do not use methyl bromide are
all certified organic, and therefore cannot use synthetic pesticides and fertilisers. This
sometimes leads to increased pest problems, especially mites and lygus bugs, and to
difficulty regulating the timing of nitrogen applications. Conventional growers who
stopped using methyl bromide would not face these constraints arid could achieve higher
yields. In experimental plots where no fumigation was used but other production
parameters were conventional, yield of non-fumigated plots was 72% that of fumigated
plots. However, the prior cropping and/or fumigation history of Ihe non-fumigated plots
used hi these trials is not known. Table 4.1.2 compares production data on conventional
fumigated strawberries and non-fumigated organic strawberries.
-------
110
Table 4.1.2 Comparison of Conventional and Organic Strawberry Production in California,
USA.
Type of
Production
Conventional
Organic
Typical Yield
(t ha"1)
60
40
Fumigation
with Methyl
Bromide
yes
no
Production
Cycle
annual
annual and
perennial
Rotation
1 crop every
year or every
other year
1 to 2 crops
every 4 to
5 years
Documentation
California Certified Organic Farmers, Santa Cruz, CA 95060 USA.
Cochran, J. 1994. Swanton Berry Farms, Davenport, CA, USA. Personal communication.
Gliessman, S. R. et aL, 1990. Strawberry production systems during conversion to organic
management California Agriculture, 44,4-7.
Liebman, LA. 1994. Alternatives to methyl bromide in California strawberry production.
IPM Practitioner, 7(16); 1-12.
Webb, R. 1994. Driscoll Strawberry Research, Watsonville, CA, USA. Personal
communication.
Welch, N.C. and JA. Beutel. 1990. Strawberry production and costs in the central coast of
California. Agric. Extension, University of California. 8 pp.
-------
111 I
Annex 4.1.1
Methyl bromide soil fumigation use survey
The following tables and figures represent data on methyl bromide consumption for soil
fumigation applications from a variety of sources including responses to a survey distributed by
the Methyl Bromide Technical Options Committee (MBTOC) and industry estimates from
various sources. The survey was sent in 1994 to 122 signatories of the Montreal Protocol. The
number of responding countries totalled 39, representing a 32 percent response rate. Industry
estimates for nine additional countries supplement the survey data. Methyl bromide use as a
soil fumigant is reported for a total of 48 countries.
The collected use statistics are provided in the following pages. First, a. table (Table 4.1.3) is
presented that identifies countries responding to the survey, whether methyl bromide is used in
responding countries as a soil fumigant, and whether crop-specific data were available on
methyl bromide use. The second table (Table 4.1.4) details the crop specific data for each
country for which data were available. As the table indicates, 50,9131 of methyl bromide were
used for soil fumigation in the listed countries. Not all countries reported the number of
hectares treated with methyl bromide, but for those that did, a total of 130,034.8 hectares were
treated.
The reported consumption of the 48 responding countries, 50,9131, accounts for roughly
89 percent of the annual worldwide production of methyl bromide for soil ifumigation
applications based on the latest (1992 data) reported figures. In 1992, iit wa.s estimated that
75,6251 of methyl bromide were produced worldwide for all applications, of which 57,4071
were for soil fumigation (i.e., pre-plant) applications.
Following the tables, six pie charts (Figures 4.1.1 - 4.1.6) are presented. The first,
Figure 4.1.1, indicates those countries with the greatest use by volume including U.S.A.,
Italy, Japan, Spain, Israel, France, Brazil, Turkey, and Greece. The following charts
distribute international methyl bromide use among the major use categories. The figures
present data for the world, U.S.A. alone, and the rest of the world (excluding U.S.A.). As the
figures indicate, soil fumigation usage with methyl bromide is greatest for tomatoes,
strawberries, cucurbits, peppers, and tobacco.
The following assumptions were made in compiling the tableland figures:
Use statistics from Canada, Denmark, and U.S.A. were for 1992, but were assumed to
remain constant.
Certain crops were grouped into categories. These groupings are:
Berries: Blackberries, boysenberries, raspberries
Citrus fruits:' Grapefruit, lemon, orange, tangerine
Cucurbits: Cucumbers, melons, pumpkins, squashes
Nuts: Almonds, pecans, walnuts
-------
112
Table 4.1.3 Responses to MBTOC survey on methyl bromide use as soil fumigant
Countries
reporting use
Countries
reporting no use
Countries
reporting use,
but not use
volume
Countries
reporting use
volume, but not
by crop
Australia
Austria
Bahamas
Belgium
Canada
Denmark
Egypt
France
Greece
Israel
Italy
Japan
Jordan
Kenya
Malaysia
Malta
Morocco
Saudi Arabia
South Africa
Spain .
Turkey
U.K.
U.S.A.
Zimbabwe
Bangladesh China
Bulgaria Peru
Finland
Germany
India
Mauritius
Namibia
Netherlands
Norway
Republic of Korea
Romania
Sweden
Taiwan
Tunisia
Tuvalu
Uganda
West Indies (St.
Lucia, St. Kitts)
Argentina
Brazil
Chile
Colombia
El Salvador
Thailand
Uruguay
-------
113
Table 4.1.4 MBTOC survey results. Methyl bromide use as soil fumigant by country and use sector
Country Data Crop
Source
Australia 1
Austria 1
Bahamas 1
Belgium 1
Brazil 4
Canada 1
Chile 5
Columbia 4
Denmark? *
Egypt 1
El Salvador 4
France 2
Cut Flowers
Fruit
Turf
Vegetable
Total:
Fruit and gardening
Cantaloupe
Green peppers
Tomatoes
Watermelon
Total:
Flowers
Melons
Nurseries
Pepper, Eggplant, Cucumber
Potting Soil
Strawberries
Tomatoes
Other
Total:
Not specified
Fruits & vegetables
Ornamentals
Strawberries
Turf and forestry
Total:
Tomatoes. peppers and chilies
Not specified
Cut flowers
Lettuce
Tomatoes
Other vegetables*
Total:
Cucumbers
Strawberries
Total:
Seedbed nurseries
Flowers
Melons
Nurseries
Pepper, eggplant and
cucumbers
Potting soil
Strawberries
Tomatoes
Other
Total:
Treated MeBr Percentage Data
Area used! of total year
(hectares) (t) crop treated
NA
NA ;
NA
NA
>300
7
27 |
12 !
77
11
NA
NA
NA
NA ;
NA
.NA
NA !
NA ;
NA
NA i
NA
NA
NA i
NA
NA
1.9 ;
>2.0
20.5
1.2
100
100 |
NA
NA
NA !
NA
NA
j
NA
NA
NA ;
NA !
245
146
117
24
319
606
3.4
29
5
61
7
102
60
0
60
40
12
2:0
200
8
400
1.120
66.6
0.3
10.0
0.8
77.7
260
102
1.7
0.7
20.4
1.2
24
50
50
100
95.4
195
75
75
225
75
375
450
30
1,5130
NA
NA
NA
NA
>10
0
100
100
100
100
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
5
>13
34
12
25
5
NA
NA
NA
. NA
NA
NA
NA
NA
NA
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1991
1991
1991
1991
1993
1993
1992
1992
1992
1992
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
a In 1993, Denmark used 13 metric tons of methyl bromide for soil fumigation.
b Other vegetables include: sweet pepper, parsley, radish, carrots, cabbage, and eggplant.
i
i
i
-------
114
Table 4.1.4 (cent) MBTOC survey results. Methyl bromide use as soil fumigant by country and use sector
Greece
Israel
Italy
Japan
3 Cucumber
Green pepper
Tobacco seedbeds
Tomatoes
Total:
1 Carrots
Cucumbers
Eggplants
Flowers
Green herbs
Legumes
Melons
Orchards
Peppers
Potatoes
Strawberries
Tomatoes
. Zucchini
Total:
2 Flowers
Melons
Nurseries
Pepper, eggplant and
cucumbers
Potting soil
Strawberries
Tomatoes
Other
Total:
1 Bed soU
Broccoli
Butterbur
Cabbage
Carnation
Celery
Chestnuts
Chive
Chrysanthemum
Cucumber
Eggplant
Chinese bell and other flowers
Ginger
Green soybeans
Kidney beans
Lettuce
Melon
Okra
Onions
Oranges
Other flowers •
Peanuts
Peas
Pepper
Pumpkins
Radish
Rice
Scallions
Spinach
Strawberries
Sweet Potatoes
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1.7
5.0
119.8
13.2
2.6
9.9
104.0
158.4
1,244.1
178.2
95.7
108.9
3.3
29.7
3.3
2,107.0
47.9
227.7
6.6
277.2
3.3
23.1
589.6
62.7
145.2
23.1
9.9
5.0
915.1
174.9
125
100
125
600
950
100
340
75
745
36
112
245
15
220
400
180
200
50
2,718
700
700
350
1,050
210
1,050
2,800
140
7,000
359
0.5
3
36
8
0.6
3
63
56
522
92
30
33
1
9
1
741
16
69
2
120
1
7
272
19
44
7
3
3
325
53
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1 NA
NA
NA
NA
NA
>1
>1
>1
2
>1
>1
5
3
12
1
14
3
>1
>1
>1
12
NA
NA
>1
1
>1
4.4
13.0
>1
>1
>1
>1
>1
9
>1
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1992
1992
1992
1992
1992
1992 1
1992
1992
1992
1992
1992
1992
1992 1
1992 j
1992 1
1992 I
1992 1
1992 1
1992 1
1992 1
1992 1
1992 1
1992 1
1992 1
1992 I
1992 I
1992 I
1992 I
1992 I
1992 •
1992 •
-------
115
Table 4.1.4 (cont.) MBTOC survey results. Methyl bromide use as soil fumigant by country and use sector
Japan (cont)
Jordan
Malaysia
Malta
Morocco
Saudi Arabia
South Africa
Spain
Turkey
United
Kingdom
Tobacco seedbeds
Tomatoes
Turnips
Watermelons
Others
Total:
1 Vegetables and seed bed
plantings
4 Floriculture and strawberries
1 Tobacco seedbeds/Other
Turf
Total:
1 Cucumbers
Eggplants
Flowers
Peppers
Strawberries
Tomatoes
Total:
3 Melons
Strawberries
Tomatoes
Total:
1 Tomatoes, cucumbers and
dates
1 Apples, pears
Flowers (ornamental)
Nurseries
Strawberries
Tobacco seedbeds
Vegetables
Total:
1 Carnations
Citrus fruits
Ornamentals
Potatoes
Other fruits and vegetables
Strawberries
Total: c
3 Flowers
Tomatoes
Total:
1 Chrysanthemum,
other flowers
Cucumber
Lettuce
Nursery Stock
Strawberries
Tomatoes
Total:
92.4
754.1
79.2
2,650.9
NA
3,360
NA
<0.1
2.3
NA
NA
NA
NA
NA
NA
NA
NA
NA
450
800
795
160
258
2,125 ,
802
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
12
2
40
2
500
50
! 28
322
24
963
2,127
6.363
280
137
<0.1
! 1.2
1.3
8
5
5
| 7
! 8
7
'40
100'
100'
400
600
200
133
71
6
i 32
i 170
41
453
50
40
i 10
50
1,430
1,260
2,840
0.2
150
800
950
9
2
1 28
! 2
i 350
35
425
>1
5
1
12
NA
NA
NA
NA
50
80
100
50
100
100
NA
NA
NA
8
1.5
35
100
67
100
1
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
4.4
< 1
2.7
< 1
30
10.0
1992
1992
1992
1992
1992
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
c According to industry estimates, the total figure for MeBr use in Spain in 1993 was approximately 4,000 tonnes.
-------
116
Table 4.1.4 (cont) MBTOC survey results. Methyl bromide use as soil fumigant by country and use sector
United States 1
Uruguay 4
Zimbabwe 1
Total
Apples
Berries
Broccoli
Carrots
Cauliflower
Cherries
Citrus
Curcurbits
Eggplant
Other fruits and vegetables
Forest seedlings, seedbeds and
grass
Grapes
Lettuce
Nuts
Peaches
Peppers
Plants
Plums and Prunes
Potatoes
Strawberries
Sweet Potatoes
Tobacco seedbeds
Tomatoes
Other
Total:
Not specified
Curcurbits
Greenhouse flowers
Roses
Shadehouse flowers
Strawberries
Summer flowers
Tobacco seedbeds
Total:
645
33
185
847
200
827
1,031
2,145
810
2,301
2,167
2,264
640
10,131
1,381
9,292
3,644
1,028
97
13,645
2,891
3,360
22,267
24,697
NA
50
60
130
60
40
200
1,100
128,460
119
9
39
162
46
82
132
473
181
404
764
876
149
770
323
2,041
1,678
86
39
2,507
595
1,678
5,062
4,536
22.716
4
4
6
12
6
4
19
550
601
50,913
< 1
0
< 1
2
< l
2.1
NA
NA
58.8
NA
NA
< 1
< 1
NA
1.9
23
NA
2
0
68
9
3
12
NA
NA
NA
NA
NA
NA
NA
NA
, NA
m
1992
1992
1992
1992
1992
1992
1992
1992
1992
1992
1992
1992
1992
1992 1
1992
1992
1992
1992
1992
1992
1992 1
1992 1
1992 1
1992 1
1993 1
1993 1
1993 9
1993 1
1993 1
1993 1
1993 1
1993 1
Daia sources: I
1.
2.
3.
4.
5.
Survey data collected by Methyl Bromide Technical Options Committee from Agricultural Ministries and 1
Departments of Environment, 1994. I
Industry estimates prepared by Eurobrom, 1994.
Industry estimates prepared by Bromine Compounds Ltd., 1994.
Okioga, David, 'Survey of Methyl Bromide Use in Article 5 Counlries'
1994.
1994, Kenya Agricultural Research Institute
Fernandez, Juan Francisco, 'Data on Imports of Methyl Bromide Compiled from Importers and Customs Office' 1
Department of Sustainable Development, Chile, 1994. ' •
-------
117
Figure 4.1.1. Global methyl bromide use for soil fumigation - by country.
1992. MBTOC survey data.
Other World Use
20%
France
Brazil 3%
2%
Figure 4.1.2. Global use of methyl bromide (excluding USA) for soil
fumigation • by use category. 1992. MBTOC survey data.
Tobacco
3%
Sweet Potatoes
Strawberries
14%
Other
14%
Replant*
1%
Curcurbits
11%
Other Produce
19%
Tomatoes
22%
Flowers
9%
Peppers
2%
Nursery Crops*
5%
-------
118
Figure 4.1.3. Use of methyl bromide in USA in 1992 for soil fumigation. - by
use category. MBTOC survey data.
Other
21%
Tobacco
8%
t Potatoes
3%
Strawberries
12%
Curcurbits
2%
Replant*
11%
Other Produce
3%
Tomatoes
23%
Flowers
Peppers
9%
Nursery Crops**
8%
Figure 4.1.4. Global use of methyl bromide for soil fumigation - by major
crop. Minor uses not included. 1992. MBTOC survey data.
Sweet Potatoes Tobacco
5%
.. Flowers
13%
Strawberries
21%
Curcurbits
17%
Peppers
3%
Nursery Crops*
7%
Tomatoes
34%
-------
1 19
Figure 4.1.5. Global use of methyl bromide for soil fumigation (excluding
USA) - for major crops only. 1992. MBTOC survey data.
Tobacco
Sweet Potatoes 8%
2%
Flowers
7%
Strawberries
20%
Curcurbits
11%
Peppers
8%
Nursery Crops**
9%
Tomatoes
35%
Figure 4.1.6. Use of methyl bromide for soil fumigationi in USA - major crops
only. 1992. MBTOC survey data.
Tobacco
12%
Flowers
0%
Sweet Potatoes
5%
Strawberries
18%
Curcurbits
3%
Peppers
15%
Nursery Crops*
12%
Tomatoes
35%
-------
120
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-------
121
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-------
124
Annex 4.1.4
Discussion on potential use rate reductions on methyl bromide conducted at
MBTOC Bordeaux meeting and through subsequent communications among
members of the Soil fumigation subcommittee
Introduction
The issue of what rate reductions in the use of methyl bromide in soils were feasible
technically, and over what timescale, was put to the subcommittee first at the last 1994 meeting
of MBTOC in Bordeaux. It was the feeling of the subcommittee, and its chair, that inadequate
time had been allotted to discussion of this important topic. Consequently, no agreement on
potential rates of reduction were achieved, and the scientific quality of the discussion on these
reductions is not at a level attained elsewhere in this Report. This Annex sets out estimates
based on the experience of several committee members. It reflects the divergence of opinion on
the matter.
Two distinct use rate patterns emerged out of the soil fumigation subcommittee's deliberations
at Bordeaux on 12 August 1994. One pattern of high use rates typical of some European
operations involved dosages of up to 90 g nr2. The other pattern, prevalent in USA, of low use
rates at about 20 g nr2.. This difference developed historically from efforts in California and
Florida to reduce rates through the years in response to environmental and economic concerns
and, inter alia, competition from other less expensive fumigants.
A second distinction that was made by the subcommittee's discussion of the problem pertained
to whether in the ten-year period an all methyl bromide system was to prevail, or a system with
alternatives could be developed.
Results of deliberations
No general agreement as to how much reduction in use rate could be attained was reached.
However, the following calculated opinions were offered in writing by various groups and
individuals who participated in the discussion. These opinions were circulated by fax by the
Chair after the Bordeaux meeting of MBTOC and amendments and corrections were made by
the contributors.
A» United States.
Opinion prepared by F. Westerlund, R. Webb, T. Duafala, R. Ross,
R. Weber, P. Vail.
DOSAGE REDUCTION (After 10 Years - Year 2004)
Given a ten (10) year time frame, a reduction of methyl bromide dosage is presented in
Table 4.1.5. These reductions are based on utilising improved application technologies (e.g.
high barrier films, extending retention of methyl bromide in the soil through longer tarping
periods, depth of soil injection, method of soil injection, soil types).
If, with additional research, reduced frequency of application (e.g. fumigation once each crop
year vs once for each two crop years), strip application (reduced amount of soil treated to
planted area only) prove effective, and with the following assumptions:
a. planting stock (root stocks, plants, seed, or other propagation material) from nurseries
remain pest free.
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b. alternative chemicals (e.g. 1,3-D, dazomet) retain registration or receive registration.
c. existing chemical fumigants maintain their registration.
d. current "known" pest complex remains constant and no new pests are introduced or are
controlled by alternatives.
.
e. no known pest tolerances occur or develop.
f. It may take the full ten years before the dosage reductions as listed in Table 4.1.5 can be
achieved.
Then: a % dosage reduction (Table 4.1.5) may be possible.
Table 4.1.5 Dosage Reduction in 10 Years (by 2004)
Percent use rate reduction expected
High rate
(90 g m-2)
Low rate*3
(20 g m-2)
Without With alternatives
alternatives
30 50
!
10 30
!
a This rate is most likely approaching the minimum rate of methyl bromide needed to achieve
economic control.
i
These figures were developed through discussions and after considerable debate without
consensus. These percentages are at the upper level of potential reduction, and involve many
uncertainties and estimates. Better estimates will be available from on going research to be
completed in 1995.
Conclusion: On a global basis taking into account the range of application rates it is estimated
that a dosage reduction between 10 to 30% on a per unit treated area basis may be achieved in
10 years. We must stress that these ranges are highly speculative. In the absence of further
research, only the lower figure of 10 percent (for low dosage users) can be considered
achievable. After research is completed we would be in a more informed position to assess if
further reductions are possible. With increased demand, this may not permit a decrease in
production for methyl bromide.
Opinion submitted by S. Daar i
It is estimated that, with all available alternatives, 100% of methyl bromide use could be
achieved within 10 years for many current uses.
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Crops currently grown in soil fumigated with methyl bromide are also successfully grown in
many locations without use of that fumigant. Use of alternative methods such as soiless
substrates, crop rotation, and alternative chemicals have produced up to 100% reductions. For
example:
• The Netherlands has replaced 100% use in greenhouse and field crops;
• Germany has replaced 100% use in greenhouse and field crops;
• Some regions of Italy reduced methyl bromide use by 50% to 70% or have eliminated it
in some greenhouse and field crops;
• Organic growers and some conventional growers in North America, Europe, and Article
5 countries have never used methyl bromide on economically viable crops that are
currently treated elsewhere with methyl bromide.
Opinion submitted byj. Curtis
The attached table describes possible reductions in methyl bromide use. The reductions are
estimates based on information from the chapter in this report on alternatives to methyl bromide
use as a soil fumigant and the experiences of individuals, regions and countries in eliminating
or reducing methyl bromide use.
These estimates are ambitious and based on numerous factors and assumptions. The most
important assumption is the availability of substantial resources for research and technology
transfer. These investments are essential given that, in mosit countries, little effort has been thus
far made to develop alternatives to methyl bromide. To ensure the long term viability of
alternatives, resources should be directed toward the development and implementation of
integrated strategies that combine multiple tactics for facilitating crop health. These strategies
should have.as their central objective the prevention of conditions that encourage pest outbreaks
and should emphasise chemical treatments only as a last resort.
An additional factor influencing these estimates is the current ban on methyl bromide
production and importation into the U.S.A. by the end of the year 2000. The U.S.A. is
responsible for approximately 45 percent of worldwide methyl bromide use as a soil fumigant.
Thus, within six years, close to half of the world's use of methyl bromide as a soil fumigant
will be eliminated.
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Table 4.1.6 Feasible reductions in methyl bromide soil fumigant use
Crop
Tomatoes0
Peppers
Cucurbits
(melons and
cucumbers)
Strawberries *
Tobacco c
Nursery crops ^
Replant e
Other/
Total MeBr use
Represented:
Total tons used 8
11,450
2,765
3,625
6,552
2,667
3,105
2,667
18,082
50,913 h
% of total
MeBr used
(1992/93)
15.7
3.8
5.0
9.0
3.7
4.3
3.7
24.8
69.8
% of Me«r
used in soil
(1992/93)
23.0
5.4 i
1
7.1
12.9 i
5.2
6.1 ;
5.2 ;
35.5
100.0 /
% feasible
reduction by
1998
70
70
70
50
30
50
50
50
50
% feasible
reduction
by 2003
100
100
100
100
100
100
50
85
90
estimates for possible reductions in methyl bromide use in vegetable production are based
on the following experiences and alternatives: strip application of meihyl bromide; reduced
application rates of methyl bromide; previous experience in Florida tomato production with the
use of 1,3-D, metam-sodium and herbicides; availability of resistant tomato varieties; the use of
son solansatton in Japanese and Italian production of tomatoes, eggplants, and cucumbers; a
100 percent reduction in methyl bromide use in greenhouse production in the Netherlands
within ten years; a 40 percent reduction in greenhouse vegetable production in Denmark in two
years using dazomet and artificial substrates.
pese estimates are also based on the assumption that the use of 1,3-D, metam-sodium and
dazomet do not cause severe phytotoxicity.
* The estimates for possible reductions in methyl bromide use in strawberry production are
based on the following experiences and alternatives: methyl bromide use was entirely replaced
m strawberry production in the Netherlands within ten years; strawberries are produced in
California organically with no use of methyl bromide; production of strawberries in the other
parts of the U.S.A. do not use methyl bromide; soil solarisation is usfxi in Japanese and Italian
strawberry production.
These estimates are also based on the assumption that plant breeding prog jams are put in place
and that resistant varieties will be available in the future. In addition, fin California, 10 to 30
percent lower yields are anticipated without the use of methyl bromide.
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c The estimates for possible reductions in methyl bromide use in tobacco production are based
on the following experiences and alternatives: methyl bromide is not used at all for field
treatments of tobacco grown in the major tobacco-producing regions of the U.S.A. including
South Carolina and North Carolina; other chemicals are available including 1,3-D and metam-
sodium; resistant varieties are available.
d The estimates for possible reductions in methyl bromide use in nursery crops are based on the
following experiences and alternatives: availability of steam, soilless substrates, cross-species
grafting; rnicrobial enhancement (i.e., beneficial organisms) of potting soil; methyl bromide use
was entirely replaced in nursery crops in the Netherlands; instead of methyl bromide, nursery
crops in Ohio use potting soil amendments; methyl bromide is not used in forest tree nurseries
in China; other fumigants and pesticides such as metam-sodium arc available.
These estimates are based on the assumption that adequate consideration is given to eliminating
industry resistance to changing conventional practices. In the nursery, methyl bromide is
generally considered inexpensive.
« Theestimates for possible reductions in methyl bromide use in replant crops (stone fruits,
citrus vineyards, nuts and berries) are based on the following alternatives and experiences:
methyl bromide is not used in many vineyards in California; other fumigants and pesticides are
available; solarisation can be used in combination with other techniques; crop rotations have
been demonstrated to be effective alternatives.
/The "Other" category includes sweet potatoes, flowers and all commodities reported to
MBTOC simply as "other" or "other produce". For the purpose of developing a pnas^-out
schedule, estimates of 50 percent reduction by 1998 and 85 percent reduction by 2003 are
conservative, based on evidence for other crops. Most of the pest problems in other crops
will be similar to those in listed crops.
8 These figures are derived from the methyl bromide use survey (Annex 4.1.1) in the soils
chapter of MBTOC report. The total methyl bromide use reported in this survey accounts for
approximately 89 percent of annual worldwide consumption of methyl bromide in soil
fumigation (Table 2.3).
h According to industry estimates, a total of 57,4071 of methyl bromide was used for soil
fumigation. The figure of 50,9131 used in this table is derived from the methyl bromide
(Annex 4.1.1) in the soils chapter of the MBTOC report
Opinion submitted by J. W. Wells
Over the many months, we have explored the technical options for the uses of methyl bromide
on soils From these deliberations, we have produced a report which considers alternatives
from a qualitative rather than a quantitative point of view. Obviously, we cannot derive a
quantitative percent reduction from the substance of the soils report, so we must consider this
section of the executive summary a new exercise rather than a conclusion or summarisation ot
our work to date.
I assume that the parameters of the question posed (we have ten years, clean nursery material,
and unlimited research funds) are intended to focus attention on the fact that the answer is to be
strictly in terms of technical possibilities. There are, of course, additional, non-technical
considerations which should be discussed in order to put any use reduction figure in context.
The economics of crop production, as well as the cost of research, must be factored into the
equation. Are we going to be producing the same variety of crops and approximating the_same
yields? Methyl bromide soil fumigation occurs in at least 150 crops in California alone. For a
number of these crops, complete replacement of methyl bromide with alternative chemicals or
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crop protection strategies would certainly be technically feasible in ten years. However, for
many, use reduction would also mean crop reduction or severe dislocation of current cropping
patterns. ™ 6
Sheila Daar qualifies her opinion by stating that 100 percent use reduction could be achieved
for many current uses", and I agree many, but not all. You (R. Rodriguez-Kabana) have
made the statement in support of 100 percent use reduction that "anything is possible" but such
a statement, without context, can be misleading. The reality is that even if research could
deliver new, environmentally acceptable compounds capable of replacing methyl bromide uses
in ten years, the time to commercial development and regulatory approval would almost
certainly exceed that period. Projecting a percent use reduction assumes that the alternatives will
be on line, not in the researcher's laboratory. Therefore, this projection must take into account
non-technical factors.
I cannot project with any degree of accuracy, a quantitative percent use reduction. I will rely
upon the scientists and production agriculture members of our committee to do so Frankly I
think the equation is not answerable at this point. I can only emphasi.se that any figure we '
derive must be put in a broader, practical and regulatory context or hie at best, meaningless and
at worst, totally misleading to the decision-making body.
Opinion submitted by R. Rodriguez-Kabana
The chairman's opinion as stated to the subcommittee at Bordeaux - anything is possible given
years, clean nursery stock, and unlimited research funds - new compounds as effective as
methyl bromide and environmentally acceptable can be developed. This together with existing
alternatives could produce a 100% reduction in the use of methyl bromide in most areas
However, in the chairman's experience of more than 30 years within the United States
agncultural research establishment, it is unrealistic to think that unlimited research funds will be
available. To have unlimited funds to research everything possible would require time and the
political will and decision shown by The Netherlands' government in that nation's successful
methyl bromide replacement program.
If funds available for research continue as they are at present, then no more than 20 - 40%
reduction in usage rate can be achieved within a ten-year period in countries with current
efficient (20 g nr2) use rates. A doubling or tripling of research investment from present level
could result in up to 50 - 80% reduction. To attain 90 -100 % reduction will require a world-
wide effort involving investments in the order of tens of millions of U.S.A. dollars This is
achievable but again will require levels of political will, consensus, and support from methyl
bromide user nations that are not currently available in most of them. In the United States the
whole issue is moot since methyl bromide is scheduled to be removed within the ten-year
period considered by the subcommittee in its discussion on the subject of use rate reduction.
B. Belgium \
|
Opinion submitted by E. van Wambeke 1
Regarding the actual dosage rate of 90 g nr2, and dealing almost exclusively with greenhouse
soil, and assuming clean nursery material is available and hygienic measures are taken:
1. Without Alternatives*
I
a. Improvement in technology (mulching material and sealing), a methyl bromide reduction
rate of 30% is believed to be achievable.
b. This improvement combined with disease monitoring and subsequent reduction of
application frequency, should lead to a total reduction of 70% of the actual rate.
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2. With Alternatives
Additionally, the inclusion of alternatives (except substrate culture), should lead to a total of
80% reduction.
* Footnotes. \
a. Improved mulching shows the feasibility of 50% dosage reduction. Safety margins press
to 30% dosage reduction.
Frequency is actually every year or every other year and practice showed that 3 or 4 years
is feasible when observing conditions of clean material and hygienic measures.
Alternatives (existing fumigants) proved to be not reliable under Belgian conditions.
£L. Japan
Opinion submitted by T. Kajiwara
The major crops considered were vegetables and specifically cucumber, melon, watermelon,
pepper, strawberry, and tomato which are the most important in the country. Use rate
reductions (in percent) expected in 10 years with alternatives are as follows:
When highly effective methods (including biological control, effective use of
chloropicrin, and other materials) to control Fusarium wilt, Phytophthbra rot and
Verticillium wilt are developed ...4U/o
b.
c.
1.
2.
3.
When effective attenuated viruses to each strain of TMV are established and
complete control methods (including use of dazomet and other chemicals) to
nematodes are developed • iu/0
When herbicides which can be used safely during crop growing season are
developed 10%
E» The Netherlands
Opinion submitted byJ.A. van Haasteren
100% replacement of methyl bromide was attained in The Netherlands. In crops which can be
grown on substrates (i.e. flowers, peppers, forestry and tobacco nurseries, strawberries,
cucurbits, tomatoes) 100% replacement is possible within 5 years.
E* Israel
Opinion submitted by J. Katan
Reducing dosages of methyl bromide by combining with other methods of control In certain
cases methyl bromide can be combined with other methods of control (chemical or
cases,' 5™?1 e g solarisation), thus resulting in effective control while reducing dosages.
'toll, such a combination may result in a 50% reduction in methyl bromide dosage.
don can be applied either simultaneously or in alternation. The following
awe 4 17) £e fibres whh low and high range of dosage reduction which may be attainable
by me year 2004 given alternatives and the conditions given in the table s footnotes.
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Table 4.1.7 Dosage reduction in 10 years
Percent dosage reduction by 2004fl>^
Low range
High range
High rate fumigation
(90 g m-2)
Low rate fumigation
(20 g m-2)
40
30
60
40
a Using all available means, including nonpermeable mulches, improved application and
nonchemical and chemical alternatives, alone or combined with methyl bromide at reduced
dosage.
* Based on the use of pest-free propagation material and on the present knowledge.
£4 Zimbabwe I
Opinion submitted by B. Blair
When MBTOC visited Zimbabwe in July 1993, they received a hand-out from J.A. Shepherd
(nematologist, Tobacco Research Board) with regard to use of methyl bromide in tobacco
seedbeds. In this he has the following to say about the consequences of withdrawal of methyl
bromide.
EDB plus burning of brushwood or corn cobs has given excellent results,, but we are reluctant
to recommend this on a wide scale because of environmental concerns. Dazomet, metham-
sodium and 1,3-D + MITC are not as reliable as methyl bromide, but can be used and results
will improve with further knowledge. The wider use of rootknot nematode-resistant grasses in
rotations in the field and seedbeds, and also the greater use of Meloidogyne javanica-rc^vsXaxA
tobacco cultivars will lessen the necessity for perfect control of nemaiodes in the seedbeds,
though the problems of disease, weed and insect control will remain. The effective use of the
fungus Trichoderma harzianum to control Rhizoctonia solani and Fusarium solani in seedbeds
is dependent on reducing competing fungi; this is most easily done with methyl bromide
fumigation. Though withdrawal of methyl bromide would be very disruptive, we believe that
many of the problems can be overcome with time.
In my opinion, we could immediately reduce usage of methyl bromide by about 30% (presently
recommended at 50 g/m2 under a 150 nm thick polythene sheet for 48 hours) by using less
permeable sheets. With the reasons given above, it is possible that there could be up to 100%
reduction in methyl bromide use after about 10 years; this does not take into account increased
costs. From our work on dazomet (past and recent), we are now thinking of a combination
treatment with EDB to give us the spectrum of control required (EDB use is presently permitted
in Zimbabwe, as it does not contaminate groundwater there).
Taking my points above into account, and those that were expressed in Bordeaux, I would
suggest that the low range could be 10 - 30% (in next 5 years), and the high range could be
50- 100% (> 5 years).
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4.2 Alternatives for treatment of durables
Executive Summary
Durable commodities are commodities of low moisture content which, typically, are stable in
storage over long periods. Durable commodities currently treated with methyl bromide include
a wide variety of dry foodstuffs; principally cereal grains, oilseeds and legumes, grain
products, dried fruit and nuts; timber and timber-containing products; and various artefacts.
Insect and mite pests can breed on these materials during storage. Pests may also be present at
time of harvest, and persist in storage or during transportation.
Control of pests infesting durables is essential to keep commodity losses to a minimum, to
maintain quality and prevent damage, and prevent the spread of pests between countries.
Fumigation is a very effective method of controlling pests. Methyl bromide and phosphine are
the two fumigants which are currently used for this. Methyl bromide is able to provide rapid
and complete control of pests, mostly within 24 hours of exposure, at a minimum temperature
of 5°C. There are no reports of development of pest resistance in over 60 years of its use.
Methyl bromide is usually the fumigant of choice for quarantine treatments, particularly against
khapra beetle and wood-destroying insects.
It is estimated that approximately 13% of the annual world non-feedstock usage (1992) of
methyl bromide is for.the disinfestation of durable commodities. Some economically important
industries have adopted methyl bromide fumigation as their principal means of pest control.
These include the dried fruit and nut industry (1990 - 93 yearly average value in excess of $US
10 billion), export/import trade in unsawn timber and storage of bagged food grain stocks in
some countries. Additionally, some countries fumigate substantial quantities of grain with
methyl bromide on import or export to meet phytosanitary requirements (e.g. Japan, 14.6 Mt in
1992). '
There are existing or potential alternatives for most uses of methyl bromide on durable
commodities. However, there are no direct in-kind replacements for methyl bromide and all
alternatives require some changes in practice. Although there are several potential alternatives,
only phosphine is extensively in use, principally for cereals and legumes. There are technical
barriers to extend its use further. Insect resistance is an emerging problem with this fumigant,
particularly in developing countries. Phosphine requires a long exposure period (5-15 days)
and usually temperatures >15°C, for effective action. With further investigation, it may be
possible to extend the use of phosphine into some other areas where methyl bromide is
currently used, but complete substitution by phosphine is very unlikely. For example, methyl
bromide is currently used to control phosphine-resistant insects.
There are several other fumigants which may have some restricted potential as alternatives for
methyl bromide. Hydrogen cyanide was widely used at one time for treatment of durable
commodities, but was superseded by methyl bromide because it was both safer and more
efficacious. Registration has lapsed in most countries. Ethyl formate is in use in some
countries for disinfestation of packed dried fruit Carbon bisulphide was once widely used but
has been discontinued in most countries. Ethylene oxide as a fumigant for food has been
withdrawn in most countries because of the production of carcinogenic residues.
Controlled and modified atmospheres provide a potential alternative to conventional fumigation
if time (2 - 6 weeks) and temperature (30 - 10°C) permit This technique is most likely to be
used selectively in countries with warmer climates. The capital cost to implement a controlled
or modified atmosphere disinfestation treatment in addition to the operational costs in some
cases will render this alternative unviable.
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Two potential new fumigants for durables are carbonyl sulphide and methyl isothiocyanate. As
sufficient data are not available, neither compound is registered as a furnigant. However,
registration and re-registration of any chemical compound as a fumigani: is likely to be a very
costly exercise because of the need to obtain extensive efficacy and toxicity data, and will also
require a minimum of 5 years to complete the process.
Contact insecticides are used extensively in certain situations to protect raw durable
commodities. Contact insecticides include synthetic chemicals, inert dusts, insect growth
regulators and plant extracts or their analogues. Various compounds are selectively effective in
controlling different insect species. One of the main constraints associated with contact
insecticides is chemical residues in treated commodities. This normally prevents their use on
processed products. Resistance is also a major problem. Although many of these are registered
for use on durable commodities, the high cost of registration is a constraint to develop new
products.
Physical methods of insect control, including cold, heat and irradiation treatments, offer further
potential as non-chemical alternatives, although difficulties exist in the practical implementation
of these methods.
Biological methods of insect control, including the use of pheromone arid microbiological
control agents are at an early stage of investigation. Their widespread use as control measures
are not expected in the near future.
Developing countries may have difficulties in the transfer of technologies to reduce or replace
the use of methyl bromide. To introduce technology for the use of new treatments may be both
time consuming and costly. Other issues include the maintenance and servicing of complex
equipment.
Introduction of better sealing techniques to improve furnigant retention should permit the
lowering of dosage rates and subsequent emission of gas to the atmosphere. The use of methyl
bromide and insecticides in durables can be reduced substantially by the: introduction of
Integrated Pest Management (IPM) systems. This will require improvements in design of
storage structures. Proper training will be required to successfully introduce such an IPM
system, and will require consistent maintenance in order to succeed.
Research priorities for replacement of methyl bromide include:
• development of physical control methods that are rapid, and have little or no effect on the
commodities;
i
• further development of IPM strategies;
• prompt evaluation of new fumigants and other alternatives, coupled with speedy
registration procedures to enable early adoption;
• development of methods to reduce emissions from methyl bromide fumigations,
including recovery and/or recycling techniques.
4.2.1
Introduction
Durables are commodities with a low moisture content that, in the absence of pest attack, can be
stored easily for long periods. Most durable commodities currently treated with MeBr are
foodstuffs that are stored post-harvest, before being consumed, processed or transported in or
out of a country .between harvests, and sometimes for even longer periods. Pest control in
durables is usually to prevent damage to the commodity. Many pests can survive and proliferate
on durables in storage. The risk of introducing and spreading infestation, either of field pests
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on the commodity or storage pests during the usual movement of commodities in trade, is a
major reason for treatment of durables.
Generally, the commodities classified as durables have less than 15% moisture content They
include:
Artefacts, including bamboo ware, museum and cultural artefacts
Beverage crops, including cocoa, coffee and tea
Cereal grains, e.g. wheat, rye, barley, rice, sorghum, maize
Dried fish, meat and derived meals
Dried fruit and nuts
Grain products, including flour, noodles, semolina
Herbs and spices
Pulses, including peas, beans and lentils
Seeds, for planting
Tobacco (post-harvest)
Unsawn timber and timber products
Fumigation is the principal means, globally, of disinfesting durable commodities in trade and in
storage. The technique has been in use for many years. Methyl bromide is one of the most
widely used of a diminishing range of fumigants available (Banks, 1994). To the knowledge of
this Committee, there are no uses of methyl bromide for durable commodities without existing
or potential alternatives. However, there are a number of constraints which must be considered.
These are discussed below.
4.2.2 Existing uses of methyl bromide
Methyl bromide has been in widespread use as a fumigant for foodstuffs and other stored
products for more than fifty years. As a result of its high toxicity to insects, exceptionally good
powers of penetration and superior handling characteristics, it largely replaced hydrogen
cyanide and ethylene oxide in many types of application. In addition, it has been successfully
utilised in the treatment of products in circumstances which were considered at one time not
suited for fumigation.
Currently, of the estimated 98551 of methyl bromide used on durables (MBTOC estimates,
Table 3.1), it is estimated that 47821 (49%) are used on unsawn timber (logs); 4721 (5%) on
dried fruit and nuts, and the remainder 46011 (47%) used mainly on cereal grain and legumes
with minor uses on other commodities, as listed above. In the absence of better figures,
estimates of dried fruit and nut usage were based on the assumption that the 1991 use of methyl
bromide in the state of California, USA of 1891 was 40% of 1992 global usage.
Methyl bromide has a rapid action on pests, with treatments of durables completed in a few
days and, in many cases, less than 24h. The treatment time includes both the actual exposure
period to the fumigant, and also times at the start when the fumigant is distributed or disperses
through the enclosure and, at the end of the exposure, when residual gas is aired off. This
speed of action makes methyl bromide fumigation a particularly convenient treatment where the
commodity cannot be held for long periods for logistic reasons, such as at ports during import
and export.
Methyl bromide is supplied as a liquid under pressure in steel cylinders and cans of various
capacities. During application, liquid methyl bromide should not come into direct contact with
the commodity, and especially with food materials, as taint, damage and excessive residues
may result. Thus, some form of vaporisation is required. Although several devices have been
developed for this purpose, typically, a coil of copper tubing immersed in hot water is used as a
vaporiser for dosing a large amount of methyl bromide, particularly in temperate climates. The
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liquid methyl bromide is run through the coil prior to introduction into the fumigation
enclosure. ;
For some applications, the liquid is atomised by forcing it through spray nozzles, causing rapid
vaporisation by absorbing heat from the atmosphere. When using disposable cans for small
scale fumigation, the fumigant is normally delivered under its own pressure by a special
puncturing applicator connected to a length of flexible tubing.
There are several manuals describing techniques for treatment of durables with methyl bromide
(e.g. Bond, 1984; Anon., 1989).
Methyl bromide can be regarded as one of the tools used to disinfeist and protect durables from
damage by pests. There are a wide variety of other measures and a large number of publications
which review and describe these measures as part of an integrated system of pest control. Most
of these apply particularly to cereal grain storage, but the principles are applicable to the
protection of durables in general. These publications include Moulton (1988, textbook on
storage of grain, pulses and oilseeds), Sauer (1992, textbook on grain storage), Bond (1984,
textbook on fumigation), Snelson (1987, review on insecticide use on grain), Jayas et al.,
(1994, reviews on techniques of pest control in stored grain) and Highley et al., (1994,
conference proceedings on advances in stored product protection).;
In general, methyl bromide plays a small, but significant, role in the overall disinfestation and
protection of durables. However, its rapid action and reliability have led to its continued use, as
the treatment of choice or as a mandatory treatment, in several important situations. These are:
• treatment of unsawn logs, traded internationally, against insect pests and some fungi;
• disinfestation of bulk grain to phytosanitary or quarantine requirements at point of import
or export;
• quarantine treatments against specific pests, particularly khapra beetle, Trogoderma
granarium, and the house longhorn beetle, Hylotrupes bajidus;
• disinfestation of stacks of bagged grain, particularly in Africia and Singapore, and
including food aid grain at point of import;
• protection and disinfestation of dried vine fruit, and of nuts iia storage and prior to sale;
• disinfestation of museum objects and cultural relics.
In all these cases, though there may be alternative approaches, methyl bromide has a history of
successful use. Hitherto, there has been no reason to change to less well tried measures, or
ones which may involve significant changes to established practice;.
4.2.2.1 Target pests
Most of the target pests of durables that are treated with methyl bromide are insects and, to a
lesser extent, mites. Fungi and nematodes are not typically target organisms, except with
unsawn timber and seeds for planting, respectively. Methyl bromide is sometimes specified for
quarantine purposes for control of other organisms (e.g. ticks, snails) that may become
entrained in durable foodstuffs or timber, but which do not normally infest and damage the
commodity.
Target pests are listed in the individual sections below.
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4.2.2.2 Types of fumigation enclosure
For safety and efficient action, it is necessary to enclose the commodity to be treated with some
form of system, the fumigation enclosure, which restricts loss of gas to a low level.
The most efficient method of fumigating bagged or cased commodities is in chambers equipped
for applying the fumigant in a manner that will ensure its rapid and even distribution, typically,
a recirculation system of some type (Bond, 1984). Fumigation of commodities is also earned
out:
under gas-proof sheets of various thicknesses
in warehouses
in specially sealed transportable plastic enclosures (bubbles)
in freight containers
in silos
in railway box-cars
in barges and ships
in specially designed and equipped vacuum chambers
Many of these applications require some form of recirculation of the atmosphere within the
treated enclosure in order to achieve good and rapid distribution of the added fumigant.
4.2.3 General description of alternatives
There are a large number, and variety, of potential alternatives to methyl bromide for
disinfestation of durable commodities. The optimum choice of alternative is very dependent on
the particular commodity to be treated and the situation in which the treatment is to be carried
out A general description of the 20 alternatives noted by MBTOC is given below, followed by
a description of the alternatives as applicable to particular commodity groups.
4.2.3.1 Fumigants and other gases
4.2.3.1.1. Phosphine
Phosphine is the only fumigant, other than MeBr, whichis widely registered and permitted for
disinfestation of most durable commodities. It ranks as one of the most toxic fumigants known,
but is used at low concentrations. Its action against pests tends to be much slower than methyl
bromide, with long exposures required, particularly under low prevailing temperatures.
Phosphine penetrates well into commodities and can be removed rapidly by aeration after
treatment. It has a low degree of sorption by most commodities and normal fumigation practice
ensures that the residues produced are well below 0.01 g f1, the current Codex Alimentarius
limit for processed cereals.
Phosphine will form an explosive mixture with air when the concentration exceeds 1.8% by
volume, but this level would not be reached in normal fumigation practice. This limit reduces at
reduced pressure and care needs to be taken in designing recirculation and vacuum systems
using phosphine to ensure the limit is not exceeded (Green et a/., 1984).
Phosphine reacts with copper, silver and gold, especially in humid atmospheres, and in some
situations this may preclude its use, e.g. detrimental effects on electrical equipment and
machinery.
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!
The use of phosphine can be restricted by four other important factors:
the commodity temperature should be more than 10°C, preferably more than 15°C;
the exposure period often needs to be prolonged for effective action against all
developmental stages of pests, typically 5 to 15 days, depending on the temperature;
proven and well controlled techniques must be used to avoid the development of
resistance; r
very dry grain (<10% moisture content) may be difficult to fumigate because of
restricted evolution of phosphine from the solid metal phosphide formulations that are
normally used.
The toxicity of phosphine to arthropod pests is well researched and dosage schedules are
available for the common stored product insects and mites (Annex 4.2.1).
The period of exposure has a much more important role than concentration levels in the toxicity
of phosphine. The use of cr-products as a measure of dosage for phosphine is not valid unless
the exposure period [over which it applies is stated. All stages in the life cycle of stored-product
insects have a broadly similar tolerance to methyl bromide (a factor of 3x or so). However
there is a high degree of variation in tolerance to phosphine, with eggs and pupae being much
Sue is ^*6 and adults> Mites m difficult to control ^ Phosphine since the egg
Resistance is an immediate, practical problem and high levels are know to occur in several
species of stored-product beetle pest (Taylor 1989; Price and Mills, 1988). High levels of
resistance have been measured in laboratory tests on field strains collected in several countries,
particularly from parts of Africa and the Indian subcontinent, resulting from frequent use of the
fumigant in conditions of poor gasughtness. There have also been control failures attributable
to this resistance. Resistance to phosphine is manageable provided that the necessary eas
concentration can be maintained for the longer exposure periods required by more tolerant
strains. In leaky situations such as silos, insect control may be carried out by a continuous
13? if VSJKusmg a Peptone-carbon dioxide mixture from a pressurised cylinder
(Winks, 1990). However, for preference, the degree of gastightness of the enclosure can be
improved, e.g. as described for enclosures around stacks of bagged grain in Anon (1989) so
that gas may be retained for a sufficient period. Multiple dosing may?lsoassi?L
There are many publications describing application of phosphine to stored grain and other
durable commodities (e.g. Bond, 1984; Banks, 1986).
Various proprietary formulations of phosphine are available world wide. Most contain
aluminium phosphide or, less commonly, magnesium phosphide, formulated with ammonium
carbamate or urea to lessen the nsk of flammability. Phosphine is generated in situ by the
reaction of atmospheric moisture with the metallic phosphide (Bond, 1984). There is also
limited availability of phosphine in pressurised gas cylinders as a non-flammable 2% mixture in
carbon dioxide, as currently utilised commercially in the SIROFLO® process (Winks, 1989).
4.2.3.1.2. Hydrogen cyanide i
Hydrogen cyanide was previously widely used as a fumigant for durable commodities It has
been largely superseded by methyl bromide and phosphine, both of which are much more
convenient and, in-many cases, more effective to use. Modern instructions for use of HCN are
given in Anon., (1989). These relate particularly to the ASEAN region, but are, in principle
suitable for most tropical countries. '
Hydrogen cyanide availability and registration or re-registration difficulties may prevent
immediate substitution of the gas for particular uses of methyl bromide should these be
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required. Cylinders of liquid hydrogen cyanide are unstable and cannot be stored for long
periods. However, hydrogen cyanide can be developed in situ from sodium cyanide (Anon.,
1989). It is the fumigant of choice, where permitted, against rodents because of its very rapid
action. The Codex Alimentarius approved residue limits for hydrogen cyanide residues in grain
and flour have recently lapsed, due to lack of support.
4.2.3.1.3. Ethyl formate
Ethyl formate was formerly used as a fumigant for grain. Its use is now restricted to use on
dried fruit and processed cereal products, where permitted.
The action of ethyl formate against pests of durable foodstuffs is quite rapid with optimum
exposures of a few hours only, but problems of distribution of this highly sorbed fumigant
usually leads to the need for exposures of several days. Typical dosages on dried vine fruits
are 3 to 6 mL per 15 kg, with action complete within 24h.
4.2.3.1.4. Carbon bisulphide
Carbon bisulphide was formally widely used as a fumigant for bulk and bagged grain, where it
was typically applied as a 'liquid fumigant' in a mixture with carbon tetrachloride or on its
own. In most countries its use has been discontinued and registration has lapsed. However, it
is still used in parts of Australia, where it is applied to farm-stored grain (typical quantities
treated are 50 tonnes). Application to large bulks is restricted by the potential fire hazard of the
material and safe methods for large scale use need to be developed.
4.2.3.1.5. Carbonyl sulphide
This is a gas with insecticidal properties (Banks and Desmarchelier, 1993), but its use as a
fumigant is not currently registered. Its use as a potential replacement for methyl bromide has
recently been patented. However, field evaluations and residue studies are not yet available. It
has good penetration properties with activity against most stored grain pests at about 200 -
600 g h nr3 at 25°C (Desmarchelier, 1994). Development of carbonyl sulphide as a fumigant
for durables, including timber, is being actively pursued.
4.2.3.1.6. Ozone
Apart from the sterilising action of ozone against bacteria and viruses, only limited information
is known about its toxicity to insects and to stored product pests in particular. It shows some
•tential as a fumigant, but will require the normal regulatory approval process to be acceptable
use, if found technically useful.
Activity has been found against Sitophilus oryzae and Oryzaephilus surinamensis (Yoshida,
1975), Tribolium spp. (Erdrnan, 1979) and Ephestia elutella (Mills, 1992).
4.2.3.1.7. Methyl isothiocyanate (MTTQ
MTTC was introduced in 1959 by Schering AG as a soil nematicide under the trade name
Trapex. It kills nematodes, certain soil fungi, soil insects and also has herbicidal qualities.
This compound is being studied as a grain fumigant and protectant (Ducom, 1994).
Preliminary studies of biological efficiency show that MTTC is very active against Sitophilus
granarius (all stages) at a very low cr-product of 8 g h nr3. For optimal results, this compound
has to be very well mixed with the grain.
4.2.3.1.8. Sulphuryl fluoride
This compound has been developed as an effective fumigant, mainly for termite control. It is
applied to residences or other buildings which are covered with gas-proof sheets. It is very
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toxic to all post-embryonic stages of insects (Kenaga, 1957; Bond and Monro, 1961), but the
eggs of many species are very tolerant In laboratory and field tests, sulphuryl fluoride
produces no objectionable colour, odour or corrosive reactions to photographic supplies,
metals, paper, leather, rubbers, plastics, clothes or many other articles fumigated (Gray, 1960).
Methyl bromide affects several of these materials adversely.
Guidelines for use, from the sole U.S.A. producer, specifically state (Dow Chemical
Company, 1963) that: "under no conditions should sulphuryl fluoride be used on raw
agricultural food commodities, or on foods, feed or medicinal products destined for human or
animal consumption or on living plants", as the product is not currently registered on
foodstuffs.
4.2.3.1.9. Ethylene oxide
Ethylene oxide was used extensively for many years to reduce microbial contamination spoilage
and in food commodities such as spices, cocoa beans and some processed foods and was also
used for insect control on grain (Cartox system). From 1980, its use was withdrawn within
the European Community but it is still used in many other parts of the world.
Because of its flammability, ethylene oxide is generally supplied in mixtures with inert diluents
such as CQz or HCFCs. Ethylene oxide reacts with chemical constituents of some food
commodities producing potentially carcinogenic compounds. The detection of the reaction
product, ethylene chlorohydrin, was reported by Wesley et aL, (1965) and ethylene
bromohydrin was found in flour and wheat previously treated with McBr followed by ethylene
oxide (Heuser and Scudmore, 1969).
Where health and environmental regulations permit, ethylene oxide may potentially replace
MeBr in some non-food uses, notably treatment of some artefacts, manuscripts and other
archive and museum materials. However, other approaches such as freezing or inert
atmospheres may be found more appropriate (see Section 4.2.9).
4.2.3.1.10. Controlled and modified atmospheres
Treatment with controlled or modified atmospheres based on carbon diioxide and nitrogen
offers alternatives to fumigations with toxic gases for insect pest control in all durable
commodities. They are ineffective against fungal pests.
Low oxygen atmospheres, typically created by adding nitrogen to a fumigation enclosure,
require that there be a maximum of 1% oxygen for effective action. Carbon dioxide
atmospheres typically are applied at about 60% COj in air. At this level there is about 8%
oxygen present, normally enough to support most stored product pests indefinitely. Cp2 thus
is regarded as having a toxic effect on insect pests (Jay 1971) and not to act just as an inert gas
that reduces the oxygen level to below that supporting life.
The effective use of CO2> for grain storage, was developed principally in Australia and the
USA, although Australia, for preference, currently uses phosphine to treat bulk grain.
However, the knowledge gained is being used for stored rice and other bagged commodities in
some ASEAN countries (Nataredja and Hodges, 1990). Until recently, use of COrbased
atmospheres were preferred over nitrogen-based ones for bulk grain for various technical
reasons. Recent developments in the on-site generation of nitrogen-based atmospheres have
made these atmospheres more competitive in price and convenience (Banks etal., 1991).
Nitrogen-based controlled atmospheres are in commercial use in Australia in an export grain
terminal in bins originally designed and equipped for methyl bromide treatments (Cassells et
aL, 1994).
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Data on exposure times for control are available for many species and stages of stored product
pests under particular sets of conditions (Annis, 1986; Bell and Armitage, 1992). Most species
arc completely controlled by exposures of 2 - 3 weeks at 25 - 30°C. As an extreme case, larvae
of T. granarium in diapause require exposures longer than 17 days at 30°C or less, with CO2
levels at or above 60% in air (Spratt et al, 1985).
Structures for use with controlled or modified atmospheres must be well sealed, if high rates of
gas usage and expense are to be avoided. The sealing level specified for methyl bromide use in
silos in Japan (see Section 3.5.2) is also suitable for either COa- or nitrogen-based CA
systems.
Use of controlled or modified atmospheres may require registration or other regulatory
approval in some countries.
4.2.3.2 Contact insecticides
Unlike fumigants, contact insecticides may provide persistent protection against reinfestation.
These chemicals can be applied either directly to grain for protection against insect pests, or to
storage buildings and to transport vehicles in order to reduce the likelihood of cross-infestation
or re-infestation of commodities. They are not normally registered for use on processed
commodities.
Generally, fumigants, such as methyl bromide, have a somewhat different action on pests and
role in stored product protection to contact insecticides. Differences, when used on stored
grain, are summarised in Table 4.2.1. Despite these differences, where permitted by market
preference and regulatory authorities, both techniques can result in pest-free end product.
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Table 4.2.1 The basic differences between contact insecticides and fumigants are:
Fumigants
Contact insecticides
No lasting protection
Grain can be treated in situ
Can be used for treating most commodities
Disinfestation can be completed within 1-15
days, according to temperature
Skilled, certified personnel only can apply
fumigants
Effective generally against all insect species
No incidence of substantial methyl bromide
tolerance known, but development of
resistance to phosphine a current concern
Lasting protection possible
Normally grain has to be moved in order to
apply insecticide
In most countries, only permitted on
commodities before processing
Disinfestation achieved over a longer period
since stages of those species which develop
within the grain are not affected until they
develop into adults
Semi-skilled operatqrs can apply contact
insecticides
Various compounds are selectively effective
against different insect species
I
Most insect pests develop resistance to
particular insecticides or groups of
insecticides, with continued use
Good penetration of grain bulks
Poor penetration of grain bulks
4;2.3.2.1. Organophosphorus compounds
£
This is an important group of grain protectants in current use. The stability of deposits on grain
vary widely with particular material and ambient conditions. The rate of degradation increases
both with temperature and water activity (moisture content). Furthermore, toxicity to insects
increases with temperature. In consequence, persistence of the biological effectiveness will
depend upon the insecticide used. For example, typically dichlorvos becomes ineffective within
several days, while malathion takes several weeks, and pyrimiphos methyl many months.
Most are poorly effective against bostrichids (Rhyzopertha dominica and Prostephanus
truncatus).
The principal materials used world-wide include: chlorpyrifos methyl,, dichlorvos, fenitrothion,
malathion, and pyrimiphos methyl. Registrations vary between different countries.
4.2.3.2.2. Synthetic pyrethroids
Synthetic pyrethroids are a group of insecticides with chemical constitution based on that of the
active ingredients of natural pyrethrum. Deposits are quite stable on grain and their insecticidal
activities may persist up to 2 years (Snelson, 1987). Their action is much less sensitive to
temperature thaaorganophosphorus insecticides. Pyrethroids are active against bostrichid
beetles at a much lower dosage than for most other insect pests of durables. Most pyrethroids
are of low acute toxicity to human beings. A disadvantage of these pesticides is their relatively
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high cost. In many situations pyrethroids are added in combination with a synergist, piperpnyl
butoxide, to increase effectiveness and reduce cost.
4.2.3.2.3. Botanicals
These compounds are derived from plants. At present, the only botanical in widespread use in
developed countries for protection of durables (grain) is pyrethrum extract Others, such as
azadirachtin, are under active investigation. A wide variety of botanicals are still used by
subsistence farmers in developing countries.
Botanicals, as natural products, are not readily patented and there is little incentive for
companies, and other organisations, to pay for the lexicological testing required to gain
registration for use.
4.2.3.2.4. Insect growth regulators (IGRs)
The term insect growth regulator (IGR) is used to describe compounds which interfere with the
life-cycle of pests. They are not normally directly toxic to adult pests.
IGRs are considered to be more pest-specific than conventional contact insecticides. One
potential disadvantage of IGRs is their long persistence on foodstuffs. This may limit their use
in some potential applications. The earliest of the IGRs developed were analogues of juvenile
hormones, and include methoprene and hydroprene.
Some IGRs act against insects via ingestion and/or contact (e.g. methoprene), whilst others act
only via ingestion (e.g. diflubenzuron). They tend to have low toxicity to vertebrates (Menn et
al., 1989) and thus to have a substantial margin of safety when used. The major disadvantages
of IGRs are the high cost and inability to control adult stages.
Methoprene has been registered for use in the protection of a variety of stored agricultural
commodities in a number of countries including the USA, Australia and the UK. It is effective
against many stored product pests, including L. serricorne, E. cautella, P. interpunctella,
T. granarium, R. dominica and O. surinamensis, but not against Sitophilus spp. (Snelson,
1987; Mkhize 1986).
Diflubenzuron and fenoxycarb have also been evaluated as a grain protectant but is not yet
registered (Samson et al., 1990).
4.2.3.2.5. Inert dusts
Various of these inert dusts are registered in some countries for treatment of grain and grain
legumes against insect pests. They are particularly useful in dry conditions as a means of
controlling pests resident in storage structures. They lose effectiveness at high relative
humidity, greater than about 75% r.h. (Le Patourel, 1986). Inert dusts may be useful as part of
an integrated system that controls pests to a level where methyl bromide use is not required.
Their use on durables, particularly grain, has recently been reviewed (Banks and Fields, 1994).
Inert dusts, such as those based on diatomaceous earth (e.g. Dryacide® (Desmarchelier and
Dines, 1987)), can provide effective pest control in dry grain. However, though direct
admixture can give long term (some years) protection from infestation and thus avoid need for
fumigation, dusts have adverse effects on the handling qualities of grain and can cause
excessive wear in handling machinery. These factors tend to prevent their use in many large-
scale storage facilities. They have some particular use as admixtures in seed storage and in
small-scale, farmer stores for animal feed.
Inert dusts, such as Dryacide, find particular application as prophylactic sprays to control insect
pests in grain storage structures as part of an integrated control program. They are widely used
for this purpose in Australia.
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There are four basic types of inert dusts:
• Clays, sands and earths. These traditional materials are used as a protective layer on top
of stored seed.
Diatomaceous earth is the fossilised remains of diatoms, microscopic unicellular aquatic
plants that have a fine shell made of amorphous hydrated silica. It consists mainly of
silica with small amounts of other minerals. Proprietary insecticidal formulations are
available. The dusts are effective against a wide range of pests when admixed to grain
even at rates of 1 kg r1 or less.
• Silica aerogels are very light, non-hydroscopic powders effective at: slightly lower doses
than diatomaceous earth formulations.
• Non-silica dusts, such as phosphate and lime. Phosphate has been used in traditional
stores in Egypt (Fam, 1974). ;
Inert dusts such as ash and lime have a long history of use for grain protection (Ebeling, 1971-
Golob and Webley, 1980; Ross, 1981; Quarles, 1992a,b). Dryacide, an activated
diatomaceous earth, is in widespread use in Australia in the grain handling industry (including
rice) using slurry application for structural spray as a prophylactic treatment against storage
pests. There is limited use in Australia as a direct admixture for preserving stock feed and seed
for planting.
Inert dusts can be quite rapid in their lethal action under favourable conditions, with complete
mortality of adult insect pests can be achieved within 7 days at low dosage rates.
Available data on responses of immature stages of grain pests is limited, although the success
of inert dusts in suppressing population growth suggests that they are likely to have a strong
effect on free living immature stages. It is not necessary for insects to be completely covered
with the inert dust for it to be active (Maceljski & Korunic, 1971).
Some inert dusts are accepted as 'organic'. Diatomaceous earths are widely used as food and
processing additives. There are no obvious environmental hazards, but there are concerns
about worker exposure to uncontrolled dust levels.
.
The main advantages of inert dusts are that they do not require capital equipment, are relatively
non-toxic, provide continued protection, and do not affect baking quality (Desmarchelier and
Dines, 1987; Aldryhim, 1990). The main disadvantages are decreased flowability of grain,
visible residues that can affect grading, and decrease the bulk density of grain. They can also
give rise to dust problems in the workspace. To alleviate the dust problem, inert dusts can be
applied as an aqueous slurry for surface treatments, as in Australia, although this can reduce
effectiveness somewhat (Maceljski and Korunic, 1971).
4.2.3.3 Physical control methods
4.2.3.3.1 Cold treatments ,
In general, cold treatments are not used specifically for disinfestation of large batches of
durables, though they may be useful in specific instances, such as small museum objects or
small quantities of cereals where a mild non-chemical disinfestation is required. Under these
circumstances, they can present an alternative to methyl bromide use.
For rapid action, a few days exposure, very low temperatures are needed to ensure
disinfestation (-15°C or below). The rate of cooling to this temperature must be rapid to avoid
acclimation (Chauvin and Vannier, 1991; Fields, 1992).
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Below about 10°C reproduction ceases and infestation of populations of most pests of durables
slowly decline. Evan at 4°C adults of most species survive for many months, though their
immature stages may be killed. Species of tropical origin such as Sitophilus oryzae,
5 zeamcds, Tenebroides mauritanicus and Lasioderma serricorne tend to be cold sensitive,
whereas some important pests including Cryptolestes spp., bruchids, mites and some
Lepidoptera are very tolerant (Armitage, 1987; Lasseran and Fleurat Lessard, 1991; Fields,
1992). In consequence, cooling typically is used to prevent damage and multiplication and
reinvasion of pests rather than as a disinfestant.
4.2.3.3.2 Heat treatment
Heat treatment technologies are notable as one of the very few pest control options for durables
which are capable of matching the speed of treatment afforded by methyl bromide and other
fast-acting fumigants. Commodities need to be heated to temperatures of 50 to 70°C and then
rapidly cooled to avoid damage to heat-sensitive products. The time required is strongly
dependent on the temperature reached and experienced by the target pest. Disinfestation from
stored product pest insects (all stages) can be achieved in less than one minute at about 65°C.
Fluid-bed heating systems for bulk grain have been developed to a commercial prototype stage,
with treatment rates of up to 1501 h-i (Evans et aL, 1983; Thorpe et a/., 1984; Fleurat-Lessard,
1985) Pilot studies have been carried out on the use of rapid heating of grain by microwaves
or radio frequency radiation for the disinfestation of grain (Nelson, 1972; Fleurat-Lessard,
1987). Installation of large scale heat treatment facilities is likely to be capital intensive.
4.2.3.3.3 Irradiation
Irradiation is a potential method of controlling pests in or on a wide variety of durable
commodities. It is already in use commercially in some situations. The process involves the use
of gamma energy, accelerated electrons or X-rays to penetrate the commodity. The
effectiveness of treatment for insect control and effects on food quality, is related to the energy
delivered.
Disinfestation by irradiation has a long history (since 1912) and a sizeable research investment
Brower and Tilton (1985) and Tilton and Brower (1987) summarised the radio-sensitivity data
on forty stored-product pest species, discussed the possible use of irradiation as a quarantine
measure for these species, and discussed irradiation disinfestation of grain and grain products.
These data showed that pests vary in their sensitivity to radiation. Generally, the
developmental stages are more sensitive than adults; females are more sensitive than males and
adults are more easily sterilised than killed. As a group, the beetles are more sensitive than
moths, and fruit flies are more sensitive than beetles. Mites have a range of sensitivity similar to
that of beetles.
The International Consultative Group on Food Irradiation (ICGFI), under the aegis of the
FAO/IAEA Joint Division, has published a provisional guideline for the irradiation of cereal
grains for insect disinfestation as a recommendation to be followed when using the technology
(ICGFI, 1988).
Selection of the type of irradiation equipment to be used depends on whether the commodity is
to be irradiated in packages or in bulk, the quantity of product to be treated and other factors.
Gamma irradiators can treat packaged or bulk products; and accelerators can more effectively
treat bulk products in thin layers (2-5cm thickness).
There are few agreements presently that allow movement of irradiated products in international
trade This is an impediment to the more widespread use of the method and is especially critical
when the irradiation is used to satisfy quarantine requirements. The food industry is concerned
about consumer acceptance of irradiated food products. There are also questions regarding the
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large initial capital expenditure required for plant construction and related logistics (Rhodes,
1986).
Disinfestation of grain, oilseeds, legumes and other dry stored products by irradiation is an
effective technique that may satisfy quarantine needs in particular situations. However, there
are no approved quarantine treatments to date.
4.2.3.3.4 Physical removal (sanitation)
i
Sanitation forms an important part of any normal management of durables in storage. It aims to
reduce the need for pest control, including reducing frequency of, or eliminating the need for
fumigation of methyl bromide, if practised. Sanitation is, in general, the application of a diverse
range of measures designed to remove pests or prevent their access to the product or
commodity. These include cleaning and removal of harbourages for pests, including removal of
food residues in which pests can multiply, and reengineering machinery and buildings. Normal
good warehousing practice, e.g. stock rotation and, where applicable, Insect proof packaging,
are also part of sanitation, as both measures reduce pest population pressure. Other measures
include application of insecticidal sprays to control pest movement :into the stored commodity.
Physical removal, sanitation and packaging as methods to assist pest control in stored grain has
recently been reviewed (Banks and Fields, 1994).
4.2.3.4 Biological methods
Biological methods have potential to provide long-term protection for stored commodities in
specific situations. Use of biological agents to control insect pests i;ti storage situations has
recently received renewed attention. Two types of biologically-based systems are considered
possible:
• from insect predators and parasitoids (classical biological control)
• from microbial pathogens
These biological agents are generally host specific and considered to be primarily preventive
control measures (prophylactic). They are not directly comparable with MeBr fumigation
because of their specificity, except in instances where only a few target pests are prevalent (e.g.
in flour mills). In some cases they have been shown to provide long teirm control and can be
used for space treatments.
4.2.3.4.1. Biological control with predaceous insects or parasitoids
The presence of beneficial predators or parasitoids as opposed to pest species in stored
products has not been addressed by many regulatory agencies. However, the US EPA recently
exempted predators and parasitoids from tolerances on various stored products. Sometimes no
differentiation is made by regulators or the market between predator or pest species, and any
insect is considered a contaminant Such considerations are impediments for introducing
beneficial insects into stored products even if their use is strictly for control without suffering
penalties in product grade. .
The situation may be different with hymenopterous parasitoids of stored-product insects which
are very active and which, because of their very small size, cannot be easily detected in
commodities. The parasitoids live outside bulk of grains and their activity remains on the
surface layer. Consequently, they are active biological control agents mainly for free living
pests. The more effective species are Bracon hebator, a larval parasitoid (Press et a/., 1982;
Brower and Press, 1990; Cline and Press, 1990) and Trichogramma evanescens, an egg
parasitoid (Brower, 1988a, 1988b). The primary target pest species are flour moth larvae or
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eggs and various beetle larvae. Bracon hebator is in use currently in South Africa for reducing
the need for fumigation of stacks of bagged grain (Anon., 1991).
The effectiveness of the warehouse pirate bug, Xylocorisflavipes, has been evaluated in
regulating stored product pest populations (Brower and Mullen, 1990; Brower and Press,
1992). After introduction of large numbers of the pirate bugs in storage premises, the
populations of Tribolium castaneum can be suppressed in a short period of time (Press et aL,
1975; Wen and Brower, 1994).
4.2.3.4.2. Insect pathogens as microbial control agents
Pathogens of insects include bacteria, viruses, protozoa, nematodes, and fungi. Among these,
the bacteria, viruses and protozoa have been most studied for use as control agents for stored
product insects. A number of baculoviruses and numerous strains of Bacillus thuringiensis
(Bt) have been registered in some countries but few have been developed for use on durables.
Bt was produced and tested commercially for durables pests as early as 1927 (Me"talnikov and
' M6talnikov, 1935). Bt is exempt from a tolerance in the USA, but not in other countries, for
use as a stored product protectant Resistance by pests in stored products to Bt has been
observed (McGaughey and Beeman, 1988).
Bt is mass-produced by fermentation processes and is highly standardised as to activity and
safety of each production lot Residual activity against susceptible insects can last for more than
a year (McGaughey, 1986). Regulatory acceptance is needed by many countries for application
of Bt to durables.
Entomopathogenic viruses (primarily baculoviruses) have been extensively studied for the
control of field pests and to a lesser extent for postharvest pests. Approximately eight
baculoviruses have been registered for use, mostly in the United States, Canada and Europe.
Thus far all have been for control of agricultural or forest pests. The granulosis virus of the
Indian meal moth has been the most studied for control of a stored product pest (Hunter et aL,
1973; McGaughey, 1982; Cowan et aL, 1986; Kellen and Hoffmann, 1987). More recently
the process for production and formulation of the virus was patented (Vail, 1991). Other
baculoviruses have been isolated from many of the important lepidopterous pests of durable
commodities (Hunter and Dexel, 1970; Hunter and Hoffmann, 1972) and need to be studied
further as potential control agents.
The protozoan pathogens of insects infesting durables have been studied extensively.
Generally, their action is chronic, not acute. However, their usefulness for population
regulation has been demonstrated (Brooks, 1971). Several have been reported to have very
broad host ranges (Kellen and Lindegren, 1973). Dissemination by the use of pheromone traps
has also been demonstrated (Burkholder and Boush, 1974; Shapas et aL, 1977). To date
protozoan pathogens have not been registered for use on durable commodities. Further studies
need to be conducted on the potential utility of these organisms.
4.2.3.4.3. Pheromones
Pheromones are chemicals that are released into the external environment by insects that elicit a
specific reaction in a receiving individual of the same species.
There is some possibility for insect pest control by manipulation of the chemical
communications which control insect behaviour (Edwards et aL, 1991). Some pheromone
molecules have been chemically characterised and synthesised. Pheromones may be used in an
insect control program in two ways: by population density surveys and direct behavioural
control. Only the latter can be considered as a true control measure. It is based either on
stimulation of behaviour of the pest species (used in mass trapping techniques) or on inhibition
of behaviour, (particularly mating disruption) (Trematera, 1988). Pheromone monitoring
systems have the potential to be used to indicate where action is required, allowing decisions to
be made to avoid treatments, including methyl bromide fumigations, when pest populations are
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147
below damaging levels. As a mating disruption agent it may decrease the reproductive potential
of the target species to a very low level when population density is initially low. If used as a
control measure, registration may be required. The registration procedures for such control
systems for stored commodities are lacking and need clarification.
4.2.4. Alternatives to methyl bromide in stored cereal grains and similar commodities
4.2.4.1 Commodities and pests
A wide variety of stored cereal grains, and grain legumes (pulses), have been treated with
methyl bromide. Examples are given in Table 4.2.2. Products made from cereals and legumes,
including flour, pastas, semolina and compounded animal feed, have also been treated. This
category also includes similar products such as sago and cassava chips. Fumigation of wheat
flour or ground legumes with MeBr is becoming less common, since odours or taint may
develop in bread or other products prepared from those finely-divided commodities.
Oilseeds (e.g. sunflower seeds, soybeans) and oilseed expeller cake are also sometimes treated
with methyl bromide for control of insect and mite pests. These materials absorb methyl
bromide strongly and, generally, other measures are used in preference (e.g. cooling,
processing).
Table 4.2.2 Examples of cereal and legume crops which may be fumigated with methyl
bromide
Common name
Scientific name
Barley
Beans
Buckwheat
Cassava
Lentil
Maize
Millet
Oats
Peanut
Peas
Pigeon pea
Rice
Rye
Sorghum
Soybean
Wheat
Hordeum vulgare
Phaeseolus spp., Vigna spp.
Fagopyrwn sagittatum
Manihot escutenta
Lens culinaris
Zeamais
Pennisetum spp.
Avena sativa
Arachis hypogea
Piswn sativum \
Cajanus spp.
Oryza sativa
Secale cerate
Sorghum bicolor
Glycine max
Triticum aestivum
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Table 4.2.3 Principal pests of cereals and similar commodities
Scientific name
Common name
Acanthoscelides obtectus
Acorns siro
Callosobruckus chinensis
Calhsobruchus maculatus
Caryedon serratus
Corcyra cephalonica
Cryptolestesferrugineus
Ephestia cauteUa
Ephestia elutella
Ephestia kuehniella
Gnatocerus cornutus
Nemapogon granettus
Niptus hololeucus
Oryzaephilus surinamensis
Plodia interpunctella
Ptinusfw
Ptinus tectus
Rhyzopertha dominica
Sitophilus granarius
Sitophilus oryzae
Sitophilus zeamais
Sitotroga cerealella
Stegobium paniceum
Tenebrio molitor
Tenebroides mawetanicus
Tribolium castaneum
Tribolium confusum
Trogoderma granarium
Zabrotes subfasciatus
*
*
*
*
*
*
Dried bean beetle
Flour mite
Cowpea beetle
Cowpea beetle
Groundnut borer
Rice moth
Rust-red grain beetle
Tropical warehouse moth
Tobacco moth
Mediterranean flour moth
Broad homed flour beetle
European grain moth
Yellow spider beetle
Saw-toothed grain beetle
Indian meal moth
White-marked spider beetle
Australian spider beetle
Lesser grain borer
Granary weevil
Rice weevil
Maize weevil
Angoumois grain moth
Drug store beetle
Yellow mealworm
Cadelle
Rust red flour beetle
Confused flour beetle
Khapra beetle
Mexican bean beetle
* Major pests
4.2.4.2 Scope of the problem
Methyl bromide is effective against all stages of stored grain pests (Thompson, 1970). The
degree of susceptibility varies somewhat with developmental stage, with pupal stages of insects
and the egg and hypopal stages of mites usually more tolerant Typical pests and dosage rates
required for control are given in Table 4.2.3 and Annex 4.2.3. Diapausing larvae of the khapra
beetle (Trogoderma granarium) (Bell et al, 1985) and warehouse moth (Ephestia elutella)
(Bell, 1976) are highly tolerant of methyl bromide and dosage/exposure periods increased to
control these species. The dosages also vary with the temperature (Bond, 1975) and the types
of commodity being fumigated (Annex 4.2.4). Psocids (Liposcelis spp.) can be controlled
effectively using MeBr (Pike, 1994). Although formerly used widely, methyl bromide is now
restricted in developed countries largely for grain disinfestation required by quarantine and
official phytosanitary regulations.
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In many countries bulk grain and animal feedstuffs are stored either in silo bins or on floor
storage. In both situations, infested commodities are treated with methyl bromide effectively
by forced air recirculation in a completely closed system (Monro, 1956; Storey, 1967,197 la,
197 Ib). Procedures employing carbon dioxide as a carrier to assist the distribution of MeBr
have also been used (e.g. Calderon and Carmi, 1973).
Bagged grain, rice or legumes can be treated in fumigation chambers, containers or under gas-
proof sheets.
4.2.4.3 Existing substitutes for cereal grain and similar commodities
There are a wide range of processes available for control of pests in stored bulk and bagged
grain. A selection of these can be used in an IPM strategy to reduce or eliminate the need for
methyl bromide treatment where this treatment is used to control infestation prior to shipment,
at import or prior to sale. Most methyl bromide used on grain is used foir this purpose.
Alternative integrated control strategies can be used to protect grain stacks from pest damage,
another major use. The alternatives given below should not be regarded solely as one-for-one
substitutes for methyl bromide use, but as a set of tactics which singly, or in combination, can
be used to achieve this aim.
1
Generally, except for specific circumstances already detailed (Section 4.2.2), methyl bromide is
little used in grain protection in store and trade, as the alternative technologies already provide
an effective solution.
4.2.4.3.1. Phosphine
Phosphine is widely used for treating infestation in bulk and bagged grain and grain products in
many countries. Typically, aluminium phosphide preparations are added to the grain, or placed
on the grain surface or near the product to be fumigated within the fumigation enclosure. These
release phosphine over a period of hours or days on contact with ambient moisture vapour.
This process has superceded use of methyl bromide in many parts of the world. However,
methyl bromide is still used, particularly at point of import or export (e.g. into Japan) or on
stacks of bagged grain (e.g. parts of Africa, Singapore). In the first case,, the. speed of action
and recognised effectiveness against pests of quarantine significance makes methyl bromide the
preferred fumigant compared to phosphine, while, in the second case, methyl bromide use has
been developed into an efficient, effective and reliable system, with no apparent need to change
until hitherto.
Where regulations permit, in-transit fumigation of bulk and bagged grain! on board ship can
replace disinfestation with methyl bromide at point of export. Shipboard in-transit fumigation
with phosphine is now a well developed technology (Leesch el al., 1978; Redlinger, et al.,
1979; Zettler, et al., 1982). It requires ships of appropriate design and stringent safety
precautions (Snelson and Winks, 1981; IMO, 1993). Several grain-exporting countries,
including Canada and Australia, require grain to be free of infestation at ]>omt of export and
thus cannot use the system. However, technically it presents a method where the slow action of
phosphine does not interfere substantially with the flow of trade through export ports and thus
presents a feasible alternative to rapid methyl bromide treatments ashore.
Presently, there is no approved substitute to methyl bromide for treatment of khapra beetle
(Trogoderma granarium) to quarantine standards in grain (and most other durable
commodities) (but see Table 4.2.15). Phosphine is highly effective against all stages of this
noxious pest (Bell et al., 1984,1985), including the normally tolerant diapause larva, provided
a sufficient exposure period can be used (5 -10 days, depending on temperature) and the
temperature is greater than 15°C (as is usual in regions where this pest occurs). Further studies
are required to provide data for approval of phosphine treatments by quarantine authorities.
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Recent developments in phosphine fumigation technology, including use of surface application
in sealed systems and supply of non-flammable phosphine formulations in cylinders at about
2% w/w in CO2 (Winks, 1985; Chakrabarti et al., 1987; Chakrabarti, 1994) have increased the
competitiveness and effectiveness of phosphine use compared with methyl bromide.
Discussion of recent advances in phosphine treatment of grain against infestation can be found
particularly in Navarro and Donahaye (1993) and Highley et al., (1994).
4.2.4.3.2 Controlled atmospheres (CA)
CA treatments based on either nitrogen or CO2 atmospheres provide technical alternatives to
methyl bromide-based disinfestations of bulk or bagged grain provided adequate exposure
periods (often more than 2 weeks) can be arranged logistically.
Controlled atmospheres require well sealed systems if they are to be effective and to avoid
excessive usage of gas to maintain the required atmospheric concentrations of oxygen and or
CQz. Silo bins sealed to a standard suitable for recirculatory fumigation with methyl bromide
are typically suitable for CA use. Application of CA may be constrained by the cost of the COi
or nitrogen required, particularly in developing countries. However, the technology of
generating nitrogen from air on-site is progressing rapidly and cheap, efficient systems can be
expected to be available in the near future. On-site generation of nitrogen and CA treatment has
been successfully dialled in a large grain export terminal in silo bins designed for methyl
bromide treatment (Cassells et al., 1994). It has not yet been adopted as an alternative
commercially.
Because of the slow speed of action compared with methyl bromide, CA is often not regarded
as a potential substitute for its use. However, if CA is regarded as a tool in an integrated
protection system it may be suitable. Under Australian conditions, where a high level of pest
control is achieved prior to moving grain to the export terminal, CA systems may then be used
to maintain grain pest-free there until exported. One terminal recently adopted this strategy in
part of the facility converting a series of silo bins, including two equipped for methyl bromide
fumigation to nitrogen-based CA use (Cassells et al., 1994).
CQz-based CA systems are used on a large scale in Indonesia for long term storage of bagged
milled rice stocks (Nataredja and Hodges, 1990). This system replaced a strategy of frequent
methyl bromide fumigation and appears technically suitable for this wherever bagged grain is
stored in warehouses long term and CC<2 is available at reasonable cost.
4.2.4.3.3 Grain protectants
Grain protectants, typically organophosphate and pyrethroid insecticides and IGRs, do not
readily penetrate bagged or bulk grain. This restricts their utility substantially as normally they
must be applied to the grain during handling, e.g. prior to bagging or on to grain on conveyors
or elevators. They are also used as sprays on storage structures and the surfaces of bagged or
bulk grain as part of a sanitation program.
The use of grain protectants varies widely with country, market preference and local
regulations. Where permitted, and where pest resistance is not a problem, they can provide a
useful means of avoiding the circumstances where fumigation, including methyl bromide, may
be otherwise used.
Dichlorvos is unique amongst the commonly used grain protectants in its rapid action against
pests and lability on grain. In the absence of resistance and, where approved, it can be sprayed
onto bulk grain within a few days of export to disinfest a cargo. Subject to an adequate
withholding period for the residues to decay to acceptable levels, such a treatment can provide a
direct alternative to dismfestation with methyl bromide.
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While dichlorvos is currently approved under the Codex Alimentarius for application to raw
cereal grains with a maximum residue level of 2 g r1, the registration is subject to debate in
some countries and its long term future use is not assured.
Inert dusts (e.g. diatomaceous earth formulations) can provide direct alternative to chemical
protectants where their adverse effects on grain characteristics and handling are acceptable. In
particular, they provide good protection against insect infestation in dry grain stored long term
for animal feed. They form a useful part of IPM strategies for grain protection in sprays applied
to the storage fabric to minimise residual infestation and migration of pests into the bulks of
stored grain. For further detail see Section 4.2.3.2.5.
4.2.4.3.4. Physical control methods
4.2.4.3.4.1. Gamma ray or accelerated electron irradiation \
Irradiation of grain, cereals and milled products is effective; little or no further research is
required (Brower and Tilton, 1985). It has been demonstrated to be effective at all temperatures
with either bulk or packaged commodities. Like methyl bromide treatment, irradiation does not
confer residual protection against pests, so irradiated products are susceptible to reinfestation.
Although irradiation is accepted by many regulatory authorities, then; an; perceived consumer
acceptance problems. Irradiation facilities require a capital investment that is considered to be
high; the need for large, central facilities may require logistical changes. Irradiation may not
immediately kill all life stages of pests, although after irradiation at sjpecified dosages all living
pests should be sterile. Since irradiation will stop germination of grains and seeds, it is not
suitable for commodities requiring germination such as malting barley or mung beans for
sprouting. Thus far, irradiation has not been accepted as a quarantine treatment for grains.
A full-scale commercial irradiator for bulk grain has been built at the port of Odessa, Ukraine
(Zakladnoi et al., 1982). This had two accelerated electron units each wilh a capacity to treat
2001 h"1, directly replacing the potential need for methyl bromide fumigation as a rapid
disinfestation system. It is reported no longer to be in operation.
A case-study for rice irradiation in Indonesia is attached (Case history 4.2.1).
4.2.4.3.4.2. Heat treatment
Heat treatment is a process which can give complete mortality of insects in grain. It is the very
few processes, considered here, with the potential to meet the treatment speeds afforded by
methyl bromide fumigation. The process still requires development for large scale use. There
are currently no installations which meet the typical handling speeds of large modem grain
terminals, often 5001 h'1 or more on one belt, but a prototype fluid bed system has been built
and successfully run at 1501 h'1 (Sutherland et al., 1987).
Pilot and laboratory studies, reviewed by Sutherland et. al. (1987) and Hanks and Fields
(1994), have typically used heated air at 90°C, or greater, as a heat transfer medium into the
grain with the objective of heating the grain briefly to above 65°C. Other heat sources, such as
microwaves, infra-red or radio-frequency irradiation can also be used (Boulanger et al., 1969;
Banks and Fields, 1994), but these have not yet been shown to be superior in practice to hot
air-based systems.
Under good process control there is no damage to the end use qualities of treated cereals at
levels of heating required to eliminate insect pests. These include breadmaking quality of
wheat, rice quality and malting quality of barley (Fleurat-Lessaid, 1985; Sutherland et al.,
1987). However, the margin of error is small and only slightly excessive treatment can cause
some adverse effects (Fleurat-Lessard and Fuzeau, 1991).
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152
Heat disinfcstation is one of the very few potential alternatives for disinfestation of bulk grain
from live snails (Cernuella and CoMicella spp.) (Cassells el al, 1994). Current
recommendations against these quarantine pests involve high dosages of methyl bromide
(Bond, 1984).
All common stored grain insect pests can be controlled in grain exposed for one week to
temperatures lower than -18°C. This type of treatment is preventatively used for the
disinfestation of high value grain, such as organically-grown rice, in some developed
countries. This technique is efficient but only practicable for small quantities in batches.
4.2.4.3.4.3. Cold treatments
Cooling of grain with aeration is in widespread use in temperate climates. Aeration is a part of
many pest management programs and plays a most important role in preventive control
measures at a cost sometimes competitive with curative disinfestation processes such as
fumigation with methyl bromide (Armitage et al., 1991).
The use of moderately low temperatures to control infestations by storage pests has long been
recommended (Burgess and Burrell, 1964; Navarro et al., 1990). Recent developments have
shown that many grain bulks in temperate climates can be cooled even in summer during the
night with ambient air aeration (Armitage, 1987; Lasseran and Fleurat-Lessard, 1991; Berhaut
and Lasseran, 1986). Cooling grain during winter to reach a temperature level below 5°C can
give a high mortality of stored product pests if kept under these conditions for at least four
months. However, some adult pests may still survive. Each store must be equipped with
appropriate ventilation ducts and ports with fans controlled to give optimum cooling
performance for particular ambient conditions.
Where ambient conditions are unfavourable for normal aeration, with high temperature or
humidity, air dehumidified and chilled using a refrigeration unit may be used for the aeration.
Many grain silos in the Mediterranean and subtropical regions use this process (Brunner,
1986). The temperature of the grain soon after harvest is reduced in a few days below the
development temperature threshold of the main insect pests. This process can be part of an
overall pest management strategy which does not include the need for fumigation with methyl
bromide. A single refrigeration unit is used for several bins in a silo system, each bin being
refrigerated in turn for a few days. The equipment is energy consuming and can be expensive.
4.2.4.3.5. Biological control methods
4.2.4.3.5.1. Biological control with predaceous insects or parasites
This is not regarded as a replacement for methyl bromide, but potentially as part of an IPM
strategy reducing dependance on methyl bromide.
4.2.4.3.5.2. Insect pathogens of microbial origin
Bacillus thuringiensis (Bt) provides control of almond moth and Indian meal moth when
applied to grain as an aqueous suspension or as a dust. It is effective as a bulk treatment where
all grain is treated or when several inches below the surface layer is treated, lepidopterous
larvae are usually living on the bulk-grain surface or near the surface. Potentially, Bt and other
pathogens can form part of an IPM strategy.
4.2.4.3.5.3. Pheromones
Use of pheromones has not been developed as an effective means of general control for insect
pests of cereals. They appear more suited as tools within an IPM strategy for the early detection
of insect infestations. Nevertheless, when insect populations are low, mass-trapping with
pheromones (Trematerra, 1991) can effectively limit multiplication of moth pests of grain, and
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possibly maintain the population under the economic threshold (Fleurat-Lessard, 1986;
Trematerra, 1988; Burkholder, 1985).
4.2.5.
Substitutes in dried fruit and nuts
4.2.5.1 Definition of commodities and pests
Two groups of commodities are described in this section - nuts and dried fruits - both of which
possess diverse physical and chemical characteristics. These commodities may be stored for
extended periods of time, both before and after processing. They may be tx>th domestic and
foreign in origin, and quarantine treatments may be necessary in some cases. The alternatives
to methyl bromide are likely to be more insect and commodity specific than current practices.
They are also likely to be more expensive and require higher technological input Overall,
substitution of methyl bromide, currently the dominant means of disinfestation of dried fruit
and nuts worldwide, is likely to need an IPM approach using a variety of imethods of pest
control together to achieve the same goal: pest free and undamaged product at point of export or
sale.
Commodities in this category, at least sometimes treated with methyl bromide and associated
target pests, are given in Tables 4.2.4 and 4.2.5.
Table 4.2.4 Varieties of nuts and fruits sometimes treated with methyl bromide
Common name
Scientific name
Nut Varieties
Almond
Beechnut
Betel nut
Brazil nut
Butternut
Cashew
Chestnut
Coconut
Cola-nut
Hazelnut (filbert)
Hickory nut
Macadamia nut
Pecan
Pinenuts
Pistachio
Walnuts
Prunus amygdalus
Fagus spp.
Areca catechu
Bertholletia excelsa
Juglans cinera
Anacardium occidentals
Costarica spp.
Cocos nucifera
Cola acuminata i
Corylus spp.
Carya spp.
Macadamia tenuifolia
Carya illinoensis
Pinus spp.
Pistacia vera
Juglans spp.
-------
Dried Fruits
Apple
Apricot
Banana
Blueberry
Cherries
Cranberry
Date
Fig
Mango
Papaya
Peach, nectarine
Pear
Pineapple
Prune
Raspberry
Sultanas, currants and raisins
Tomato
154
Malus spp.
Prunus artneniaca
Musa spp.
Vaccinium spp.
Prunus cerasus
Vaccinium macrocarpon
Phoenix dactylifera
Ficus carica
Mangifera indica
Carica papaya
Prunus persica
Pyrus spp.
Ananas comosus
Prunus domestica
Rubus idaeus
Vitis spp.
Lycopersicon esculentum
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155
Table 4.2.5 Target pests of dried fruits and nuts
Scientific name
Common name
Host*
Acarus siro
Alphitobius laevigatus
Amyelois transitella
Anarsia lineatella
Araecerusfasciculatus
CadrafigulMla
Carpoglyphus lactis
Carpophilus spp.
Cryptolestesferrugineus
Cryptolestes pusillus
Curculio carvae
Curculio nasicus
Cydia caryana
Cydia pomonella
Dermaptera
Dermestidae
Drosophila spp.
Ephestia cautella
Ephestia elutella
Forficida auricularia
Formicidae
Lasioderma serricorne
Oryzaephilus mercator
Oryzaephilus surinamensis
Plodia interpunctella
Spectrobate ceratoniae
Stegobium paniceum
Tephritidae
Tribolium castaneum
Tribolium confuswn
Trogoderma granarium
Typhaea stercorea
Vitula edmandsae serratilinella
*
*
Flour mite
Black fungus beetle
Navel orange worm
Peach twig borer
Coffee bean weevil
Raisin moth
Dried fruit mite
Dried fruit beetles
Rust red flour beetle
Flat grain beetle
Pecan weevil
Curculio
Hickory shuckworm
Codling moth
Earwigs
Dermestids
Vinegar flies
Almond moth
Warehouse moth, tobacco moth
Common earwig
Ants
Cigarette beetle
Merchant grain beetle
Saw-toothed grain beeiie
Indian meal moth
Carob moth ;
Drugstore beetle
Fruit flies
Red flour beetle
Confused flour beetle
Khapra beetle
Hairy fungus beetle
Dried fruit moth
F
N
F, N
F, N .
F
F, N
F
F, N
N
N
N
N
N
F, N
F
N
F
F, N
F, N
F
F, N
F, N
F, N
F, N
F, N
F
N
F,N
N
F, N
F, N
F
F
a F = principally dried fruit pest, N = principally pest of nuts
*Major pests
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156
4.2.5.2 Scope of the problem
Pests of dried fruits and nuts can be found any time after harvest and until eventual
consumption. These pest problems occur internationally, but there may be some pest species of
importance only regionally.
Some of the pests originate in the field and do not persist and reproduce in storage (e.g. codling
moth, Dandekar, 1989), while others are the stored product pests (e.g. saw-toothed grain
beetle) which may attack a wide range of commodities apart from dried fruit and nuts (e.g.
grain). The field pests may require treatment to meet quarantine or phytosanitary requirements
of producer or importing countries, while the stored product (storage) pests must be treated in
order to avoid damage to the product as well as sometimes to meet market or regulatory
standards. Reinfestation by storage pests may occur in local and importing country storage,
during transit and subsequently in marketing channels and consumer storage.
Most dried fruits and nuts are harvested over a relatively short period and at the same time -
August to November in the northern hemisphere. Therefore, very large volumes have to be
treated quickly. For instance, receiving stations in the USA can handle 26,000 tons per day of
dried fruits and nuts at the peak of the season. The average yearly world production of only 6
of the 35 listed commodities is approximately 3.3 million metric tons (see Table 4.2.6 below).
Based upon a conservative value of $US 1.43 per kg, the farm value of these 6 commodities is
of the order of $4.8 billion per year. The remaining 29 commodities place the value of the
world production of dried fruits and nuts in excess of $10 billion. Obviously, these high value
commodities require high quality insect control, particularly when value-added costs are
•considered. Currently, most dried fruits and nuts are treated at least once with methyl bromide.
The frequency depends on the time interval in storage prior to processing (over one year, in
some cases) and local conditions. Loss of methyl bromide is predicted to have (Anon., 1993a)
a severe impact on the costs of pest control, as currently used, and secondary or indirect effects
on storage, handling, and processing for both domestic and foreign markets need to be
considered.
Table 4.2.6 World Production of Main Dried Fruits and Nut Crops.
3 Year Average (1990/91 -1992/93)
Commodity
Quantity (t)
Prunes
Raisins, sultanas and currants
Almonds
Walnuts
Hazelnuts
Pistachios
315,498
910,098
526,823
573,928
863,647
153,077
Total
3,343,071
Source: Horticultural Products Review, USDA/FAS, 1993
A recent USDA-sponsored workshop (Anon., 1993c) specifically considered the availability
and technical feasibility of alternatives to methyl bromide. Participants included research and
regulatory personnel as well as key industry representatives. The workshop provided the basis
for some of the recommendations in this section.
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157
Of particular concern were the extended times for application and treatment, and reduced
efficacy of a number of the alternatives. Furthermore, no single alternative has been
demonstrated to provide the complete eradication of insects required for quarantine treatments.
The development of substitute quarantine treatments to replace methyl bromide will require long
term effort, not only for developing efficacy data, but also for gaining regulatory acceptance.
Some commodities may be damaged by the alternatives proposed; thus, the alternatives may be
commodity specific. A systems approach incorporating several alternatives will be required to
provide adequate protection and quarantine security. Considerable engineering and technology
transfer will be required for the alternatives to be economical and in place on a timely basis.
Enclosures can vary from a few cubic meters to more than 30,000 m3 itreating from a few
kilograms to more than 10 million kilograms of commodity. The situation would pose
particular difficulties for Article 5 countries.
4.2.5.3 Existing substitutes
Methyl bromide fumigation is currently the only currently approved treatment for quarantine for
dried fruit and nuts. Irradiation and controlled atmospheres are currently not used to any great
extent for dried fruits/nuts (see advantages/disadvantages of each below).
i
There are a variety of techniques which can potentially be used to control storage pests of dried
fruit and nut pests. An IPM strategy, involving a number of techniqueis, may be required if the
need for methyl bromide treatments is to be reduced substantially.
Dried fruit and nuts have particular quality characteristics which must t>e taken into account
when considering application of technologies developed for pest control. In particular,
sultanas, raisins and currants are susceptible to sugaring when held at low temperatures, and
sultanas may change colour (increased brownness) and lose grade when subject to high
temperatures for extended periods. Other technologies may be beneficial, e.g. nitrogen-based
CA, in controlling rancidity as well as pests in some nuts.
Alternatives to methyl bromide treatments, specifically for dried fruit and nuts, are set out
below.
4.2.5.3.1. Phosphine
This fumigant is used to control stored product pests (Nelson, 1970; Hartsell et aL, 1991). It
is already in use for control of pests of dried vine fruit in storage and IK> further research is
needed. Most pests of dried fruit and nuts are highly susceptible to phosphine and shorter
exposure times can be used than with stored grain. In the latter case, longer periods are needed
to control Sitophilus spp. These do not attack dried fruit or nuts. Advantages include:
registered; efficacious for relevant pests; relatively cost effective; widely accepted; and low
residues. Disadvantages include: fumigation time of 3 to 12 days; off-flavour in some
commodities, e.g. walnuts; not effective under 10°C in dried fruit and nuts; corrosive to copper
and alloys; vacuum fumigation is not recommended because of possible explosion hazard. In
most countries phosphine can be used on dried fruits and nuts, with the exception of walnuts.
Phosphine has not been developed to a level approved for quarantine treatments.
4.2.5.4 Other fumigants and gases
4.2.5.4.1. Hydrogen cyanide ;
Not currently in use on dried fruit and nuts and no longer registered in most countries. Dried
vine fruit tend to absorb hydrogen cyanide with formation of quite stable cyanhydrins.
Advantages: efficacious against stored product pests. Disadvantages: bad public image;
explosive and flammable.
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4.2.5.4.2. Ethyl formate
In use in some countries (e.g. Australia, South Africa) as a fumigant for packaged dried vine
fruit, directly substituting for the need for methyl bromide treatment soon after packing.
Advantages: efficacious against stored products pests; and can penetrate packaging material.
Disadvantages: flammable and explosive; not registered for use in USA and Europe; 72-hour
minimum exposure required for efficacy; corrosive to unpainted metals, especially iron and
steel.
4.2.5.5 Controlled atmospheres
Modification of air space to suffocate insects (low Oa, high CO2 or high N2 or hyperbaric
pressure) requires purging and displacing atmosphere (Soderstrom et al, 1984; Navarro and
Donahaye, 1990). Some research on sealing and efficacy may be required.
Controlled atmospheres (CA) have been used to some extent to replace methyl bromide for
disinfesting dried fruits and nuts. The latest method under development (Reichmuth, 1990),
combines carbon dioxide with high pressure of 20 to 40 bar and controls all stages and species
of pest insects within less than three hours. It requires a gastight chamber which can withstand
pressure of this magnitude and will be capital intensive to install.
Treatment of almonds in silo with CA has been successfully demonstrated under full scale
commercial conditions (Soderstrom et. al, 1984). Use of CC>2 as an alternative to methyl
bromide has been successfully trialled for sultanas in cartons in stacks (Tarr et al., 1994), and
in export freight containers (Banks et al., 1993). Improvements in on-site generation of
nitrogen (Navarro and Donahaye, 1990; Banks et al, 1993) and improved quality retention
under CA may make CA treatments an attractive alternative to methyl bromide. Some
modification of sealing techniques, already developed for stored grain (e.g. Ripp et al, 1984;
Annis and Graver 1990), will be required to suit the dried fruit and nut industries.
Advantages include: absence of residues; proven efficacy; and decreasing cost of nitrogen
production technology. Disadvantages include: need for well-sealed enclosures; often high
capital and operating costs; slow acting, long time period necessary (1 - 2 weeks); temperature
dependent and only slowly effective under 15°C; no residual activity; not accepted for
quarantine; will require retraining on the process and its variables; unless maintenance levels are
used, commodity is immediately susceptible to reinfestation (as is the case with all fumigants).
4.2.5.6 Contact insecticides and inert dusts
Malathion. Advantages include: short-term residue; and history of usage in the grain industry.
Disadvantages include: odour, surface protectant only, no penetration and potential residue and
resistance problems.
Inert dusts. Even though they may be efficacious in controlling insect pests, they are not likely
to be used because of quality and consumer acceptance problems.
Insect growth regulators. These include insect hormones or synthetic analogues capable of
affecting insect growth, development, and reproduction (Mkhize 1986; Samson et al, 1990).
These can be used only as protectants. Advantages include: demonstrated effective as a
protectant of peanuts, rice, and wheat; host specificity; low mammalian toxicity; and long term
protection. Disadvantages include: not approved for food products; not approved for
quarantine; slow acting; and host specificity.
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[
4.2.5.7 Physical methods
4.2.5.7.1. Irradiation
Irradiation of dried fruits and nuts is effective (Kader etaL, 1984; Rhodes, 1986); this
effectiveness has been commercially demonstrated. Irradiation does cause off flavour in
walnuts above 0.9 kGy. Irradiation, as methyl bromide fumigation, does not confer residual
protection on commodities and irradiated products are immediately susceptible to reinfestation.
Irradiation is not temperature dependant and bulk or packaged product can be treated. Although
irradiation is generally accepted by international trade and regulatory agencies, there are
perceived consumer acceptance concerns. High capital costs, logistics and the possible
presence of live but sterile pests have been mentioned as possible problems in application of
this technology. Thus far, irradiation has not been accepted as a quarantine treatment for these
commodities.
4.2.5.7.2. Optimised hot and cold treatments
Both heat and cold treatments have potential as disinfestation procedures for specific dried fruit
and nuts. Both will need to be researched carefully before adoption to determine effects on
quality of the treated product It is already known that low temperature storage of processed
sultanas can lead to sugaring and high temperature storage or treatment of many dried fruit and
nuts can lead to detrimental colour change or rancidity. Heat treatments may be capable of
development for dried fruit and nuts as a rapid alternative to methyl bromide treatment.
Cooling to very low temperatures (-10 to -18°C) is an established system of disinfestation of
dates, replacing methyl bromide treatment. It is most effective when combined with a brief
exposure to low pressure or 2.8% oxygen, which causes insects to leave the centre of the fruit
(Donahaye et al., 1992), making them vulnerable to the cold treatment. 10.5 hour exposure to
-10°C, or 2.25 hour exposure to -18°C, killed all stages of the relevant insect pests (Donahaye
et al., 1991). A similar treatment is increasingly replacing methyl bromide for disinfesting dates
in Israel. The utility of very low temperatures as disinfestants needs to be checked for other
dried fruit and nuts.
Cooling, combined with nitrogen CA treatment in sealed, white-painted silo bins is in use in
Australia for protection and disinfestation of in-shell almonds (Banks, H.J. pers. comm.).
Similar technologies may prove suitable for most bulk stored nuts, under appropriate climatic
conditions giving high quality storage without need for periodic methyl bromide treatments.
Advantages include: no residues; public acceptance; environmentally safe; and worker safe.
Disadvantages include: not currently accepted for quarantine treatment; exjxjsure time may
affect quality; needs uniformity of application; no residual activity, high energy costs; at low
temperatures can cause sugaring of dried fruit.
4.2.5.8 Biological methods •
Further data is needed before biological methods can be confidently applied in dried fruit and
nuts. In particular, information is needed on insect commodity preferences and effect of
commodity and environmental conditions on insect growth and development, survival, and
reproductive capacity (Johnson et al., 1992; Vail et al., 1993a, 1993b). This data should
assist in die evaluation of proposed treatments using microbial pathogens, mating disruption
and classical biological control in the dried fruit and nut industry. It would also assist in
determining the best role of biological methods in an IPM system.
Microbial control involves use of insect-specific pathogens for control. It can be used primarily
for long-term protection after an initial disinfestation treatment (Hunter, 1973; McGaughey,
1986; Cowan et al., 1986; Vail et al., 1991). Advantages include: no chemical residues;
specificity; long term protection; potential to reduce number of chemical treatments required
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Disadvantages include: may be too specific; registration and labelling issues; not readily
available; yet to be accepted by consumer, commodity, and regulatory agencies.
Mating disruption - This control method is based on behaviour modifying chemicals, Le.
pTeromoWto control insect mating and reproduction. Advantages include: host specificity;
es
peromoo con .
compatibility with other methods; worker safe and environmentally safe Disadvantages
indude- used only as protectants, not as an eradication method; not likely to be acceptable for
quarantine use; species specific and probably will control only low populations.
Classical biological control - This involves use of predators and parasitoids for insect control
SSSSwS. 1982; Brower 1988a, 1988b; Cline and Press 1990). This method can be
used primarily as a space treatment when commodity is not present There appears to be a role
for biological control of moth pests, often the main pest of dried fruit and nuts as part of an
IPM program. They are quite susceptible, and several effective predators and parasitoids are
available Advantages include: long-term population suppression; specificity; worker nfe ^and
environmentally safe. Disadvantages include: host specificity; availability; not for quarantine.
quality control; and not compatible with chemicals.
4.2.5.9 Others
4.2.5.9.1. Packaging and containerisation
This involves use of insect-resistant packaging for bulk and consumer packed goods. This
method may be used as a treatment by itself or after other treatment to prevent re-infestation.
Advantages include: unitised packaging could limit infestations and losses; can be used in
combination with controlled atmospheres, irradiation and other technologies; provide protection
in marketing channels and may eliminate need for large storage facilities. Disadvantages
include: problem as to scale; costs; needs to be combined with other technologies; and need for
assurance of low infestations when containerised.
4.2.5.9.2. Detection, sorting, certification
These include methods to reduce or determine infestation levels to reduce or eliminate need for
specific treatments. Advantages include: environmentally benign; reduce need for treatments,
andimproved worker safety. Disadvantages include: requires high technology; unknown
costs; and regulatory acceptance.
4.2.5.9.3. Engineering
Many of the alternatives will require considerable engineering research in order to be applied
efficiently. New methods of application, increased energy efficiency, and sealing me&ods for
existing or new structures will have to be identified or developed Specific facilities ^ need
to be df signed for use of multiple technologies. Advantages include: helpful in maximising the
efficiency of newly developed control procedures. Disadvantages: none identified.
4.2.5.9.4 Genetic engineering
Insertion of specific genetic material into plant genomes (transgenic plant straints) to pwjjje
St control i (Dandlkar 1989; Vail et al, 1991). Advantages include: specificity; no residues,
long-term protection; safe; and no energy requirements. Disadvantages include: consumer
acceptance; regulatory acceptance; cost of development; and specificity.
4.2.5.9.5 Combination of processes - IPM systems
Many of the processes and technologies given above may be better used in combination, rather
tanas a 'stand-alone' measure for pest control. In that form they may provide both an
alternative to methyl bromide use and improved storage. Examples include use of permanent
sheeting over carton stacks of dried vine fruit combined with hygiene and a disinf estauon
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treatment, e.g. COa or phosphine, or use of cooling and CA in a sealed system for nuts. Also,
efficient sorting machines, removing damaged or infested nuts could be used in combination
with sanitation and packaging, and beneficial insects (predators), to give an acceptable level of
control. High efficiency sorting machines may be used together with protectants and/or
physical treatment to provide acceptable control levels. Beneficial insects might be used for
space treatments and sanitation. Further research is required to substantiate and develop DPM
options as alternatives. Advantages include: reduction of need for specific control systems.
Disadvantages include: dependence upon control strategies used; more emphasis on sanitation
and source reduction is assumed in IPM systems; cost and additional training; difficult for
regulatory agencies to monitor; difficult to obtain quarantine approval.
4.2.6. Beverage crops
4.2.6.1 Definition of commodities and pests
Beverage crops include coffee and cocoa beans and tea. Of these, only cocoa beans are
commonly infested in storage, though the coffee bean weevil may cause problems in coffee,
particularly if stored in poor conditions at high humidity. Tea is only infested by insects arising
as cross-contamination from other commodities.
Table 4.2.7 Target pests in beverage crops
Scientific name
Common name
Araecerusfasciculatus
Ahasverus advena
Carpophilus dimidiatus
Corcyra cephalonica
Cryptolestes ferrugineus
Ephestia cautella
Ephestia elutella
Hypothenemus hampei
Lasioderma serricorne
Ptinus tectus
Oryzaephilus mercator
Triboliwn castanewn
Coffee bean weevil
Foreign grain beetle
Dried fruit beetle
Rice moth
Rust-red grain beetle
Tropical warehouse moth
Warehouse (cocoa) moth
Coffee berry l>orer
Cigarette beetle
Australian spider beetle
Merchant grain beetle
Rust red flour beetle
* Major pests
4.2.6.2 Scope of the problem
These high value products are typically produced in developing countries: and shipped to
developed countries that demand a high standard of quality and total absence of infestation by
pests. In many production areas storages are of inadequate quality to protect the commodities
from invasion by pests and the ambient high temperatures and humidities may favour their
rapid multiplication. Infestations can lead to severe economic losses unless effective control
measures are applied. Losses result not only from direct damage and dovmgrading as a result
of pest activity, but also from charges levied by importing countries where compulsory
fumigations may be carried out at point of import, should infestations be detected.
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Cocoa and coffee beans may be shipped either in bag or bulk, while tea tends to be shipped in
ply boxes. Techniques for treatment with methyl bromide, the preferred fumigant by some
exporters and also, frequently, by importers, is applied similarly to when it is used on grain.
Some beverage crops, notably cocoa, have high fat content and tend to build up residues of
inorganic bromide. This can preclude multiple treatments with methyl bromide if residue
tolerances are not to be exceeded.
4.2.6.3 Existing substitutes
4.2.6.3.1. Phosphine
Phosphine is widely used to control insects in beverage commodities (Clifford and Wilson,
1985; Wood and Lass, 1990). It is claimed that in certain circumstances phosphine may taint
cocoa beans. However, there is no firm evidence of such occurrences when the fumigation is
carried out in a well controlled manner according to established procedures. For information
on advantages and disadvantages, see Section 4.2.3.1.1 on general attributes of alternatives.
4.2.6.4 Other fumigants and gases
4.2.6.4.1. Hydrogen cyanide
This can be potentially used on beverage crops as an alternative to methyl bromide, but is not
currently, used for this purpose.
4.2.6.4.2. Controlled and modified atmospheres
For many years, controlled atmospheres have been used to replace methyl bromide for
disinfecting beverage crops. A recent innovation combines carbon dioxide with high pressure
of 20 to 40 bar and controls all stages and species of pest insects in less than three hours. It
requires a gas tight chamber which can withstand pressure of this magnitude. It is currently in
limited use in Germany (Frozel! and Reichmuth, 1990).
4.2.6.5 Contact insecticides
Contact insecticides are not applied directly to these products. However, they may be used as
part of an IPM program to protect bagged products from insect invasion, using surface
application to the bags and the store fabric.
4.2.6.6 Physiqal methods
4.2.6.6.1. Irradiation
In cocoa, a dose of 0.8 kGy caused a 100% mortality of Epkestia cautella, Lasioderma
serricorne, Araecerus fasciculatus, and Tribolium castaneum within five days of irradiation
(Appiah, undated; Amoako-Atta, undated). At that dose, the cocoa beans still met the highest
quality standards, a measurement that includes insect damage. A dose of 0.50 kGy prevented
adult emergence from the irradiated eggs and younger larvae, while doses of 0.10 - 0.25 kGy
eliminated adult survival from the irradiated older larvae and pupae (Manoto et al., 1987;
Appiah et al.t 1981). The process is not in commercial use for cocoa beans.
Herbal teas have been commercially irradiated to eliminate bacterial contamination at a higher
dose than required for disinfestation. While irradiation has not been used commercially to
disinfest cocoa or coffee, the process has been shown in research studies to be effective.
Indonesian researchers recommended a dose higher than 0.40 kGy be used to obtain 100%
mortality of pests infesting coffee within one week (Hoedaya et a/., 1985,1987). Research in
Brazil and the Philippines showed that a dose of 0.50 kGy was sufficient to result in about
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98% mortality of adult coffee bean weevil and prevent adult emergence from irradiated eggs
(Manoto etal, 1987).
4.2.6.6.2. Temperature Control
Heat and cold can potentially be used to control insects in beverage crops in bag or in bulk.
Methods need to be developed and trialled.
4.2.7 Herbs and spices
4.2.7.1 Definition of commodities and pests
The fruits, leaves and other parts of many dried plants are used for medical and food purposes.
Many of these materials are subject to infestation by stored product pests and may be treated
with methyl bromide as one of the measures used for their control.
i
Table 4.2.8 Herbs and spices sometimes disinfested with methyl bromide
Common name
Scientific name
Basil
Bay
Chillies
Cinnamon
Cloves.
Coriander
Fenugreek
Ginger
Marjoram
Mint
Mustardseed
Nutmeg/mace
Oregano
Parsley
Pimento
Rosemary
Saffron
Sage
Sesame
Tarragon
Thyme
Turmeric
Vanilla
Ocimwnbasilium
Laurus nobilis
Capsicum spp.
Cinnamonum zeylanicim
Syzygium aromaticwn
Coriandrum sativwn
Trigonellafeonum-graecum
Zingiber officianale
Origanum marjorana
Mentha spp.
Brassicajuncae
Myristicafragrans
Origanum vulgare
Petrosettnum crispiun
Pimento dioica
Rosemarinus officianaUs
Crocus sativus
Salvia offlcianalis
Sesamum indicum
Artemesia dracunculus
Thymus vulgaris
Curcuma domestica
Vanilla fragrans
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Table 4.2.9 Some target pests in herbs and spices
Scientific name
Common name
Araecerusfasdculatus
Ephestia cautella
Lasioderma serricorne
Necrobia ruftpes
Oryzaephilus spp.
Plodia interpunctella
Stegobium paniceum
Hum spp.
Coffee bean weevil
Rice moth
Cigarette beetle
Copra beetle
Grain beetles
Indian meal moth
Drugstore beetle
Flour beetles
*Major pests
4.2.7.2 Scope of the problem
These high value products are usually grown in tropical regions. They may become infested
prior to harvest, or in store in the country of production. These infestations can lead to severe
economic losses if no control procedures are applied.
Methyl bromide is currently used for insect pest control in a variety of spices and herbs.
Treatments are mostly bagged and baled commodities, either under gas proof sheets in
warehouses, in chambers or in shipping containers. Products may also be fumigated during sea
transit in shipping containers. Dosages of methyl bromide vary between 15 to 30 g nr3, and
exposure periods are in the range of 1 to 2 days. Residue of inorganic bromide can accumulate,
particularly in products with high fat and protein content. Multiple fumigations should therefore
be avoided to ensure permitted residue levels are not exceeded.
Many spices and herbs are produced under conditions where there may be excessive bacterial
contamination for particular markets. Treatments with fumigants other than methyl bromide are
normally used to sterilise herbs and spices. These will normally control pests too.
4.2.7.3 Existing substitutes
4.2.7.3.1. Phosphine
Phosphine is often used to disinfest herbs and spices, particularly where there may be the
possibility of excessive residues with methyl bromide.
4.2.7.4 Other fumigants and gases
4.2.7.4.1. Ethylene oxide
Some countries still allow the use of ethylene oxide for pest control. It is the fumigant of choice
where sterilisation, as well as pest control, is required. This substance has been withdrawn
widely due to its reaction with chloride and bromide in commodities to produce potentially
carcinogenic compounds. Ethylene oxide should not be used on herbs, vegetable seasonings or
spice mixtures that include salt because of formation of these materials. Apart from MeBr,
phosphlne and ethylene oxide, there are no other fumigant gases used for pest control in these
products.
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4.2.7.4.2. Controlled and modified atmospheres
Carbon dioxide or nitrogen-based controlled atmospheres are very useful alternatives for
methyl bromide for pest control in herbs and spices. Since many of the processing factories
already have gas-tight chambers, a change from methyl bromide to controlled atmospheres
might not be too difficult. The main change would be the increase in the treatment period to 2 to
6 weeks depending on the temperature and species of the insect to be controlled. The latest
method (Prozell and Reichmuth, 1990; Reichmuth, 1990) combines carbon dioxide with high
pressure of 20 to 40 bar and controls all stages and species of insects within less than three
hours. It requires a gas-tight chamber which can withstand pressure of this kind and may
require high capital investment
i
4.2.7.5 Contact insecticides
High value products such as herbs and spices are often directly used for human consumption
without any further processing. These are, therefore, not normally treated with any substances
with contact insecticides because of potential problems.
4.2.7.6 Physical control methods i
i
4.2.7.6.1. Irradiation
i
Spices, herbs and vegetable seasonings are commercially irradiated for control of bacterial
contamination in many countries. The dosages necessary for this purpose are higher than those
required for disinfestation from insect pests. (Marcotte, 1994; Jategaonkar and Marcotte 1993-
Katusin-Razem et al., 1985; Saint-Lebe et al., 1985; Urbain, 1986). For most of these
products there ate no significant changes in sensory evaluations as a result of irradiation in the
dose range of 5.0 - 10.0 kGy, sufficient for sterilisation, and thus no adverse effects can be
expected at the much lower dosage required for insect pest control.
4.2.7.6.2. Heat and cold treatments
.
Since herbs and spices contain volatile compounds which are responsible for their identity and
quality, heat treatments are usually avoided. Cooling to a sub-zero temperature may preserve
the quality and can also serve as a control measure against insect pests. Both approaches appear
to be promising as alternatives to methyl bromide for specific products, but require further
research to show they can effect disinfestations while not adversely affecting quality.
4.2.8 Tobacco !
4.2.8.1 Definition of commodities and pests I
Tobacco is a high value commodity which is transported internationally either raw or as
finished products (cigars, cigarettes). In the trade, a nil infestation is generally expected.
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Table 4.2.10 Target pests in tobacco and related products:
Scientific name
Common name
Ephestiaelutella
Gtycyphagus domesticus
Phthorimaea operculella
Lasioderma serricorne
Warehouse moth, tobacco moth
House mite
Potato tuber moth
Cigarette beetle
* Major pests
4.2.8.2 Scope of the problem
Methyl bromide was formerly used to control tobacco pests in many countries (Manzeffi,
1987) Nearly 40% of the 81 organisations from 43 different countries declared that they use
methyl bromide. Even though the treatments are very efficient, they are usually more expensive
than with phosphine. There are indications now that fewer countries are using methyl bromide
for tobacco fumigation in storage, and its use generally is declining for this purpose.
In France, for example, methyl bromide is now little used to control insects during tobacco
storage. Only the harbour unit of Le Havre, under the control of the Plant Protection
Department of the Ministry of Agriculture, fumigate imported tobacco with methyl bromide. In
most countries, methyl bromide is used under vacuum, but, in some cases, it is applied at
atmospheric pressure under gasproof sheets.
The main advantages of methyl bromide are that it can be used at atmospheric pressure or under
vacuum at low temperatures and it kills all development stages of the insects. One disadvantage
(Benezet, 1989) is its adverse effects on the flavour of the tobacco product Methyl bromide
dosage rates vary from 20 to 100 g nr3 depending on conditions, with a 4 h exposure under
vacuum or 72 h at normal atmospheric pressure.
4.2.8.3 Existing substitutes
4.2.8.3.1. Phosphine
In those areas where the ambient temperature is above 15°C, phosphine is predominantly used
globally for tobacco disinfestation. It is used at atmospheric pressure, has excellent penetration
and is effective against all development stages of insects. The rate of use vanes between 1 and
4 g m-3 and the duration of treatment from 5-15 days according to the temperature (Geneve,
1972; Geneve et al, 1986).
4.2.8.4 Contact insecticides
Methoprene, an insect growth regulator, is finding increasing use in stored tobacco against the
principal pest, Lasioderma serricorne, removing the need for methyl bromide (or other)
treatments.
4.2.8.5 Physical control methods
4.2.8.5.1. Irradiation
Irradiation studies on cigarette beetle, Lasioderma serricorne, indicated that a dose in the range
of 0.6 -1.0 kGy can control all developmental stages. A dose of 5.0 kGy had no effect on
nicotine content, volatile oil content, composition or pH of tobacco (Hoedaya et al., 1987).
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4.2.8.5.2. Heat and cold treatment
The lethal effects of a range of exposures of extreme temperature to adults, pupae, four-week-
old larvae, two-week-old larvae and eggs of the cigarette beetle, Laswderma serricorne, have
been investigated (Meyer, 1980). Adults were generally the most susceptible and large larvae
the most resistant stages to both hot and cold temperatures in the laboratory. Pupae were also
very susceptible to cold temperatures. All stages could withstand up to 3 hours at -15°C. At
50°C the lethal exposure for larvae was 3 hours and at 55°C an exposure of 1 hour was lethal.
At the higher temperatures, ranging from 60°C to 70°C, an exposure; of 6 to 15 minutes was
lethal at all stages (Meyer, 1980).
4.2.9 Artefacts
4.2.9.1 Definition of commodities and pests |
Many of the objects held in museums, libraries and similar repositories are subject to attack by
insect pests and, at high humidity, by fungi. Infestable materials include those made of wood,
paper, leather and skins, feathers, natural fibres (particularly wool). Artefacts and similar
objects made of organic materials (e.g. natural history specimens) are also objects of trade
internationally and may carry pests of quarantine significance.
Some of the pests attacking artefacts are listed in Table 4.2.11. •
Table 4.2.11 Some common pests of artefacts made of wood, skin, feathers, wool and
other organic materials
Scientific name
Common name
Anobium punctatum
Anthrenus spp.
Attagenus pellio
Dermestes lardarius
Dermestes maculatus
Dinoderus ntiwtus
Hylotrupes bajulus
Lasioderma serricorne
Lyctus spp.
Stegobium panicewn
Tinea spp.
Tineola bisselliella
Trogoderma granariwn
*
*
Furniture beetle
Carpet.beeties ,
Museum beetle
Larder beetle
Hide beetle
Smaller bamboo shot hole borer
House longhorn beetle
Cigarette beetle
Powder-post beetles
Drugstore beetle
Clothes moths
Clothes moth
Khapra beetle
* Major pests
Pest insects are often hidden deep in the material and can effectively Jind quickly be treated with
fumigants with high penetrability. In some cases heat and cold are us
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If there is a risk that artefacts may harbour a pest of quarantine significance, notably
Trogoderma granarium, many quarantine authorities will impose a mandatory methyl bromide
treatment
4.2.9.2 Scope of the problem
Artefacts can be severely damaged by attack from only one insect. Some artefacts are of
substantial value or may be of irreplaceable cultural significance. Museums are acutely aware of
this fact and try to avoid infestation and damage to then' most valuable and unique objects.
Therefore, many museums have installed a quarantine system which ensures that only insect-
free artefacts are stored. Infested artefacts are fumigated in gas tight chambers, sealed rooms or
under gas proof plastic sheets.
Methyl bromide is typically applied at 24 g nr3 over 24 h at atmospheric pressure or 50 g nr3
for 24 h under vacuum in gastight chambers. About 90% by weight of the applied gas is
estimated to be emitted to the atmosphere (Unger et al., 1992).
4.2.9.3 Existing substitutes
Methyl bromide use on artefacts is now declining in some countries and being replaced by a
choice of alternatives, each with particular advantages and disadvantages. The choices for pest
control on museum artefacts have recently been reviewed (Pinniger, 1991).
4.2.9.3.1. Phosphine
Phosphine is used to fumigate wooden objects, paper and other materials of vegetable origin.
With some materials, e.g. furs, phosphine may be preferred over methyl bromide, because of
the reduced risk of taint Because the gas may adversely effect metals and pigments in paintings
it is rarely used for treating objects of this type. Fumigation with phosphine will require a
longer exposure period than methyl bromide for complete control of insects.
4.2.9.4 Other fumigants and gases
Carbonyl sulphide and ethyl formate may be alternatives to MeBr, but no practical data are
available on their use for this application. Sulphuryl fluoride is widely used to control wood-
destroying insects, but usually not used for artefacts at present Hydrogen cyanide is also used
for pest control in artefacts, with a recommended dosage of 20 g nr3. for 72 hours exposure.
Hydrogen cyanide is in very limited use because of its high solubility in water, low fungicidal
effect and slow desorption, as well as possible reaction with the treated material.
4.2.9.4.1. Controlled/modified atmospheres
Controlled atmospheres are being increasingly used for insect control in artefacts, although
depending on the temperature, treatment may take two to eight weeks in a gas-tight chambers
(Newton, 1993). There is limited but increasing use of controlled atmospheres for artefacts in
Germany (Reichmuth et al., 1992), the UK and possibly elsewhere.
4.2.9.5 Contact insecticides
Contact insecticides, including dichlorvos, may be used as part of pest management strategy in
museums and repositories.
4.2.9.6 Physical methods
4.2.9.6.1. Irradiation
Irradiation has been used to control insect and fungal problems in historical artefacts, art
objects, books and paper archives with good results in France, Czechoslovakia and China.
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Ornamental wood products arc sometimes irradiated commercially againsit pests in Australia
after importation from Indonesia (Marcotte, 1994). The minimum recommended dose for pest
control ranged between 0.50 kGy for pest control to 1.6 kGy and 18 kGy to control fungal
infections (Ramiere, 1982; Fan et al., 1988; Anon., undated).
4.2.9.6.2. Heat and cold treatment
Heat and cold treatment can be used with care to disinfest artefacts provided condensation and
cracks in wood and other sensitive materials can be avoided by appropriate control of moisture.
Exposure to -18°C can give disinfestation of woollen artefacts from clothes moths in a few
days (Brokerhofe/fl/., 1994).
4.2.10 Logs, timber, bark and wood products
Treatment of export logs or at point of import, is a major use of methyl bromide fumigation.
The treatments are typically against quarantine pests and are required by plant quarantine
authorities as a condition of importation.
Methyl bromide has been in use for timber treatment for many years. Its continued successful
use has tended to restrict possible development of alternatives.
Two major classes of pest require control: insects and fungi. There may also be instances
where control of mites, snails and slugs, and/or nematodes, may be needisd. All of these
classes of pest include species declared in some countries as specific objects of quarantine.
4.2.10.1. Insect control
4.2.10.1,1 Definition of commodities and pests
Commodities: Logs, timber and bark products such as particle board, wood chips as well as
wooden products, containers, pallets toys and sports goods all come under either phytosanitary
or quarantine regulations in international trade. Minor uses such as for cotton, packaging
materials used for brassware also require quarantine treatments.
Target pests: Target pests and some wood-based commodities are subject to plant quarantine
regulations and may be specific in each country. In some countries, particle board, wood chips
for pulp and timber for building as well as wooden products such as containers, pallets,
instruments, toys, sport goods and even plywood are subject to plant quarantine. When pests
are found during inspection, the consignments are treated at the port of importation. Some
countries are required to include phytosanitary certificate with export consignments.
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Table 4.2.12 Target insect pests in logs, timber and bark products.
Scientific name
Common name
Acanthocinus
Arixyleborus spp.
Cerambycidea scofytidea
Dentroctonus spp.
Diapus pusillimus
Diapus qmnquespiratus
Gnathotrickus retsus
Gnathorticus sulcatus
Hylastes ater
Ips spp.
Lyctus spp.
Monochamus spp.
Orthotomcus sutwalis
Platypus spp.
Polygraphus subopacits
Rhagium spp.
Scolytus spp.
Tetropium cinnamopterum
Trypodendron tineatum
Urocerus gigas
Xyleborus spp.
Xylotkrips spp.
Pine bark borers
Longhom beetle
Book beetles
Walnut pinhole borer
Ambrosia beetle
Ambrosia beetle
Black pine bark beetle
Bark beetles
Powder-post beetles
Sawyer beetles
Bark beetles
Ambrosia beetles
Bark beetle
Bark beetles
Eastern larch borer
Striped ambrosia beetle
Woodwasp, Sirex
Ambrosia beetles
*Major pests
4.2.10.1.2 Scope of the problem
Treatments of timber may be carried out as part of a routine export system, or they may be
ordered as a result of detection of pests on importation. Principal insect pests are given in
Table 4.2.12.
Treatments are normally carried out for logs, timber and bark materials either under gas-proof
sheets or on board ships. A dose of 32 g nr3 at temperatures of 15°C or over is normally
applied when fumigated under gas-proof sheets of 150 micron thickness for a 24 hour period.
For in-ship fumigation a dose of 48 g rrr3 is recommended for the same period of exposure.
Methyl bromide is absorbed significantly by woody materials and only slowly released at the
end of a fumigation. It is estimated (Annex 3.1) that about 88% of the methyl bromide applied
to logs in ship's holds is released to the atmosphere over a period of 1-2 weeks subsequent to
treatment.
4.2.10.1.3 Existing substitutes
It will be noted that while there are a variety of potential substitutes, research is required to
establish them as satisfactory treatments that meet standards required by quarantine authorities.
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4.2.10.1.3.1. Phosphine
Fumigation of logs using phosphine is effective in controlling bark beetles, wood-wasps,
longhorn beetles and platypodids at a dose of 1.2g nr3 for 72 hours exposure at the
temperature of 15°C or more. This schedule is registered only in the United States. The length
of time required to complete treatments restricts its commercial acceptability.
4.2.10.1.3.2. Sulphuryl fluoride
This is effective against major insect pests of timber, including bark teetles, wood-wasps,
longhorn beetles, powderpost beetles and dry wood termites. It is applied for log disinfestation
and for fumigation of dwellings in the USA. Generally, the dose applied is 64 g nv3 for
16 hours exposure at a temperature of not less than 21°C. Advantages of this gas are that it
penetrates very well, and is very effective against all wood infesting adult insects.
Disadvantages are that it will only control egg stages at very high dosages and is not registered
in many countries. The potential of this chemical needs to be investigated regarding its
suitability for timber treatment for plant quarantine purposes.
4.2.10.1.3.3 Contact insecticides
There is an approved treatment for logs to be kept immersed in water for more than 30 days in
order to control jpests by suffocation. The upper surface of the logs above the water level is
sprayed with an insecticide mixture. In Japan, approximately 14% of the logs imported in 1992
were treated using this technique. In the USA and Japan, dip-diffusion treatment in a solution
of borate is registered.
4.2.10.1.4 Physical control methods
4.2.10.1.4.1. Irradiation
There are very limited published data on the irradiation of timber and itimter products.
However, American researchers have reported that a dose of 6 - 8 kGy will kill the nematode
Bursaphelenchus xyfaphilus, an economic pest of timber (Eicholz et«/., 1990).
4.2.10.1.4.2. Other methods
There are three other methods of treatment available: dry heat, under waterdipping and bark
removal.
Dry heat treatment could be an alternative for very small amount of logs. However, it does not
appear practical for large amounts. Heat treatments (steam or hot water dips) used to control
fungi (Section 4.2.10.2.3.1) will presumably give complete disinfestation from insects, mites
and snails.
Under water dipping treatment of logs for plywood is a necessary process at it improves the
quality of the products. However, it needs broad water area and a long exposure time. There is
an approved treatment for logs to be kept immersed in water for more: than 30 days in order to
control pests. The upper surface of the logs above the water level is sprayed with an insecticide
mixture. In Japan, approximately 14% of the logs imported in 1992 were treated using this
technique, replacing the alternative methyl bromide treatment.
At present, removing bark from logs prior to export is practiced to a very limited extent as a
control measure against pests, particularly bark beetles. Debarking, together with conversion to
sawn timber in country of origin, appears to have potential to reduce meed for methyl bromide
where bark-borne pests are the object of the treatment, including quarantine treatments.
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4.2.10.2. Control of fungi
Methyl bromide is sometimes applied for control of fungi in timber, often as a quarantine
measure. MBTOC did not review this use and alternatives in detail, and will provide further
information at a later date.
4.2.10.2.1 Target pests
Some wood inhabiting fungi which need to be controlled, usually for quarantine purposes, are:
Antroida carbonica
Ceratocystisfagacearum
Gloeophyllum sepiarium
Lentinus lepideus
Lenzites sepiaria
Lenzites trdbea
Postia placenta
Serpula lacrimans
Timber, which is infested by Ceratocystisfagacearum, is usually fumigated with methyl
bromide prior to export to Europe under gas-proof sheets or in chambers at the high rate of
240 g m-3 (Liese and Ruetze, 1985). This fungus is regarded as a particular quarantine
problem in Europe.
4.2.10.2.2. Contact fungicides (Wood preservatives')
These are effective against surface-living fungi but will not penetrate deep into the wood to kill
the spores. Research is necessary to investigate their combined effectiveness with heat and/or
fumigation.
4.2.10.2.2.1. Bifluorides
The timber is immersed in a 10% solution of the chemical for 5 to 10 minutes. No monitoring
equipment required. Temperatures must be above freezing. The treatment is not registered in
the USA, but is acceptable in many European countries. It is a relatively inexpensive treatment
Bifluorides are commercially used in Europe and are a component of some preservatives used
in the USA. Overall assessment of die alternative in relation with MeBn a very effective
treatment but not approved in all countries.
4.2.10.2.3 Physical control methods
4.2.10.2.3.1. Heat treatment
Steam heat or hot water dips are generally most suitable, but kiln drying or dry heat is suitable
for sawn timber. Heat treatment by steam has been shown to eradicate all tested fungi when
66°C is held at the centre of wood for 1.25 hours (Chidester, 1991; Mine and Willeitner, 1990;
NewbiU and Morrell, 1991). More research using logs is needed. Using microwave energy as a
heat source is a possibility but more research is needed. (Vijam, 1983).
4.2.11 Seeds for planting
4.2.11.1 Scope of the problem
Several nematode genera are known to be seed-borne. The most important in agriculture are
Anguina, Aphelenchoides andDitylenchus (Bacci Del Bene and Cancellara, 1973). Many crop
species may be infested, including rice, wheat, leguminous plants and onions (Table 4.2.13
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lists some of the nematodes transmitted on seeds). These nematodes may be also transmitted by
propagules: bulbs, stolons, and cuttings.
Table 4.2.13 Some nematodes transmitted by seeds:
Nematodes
Aphelenchoides besseyi
A. ritzemabosi
A. blastophthorus
Anguina tritici
A. agrostis
A. funesta
A. amsinckiae
Subanguina chrysopogoni
Ditylenchus angustus
D. dipsaci
*
D. destructor
Heterodera schachtii
Panagrolaimus spp.
Rhadinaphelenchiis
cocophilus
Seed
rice
aster
-
wheat, rye
bentgrass
rye grass
?
grass
rice
oat
onion
shallot
beet
fuller's teasel
cat's ear
lucerne
plantain
dandelion
clover
field bean,
broad bean
carrot
runner bean
pea
buckwheat
spring vetch
groundnut
beet
pearl
millet
coconut
species
Oryza sativa
Callistephus sinensis
-
Triticum, Secale
Agrostis, Loliwn
Lolium rigidwn
Amsincka
Chrysopogon fubus
Oryza sativa
Avena
Allium
-
Beta
Dipsacus fullonwn
Hypochaeris radicata
Medicago
Plantago
Taraxacum officinale
Trifolium
Viciafaba
Daucuscarota
Phaseolus
Pisum sativum
Fagopyrum
sagittatum
Vicia sativa
Arachis hypogea
Beta
Pennisetum
americanum
Cocos nucifera
Distribution
Asia, America,
Africa
Europe
r-
Europe, Asia
Europe, USA,
Australia
Australia
America
Asia
Asia, Egypt
Europe
Europe
Europe
Europe
Europe, America
America
Europe, New
Zealand
America
Amsrica
Europe
Europe, Africa,
Middle East
tf
fi
! tl
i tf
fl
|
.Africa
Europe
.Asia
Tropical America
i
The increase in international exchanges of seed increases the risk of dispersal of seed-borne
nematodes. Regulations and certification schemes are required to improve the chances of
limiting the dispersal of these important plant pests.
Methyl bromide is a standard technique for destroying dormant nematodes in seed lots. No
harmful effects oh seed germination were found after treatment (Strong and Lindgren, 1961)
and fumigation of seeds is used as a routine as prevention treatment and. application of
quarantine measure. Test have been carried out with various combinations of concentrations
and exposure times (Marre et al., 1983).
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Developing countries are particularly dependent upon the use of MeBr for quarantine treatments
of seed lots because imports are often only permitted if fumigated in the country of origin or at
ports of entry.
At present, there is no single approved alternative to or substitute for MeBr. However, there are
substitute chemicals and alternative procedures for specific application which could
substantially reduce the use of MeBr.
4.2.11.2 Existing substitutes
4.2.11.2.1. Phosphine
Phosphine is not typically effective against seed-infesting nematodes. However, experimental
application of phosphine were effective in controlling nematodes in water suspension (Rout,
1966).
4.2.11.3 Chemical soaking and fumigation
Promising results were obtained in the control of A. besseyi (Fortuner and Orton Williams,
1975) by soaking rice in aqueous solution of systemic organophosphorous compounds. The
compounds are not phytotoxic. Prasad (1992) eliminated A. besseyi in rice seeds by soaking
them in a solution of mancozeb and monocrotophos followed by fumigation with phosphine at
a dose of 9.3 g nr3.
4.2.11.4 Physical control methods
4.2.11.4.1. Cleaning
As some species are associated with plant debris, thorough cleaning reduces the chance of
infestation. Measures such as seed cleaning and physical and chemical control help to limit the
risks of infestation by seed-borne nematodes and reduce need for methyl bromide curative
treatments.
4.2.11.4.2. Hot water treatment
Hot water treatment may be used to control Anguina agrostis in bent grass (Agrostis
stolonifera), but a treatment of 15 minutes at 52.2°C reduces the germination rate.
Hot water treatment following pre-soaking the seeds provides the most effective control of
white-tipped nematode (A. besseyi). This may be a mandatory quarantine treatment. The pre-
soaking activates their dormant state and subsequent soaking at 51°C for seven minutes
controls the nematode. However, some injury to germination may be observed.
4.2.12 Dried fish, meat and seafood
4.2.12.1 Definition of commodities and pests
Commodities damaged by pests include both saltwater and freshwater dried (cured) fish, dried
meat and meat products.
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Table 4.2.14 Common pests in dried fish, meat and seafood:
Scientific name
Acarus siro
Attagenus spp.
Dermestes spp.
Necrobia ruficollis
Necrobia nftpes
Trogoderma spp.
Tyrophagus spp.
"Common name
Flour mite
Carpet beetle
Hide beetle
Red-necked bacon beetle
Copra beetle
Khapra beetle, warehouse beetle
Cheese and bacon mite
*Major pests
4.2.12.2 Scope of the problem
Dried fish is particularly prone to infestation by several species of dermestid beetles and to a
lesser extent by Necrobia spp. Damage caused by dermestids can be particularly severe, and it
has been reported from inland fisheries in Africa, that if infestation is not controlled, losses
approaching 50% of the commodity can result (FAO, 1981). Dried meat may also become
infested by similar insect pests, but no information is'readily available on economic losses
caused to this product.
Methyl bromide has been recommended for the disinfestation of dried fish in several African
countries where experimental trials have been carried out, but little information is available to
indicate its commercial use (Friendship, 1990).
4.2.12.3 Existing substitutes
4,2.12.3.1. Phosphine
Disinfestation of dried fish using phosphine has been reported by Friendship (1990) and this
fumigant would appear to provide effective control of the common insect pests infesting this
commodity.
4.2.12.4 Contact insecticides
Pyrethrins synergised with piperonyl butoxide have been recommend*^ as an aqueous dip for
protecting dried fish from insect infestation (Proctor, 1972), and more recently pirimiphos
methyl has been recommended for the same purpose (Golob et al, 1987). A maximum residue
limit of 10 mg/kg was recommended for pirimiphos methyl by the FAO/WHO Committee on
Pesticide Residues (FAO, 1986).
4.2.12.5 Physical control methods
4.2.12.5.1. Irradiation
i
Irradiation has been used to disinfest dried fish in Bangladesh and the Philippines (Matin and
Bhuia, 1990; Manoto etal, 1985)
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4.2. 1 3 Reducing emissions
The overall quantity of methyl bromide released into the atmosphere may be reduced by several
measures in addition to adoption of alternatives. These include:
• revision of dosage rates to avoid overdosing;
• improvement in gastightness of enclosures to reduce leakage and permit lower dosage
rates and prolonged exposure periods;
reducing the frequency of treatments by preventing or reducing reinvasion of pests
subsequent to fumigation.
Methyl bromide dosage schedules (Annex 4.2.4) have been produced with commodities
grouped on the basis of their general rate of sorption and penetration of the furmgant. 1 ne
dosage rates apply to well sealed enclosures such as chambers, freight containers and stacks
covered with gas-proof sheets in good condition and only to commodities packed in woven
sacks paper bags, boxes or cartons without special seals or impermeable liners. Although the
rates of application vary with temperature, broadly, cf-product of 300 g h m-3 is preferred for
temperatures below 15°C and 200 g h m-3 above 15°C. The nominal cf-product below 10°C
for Group 5 commodities (Annex 4.2.4) is 3600 g h m-3 (75 g m-3 x 48 hours), an excessive
dose recommended to compensate for sorption and penetration so as to achieve an. actual ct-
product of about 300 g h nr3. This table was produced many years ago and is used universally
without taking into consideration various factors, particularly high temperatures. There is scope
for revision, which may help to reduce the current dosage levels and, consequently, emissions.
Possibilities exist to reduce MeBr dosage by increasing the exposure temperatures without
losing effectiveness.
Rtinfestation after fumigation will cause further treatment to become necessary, possibly a
further fumigation. Precautionary measures are to be taken to prevent this but the steps to be
taken will vary widely according to circumstances.
Good warehouse hygiene (sanitation) is essential, including regular cleaning (preferably by
vacuum cleaning) and immediate removal and burning of sweepings to reduce insect
populations in stores and other structures. Insecticidal treatment of the fabric (floors and walls)
of the building and the stored commodity at the time of fumigation may delay reinfestatton. In
some circumstances it may be possible to leave the commoditycovered throughout the storage
period, as done in Indonesia after CO2 fumigation of bagged rice (Nataredja and Hodges,
1990) in order to provide a physical barrier against reinfestation. In certain cases however, the
possibility of moisture migration, leading to mould development, must be taken into account.
The use of less permeable sheeting materials and better sealing of the existing structures will
help to improve gas retention, and may permit fumigant application rates to be reduced and/or
frequencies, particularly under tropical climatic conditions, since fumigants are more ettecttve
athigh temperatures. The use of supported and unsupported laminated sheets and specially
made gas proof sheets for tropical countries is to be encouraged.
A workshop was recently held in Burlingame, California, USA, to assess tbe state-of-the-art of
methyl bromide emission reductions and research and extension priorities (Anon, lyy^o;.
Conclusions of the workshop were that significant short-term gains in reducing emissions of
methyl bromide to the atmosphere may be realised by using the following current or developing
research technologies:
• Redesigned systems are needed for complete containment and recovery of methyl
bromide.
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New packaging. When products are placed in packaging after fumigation the packaging
material or a specific sorbent should be designed to absorb emitted methyl bromide as it
desorbs from the product If the product is fumigated in packaging, develop a package
that will not absorb methyl bromide.
Develop accurately calibrated treatments where they do not already exist, for quarantine
procedures. Develop fumigation concentrations that will meet quarantine standards with
methyl bromide alone or in combination with other insecticidaJl treatments (other
fumigants, CA, etc.).
Determine the exact fate of methyl bromide in products. Measure the quantity of methyl
bromide that goes into the system, measure that which comes out and that which stays in
the product or packaging material or is degraded. Determine tide changes in residues on
products as a result of altering exposure times versus dosages (concentrations) to reduce
absorption and tailor dosages accordingly.
Measure residual level in product and losses after fumigation. It is not possible to
completely eliminate emissions from treated products. Measure loss of methyl bromide
in secondary processing of treated products, for example manufacturing using methyl
bromide treated logs.
Improved sealing combined with pressure testing of the enclosure prior to treatment will
effectively reduce gas loss during the treatment. This will permit dosage reduction and recovery
of greater proportions of MeBr.
4.2.14 Transfer of knowledge and training in improvements and alternatives
Many of the chemical alternatives to methyl bromide and non-chemical methods of treating
durable commodities need further research. Information on these is either incomplete or, in
certain cases, non-existent. Improved technology for sealing a fumigation area and better
application methods would reduce dosages, resulting in subsequent reductions in emissions.
to disseminate acquired knowledge, key personnel should organise and attend conferences,
workshops and training courses. Publications in scientific journals and bulletins will also reach
personnel with similar interests. Exchanges of technical experts would foe the quickest way to
transfer knowledge, and sufficient funds will need to be made available for this purpose.
International companies which trade in developed countries should be encouraged to increase
their expenditure for training key personnel.
4.2.15 Research priorities
Note: long term: more than 10 years.
Higher Priority, Short Term
• Develop technology to reduce emissions of methyl bromide to the atmosphere.
• Develop basic biology and physiology data bases for Integrated Pest Management
systems.
• Develop methods to reduce application times of controlled atmosphere treatment for
quarantine use, probably in combination with high temperatures.
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• Develop method(s) to discriminate between irradiated and unirradiated insects, for
regulatory purposes.
• Determine available useful technologies for detection, sorting, and certification; determine
feasibility and limits of the selected systems.
• Optimise controlled atmospheres; develop data on exposure times required by various
atmospheres at elevated temperatures (>27°C); optimise application methods.
• Optimise hot and cold treatment methods so that the treatments are rapid and have little or
no effect on quality; develop new application technologies.
• Develop commercially available microbial control agents as protectants.
• Develop insect growth regulators and formulations for long-term control.
• Develop improved packaging and containerisation technologies with special emphasis on
research on practical volumes of commodities for storage, influence of environmental
factors and possibilities for re-use in combination with specific insecticidal treatments.
• Develop suitable engineering components in support of priority research needs with
special emphasis on problems as to scale, blending of the alternatives into systems, and
designing facilities specifically for the use of alternatives.
Higher Priority, Long Term
• Develop basic biology and physiology data bases as described above.
• Develop IPM systems that provide predictable long term control using alternatives.
• Develop formulation and delivery systems for microbial control agents; concert efforts to
isolate useful pathogenic micro-organisms for coleopterans; develop safety data for
registration.
• Optimise large scale irradiation and heat disinfestatipn technologies for durables, with
particular emphasis on logistic problems and minimising capital expense.
Lower Priority, Short Term
None
Lower Priority, Long Term
• Conduct surveys of natural enemies of dried fruit and nut pests for classical biological
control; determine control potentials of candidate organisms; develop application methods
of use; efficacy data.
• Establish control levels for mating disruption chemicals; concentrations, persistence, and
formulation must be considered.
• Isolate useful genes with high expression levels for insect control by genetic engineering.
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4.2.16 Uses without known alternatives
To the knowledge of this Committee, there are no uses of methyl bromide for durable
commodities without potential alternatives. However, there are a number of constraints which
need to be considered, and these are discussed in the following Section.
i
4.2.17- Constraints
Methyl bromide has been used universally for the disinfestation of post-harvest commodities
for over 50 years. Due to its ease of application and effectiveness against a wide range of pest
species in differing circumstances, trading nations and the trade in general! did not feel any
urgency to look for alternatives as methyl bromide conveniently suited their purposes.
Situations such as this have certainly influenced the lack of development of other alternatives to
replace methyl bromide. However, in most cases, other potential fumigants and methods do
exist to supplement the use of methyl bromide.
The immediate constraints in using alternatives will be mainly technological, logistical and
economic. Where alternative chemicals are used, the lexicological properties will also need to
be taken into account (Annex 4.2.2). Probably a number of steps or procedures will need to be
performed to replace a single methyl bromide fumigation, and these will have to be developed
for each individual commodity held under different conditions. The technological innovations
and economics of such procedures will have to be established before a new regimen of
treatments can be introduced.
4.2.17.1 Consumer acceptance and registration of chemicals
Registration of a new chemical may take about ten years. In addition, die costs related to
registration of new chemicals are extremely high (US$ 35 million or more) as full evaluations
are demanded by consumers and regulators.
i
Although most of the insecticide applied to raw grains degrades or is removed before it reaches
the consumer, residue levels in processed and unprocessed food are a sensitive issue.
Tolerance levels can vary from country to country for particular materials. At an international
level, an ad hoc committee examines scientific data submitted in accordance with a protocol of
requirements used by the Joint FAO/WHO Meeting of Experts on Pesticide Residues (JMPR)
in order to determine safe and acceptable levels of residues of chemicals in raw agricultural
commodities and foods (Snelson, 1981).
Maximum levels for residues are based on experiments designed to determine the nature and
level of residues resulting from the application of the chemical in accordance with good
agricultural practices. The safety and acceptability of these residues is determined by
comparison with extensive lexicological studies carried out on laboratory animals. Studies for
carcinogenicity, mutagenicity, teratogenicity, and effects on reproduction are also required.
Recommendations for maximum residue limits (MRLs) are made by the Codex Alimentarius as
a result of these studies, but many countries also make their own legislation.
4.2.17.2 Technical aspects
There are technical barriers to the use of some substitutes or alternatives. Furthermore, most of
the alternatives and substitutes do not have the same spectrum of activity as methyl bromide.
Some may be regarded as inferior in effectiveness to methyl bromide requiring more time of
exposure to be fully effective, or to be used in combination with other measures in an integrated
system to give an adequate level of pest control.
Phosphine, in particular, has different properties to methyl bromide lhat may make it technically
inappropriate as a substitute in some situations. In many situations, it is a simple alternative,
and in some, it may be preferable to methyl bromide, with lower residue and taint potential.
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However, it has very little activity against fungi and requires relatively long exposures to
control some stages of some pests, particularly at low temperatures. Electrical equipment
containing copper may be corroded and precautions must be taken to avoid flammability and
explosion hazards.
Inert dusts may present another alternative useful in some particular situations. However, they
require dry conditions for best effectiveness, may cause excessive wear in machinery, may give
rise to dust problems in the workplace and can alter handling characteristics. Contact
insecticides present an effective alternative in some situations. However, there is a possibility
that particular materials may become ineffective with frequent use because of buildup of
resistance by the pests. Some markets may also not accept treatments with contact insecticides.
Overall, the disadvantages of particular alternatives need to be assessed against the recognised
operational disadvantages of methyl bromide, in addition to its effect on the ozone layer. These
include the need for strict safety precautions to ensure worker safety and safety in the local
environment, provision of gastight enclosures, lack of access to the commodity under
treatment, problems of residues (excessive bromide ion) and taint on some commodities, and
problems of phytotoxicity with some seeds.
Alternatives will continue to heed to be assessed on a case-by-case basis, taking into account
the local environment, the commodity treated, target pests, and the market and use for which
the commodity is destined. Economics, logistics and engineering of installations will all need to
be considered when introducing alternatives. Some promising alternatives for many durables,
notably heat, cold and controlled atmospheres will need commodity- and situation-specific
development, before they can be applied routinely. However, it is vital to expedite development
of substitutes now. Scientists, industry and regulatory agencies need to address this issue
actively.
4.2.17.3 Quarantine
There are currently very few disinfestation treatments for durable commodities which can be
used for quarantine purposes and to protect them from pests at the point of importation which
are as effective within die same time scale. With the alternatives now available, commodities
may fail to get customs clearance resulting in reshipment or incineration, or may need much
more time to disinfest to the level required by the regulatory agency.
4.2.18 References
Aldryhim, Y.N. 1990. Efficacy of amorphous silica dust, Dryacide, against Tribolium
confusion Duv. and Sitophilis granarius (L.) (Coleoptera; Tenebrionidae and
Curculionidae). Journal of Stored Products Research, 26(4), 207-210.
Amoako-Atta. B. (no date). Simulated radiation disinfestation of infested cocoa beans in
Ghana. Legon, Ghana, Ghana Atomic Energy Commission.
Annis, P.C. 1986. Toward rational controlled atmosphere dosage schedules: a review of
current knowledge. In: Donahaye, E. and Navarro, S., eds., Proceedings of the 4th
International Working Conference on Stored-Product Protection, 21-26 September, Tel
Aviv, Israel, 128-148.
-Annis, P.C. and Graver, J. van S. 1990. Suggested recommendations for the fumigation of
grain in the ASEAN region. Part 2. Carbon dioxide fumigation of bag-stacks sealed in
plastic enclosures: an operations manual. ASEAN Food Handling Bureau, Kuala
Lumpur, Malaysia and ACIAR, Canberra, Australia, 58p.
-------
181
Anonymous. Undated. Nucleart. Centre d'Etudes Nucteaires de Grenoble, Service
d'Application des Radioe*lements et des Rayonnements. Project: Nucleart. Commission zt
1'Energie Atomique, France. 92-100.
Anonymous. 1989. Suggested recommendations for the fumigation of gntin in the ASEAN
region. ASEAN Food Handling Bureau, Kuala Lumpur and Australian Centre for
International Agriculture Research, Canberra, 131 p.
Anonymous. 1991. Grain Insect Control. Department of Agricultural Development, Pretoria,
Republic of South Africa, 2 pp.
Anonymous. 1993a. Biologic and economic assessment of methyl bromide ban. National
Agricultural Pesticide Impact Assessment Program, U.S. Department of Agriculture,
April 1993.
Anonymous. 1993b. Methyl bromide atmospheric emissions reduction/postharvest commodity
treatments: Assessment of research and extension needs and priorities. Proceedings of
the Crop Protection Coalition Conference, 14-15 October, 1993, Burlingame, California,
28 p.
Anonymous. 1993c. Alternatives to methyl bromide: Assessment of research needs and
priorities. Proceedings of a USDA Workshop on Alternatives to Methyl Bromide, 29
June -1 July, 1993, Arlington, Va, 88 p.
Appiah, V., Odamtten, G.T. andLangerak, D. 1981. The evaluation of quality parameters of
cocoa after the combination of heat and radiation. Proceedings of the 8th International
Cocoa Research Conference, Cartegena, Columbia.
Appiah, V. (undated). Radiation disinflation of grains and cocoa beans* Legon, Ghana,
Ghana Atomic Energy Commission.
Armitage, D. M. 1987. Controlling insects by cooling grain. In: Lawson, T.J., ed., Stored
products pest control. BPCA Monograph No.37,219-228.
Armitage, D.M., Wilkin, P.R. and Cogan, P.M., 1991. The cost and effectiveness of aeration
in the British climate. In: Heurat-Lessard, F. and Ducom, P., eds., Proceedings of the
5th International Working Conference on Stored-product Protectioni, 9-14 September,
Bordeaux, France, III, 1925-1933.
Bacci Del Bene, G. and CancellaraD, 1973. Preliminary trails on methyl bromide fumigation
of broad bean seeds infested with Ditylenchus dipsaci. Atti Giomate Fitopathologiche, 5,
111-118.
Banks, H.J. 1986. The application of fumigants for the disinfestation of grain and related
products. ACIAR Proceedings No. 14, 291-298.
Banks, H.J. 1994. Fumigation - an endangered technology? In: Highley, E. etal., eds.,
Stored-Product Protection: Proceedings of the 6th International Working Conference on
Stored-product Protection, 17-23 April, Canberra, Australia, 2-6.
Banks, HJ., Annis, P.C. and Rigby, G.R. 1991. Controlled atmosphere storage of grain: the
known and the future. In: Fleurat-Lessard F. and Ducom, P., eels. I'roceedings of the
5th International Working Conference on Stored-Product Protection, 9-14 September,
Bordeaux, France, 695-706.
i
Banks, H. J. and Desmarchelier, J. M. 1993. Carbonyl sulphide fumigant and method of
fumigation. International Application Published under the Patent: Cooperation Treaty.
International Publication Number. WO 93/13659,43p.
-------
182
Banks, H.J., Hilton, S.J., Tarr, C.R. and Thorn, B. 1993. Demonstration of carbon dioxide
disinfestation of containerised dried vine fruit in export cartons. CSIRO Division of
Entomology Report No. 54,9pp.
Banks, J. and Fields, P. 1994. Physical methods for insect control in stored-grain ecosystems.
Chap. 11. In: Jayas, D.S., White, N.D.G. and Muir, W.E., eds., Stored-grain
Ecosystems, Marcel Dekker Inc., New York, pp 353-409.
Bell, C H. 1976. The tolerance of immature stages of four stored product moths to methyl
bromide. Journal of Stored Products Research, 12,1-10.
Bell, C. H., Hole, B. D. and Wilson, S. M. 1985. Fumigant doses for the control of
Trogoderma granarium. Bulletin OEPP/EPPO Bulletin, 15,9-14.
Bell, CJH., Wilson, S.M., Banks, HJ. and Smith, R.H. 1984. An investigation of the
tolerance of stages of Khapra beetle (Trogoderma granarium Everts) to phosphine.
Proceedings of the 3rd International Working Conference on Stored-Product Protection,
Manhattan, 23-28 October. 375-390.
Bell, C. H. and Armitage, D. M. 1992. Alternative Storage Practices. In: Sauer, D. B., ed.
Storage of Cereal Grain and their Products. 4th edition. StPaul Minn., American
Association of Cereal Chemists, 249-311.
Benezet, HJ. 1989. Chemical control of pests in stored tobacco. 43rd Tobacco Chemist's
Research Conference, 15,1-25.
Berhaut, P. and Lasseran, J. C. 1986. Conservation du ble" par la ventilation. Perspectives
agricoles (ITCF), 97, 32-39.
Bond, E. J. 1975. Control of insects with fumigants at low temperatures: response to methyl
bromide over the range 25°C to 6.7°C. Journal of Economic Entomology, 68,539-542.
Bond, E. J. and Monro, H. A. U. 1961. The toxicity of various fumigants to the cadelle,
Tenebriodes mauritanicus. Journal of Economic Entomology, 54,451-454.
Bond, E. J. 1984. Manual of fumigation for insect control. FAO Plant Production and •
Protection Paper No. 54, FAO, Rome, 432 p.
Boulanger, R., Boemer, W. and Hamid, M, 1969. Comparison of microwave and dielectric
heating systems for the control of moisture content and insect infestations of grain. The
Journal of Microwave Power, 4,194-208.
Bowley, C. R. and Bell, C. H. 1981. The toxicity of twelve fumigants to three species of mites
infesting grain. Journal of Stored Products Research, 17,83-87.
Brokcrhof, A.W., Morton, R. and Banks, HJ. 1992. Time-mortality relationships for
different species and developmental stages of clothes moths (Lepidoptera: Tineidae)
exposed to cold. Journal of Stored Products Research, 29.277-282.
Brooks, W. M. 1971. Protozoan infections of insects with emphasis on inflammation.
Proceedjuigs IVth International Colloq. Insect Pathology and Soc. Invertebrate
Pathology, College Park, Maryland, 1127.
Brower, J. H. 1988a. The natural occurrence of the egg parasite, Trichogramma, on almond
moth eggs in peanut storages in Georgia. Journal of the Georgia Entomological Society,
19, 285-290.
-------
183
Brewer, J. H. 19885. Population suppression of the almond moth and the Indian meal moth
(Lepidoptera: Pryalidae) by release ofTHchogrammapretiosuns (Hymenoptera:
KIC!!!?ftiS?2Mtidac) into simulated Peanut storages. Journal of Economic Entomology,
81, 944—948. °J
Brower, J H. and Mullen, M. A. 1990. Effects of Xylocoris flavipes (Reuter) (Hemiptera-
Anthocondae) releases on moth populations in experimental peanut storage. Journal of
entomological Science, 25, 268-276.
Brower, J. H. and Press, J. W. 1990. Interaction of Bracon hebetor (Hymenoptera-
Bracomdae) andTrichogranunapretiosum product moth populations in small in shell
peanut storage. Journal of Economic Entomology, 83, 1096-1 101.
Brower, J. H. and Press, J. W. 1992. Suppression of residual populations of stored-product
pests in empty corn bins by releasing the predator, Xylocoris flavipes (Reuter)
Biological Control, 2, 66-72.
Brower, J. H. and Tilton, E W. 1985. The potential of irradiation as a quarantine treatment for
insects infesting stored-food commodities. In: Proceedings FAO/IAEA Symposium
Radiation Disinfestation of Food and Agricultural Products, Vienna; Austria, 75-86*
Preservation of grain. In: Donahaye, E. and Navano, S., eds.,
C°nferenCe °n Sto-d-product Protection,
Surges H. D. and Burrell, N. J. 1964. Cooling bulk grain in the British climate to control
storage msec* and to improve keeping quality. Journal of the Science of Food and
Agriculture, 15, 32-50.
Burkholder, WE. and Boush, G. M. 1974. Pheromones in stored product insect trapping and
pathogen dissemination. Bulletin OEPP/EPPO Bulletin, 4, 455-461. u J*
Chakrabarti B 1994. Methods of distributing phosphine in bulk grain,! London, Home Grown
Cereals Authority Research Review No.27, 44 p.
Chauvin, G. and Vannier, G. 1991. La resistance au froid et a la chaleun d
-------
184
Chidester, S. 1991. Temperatures necessary to kffl fungi in wood, ftoceedings of the 23rd
Annual Meeting ofthe American Wood-Preservers' Association, 316-324.
Claflin J K Evans, D. EM Fane, A. G. and Hill, R. J. 1984. Thermal dismfestation of
wheaVin a scouted bed. In: Proceedings of the Third International Working Conference
on Stored-product Entomology, Manhattan, 23-28 October, Kansas, 531-537.
Claflin, J. K., Evans, D. E., Fane, A. G. and Hill, R J. 1986. The thennal disinfestation of
wheat in a spouted bed. Journal of Stored Products Research, 22, 153-161.
Clifford, M. N. and Wilson, K. C., eds. 1985. Coffee Botany, Biochemistry and Production
of Beans and Beverage. Beckenham, Kent, Groom Helm, 215 p.
Cline L D and Press, J. W. 1990. Reduction in almond moth (Lepidoptera: Pyralidae)
infestotions using commercial packaging of foods in combination with the parasitic wasp,
Bracon hebetor (Hymenoptera: Bracondiae). Annals of the Entomological Society of
America, 83, 1110-1113.
Codex Alimentarius Commission. 1992. Codex maximum limits for pesticides residues.
FAO/WHO . CX/PR - 1992.
Cowan, D. K., Vail, P. V., Kok-Yokomi, M. L. and Schreiber, F. E. 1986 .Formulation i of a
Imuiulosis virus of Plodia intetpunctella (Hiibner) (Lepidoptera: Pyrahdae): Efficacy,
persistence, and influence on oviposition and larval survival. Journal of Economic
Entomology, 79, 1085-1090.
Dandekar, A. M. 1989. New frontiers in codling moth control. In: Proceedings of the
Washington State Horticultural Association 85th Annual Meeting, 4-6 December,
Wenatchee, Washington, 70-80.
Desmarchelier, J.M. and Dines, J.C. 1987. Dryacide treatment of stored wheat: its efficacy
against insects, and after processing. Australian Journal of Experimental Agriculture, 27,
309-312.
Desmarchelier, J.M. (1994) Carbonyl sulphide as a fumigant for control of insects and mites.
In: Highley, E., et al., eds., Stored-ProductProtecnon: Proceedings ^^6*
International Working Conference on Stored-product Protection, 17-23 Apnl, Canberra,
Australia, 78-82.
Detia Degesch manual for safe practices in handling and use of phosphine fumigants.
Germany, Detia Degesch GMBH, 25 p.
Donahaye, E., Navarro, S. and Rindner, M. 1991. The influence of low temperatures on two
speciesof Carpophilus (Col., Nitidulidae). Journal of Applied Entomology, 111,297-
302.
Donahaye, E., Navarro, S., Rindner, M. and Dias, R. 1992 Artificial feeding site to
investigate emigration if Nitidulid beetles from dried fruits. Journal of Economic
Entomology, 85, 1990-1993.
Dow Chemical Company (1963). Vikane; technical data bulletin. Midland, Mich., Dow
Chemical Company.
Ducom V 1994 Methyl isothiocyanate as a grain fumigant. In: Highley, ,E., etai, eds.,
^tored-ft«iuc?]S)tection: Proceedings of the 6th International Working Conference on
Stored-product Protection, 17-23 April, Canberra, Australia, 91-97.
-------
185
Ebeling, W. 1971. Sorptive dust for pest control. Annual Review of Entomology, 16,123-
158.
Edwards, J. P., Short, J. E. and Fisher, L. 1991. Large scale evaluation of the insect juvenile
hormone analogue fenoxycarb as a long-term protectant of stored wheat. Journal of
Stored Products Research, 27, 31-39.
Eicholz, G.G., Bogdanov, A. and Dwinell, L.D. 1990. Radiation sensitivity of pine wood
nematodes in woodchips. Applied Radiation and Isotopes. International Journal of
Radiation Applications and Instrumentation, Part A.
Erdman, H. E. (1979). Ecological aspects of control of a stored product insect by ozonation.
In: Proceedings of the Second International Working Conference on Stored-Product
Entomology, 10-16 September, Ibadan, Nigeria, 75-90.
European Plant Protection Organisation. 1993. Methyl bromide fumigation of stored products
to control stored-product insect pests in general. Standard No. 12. Bulletin OEPP/EPPO
Bulletin 23,207-208.
European Plant Protection Organisation. 1984. Phosphine fumigation of stored products.
EPPO Bulletin, Vol 14, No. 4, pp 598-599.
Evans, D. E., Thorpe, G. R. and Sutherland, J. W. 1983. Large scale evaluation of fluid-bed
heatings a means of disinfesting grain. In: Proceedings of the Third International
Working Conference on Stored-product Entomology, 23-28 October, Manhattan,
Kansas, 523-530.
Fam, E.Z., El-Nahal, A.K.N. and Fahmy, H. 1974. Influence of greiin moisture on the
efficacy of silica aerogel and katelsous used as grain protectants. Bulletin of the
Entomological Society of Egypt, Economic Series, 8,105-114.
Fan, C, Tian, K., Zhang, Y., Gan, S., Wang, Z. and Xiang, J. 1988. The gamma ray
radiation preservation technology for files and books. Radiation Physics and Chemistry,
31(4-6), 757-759.
FAO. 1981. The prevention of losses in cured fish. FAO Fisheries Technical Paper No. 210,
87 p.
FAO. 1986. Pesticide residues in food -1985. Evaluations Part 1. Residues. FAO Plant
Production and Protection Paper 72/1,372 p.
Fields, P.G. The control of stored-product insects and mites with extreme temperatures.
Journal of Stored Product Research, 28, 89-118.
Fleurat-Lessard, F. 1984. Desinsectisation du ble tendre par un choc thermique en lit fluidise".
Aspects entomologiques, microbiologiques et technologiques. Les ATP de 1'INRA No. 1
"La conservation des Cereales en France". Versailles, France, INRA editions, 150-166.
Fleurat-Lessard, F. 1985. Les traitements thermiques de de'sinfestation des ce're'ales et des
produits cergaliers: possibilite d'utilisation pratique et domaine d'application. Bulletin
OEPP/EPPO Bulletin, 15,109-119.
Fleurat-Lessard, F. 1986. Utilisation d'un attractif de synthese pour la surveillance et le
piegeage des pyrales Phyciiinae dans les locaux de stockage et de conditionnement des
denrees alirhentaires ve'ge'tales. Agronomic, 6,567-573.
-------
186
Fleurat-Lessaid, F. 1987. Control of stored insects by physical means and modified
environmental conditions. Feasability and applications. In: Lawson, T.J., ed., Stored
products pest control. BCPC monograph No. 37, 209-218.
Fleurat-Lessard, F. and Fuzeau, B. 1991. Une nouvelle technique disponible pour la
stabilisation sanitaire des produits agro-alimentaires conditionnes: 1'etuvage en four-
tunnel a haute frequence (H.F.). Proceedings EOF microwave club meeting, EDF-DER
ed., Moret-sur-Loing, France.
Fortuner, R., and Orton Williams, K. J. 1975. Revue de la litterature sur Aphelenchoides
besseyi n&natode causant la maladie "white-tip" du riz. Helminthological Abstracts, 44,
1-140.
Friendship, R. 1990. The fumigation of dried fish. Tropical Science, 30,185-193.
Geneve, R. 1972. Les insectes parasites des tabacs entrepose"s et manufactures en France, Note
Interne Seita, 18 p.
Geneve, R., Ducom, P., Branteghem, V. and Delon, R. 1986. D6sinsectisation d'un entrepot
de tabac de 220 000 m3 par le phosphure d'hydrogene. Annales du tabac, 20,93-104.
Golob, P., Cox, J. R. and Kilminster, K. 1987. Evaluation of insecticide dips as protectants of
stored dried fish from dermistid beetle infestation. Journal of Stored Products Research,
23, 47-56.
Golob, P. and Webley, D.J. 1980. The use of plant and minerals as traditional protectants of
stored products. London, Tropical Products Institute, G138, 32 p.
Gras, P. W. and Bason, M. L. 1990. Biochemical effects of storage atmosphere on grain and
grain quality. In: Champ, B.R., Highley, E. and Banks, H.J., eds., Fumigation and
Controlled Atmosphere Storage of Grain, ACIAR Proceedings No.25, 83-91.
Gray, H. E. 1960. Vikane, a new fumigant for control of dry wood termites. Pest Control, 10,
43-46.
Green, A.R., Sheldon, R. and Banks, H.J. 1984. The flammability limit of phosphine-air
mixtures at atmospheric pressure. In: Ripp, B.E. et al. eds., Controlled atmosphere and
fumigation in grain storages. Elsevier, Amsterdam, 433-449.
Hartsell, P. L., Tebbets, J. C. and Vail, P. V. 1991. Citrus, nut and avocado. Insecticide and
Acaricide Tests 16, U.S.D.A., A.R.S., 42 p.
Heseltine, H.K. and Thompson, R.H., 1974, Fumigation with methyl bromide under gas-
proof sheets, MAFF, HMSO, Edinburgh, p 41.
Heuser, S. G. and Scudamore, K. A. 1969. Formation of ethylene bromohydrin in flour and
wheat during treatment with ethylene oxide. Chemistry and Industry (London), (31),
1054-1055.
Highley, E., Wright, E.J., Banks, HJ. and Champ, B.R. eds. 1994. Stored Product
Protection. CAB International, Wallingford, Oxon. 1274 pp.
Hoedaya Soemartaputra, M., Rosalina, S. H., Rahayu, A., Harsojo and Kardha, S. 1985.
Radiation disinfestation of tobacco leaves and coffee beans. In: Moy, J. H., ed.,
Radiation and Disinfestation of Food and Agricultural Products, Proceedings of an
International Conference, Honolulu, Hawaii Institute of Tropical Agriculture and Human
Resources, 226-239.
-------
187
Hoedaya Soemartaputra, M., Purwanto, Z. L, Chosdu, R., Hardyadi, R. S. and Rahayu, A.
1987. Radiation disinfestation of dry leaf tobacco and coffee beans. In: Insect
Disinfestation of Food and Agricultural Products by Irradiation, Proceedings of the final
research co-ordination meeting, Beijing, China, 153-178.
Hunter, D. K., Collier, S. J. and Hoffmann, D. F. 1973. Effectiveness of a granulosis virus
of the Indian meal moth as a protectant for stored inshell nuts: Preliminary observations.
Journal of Invertebrate Pathology, 22,481.
International Maritime Organisation. 1993. Recommendations on the siafe use of pesticides in
ships. International Maritime Organisation, 23 p.
International Consultative Group on Food Irradiation. 1988. Provisional guideline for the
irradiation of cereal grain for insect disinfestation. Vienna, Joint FAQ/IAEA Division.
Jategaonkar, L. and Marcotte, M. 1993. Effects of irradiation on spices, herbs and seasonings:
A review of selected literature. Market Development, Food Irradiation Division, Nordion
International, 24 p.
Jay E G 1971. Suggested conditions and procedures for using carbon dioxide to control
insects in grain storage facilities. Washington, DC., USDA Agriculture Research Service
Bulletin No. 51-46, 6 p.
Jayas, D.S., White, N.D.G. and Muir, W.E. 1994. Stored-Grain Ecosystems. Marcel Dekker
Inc., New York, 784 pp.
Johnson, J. A., Wofford, P. L. and Whitehand, L. C. 1992. Effect of diet and temperature on
development rates, survival and reproduction of the Indian meal moth (Lepidoptera:
Pyralidae). Journal of Economic Entomology, 85,561-566.
Kader, A. A., Lipton, W. J., Reitz, J. H., Smith, D. W., Tilton, E. W. and Urbain, W. M.
1984. Irradiation of plant products. Comments from Council for Agricultural Science and
Technology, Ames, Iowa.
Katusin-Razem, B., Razem, D., Dvomik, I., Matic, S. and Mihokovic, V. 1985. Radiation
decontamination of dry chamomile flowers and chamomile extract. In: Food Irradiation
Processing, Proceedings of an International Symposium on Food Irradiation,
Washington, D.C., 69-77.
Kellen W. R., and Hoffmann, D. F. 1987. Laboratory studies on the dissemination of a
granulosis virus by healthy adults of the Indian meal moth, Plodia interpunctella
(Lepidoptera: Pyralidae). Environmental Entomology, 16,1231-1234.
Kellen, W. R., and Lindegren, J. E. 1973. New host records for Helicosporidiumparasiticwn.
Journal of Invertebrate Pathology, 22,296-297.
Kenaga, E. E. 1957. Some properties of sulphuryl fluoride as an insecticidal fumigant. Journal
of Economic Entomology, 50,1-6.
Lasseran, J. C. and Fleurat-Lessard, F. 1991. Aeration of grain with ambient or artificially
cooled air- a technique to control weevils in temperate climates. In: Fleurat-Lessard, F.
and Ducom, P., eds., Proceedings of the 5th International Working Conference on
Stored-product Protection, 9-14 September, Bordeaux, France, II, 1221-1231.
Leesch, J. G., Redlinger, L.M., Gillenwater, H.B., Davis, R. and Zehner, J.M. 1978. An in-
transit ship-board fumigation of corn. Journal of Economic Entomology, 71,928-935.
-------
188
Lcesch, J.G. Davis, RM Zettler, J.L., Sukkestad, D.R., Zehner, J.M. and Redlinger, L.M.
1986. Use of perforated tubing to distribute phosphine during the in-transit fumigation of
wheat. Journal of Economic Entomology, 79,1583-1589.
Le Patourel, G.NJ. 1986. The effect of grain moisture content on the toxicity of a sorptive
silica dust to four species of grain beetle. Journal of Stored Products Research, 22,63-
O«/«
Liese, W. and Ruetze, M. 1985. Development of a fumigation treatment of oak logs against
Ceratocystisfagacearum. Bulletin OEPP/EPPO Bulletin, 15,29-36.
Lung Escarmant, B., Tans, B., Ducom, P., Lanusse, M., Tarlet, G. P. and Malato, G. 1985.
Action et comportement in situ du bromine de m6thyle sur le developpement d'Armillaria
obscura, un parasite du pin maritime dans le sud ouest de la France. Bulletin
OEPP/EPPO Bulletin, 15,97-104.
Maceljski, M. and Koranic, Z. 1971. The results of investigation of the use of inert dusts in
water suspensions against stored-product insects. Zastita Bilja, 23,376-387.
ManotoTE.C., Blanco, L.R., and Resilua, S.S. 1985. Disinfestation of copra and coffee beans
by gamma radiation: studies on population density, rearing, biology and adult irradiation.
In: Moy, J.H. ed., Radiation Disinfestation of Food and Agricultural Products
University of Hawaii, 199-206.
Manoto, E.C., Blanco, L.R., Mendoza, A.B. and Resilva, S.S. 1987. Disinfestation of copra,
desiccated coconut and coffee beans using gamma irradiation. In: Insect Disinfestation of
Food and Agricultural Products by Irradiation, Proceedings of the final research co-
ordination meeting, Beijing China, 105-126.
Manzelli, A. M. 1987. Control of the cigarette beetle in stored and processed tobacco Tobacco
Journ. Int. 6, 373-378.
Marcotte, M. 1994. Commercial irradiation of food and agricultural commodities, market tests
and consumer attitude research - Summary tables. Nordion International Inc., Kanata
Canada.
Marre, R., Caubel, G., Champion, R. and Pedron, J. P. 1983. Traitrement des semences de
luzerne et de trefle au bromure de mgthyle centre le ndmatode des tiges. Phytoma-
DSfense des Cultures, 353,48-50.
Matin, M.A. and Bhuiya, A.D. 1990. Test marketing and consumers' acceptability of irradiated
foods in Bangladesh. Food Irradiation Newsletter. Vienna, Joint FAO/IAEA Division.
McGaughey, W. H. 1982. Evaluation of commercial formulations of Bacillus thwingiensis for
control of the Indian meal moth and almond moth (Lepidoptera: Pyralidae) in stored
inshell peanuts. Journal of Economic Entomology, 75,754-757.
McGaughey, W. H. 1986. Bacillus thuringiensis: a critical review. In: Donahaye, E. and
Navarro, S., eds., Proceedings of the 4th International Working Conference on Stored-
product Protection, 21-26 September, Tel Aviv, Israel, 14-23.
McGaughey, W.H. and Beeman, R.W. 1988. Resistance to Bacillus thuringiensis in colonies
of Indianmeal moth and almond moth (Lepidoptera: Pyralidae). Journal of Economic
Entomology, 81,28-33.
Menn, J. J., Raima, A. K. and Edwards, J. P. 1989. Juvenoids and neuropeptides as insect
control agent: retrospect and prospects. In: Progress and prospects in insect control.
BCPC Monograph No.43, 89-106.
-------
189
Mdtalnikov, S. and M&alnikov, S. S. 1935. Utilisation des microbes dans la lutte contre les
insectes nuisibles. Annales de 1'Institut Pasteur, 55,709.
Meyer, A., 1980. The use of lethal temperatures in the control of cigarette beetle, Lasioderma
serricorne. Proceedings of the Entomological Society of South Africa, 3rd Congress,
Pretoria.
Mills, K. A. 1992. To assess the toxicity of ozone in low oxygen atmosphere to the warehouse
moth Ephestia ellutella. CSL contract report, 23.
Mine, M. and Willeitner, H. 1990. Lethal temperature for some wood-destroying fungi with
respect to erradication by heat treatment Hamburg, Institute of Wood Biology and Wood
Preservation, 24 p.
Mkhize, J. N. 1986. Activity of insect growth regulators with juvenile hormone-like affects
against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae). Tropical Pest
Management, 32, 324-326.
Monro, H. A. U. 1956. The history of the use of recirculation method for applying fumigants
in grain storage. Down to Earth, 11,19-21.
Moulton, J.L. ed. 1988. Preservation and storage of grains, seeds and thear by-products.
Lavoisier Publishing Inc., New York. 1095 pp.
Nataredja, Y.C. and Hodges, RJ. 1990. Commercial experience of sealed storage of bag
stacks in Indonesia. In: Champ, B.R., Highley, E and Banks, H.J., eds., Fumigation
and Controlled Atmosphere Storage of Grain, ACIAR Proceedings No. 25, 197-202.
Navarro, S. and Donahaye, E. 1990. Generation and application of modified atmospheres and
fumigants for the control of storage insects. In: Champ, B. R., Highley, E. and Banks,
H. J., eds., Fumigation and Controlled Atmosphere Storage of Grain, ACIAR
Proceedings No.25, 152-165.
Navarro, S. and Donahaye, E. 1993. eds. CAP Proceedings of an International Conference on
Controlled Atmosphere and Fumigation in Grain Storages. Caspit Press, Jerusalem,
560 p. ;
Nelson, H. D. 1970. Fumigation of natural raisins with phosphine. U.S.D.A., Marketing
Research Report 886,8 p.
Nelson, S. O. 1972. Possibilities of controlling stored grain insects with RJ7. energy. The
Journal of Microwave Power, 7, 231-239.
Newbill, M. A. and Morrell, J. J. 1991. Effects of elevated temperatures on survival of
Basidiomycetes that colonize untreated Douglas-fir poles. Foresit Pioducts Journal, 41,
31-33.
Newton, J. 1993. Carbon dioxide as a fumigant to replace methyl bromide in the control of
insects and mites damaging stored products and artefacts. In: Wildey K. B. and
Robinson, W. H., eds., Proceedings of an International Conference; on Insect Pests
Damaging the Environment, Cambridge, UK, 329-338.
Pike, V. 1994. Laboratory assessment of the efficacy of phosphine and methyl bromide
fumigation against all life stages of Liposcelis entomophilus (Emderlein). Crop
Protection, 13,141-146.
-------
190
Pinnigcr, D.B. 1991. New developments in the detection and control of insects which damage
museum collections. Biodeterioration Abstracts 5,125-130.
Powell, D. F. 1974. Fumigation of field beans against Ditylenchus dipsaci. Plant Pathology,
23, 110-113.
Prasad, S. 1992. Elimination of white-tip nematodes, A. besseyi, from rice seed. Fundamental
and Applied Nematology, 15,305-308.
Press, J. W., Cline, L. D. and Flaherty, B. R. 1982. A comparison of two parasitoids, Bracon
hebetor (Hymenoptera: Braconidae) and Venturia canescens (Hymenoptera:
Ichneumpnidae), and a predator Xylocoris flavipes (Hemiptera: Anthocoridae) in
suppressing residual populations of the almond moth, Ephestia cautella (Lepidoptera:
Pyralidae). Journal of the Kansas Entomological Society, 55,725-728.
Press, J. W., Flaherty, B. R. and Arbogast, R. T. 1975. Control of the red flour beetle,
Triboliwn castaneum, in a warehouse by a predaceous bug, Xylocoris flavipes. Journal
of the Georgia Entomological Society, 10,76-78.
Price, L. A. and Mills, K. A. 1988. The toxicity of phosphine to the immature stages of
resistant and susceptible strains of some common stored product beetles and implications
for their control. Journal of Stored Products Research, 24(1), 51-59.
Proctor, D. L. 1972. The protection of smoke-dried freshwater fish from damage during
storage in Zambia. Journal of Stored Products Research, 8,139-149.
Prozell, S. and Reichmuth, C. 1990. Response of the Granary weevil Sitophilus granarius (L.)
to controlled atmospheres under high pressure. In: Fleurat-Lessard, F. and Ducom, P.,
eds., Proceedings of the 5th International Working Conference on Stored-product
Protection, 9-14 September, Bordeaux, France, H, 911-918.
Quarles, W. 1992a. Diatomaceous earth for pest control. EPM Practitioner, 14,1-11.
Quarles, W. 1992b. Silica gel for pest control. IPM Practitioner, 15,1-11.
Ramierc, R. 1982. Protection de 1'environement culturel par les techniques nucleires. In:
Industrial Application of Radioisotopes and Radiation Technology, Vienna, IAEA.
Proceedings of international conference on industrial application of radioisotopes and
radiation technology. Grenoble, France, 255-269.
Redlinger, L. M., etal. 1979. In-transit ship-board fumigation of wheat. Journal of Economic
Entomology, 72, 642-647.
Reichmuth, C. 1990. New techniques in fumigation research today. In: Fleurat-Lessard, F.
and Ducom, P., eds., Proceedings of the 5th International Working Conference on
Stored-product Protection, 9-14 September, Bordeaux, France, II, 709-724.
Reichmuth, C, Unger, A., Unger, W., Blasum, G., Piening, H., Rohde-Hehr, P., Plarre,
R., Poschko, M. and Wudtke, A. 1992. Nitrogen-flow fumigation for the preservation
of wood, textiles, and other organic material from insect damage. In: Navarro, S. and
Donahaye, E., eds., Proceedings of an International Conference on Controlled
Atmosphere and Fumigation in Grain Storages, 11-13 June, Winnipeg, Canada, 121-
128.
Rhodes, A. A. 1986. Irradiation disinfestation of dried fruits and nuts: A final report from the
United States Department of Agriculture, Agricultural Research Service and Economic
Research Service to United States Department of Energy, Energy Technologies Division,
Interagency Agreement Number DE-A104-83AL24327.
-------
191
Ripp, B.E., Banks, H.J., Bond, E.J., Calverley, D.J., Jay, E.G. and Navarro, S. eds. 1984.
Controlled Atmosphere and Fumigation in Grain Storages. Elsevf.er, Amsterdam, 798 p.
Rout, G. 1966. Observations on hydrogen phosphide as a nematicide. Current Science, 35,
577.
Samson, P. R., Parker, RJ. and Hall, E. A. 1990. Efficacy of the insect growth regulators
methoprene, fenoxycarb and diflubenzuron against Rhyzopertha dominica (F.)
(Coleoptera: Bostrichidae) on maize and paddy rice. Journal of Stored Products
Research, 26, 215-221.
Saint-Lebe, L., Henon, Y. and Thery, V. 1985. Ionizing radiation treatment of dry and
dehydrated products: case of medicinal plants intended for infusion. In: Proceedings of
International Symposium on Food Irradiation, Washington, D.C., 9-16.
Sauer, D.B. ed. 1992. Storage of cereal grains and their products. 4th ed. American
Association of Cereal Chemists, St. Paul. 615 pp.
Schitz, P. 1975. Informations recueillies au cours d'une enquete intemationale sur Ephestia
elutella etLasioderma serricorne. Bull. Inf. CORESTA (1), 59-67.
Shapas, T. J., Burkholder, W. E., and Boush, G. M. 1977. Population! suppression of
Trogoderma glabrum by using pheromone luring for protozoan pathogen dissemination.
Journal of Economic Entomology, 70,469-474.
Snelson, J. T. 1981. Regulation of chemical use of Australia. In: Champ. B.R. and Highley,
E., eds., Grain Storage Research and its Application in Australia. Canberra, CSIRO
Division of Entomology, 91-100.
Snelson, J. T. 1987. Grain protectants. Canberra, ACIAR, 448 p. (ACIAR Monograph No. 3)
Snelson, J.T. and Winks, R.G. 1981. In transit fumigation of large grain bulks in ships. In:
GASGA Seminar. The appropriate use of pesticides for the control of stored product
pests in developing countries. Tropical Development and Research Institute, Slough,
UK, 119-130.
Soderstrom, E. L., Gardner, P. D., Baritelle, J. L., De Lozano, K. N. and Brandl, D. G.
1984. Economic cost evaluation of a generated low-oxygen atmosphere as an alternative
fumigant in the bulk storage of raisins. Journal of Economic Entomology, 77,457-461.
Spratt, E., Dignan, G. and Banks, H. J. 1985. The effect of high concentrations of carbon
dioxide in air on Trogoderma granarium Everts (ColeoptenuDermestidae). Journal of
Stored Products Research, 21,41-46.
Storey, C. L. 1967. Comparative study of methods of distributing methyl bromide in flat
storages of wheat: gravity penetration, single pass and closed circulation. Washington,
D. C., USDA Marketing Research Report No. 794,16 p.
Storey, C. L. 197 la. Distribution of grain fumigants in silo-type elevator tanks by aeration
systems. Washington, D.C., USDA Marketing Research Report No. 915, 17 p.
Storey, C. L. 197 Ib. Three methods for distributing methyl bromide in farm-type bins of
wheat and corn. Washington, D.C., USDA Marketing Research Report No. 929,8 p.
Strong, R. G. and Lindgren, D. L. 1961. Germination of small legume seeds after fumigation
with methyl bromide and cyanhydric acid. Journal of Economic Entomogy, 54,21-25.
-------
192
Sukprakarn, C., Attaviriyasook, K., Khowchaimaha, L., Bhudhasamai, K. and Promsatit, B.
1990. Carbon di9xide treatment for sealed storage of bag stacks of rice in Thailand. In:
Champ, B.R., Highley, E. and Banks, H. J., eds., Fumigation and Controlled
Atmosphere Storage of Grain, ACIAR Proceedings No. 25, 188-196
Sutherland, J.W., Evans, D.E., Fane, A.G. and Thorpe, G.R. 1987. Disinfestation of grain with
heated air. Proceedings of the 4th International Working Conference on Stored-Product
Protection, Tel Aviv. pp. 261-274.
Tarr, C., Hilton, S.J., van S. Grayer, J. and Clingeleffer, P.R. 1994. Carbon dioxide
fumigation of processed dried vine fruit (sultanas) in sealed stacks. In: Highley, E., et
a/., eds. Stored Product Protection: Proceedings of the 6th International Working
Conference on Stored Product Protection, 17-23 April, 1994, Canberra, Australia, 204-
209.
Taylor, R.W.D. 1989. Phosphine - A major grain fumigant at risk. International Pest Control,
31(1), 10-14.
Thompson, R. H. 1970. Specifications recommended by the UK Ministry of Agriculture,
Fisheries and Food for the fumigation of cereals and other foodstuffs against pests of
stored products. Bulletin OEPP/EPPO Bulletin, Ser. D. No. 15, 9-25.
Thorpe, G. R., Evans, D. E. and Sutherland, J. W. 1984. The development of a continuous-
flow fluidized-bed high-temperature grain disinfestation process. In: Ripp, B.E. et al.,
eds, Controlled Atmosphere and Fumigation in Grain Storages. Amsterdam, Elsevier,
617.-622.
Tilton, E. W. and Bower, J. H. 1987. Ionizing radiation for insect control in grain and grain
products. Cereal Foods World, 32, 330-335.
Trematerra, P. 1988. Suppression of Ephestia kehniella Zeller by using a mass trapping
method. Tecnica Molitoria, 39, 865-869.
Trematerra, P. 1991. Attracticide method in the control of Ephestia kuehniella Zeller: Studies
on effectiveness. Journal of applied Entomology, 111, 451-456.
Unger, W., Reichmuth, C., Unger, A. and Detmers, H. 1992. Zur Bekampfung des echten
Hausschwamms \Serpula lacrymans (Wulf. Fr) Schroet] in Kunstgutem mit
Brommethan. Zeitscnrift fiir Kunsttechnologie und Konservierung, 2, 244-259.
Vail, P". V. 1991. Novel virus composition to protect agricultural commodities from insects.
U.S.A. Patent No. 07/212, 641.
Vail, P. V., Tebbets, J. S., Hoffmann, D. F. and Dandekar, A. M. 1991. Responses of
production and storage walnut pests to Bacillus thuringiensis insecticidal crystal protein
fragments. Biological Control, 1, 329-333.
Vail, P. V., Tebbets, J. S., Mackey, B. E. and Curtis, C. E. 1993a. Quarantine treatments: A
biological approach to decision-making for selected hosts of codling moth (Lepidoptera:
Tortricidae). Journal of Economic Entomology, 86, 70-75.
Vail, P. V., Tebbets, J. S., Curtis, C. E. and Jenner, K. E. 1993b. Infestation rates and
biological observations after harvest of codling moth (Lepidoptera: Tortricidae) in stored
in-shell walnuts. Journal of Economic Entomology, 86, 1761-1765.
Vijam, H. F. M. 1983. The use of bifluorides in remedial 'treatment by IRG. Document
IRG/WP.3256.
-------
f
193
Wen, B and Brower, J. H. 1994. Suppression ofSitotroga cerealella in shelled corn by the
parasitoid Pteromalus cerealellae. Journal of Entomological Science, 29,254-258.
Wesley, R, Rurke, B. and Darbishire, O. 1965. The formation of persistent toxic chlorohyrins
in food by fumigation with ethylene oxide and propylene oxide. Journal of Food
Science, 30, 1037-1042.
White, G.D., Berndt, W.L. and Wilson, J.L. 1975. Evaluating diatomaceous earth, silica-
aerogel dusts and malathion to protect stored wheat from insects. USDA, Marketing
Research Report No.1038,18 p.
Winks, R. G. 1990. Recent developments in fumigation technology, with emphasis on
phosphine. In: Champ, B. R., Highley, E. and Banks, H. J., eds., Fumigation and
controlled atmosphere storage of grain. ACIAR Proceedings No. 25,144-157.
Winks, R.G. 1993. The development of Siroflo® in Australia. In: Navarro, S. and Donahaye,
E. CAF Proceedings of an International Conference on Controlled Atmosphere and
Fumigation in Grain Storages. Caspit Press, Jerusalem, 399-410.
Wood, G. A. R. and Lass, R. A. 1985. Cocoa. Harlow, Essex, UK, Ixmgmans, 4th ed.,
620 p.
Yoshida, T. 1975. Lethal effect of ozone gas on the adults of Sitophilm oryzae and
Oryzaephilus surinamensis. Scient. Rep. Fac. Agric. Okayama Univ., 45,9-15.
Zakladnoi, G.A.; Men'shenin, A.I.; Pertsovskii, E.S.; Salimov, R.A.; Cherepkov, V.G. and
Krsheminskii, V.S. 1982. Industrial application of radiation deinsectification of grain.
Soviet Atomic Energy 52:74-78.
Zettler, J. L., Gillenwater, H.B., Redlinger, L.M., Leesch, J.G., Davis, R., McDonald, L.L.
and Zehner, J.M. 1982. In-transit shipboard fumigation of corn on tanker vessel. Journal
of Economic Entomology, 75,804-808.
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Case History 4.2.1: Rice Irradiation in Indonesia
N
1. Commodity: Rice Pest: Sitophilus oryzae
2. History
The Indonesian government, through its National Logistics Agency, BULOG, protects its
general populace and its rice farmers against the effects of drought, floods and other natural
disasters. Since an average Indonesian consumes 149 kg of raw rice per annum, BULOG buys
locally produced rice to maintain the stability of rice prices and to control the market through
storage of the rice for later sale and distribution. The quantity of rice stored, upwards of 2.0
million tonnes, is also sufficient to help ensure food security in an emergency. The rice is
stored in 50 kg bags (6 - 9 mil polyethylene - polyester co-polymer, sewn shut). The bags are
stacked seven meters high in large storage sheds. Currently the Indonesian government uses
several methods to disinfest the rice: fumigation with methyl bromide, phosphine and
controlled atmosphere (CC>2). With concerns about the use of chemical fumigants, and cost
difficulties with controlled atmosphere, the government indicated an interest in developing
another treatment
3. Description of the alternative
Pt. Perkasa SteriGenics, a joint Indonesian and American commercial venture, operates a
commercial contract irradiator in Jakarta. The facility is a modified tote/carrier - product overlap
irradiator, suitable for the irradiation of a wide variety of products: A commercial efficacy test
irradiation of 50 kg bags irradiated at 0.40 kGy minimum dose was conducted in 1993 and the
rice was evaluated over several months for quality, the presence of weevils and other pests.
4. Regulatory agency acceptance
The irradiation of rice has been well researched and approved by the Codex Alimentarius and
many other food regulatory agencies worldwide. Following the successful completion of the
rice irradiation studies in Indonesia and demonstration of the scale up logistics required to
commercially irradiate rice, the project was approved by the Chairman of BULOG on a limited
basis.
5. Current commercial use
Commercial rice irradiation will begin in August, 1994 with 3 - 5,000 tonnes per month with
the figure increasing after the 1994 harvest to 8 - 10,000 tonnes per month. Irradiation is
carried out by Pt. Perkasa SteriGenics under contract to BULOG with rice storage in BULOG
facilities.
6. Was the treatment difficult to develop?
Although weevils are more difficult to kill than some other pests, the dose delivered (0.40 kGy
minimum) resulted in complete control of the pest at all life stages. While there was concern
that the packaging material used may allow for re-infestation, it performed reasonably well in
tests.
7. Was the treatment difficult to implement?
Yes. Processing substantial commercial amounts of packaged rice required sophisticated
synchronisation of multiple disciplines and departments within BULOG with Pt Perkasa
Sterigenics. The success of the packaging system will continue to be evaluated and amended as
required. As the projected volumes increase, the fine tuning of shipping/delivery schedules will
determine the success of the facility to meet the total needs of BULOG.
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195
8. Is the effect of this treatment on other crops being determined?
The Indonesian government through their radiation research organisation, (Centre for the
Application of Isotopes and Radiation, BATAN, conducts research to assess the effect of
irradiation on a wide variety of products. Currently the iiradiation of mangoes, strawberries
and frozen shellfish are under review.
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196
Annex 4.2.1
Table 4.2.15 Minimum exposure periods (days) required for control of all stages of the
stored product pests listed, based on a phosphine concentration of 1.0 g m-3 This dosage is
afrcTommended for good conditions and the dosage applied will usually need to be increased
considerably in leaky situations (EPPO 1984).
Species
Oryzaephilus surinamensis
Cryptolestes pusillus
Oryzaephilus mercator
Tribolium castaneum
Lasioderma serricome
Afnntliner0Jistt>V fthtPrtllS
Common names
Saw-toothed grain beetle
Flat grain beetle
Merchant grain beetle
Rust-red flour beetle
Cigarette beetle
Dried bean beetle
10-20°C
3
5
5
8
20 - 30°C*
3
4
5
5
Corcyra cephalonica
Cryptolestes ferrugineus
Plodia interpunctella
Ptinus tectus
Rhyzopertha dominion
Sitotroga cerealella
Tribolium confiisum
Ephestia cautella
Ephestia elutella
Ephestia kuehniella
Caryedon serratus
Sitophilus granarius
Sitophilus oryzae
Sitophilus zeamais.
Trogoderma granarium
Rice moth
Rust-red grain beetle
Indian-meal moth
Australian spider beetle
Lesser grain borer
Angoumois grain moth
Confused flour beetle
Tropical warehouse moth
Warehouse moth
Mediterranean flour moth
Groundnut borer
Grain/granary weevil
Rice weevil
Maize weevil
Khapra beetle
10
10
16
8
8
* All species listed succumb to a 4-day exposure at this dosage level at 30°C or above.
For certain commodities in long-term storage where it is necessary to control a mite infestation
two fumigations may be carried out separately by an interval dependent on ambient _
temp^rSuVeT lowing eggs surviving fee first fumigation to hatch. This interval vanes from 2
weeks at 20°C to 6 weeks at 10°C (Bowley and Bell, 1981).
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Annex 4.2.3
Table 4.2.16 Estimates of the minimum c/-product (g h rrr3) of methyl bromide for a 99.9
per cent kill of various stages of a number of insect species at 10,15,25 and 30°C and 70 per
cent RH. (Heseltine and Thompson, 1974)
Species
Ccdlosobruchus chinensis
Cryptolestes minutus
Ephestia cautella
Ephestia elutella
Ephestia kuehniella
Lasioderma serricorne
Oryzaephilus surinamensis
Plodia interpunctella
Ptinus tectus
Ptinus tectus
Rhyzopertha dominica
Rhyzopertha dominica
Rhyzopertha dominica
Sitophilus granarius
Sitophilus granarius
Sitophilus granarius
Sitophilus oryzae .
Sitophilus oryzae
Tribolium castaneum
Tribolium castaneum
Tribolium confusion
Tribolium confusion
Trogoderma granarium
Stage
pre-adult stages
cocoons
pupae
diapausing larvae
pupae
cocoons
adults
diapausing larvae
cocoons
adults
early pre-adult stages
later pre-adult stages
adults
early pre-adult stages
later pre-adult stages
adults
pre-adult stages
adults
pupae
adults
pupae
adults
larvae
Temperature (°C)
10
175
170
r
360
-
i
85
300
170
155
80
115
200
55
50
125
230
115
290
15
85
145
70
360
75
180
85
250
155
125
40
75
65
75
115
55
105
30
80
180
85
190
25
40
125
55
205
60
100
50
105
100
85
40
45
40
50
65
35
85
30
125
60
90
60
110
30
.
-
-
180
-
-
40
-
-
-
50
65
15
100
50
45
70
(A dash in the table indicates that no test was carried out).
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202
Annex 4.2.4
Table 4.2.17 Methyl bromide dosage table. European Plant Protection Organization (1993)
Group
Commodities
Notes:
Dosage (g in*3)
Exposure
<10°C 10-20°C >20°C period (h)
1.
2.
3.
4a
4b
5.
6.
7.
Rice, peas, beans, cocoa
beans, dried vine fruits
Wheat, barley, oats,
maize, lentils
Pollards, rice bran
Sorghum, nuts, figs
Groundnuts, oilseeds,
dates, empty sacks
Oilseeds, cakes and meals
Fishmeal, dried blood etc.
Flour
.25
50
70
75
75
120
140
50
15
35
45
50
50
85
100
50
10
25
30
35
35
60
65
40
24
24
48
24
48
48
48
48
1. These dosage rates apply to fumigations under gas-proof sheets and in freight containers
which are usually fully loaded. If this method is to be used for mites, dosage rates should
accordingly be doubled.
2. Penetration of methyl bromide into commodities in Groups 5 and 6 is poor and
fumigation may be uneconomic using the recommended dosage rates. In such cases the use of
phosphine should be considered and this is the preferred fumigant for Group.7 (flour).
3. To reduce the possibility of taint the dose for flour should never exceed 50 g nr3.
4. Diapausing larvae ofTrogoderma granarium (khapra beetle) and Ephestia elutella
(warehouse moth) are highly tolerant of methyl bromide. In this case, these dosages should be
increased by one half and, where applicable, exposure periods increased to 48 h in order to
achieve the requisite cr-products.
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203
4.3 Alternatives for treatment of perishables
Executive Summary
Perishable commodities include fresh fruit and vegetables, cut flowers, ornamental plants,
fresh root crops and bulbs.
Although there are eleven different types of existing alternative treatments for disinfestation
which are approved for commercial use on specific commodities, very few of the alternatives to
methyl bromide studied by the Committee were found to be in commercial use. Ideally, an
existing alternative is fully tested, efficacious, non-phytotoxic and economical. For example,
this report shows 6 commodities have approval for disinfestation using heat, 5 using chemical
treatments, nine using cold treatment, and four using pest-free zones.
When compared to methyl bromide, potential alternatives require more data showing efficacy
and phytotoxicity responses. Some potential alternatives will be more commodity specific than
methyl bromide requiring more research at the plant species and cultivar levels. Alternatives
are generally more complex than methyl bromide which increases their costs of
implementation. Potential alternatives show promise and need further research to determine
their suitability for various commodities.
Currently, there are no existing alternative treatments for apple, pear, and stonefruit exports
that are host to codling moth; for berryfruit; for grapes from Chile exported to the United
States; and for many rootcrops that are exported to developed countries from Article 5 (1)
countries.
For this reason, further international co-operation is imperative for the development of
alternative treatments based on globally-accepted phytosanitary standards.
The Committee recognised methyl bromide fumigation as the predominant treatment when
disinfestation is required for perishable commodities.
Using currently available estimates, about 22% of the non-feedstock methyl bromide consumed
globally is used for disinfestation of both durable and perishable commodities. The percentage
of this global consumption used for perishable disinfestation is estimated as 8.6%. The
majority of these treatments are carried out on arrival in an importing country if undesirable live
pests are intercepted, or occasionally prior to export if the importing country deems the pest to
be a serious threat to their agricultural security. Some countries take a precautionary approach
to meet export requirements. For example, countries sometimes fumigate perishable
commodities prior to export in order to ensure their release onto the retail markets is not
delayed and to avoid more expensive fumigation costs on arrival.
In a MBTOC survey of 22 industrialised and Article 5 countries, on average almost half of the
tonnage of methyl bromide used on perishable commodities was for disinfestation of exported
fruit A minor quantity of methyl bromide was used to prevent the spread of pests within the
same country.
Until recently there has been little perceived need to investigate alternatives to methyl bromide
because it is lethal to a broad spectrum of pests, easily applied, cost-effective, and accepted by
most countries. There has been, therefore, insufficient time and resources dedicated to
generating scientific data to support the ability of potential alternatives to control pests without
damaging the commodity. Most alternative treatments are more commodity and pest specific,
require more complex equipment or procedures, and are often more expensive than methyl
bromide. However, it was noted that methyl bromide does cause some injury to some
products (e.g. cut flowers), and less harmful, though still effective, alternatives would be
desirable.
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204
Alternatives can be divided into those that require no postharvest treatment, and those that
require either a postharvest chemical or non-chemical treatment
Alternatives avoiding postharvest treatment
At least three countries (e.g., the United States, Japan, New Zealand) accept certain
commodities certified by government officials as originating from geographically defined
regions free of quarantine pests. Pest-free zones require justification through monitoring,
reporting and continuous enforcement. A regulatory agency may require justification for many
years because their acceptance is based on extensive knowledge of both the pest and
commodity biology and phenology.
Inspection of a sample of the commodity before shipment by inspectors from the importing
country, while labour intensive and relatively costly, is carried out by some countries such as
those exporting to the United States, Japan and New Zealand.
The systems approach relies on preharvest management of pests in the orchard or field,
followed by packhouse procedures to reject infested fruit. Generally, the pests are present in
very low numbers and can be easily controlled. Preharvest control practices rarely exceed 90%
pest mortality and are insufficient to comply with the predominant concept of quarantine
security of greater than 99.9968% mortality. However, the desired level of security may be
achieved, for example, if preharvest insect reduction practices (e.g., pesticides, pest attractants,
pest resistant cultivars) are combined with packhouse sorting procedures. Systems
approaches, demonstrating pest reduction from field to packed commodity, require detailed
monitoring and documentation in order to be acceptable to regulatory agencies. Currently,
watermelon exported from Tonga to New Zealand is the only example known to MBTOC of
the systems approach in commercial practice.
Chemical alternatives
Chemical treatments using, for example, hydrogen cyanide have very limited commercial
application because they are difficult to apply, have a narrow pest spectrum of activity, can
severely damage many commodities, and are not approved for use in some countries. Others,
such as carbon dioxide and sulphur dioxide, are at the experimental stage of development.
Aerosol formulations of some plant (e.g., ethyl formate) and non-plant (e.g., dichlorvos)
chemicals and immersion in dilute insecticide solutions are sometimes used on non-food,
perishable exports such as cut-flowers. Apart from the difficulty of synthesising and
registering a new, highly pesticidal molecule, chemical treatments are not being investigated
because consumers increasingly prefer food with no pesticide residues. Registration of new
chemical fumigants is also very costly (estimated to be at least US$35M) and time consuming
because many countries now require extensive tests demonstrating safety to humans and the
environment. Registration for this very limited postharvest use alone can take considerable
time and is costly.
Non-chemical treatments
Most non-chemical treatments do not leave residues and therefore are more acceptable to
consumers than methyl bromide or other chemical treatments.
The most widely used non-chemical technique is short term cold storage at -1°C to + 2°C for
10 - 15 days to kill tropical fruit flies on citrus, grapes, papaya, avocado and kiwifruit. Cold
treatment is carried out commercially in-transit or using land-based facilities, and require
precise records of the temperature and duration showing compliance with the phytosanitary
treatment specifications in order to be acceptable as a disinfestation treatment.
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Heat treatments at 40 - 50°C for less than eight hours are also becoming more common for fruit
fly control in tropical commodities, particularly those that are based on heated air rather than
hot water immersion. Heat for disinfestation is being tested on some temperate commodities.
The temperature, duration, and application method must be very precise to kill pests without
damaging the commodity. Heat is unsuitable for highly perishable, products such as asparagus
cherries or leafy vegetables as their shelf-life and marketability is reduced '
Some pests can be killed by 1 - 2 months storage at low temperatures under low oxygen/high
carbon dioxide conditions (Controlled Atmosphere (CA)). The time can be reduced
considerably by raising the temperature above 30°C. However, adoption of this technology is
limited mainly by inadequate data on the responses of pests and commodities to high-
temperature CA and the difficulty of designing large, high-temperature, CA disinfestation
facilities with adequate gas retention. Gas retention is particularly important under CA
compared to gas retention with fumigants alone. There is no commercial application known to
MBTOC at present illustrating the use of CA for disinfestation.
On a much smaller scale, atmospheres immediately surrounding the commodity can be
modified (termed Modified Atmosphere (MA)) to kill pests using polyfilms or coatings made
rrpm wax or cellulose-based compounds. There are no commercial examples of MA for
disinfestation as this treatment is under development
Irradiation (X-rays, electron beam or isotope) can control many pest species and has additional
advantages of treating the commodity in the final packaging with no appreciable change in
temperature or atmosphere. Few commercial irradiators have been developed for
disinfestation. Low doses are capable of achieving quarantine security by sterilising pests
Thirty five countries have approved the use of irradiation on over 50 specific food commodities
including apples, banana, garlic, mango, onions, papaya, potatoes, stonefruit, and
strawberries. United Nations agencies have recognised the similarity in response of fruit fly
species and, in order to avoid unnecessary experiments, has recommended a minimum
effective dose regardless of their host commodity. Among the factors currently influencing the
adoption of this specific technology for disinfestation are widespread consumer, industry, and
regulatory acceptance. Some of these factors are insufficient commia-cial-scale assessments of
cost-benefit, verification of live but sterile pests, and perceived public concern with the safety
of isotope transport, long-term storage and facility location.
Disinfestation treatments can be combined to achieve the required pest mortality. For example
chenmoya fruit exported from Chile to the USA can be treated with a mixture of soapy water
and a wax coating; and lychees exported from Taiwan to Japan can be treated with vapour heat
followed by a cold treatment to achieve quarantine acceptance. Combination treatments are
rare, probably because of the more extensive technical documentation required to demonstrate
treatment efficacy for regulatory agencies, compared with single treatment applications.
However, combined treatments or procedures will, in many cases, offer greater quarantine
security than a single treatment Additionally, combined treatments may allow a reduction in
the amount of methyl bromide required for pest mortality, thus reducing the potential for
commodity damage and the amount released to the atmosphere.
Constraints to the development of alternatives i
Alternatives have to be adapted to suit the combination of pests and commodities that occur in
specific countries. Commercial implementation requires the completion of several
developmental phases including laboratory experimentation, regulatory agency approval of the
experimental data and proposed commercial method, engineering design and construction, and
equipment certification. So far it has not been possible to completely transfer disinfestation
technology between countries because each has commodities and pests that differ in tolerance
to the proposed treatment and each has adopted particular phytosanitary principles. Because
each potential alternative treatment must be adapted to the new country, their development
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requires skilled research, is labour intensive, time-consuming and costly. Commercial
application typically requires from 3 to 7 years for adapting existing alternatives to a new
country. Normally about 10 or more years may be needed if an entirely new quarantine
treatment technology is to be developed.
Methyl bromide recycling and recovery
Because most fumigations of perishable export commodities are carried out using solid-wall
fumigation facilities that retain most of the gas, there is opportunity for recovering and
recycling methyl bromide. Unlike durable commodities, such as wheat, that absorb relatively
large amounts of methyl bromide, perishable commodities absorb relatively little, leaving 85 -
95% available for recovery. Equipment for recovering and recycling methyl bromide requires
considerable further technological development before it can be adopted widely, and is likely to
be expensive.
Developing country issues
Special attention must be paid to the needs of developing countries. They are heavily
dependent on technology developed in other countries. To facilitate development of
alternatives, funds are required to allow researchers and quarantine personnel to attend
conferences, workshops and training courses on a regular basis. Regulatory agencies in
industrialised countries should review existing quarantine policies in line with international
changes in phytosanitary concepts. They must ensure that clear disinfestation guidelines are
made available and, if necessary, provide a technical advisor to assist with experimental design
and report documentation. Opportunities for accommodating Article 5 country staff for an
appropriate period of time in the laboratories of scientists developing alternative treatments
should be encouraged. To ensure continuity of skilled personnel, students and quarantine
officers should be encouraged at secondary and tertiary educational levels to undertake courses
essential to the development and implementation of environmentally-sound alternatives.
4.3.1 Introduction
Although pesticides and other control measures are often used to kill pests in the orchard or
field, \hzstpreharvest treatments cannot guarantee that all pests are killed. In contrast,
postharvest disinfestation treatments are carried out under precisely controlled procedures to
ensure that pests of quarantine importance are killed and not transported to other areas where
they do not occur. Ideal disinfestation treatments need to be effective in controlling a broad
spectrum of pests, rapid if required, non-detrimental to the commodity and the facility, safe for
the operator and consumer, easily applied, environmentally sound, large scale efficiency,
render the commodity safe, be cost effective, readily acceptable to the consumer and regulatory
agencies.
Almost all postharvest treatments on perishable commodities are carried out for quarantine
purposes. Unlike stored products where pests destroy the commodity during storage unless
controlled, there is negligible damage of perishables due to pests. Considering all the
disinfestation treatments currently applied in world markets, methyl bromide fumigation is by
far the predominant quarantine treatment for fresh fruits, vegetables and cut flowers. Few
approved quarantine treatments exist that do not use methyl bromide, and the few that do have
a very narrow application (Anon., 1988,1992).
A large number of treatment schedules has been developed to control a wide range of pests that
could be present on imported fresh produce. Most countries apply a disinfestation treatment to
imports if live pests are intercepted. Occasionally, the importing country requires a
disinfestation treatment to be undertaken in the exporting country to control pests considered
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extremely damaging if accidentally imported. Any treatment developed to control pests must
meet the level of quarantine security acceptable to the importing country and ensure commodity
marketability. J
If an alternative treatment to methyl bromide is not available, the importing country is most
likely to notify the exporting country of the inability to disinfest the product on arrival if
necessary, and that if quarantine pests are detected on arrival, the product will be re-shipped or
destroyed. Thus, exporting countries without acceptable alternatives will face a loss of export
revenue, and importing countries will not allow commodities to be imported resulting in fewer
varieties of fresh commodities available for the consumer.
Section 4.3.2 quantifies methyl bromide fumigation of exported and imported perishable
commodities by each country, and the amount used for those transported within the same
country.
Section 4.3.3 gives a general description of alternatives to methyl bromide. Those most
commonly used are discussed first. Alternatives are categorised into those that minimise pest
incidence and avoid the need for a postharvest treatment (i.e., those based on preharvest
procedures), and those that apply a postharvest disinfestation treatment for pest control.
Section 4.3.3.2.3 outlines the major constraints restricting the development and implementation
or alternatives to methyl bromide.
Section 4.3.4 discusses examples of existing alternatives to methyl bromide currently in use for
each commodity, and then describes potential alternatives with specific examples and key
citations. These examples are not an exhaustive list of all those that are currently under
development but rather illustrative of the range of alternatives that are; under consideration
Information on research and development is being collated by a number of agencies around the
world and inclusion in this chapter would require considerably more space than permissible
Commodities are grouped according to their horticultural similarity or by pests associated with
The key treatments and their potential uses are summarised in Section 4.3.5.
For some perishable commodities that are economically important, cammerciaUy-viable
alternatives are not available to replace methyl bromide. These are listed and briefly discussed
in Section 4.3.6. •
For those commodities without alternatives or where alternatives are riot immediately available
it will be important to reduce methyl bromide emissions as much as possible. Although
emission reduction is discussed generally in Section 3.5.2, the possibilities for emission
reduction for perishable commodities are highlighted in Section 4.3.7.
Sections 4.3.8,4.3.9 and 4.3.10 highlight research priorities and the transfer of technical
knowledge, particularly in relation to developing countries.
4.3.2 Existing uses of methyl bromide
Forty nine government organisations within major fruit exporting countries (listed in
Annex 4.3.1) were sent forms (refer Annex 4.3.2) requesting information on the postharvest
use of methyl bromide on perishable commodities.
Information was requested on:
1) Perishable commodities fumigated by the importing country as a condition of entry;
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2) Perishable commodities fumigated in the country of origin before export; and
3) Perishable commodities fumigated before shipment within the same country which, for
example, seeks to prevent the spread of pests from regions within a country.
Twenty-two countries replied to the survey, and their responses are shown in Annex 4.3.4
(fumigation of imports), Annex 4.3.5 (fumigation of exports) and Annex 4.3.6 (examples of
fumigation for shment within die same country).
4.3.3 Characteristics of potential alternatives
This section describes 14 general alternatives or potential alternatives to methyl bromide for
meeting quarantine security. Few alternative treatments have been developed for commercial
use. They are more pest and commodity specific than methyl bromide, and none have all the
attributes of the ideal disinfestation treatment listed. Alternative treatments may require
modification to adapt them to effectively control pests without damaging the commodity.
Alternative quarantine treatments typically require 3-7 years for adaptation under non-urgent .
conditions in order to complete the technical requirements. Possibly 10 or more years are
needed under non-urgent conditions if an entirely new quarantine treatment is to be developed
However, the development of alternatives could be expedited by developing and adopting
international standards (see Section 4.3.3.2.3 on constraints) for quarantine treatments.
Although this section lists a large number of alternative treatments, the potential for success of
each treatment depends on the physiological responses of the commodity and the pests
associated with each commodity. With this in mind, for each commodity grouping there are
relatively few alternatives currently in use because each is developed to control one or more
pests on a specific commodity, although with further research a number of potential alternatives
will be developed and implemented. Until recently, there has been little impetus to develop
alternatives to methyl bromide because there have been no regulatory constraints, the chemical
is lethal to many pests, and it is cost-effective.
4.3.3.1
Preharvest practices and inspection procedures
The presence of pests postharvest indicates insufficient preharvest_ control to comply with strict
phytosanitary standards, and therefore considerable attention is paid to controlling them before
harvest Inspection can be carried out to determine the effectiveness of the preharvest
treatments, and if through sampling a proportion of the packed consignment the pest incidence
is determined to be nil or very low, the product may be exported without a postharvest
treatment. However, field control of a pest has rarely provided quarantine security. As a
general rule, 90% of the pesticide applied does not hit the target pests (Luckmann and Metcalf,
1982). This results in field levels of control rarely exceeding 90% pest mortality which is an
insufficient level of control for the present concept of greater than 99.9% mortality for
quarantine security (Baker, 1939; Couey and Chew, 1986).
4.3.3.1.1 Cultural practices leading to pest reduction
At each stage of the commodity production and packing process, there is a reduction in pest
population mainly because of the application of pesticides and sorting of pest-infested fruit by
grading personnel and machinery (Mr T. Main, Manager, Aweta, Israel, pers. comm. 1994).
These pest reductions can be quantified at key points in the production-to-export chain (hence
the term 'Multiple Pest Decrement' or 'Systems Approach1). The systems approach is highly
dependant on a knowledge of the pest/host biology and phenology. Using pest risk analyses,
the probability of accidentally exporting the pest is often shown to be minimal and in some
cases exceeds the level of quarantine security achieved by fumigation alone (Moffitt 1990).
Provided there is no pest breeding in storage, multiple pest decrement can achieve or exceed the
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level of quarantine security acceptable to an importing country (Vail etal, 1993). However,
none has been approved as a stand-alone disinfestation treatment.
Reduction in insect populations can be achieved by cultural practises such as planting
genetically modified commodities that are no longer the preferred host of the insect (host plant
resistance), by harvesting when the commodity is not susceptible to attack (e.g., papaya which
is harvested immature and ripened later), by harvesting when the pest is not active (e.g,
diapausing or overwintering stage of the pest), by improved harvesting practices that remove
'hitchhiker pests' in the field or orchard, by the addition of biological, agents such as
parasitoids and predators, by releasing sterile insects, by using pheromones, or by using
microbial agents as pest pathogens. However, in some cases the presence of biological and
microbial agents on the commodity after harvest may cause quarantine concern.
Multiple pest decrement procedures lead to a reduction of the pests that currently occur in most
horticultural production. They may substitute for a postharvest treatment if the level of
quarantine security is acceptable. To date, inter-governmental agreements on multiple
decrement are rare because these procedures are time-consuming, difficult to document and
regulate.
i
4.3.3.1.2 Pest-free zones and periods
Pest-free zones have been established by some countries and consist of geographic areas where
commodities may be produced and exported because of the absence of pasts of quarantine
importance. Japan accepts melons from the Hsingchang Uighur Autonomous Region in China
based on this area being a melon, fty free zone (Anon., 1988b), and Japan accepts commodities
produced in Tasmania (AusteaHa) as free from Mediterranean fruit fly (C capitata) and
Queensland fruit fly (Bae&ocera tryoni) (Anon., 1989). In the future, it may also be possible
for the-development of pest-free periods providing importing authorities can be assured of
periods when it is not possible for the pest to infest the commodity.
As no direct treatment is applied, marketability of the commodity is not impaired. However,
these zones are often restricted to geographically isolated areas with buffer zones that exclude
host plants and residential areas where possible, require continuous enforcement, monitoring
and reporting, are based on extensive knowledge of the pest and commodity biology, and are
generally expensive because of all these factors.
4.3.3.1.3 Inspection and certification
Some countries inspect a sample of the produce prior to export (termed pie-shipment
inspection) and certify each consignment based on levels of acceptability for pests of quarantine
importance. However, this usually does not preclude further inspection on arrival. For
example, Japanese quarantine officials inspect cut flowers in the Netherlands which reduces the
need for inspection and disinfestation on arrival in Japan. Some commodities are accepted only
after inspection of the packed commodity and endorsement of the procedures used by the
importing country to kill any live pests (e.g., Japan, United States, New Zealand), or that live
pests are within permissible limits (e.g., New Zealand) (Baker et al., 1990).
Inspection is environmentally acceptable but labour intensive. The costs of inspection are
typically borne by the exporting country for pre-shipment certification and by the importing
country for inspection on arrival. These costs may be stabilised in the future by the use of
automatic inspection systems (such as low dose X-rays to "see pests",, or trace detection
systems to "smell pests" by detecting pest-specific chemicals) under development to
individually inspect perishable commodities.
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4.3.3.2 Postharvest treatments
4332.1 Non-chemical alternatives
order to kill pests without damaging the commodity.
jrsss^"s«^
treatments.
4.3.3.2.1.1 Cold treatment
PnM treatment is generally applied to fruit potentially infested with tropical pests which have
SeWSSfSSSS - 1°C to + 2°C) depend on pest susceptibility and fruit to erance to
al, 1990b). Cold treatment is used commercially ror control of fruit tlies in grapes, Kiwuruu,
and citrus (Anon., 1992).
4.3.3.2.1.2 Heattreatment
eneral heat treatments are carried out for 10 minutes to eight hours (Anon., 1992) at
control surface pests.
Commercial shipments of tropical fruit such as mango are immersed for short periods of time
m w^atiaU6 1°C and above for 65 - 90 minutes to kill any pests that might be present
(AnoTl992{ Tte waterlemperature and immersion period are precisely maintained so that
Sl^Sdally infesttog this commodity. Laborawry tests are being caattactri 1 to
their storage life.
Heat is an environmentally acceptable but energy intensive alternative
suitable for controUing pests found in or on most ttopical and some subffogcal
duration and application method must be precise to tall pests
Sow^ver, heat is unsuitable for many highly perishable products
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21 f
such as asparagus, cherries or leafy vegetables as their shelf-life and marketability is
significantly reduced by the treatment.
4.3.3.2.1.3 Controlled atmosphere
Fruit shelf-life can be extended by altering the normal atmosphere of 21% oxygen and 0.03%
carbon dioxide to about 0.5 - 3% oxygen and 2 - 5% carbon dioxide, and controlling it at these
atmospheres. Typically the treatments are carried out for many months at low temperatures
(e.g., 0 - 2°C) and are not suitable for tropical commodities because they cause chilling injury.
The exact atmosphere and temperature vary according to the fruit and variety. CAs have been
widely used for at least 30 years for prolonging the storage life of apples and pears. More
recently CAs have proven effective on a laboratory scale for quarantine control of temperate
pests, particularly when combined for short durations with temperatures above 30°C (Whiting
et al., 1991). Unfortunately, in some cases the requirements for insect control damages the
commodity (Smilanick, 1992).
CA is an environmentally sound treatment that is particularly suitable for controlling some pests
on perishable products that store well such as apples (Batchelor et al., 1983; Whiting et al.,
1991 for control of Lepidoptera under low and high temperature CA; Dickler et al., 1975 for
low temperature control of scale insects). There are few commercial uses of CA for
disinfestation of fresh products because lengthy periods in standard CA cool storage are
required to achieve high pest mortality which results in an unacceptable reduction in commodity
quality (Meheriuk et al., 1994). Other factors limiting widespread adoption of this technology
are inadequate data on the responses of pests and commodities to high-temperature CA, the
difficulty of designing large high-ternperature CA disinfestation facilities with adequate gas
retention, and regional variation in the cost of gases for CA (Whiting et al., 1991; Benshoter,
1987).
4.3.3.2.1.4 Modified atmosphere
The shelf-life of fruit can also be extended by allowing fruit respiration to modify the
atmosphere, reducing oxygen and elevating carbon dioxide. The final atmosphere and the time
to establish equilibrium is not easily controlled or predictable as it depends on the biological
process of fruit respiration which, for example increases with increasing temperature.
Modified atmospheres (MAs) are typically generated by wrapping various types of polyfilms
around the commodity (Shetty et al., 1989). In some cases, the commodity is palletised and
wrapped, and then flushed with gases to establish the desired atmosphere. Film permeability
varies with film type and temperature, making MA control difficult under the changing
temperatures commodities may experience in transit. Consumers, however, may eventually
limit the widespread use of this technology due to concerns with excessive use of packaging
materials.
Specialised films for maintaining commodity quality using atmosphere-absorbing compounds
impregnated into the film are becoming available. Such films are called 'active packaging' and
are sometimes temperature activated. They are likely to be important in the future, particularly
if they have a disinfestation role in addition to increasing shelf-life.
More recently, applying specialised coatings made of wax or cellulose to citrus has proven
effective in the laboratory for killing Caribbean fruit fly (Greeney and McDonald, 1993; Sharp,
1990). Wax treatment of a commodity may not be acceptable to the consumer.
MA is an environmentally sound treatment that is particularly suitable for controlling pests on
perishable products that can store for at least 7 days such as strawberries. However, there are
currently no commercial examples of using MA for disinfestation of perishable commodities.
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4.3.3.2.1.5 Irradiation
irradiation can control many pest species and has additional advantages of allowing the
storage and facility location.
SSflv swdto fe order to avoid unnecessary disinfestation experiments, they have
fruit fly and rnites (ICGFI, 1989).
4.3.3.2.1.6 Microwaves
be advantageous for quarantine treatment of small shipments.
4 3 3 .2. 1 .7 Physical removal
SepS She tSnce of the commodity to the treatment or convenience of use in the
packing operation.
433218 Combination treatments
imported from Taiwan by Japan (Anon., 1980).
The two combination treatments cited are the only known ones . .
awepTed by regulatory agencies. The rarity of combination treatments is probably due to the
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extensive technical documentation required to demonstrate treatment efficacy for regulatory
agencies compared with single treatment applications. s^<«ory
4.3.3.2.2 Chemical alternatives
4.3.3.2.2.1 Fumigation
This is the act of releasing and dispersing a pesticidal chemical so that it reaches a pest
completely or partially while in the gaseous state. ^
Fumigation treatments using, for example, sulphur dioxide, and hydtogen cyanide depend on
^nl^^u?™™***0^' temPeratures «*t d^tions to kill pests without dlmagiSg
?™TT?T Hydrogen cyanide may not be approved for use in all countries. Bond (1984)
provides details of furmgant properties and methods of application.
Sulphur dioxide is used mainly for fungus control in cool stored grapes, and recent research
has shown a potential to control mealybug and lepidopteran insecls (Vail etal, 1991)
commodities for con1^ * pests such as
n1 U^u°f Plant V°latiies such as ^Pa™6 applications of ethyl or methyl
formate and acetaldehyde (Aharoni etal., 1979; Stewart and Monf 1984), but none are
SSE?y re?stered as fumigation treatments. Ethyl and methyl formate are inflammable and
explosive when mixed with air at concentrations required to kill pests: and may require
H25ST? ™ mCrt Ethyl formate is less Pesticidal than methyl formate
s: gsr16 than a pesticide- and * safety to humaL has
USing natUr plant products e'g" Pyrcthroids, or dichlorvos insecticide,
countries such as New
u suitable for killing Pests that could be
r they are not favoured by consumers seeking food with no
residues. Registration of new chemical fumigants is also costly and time consuming
as many countries now require extensive safety tests.
4.3.3.2.2.2 Chemical dips
Commodities can be dipped in a very dilute pesticide solution after harvest to kill targeted pests
Aatrmght be present in or on the commodity. For example, Australian tomatoes exported to
m^SS^;^^ m lflS,f tid^ toucontrol Queensland fruit fly (Bactrocera trjonf)
SSS? ^ : ' ? P°tentially lnside the commodity; and some cut flowers are immersed in
insecticide to control pests on the surface (Hansen et al, 1992; Hata et at., 1992).
disc°urage theruf of chemical dips because of consumer concern for chemical
» w AT dlSP°Sal °f th^ pesticide solution after treatment is often environmentally
unacceptable. Other countries such as New Zealand and Singapore accept the treatment
providing the maximum residue limits are not exceeded. For these reasons, a chemical dip is
andX fSwers O" n°n'edlble commodities such as ornamental plants, bulbs, nursery plants
4.3.3.2.3 Constraints to acceptance of alternatives
The main constraints to the development and acceptance of a potential alternative quarantine
treatment have been outlined in Section 2.0. Alternative treatments are developed and
implemented by integrating many technical, environmental, and regulator/ factors
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Economics, logistics and engineering considerations are also key factors in the acceptability of
an alternative treatment.
particularly for sensitive commodities.
approval of quarantine treatments.
as rapidly as possible.
'4.3.4 Suitability of alternatives for controlling pests on each group
of commodities
4341 Apples and pears
quarantine concern.
United States.
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215
Existing alternatives: There are few commercial treatments for apples and pears to control
pests. Pre-shipment certification is carried out successfully by several countries exporting to
the United States including New Zealand and Chile. Cold storage with CAs have been used to
kill scale insects on apples exported from Canada to California (Didder et al., 1975). USDA-
APHIS approves a cold treatment to control fruit fly in apples or peai-s imported into the United
States from Chile, France, Israel, Italy, Jordan, Mexico, South Africa, Spain, and Uruguay
(Anon., 1992). Irradiation is used to increase the shelf-life of apples on a small scale in China
(Xu et al., 1993).
Potential alternatives: CA at low temperature kills some lepidopterous species, but shorter
and more economical treatments may be achieved by combining CAs with heat, or by using
heat alone. The relative tolerance of the pest compared to the commodity when exposed to CA
alone, or when combined with heat, is currently being determined (V^hiting et al., 1992).
There is an urgent need to gain a better understanding of pest and fruit physiology under
CA/heat or heat alone in order to optimise treatment parameters.
A codling moth pest-free zone is feasible in Western Australia since ihis pest is absent in apple
and pear production areas. Sterile codling moths are currently being released in the Okanagan
Valley region in Canada to establish a pest-free zone (Proverbs et al, 1982).
Multiple decrement is feasible, particularly as the reduction in codling moth population in
apples has been documented for some packhouse operations in Washington State (Moffitt,
1990). There is potential to reduce the incidence of orchard pests by improving orchard and
packhouse management practises.
The response of all stages of codling moth to irradiation has been defined (Burditt and Moffitt,
1985). 'Red Delicious' apples irradiated up to 1 kGy were marketable even after 11 months
storage (Olsen et al., 1989). Further research on the tolerance of apple varieties is required.
4.3.4.2
Stonefruit
Stonefruit includes peaches, plums, cherries, apricots, and nectarines. Exports are
economically important for: Canada, Chile, France, New Zealand, United States, and some
Mediterranean countries.
Although Stonefruit are infested by a large number of pests, for most countries codling moth,
fruit flies, oriental fruit moth, walnut husk fly, mites and thrips are the major pests of
quarantine concern.
!
Some countries, e.g., United States (Yokohama et al., 1987), New Zealand and Canada, have
developed a mandatory methyl bromide fumigation treatment for exports of cherries and
nectarines to Japan. The US DA-APHIS accepts a cold treatment alone for some Stonefruit
including cherries imported from Chile, plums from Israel, and apricots, peaches and plums
from Morocco (Anon., 1992).
Existing alternatives: Australia has set maximum pest levels and accepts pre-shipment
certification from New Zealand that these are not exceeded on nectarine and apricot exports.
About 14 tonnes of fresh plums imported by South Africa from France were irradiated at
2 kGy for insect disinfestation (Mr Du Plessis, Managing Director Gammatron, South Africa,
pers. comm. 1994).
Potential alternatives: Stonefruit tolerate low oxygen CAs (0.25 - 0.5% oxygen) (Kader,
1985) for 8-40 days depending on the commodity and the temperature. CA combined with
high temperatures may damage the quality of Stonefruit (Smilanick and Fouse, 1989). The
potential for controlling pests under CA at a range of temperatures is currently being
determined.
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216
Preliminary research has shown some varieties of nectarines tolerated 24 hours exposure to
heat using 41°C moist air to kill some thrips species (Lay-Yee and Rose, 1994). Immersion of
apricots in water heated from 25 - 45°C for 10 - 30 minutes damaged fruit quality, probably
due to inoculum in the water being carried into the core cavity of the fruit (Lay-Yee and Rose,
1994). 'Bing' cherries heated in moist air at 47°C for 35 minutes and then stored at 0±1°C for
less than 14 days tolerated the treatment (E. Mitcham University of California (Davis) pers.
comm. 1993) which may also control codling moth (Neven, 1993).
New Zealand accepts a pest-free period for walnut husk fly on nectarine exports from the
United States (Yokohama et al, 1992).
Cherries, nectarines and peaches are the most tolerant of all the stonefruit to irradiation and
therefore this treatment offers potential for insect control. Doses up to 1 kGy did not damage
'Rainier1 cherries which is approximately 3 times the dose required to kill the most tolerant
stage of codling moth (Drake et al, 1994).
Cherries are particularly tolerant of high carbon dioxide levels generated by a modified
atmosphere treatment which may be effective for controlling pests.
Cherries and nectarines are extremely poor hosts to codling moth (Vail et al., 1993; Curtis et
al., 1991). This fact combined with pesticides applied in the orchard and sorting in the
packhouse (multiple decrement) achieves a level of security which should meet the
requirements of most countries. Nectarine varieties vary in their susceptibility to field
infestation levels of codling moth which suggests commodity resistance has potential (Curtis et
al., 1991).
4.3.4.3
Citrus
Citrus includes oranges, grapefruit, lemons, limes, tangeloes, tangerines and pummelos.
Exports are economically important for: Australia, Brazil, Israel, Japan, South Africa, United
States, and some other Mediterranean countries.
Although citrus are infested by a large number of pests, for most countries fruit flies, scale
insects, and Fullers rose weevil are the main pests of quarantine importance.
Methyl bromide often damages citrus at concentrations required to kill fruit fly, limiting its use.
Existing alternatives: Japan accepts citrus from Florida exposed to 10 - 14 days cold
treatment at 0.6°C to control Caribbean fruit fly (Anastraepha suspensa); citrus from South
Africa after 12 days cold treatment at -0.6°C to control Mediterranean fruit fly (C. capitata); and
citrus from Israel after 13-14 days cold treatment at 0.5°C to control the same species.
USDA-APHIS accepts cold treatment for 11 - 22 days depending on the temperature for
control of fruit fly species in some varieties of citrus from 23 countries (Anon., 1992).
Sometimes preconditioning at warm temperatures is necessary for citrus fruit to tolerate cold
treatment (Houck et al, 1990a,b; Kitagawa et al, 1988). Hydrogen cyanide fumigation is
used to kill scale insects. Heated dry air that increases the temperature of the fruit centre of
grapefruit to 47.8°C over at least a 3 hour period is an approved quarantine treatment to control
Mexican fruit fly (Anastraepha ludens) (Anon., 1992). Heated moist air to a fruit centre
temperature of 43.3°C and held for 6 hours is approved for control of this pest in grapefruit,
orange, and tangerine from Mexico (Anon., 1992).
Potential alternatives: These include irradiation for some varieties of oranges, grapefruit
and lemons (Thomas, 1986, Johnson.et al, 1990). Limes exhibit significant radiation injury
(Maxie et al, 1969). Some citrus is individually wrapped with fungicidal film, and the
modified atmosphere generated may also kill pests if insects inside the fruit do not break the
film. Some MA treatments damage citrus (Houck and Snider, 1969) limiting its widespread
use. Heat treatments for control of different species of fruit fly are under development for
-------
21 7-.
grapefruit (Sharp, 1993 in Florida; Mangan and Ingle, 1994 in Texas), and for grapefruit and
'Valencia' oranges (J.W. Armstrong, USDA-ARS Hilo pers. comm. 1993 in Hawaii). Citrus
phytotoxicity as a result of heat treatment has been previously reported (Houck, 1967). There
may also be opportunities for pest control by genetically inducing resistance in citrus to pests,
by adding coatings to the surface of the fruit (in combination with dimethoate insecticide or
heat) which reduce the ability of the internal atmosphere of the fruit to sustain pests
(J.D. Hansen, USDA-ARS Miami, pers. comm. 1993), by demonstrating pest-free zones and
pest-free periods, or by documenting pest reduction due to a series of control measures applied
in the production of the commodity (multiple decrement). Experiments have shown high
pressure water washes scale insects and Fuller's rose weevil off citrus (.T.G.Morse,
UC Riverside, pers. comm. 1994).
4.3.4.4
Grapes
Grape exports are economically important for: Australia, Brazil, Chile, Israel, South Africa,
the United States and many European countries.
The main pests of quarantine concern on grapes are fruit flies, Lepidoptera, mealybug, and
mites.
The USD A-APHIS accepts cold treatment from 30 countries for control of vine moth Lobesia
botrana and other insects in grapes providing the treatment is combing with methyl bromide
fumigation. Grape exports to the United States from Chile are accepted from a Mediterranean
fruit fly free zone providing they are also fumigated with methyl bromide to control the mite
Brevipalpis chilensis.
Existing alternatives: Japan accepts 12 days cold treatment at 0.5°C for control of
Mediterranean fruit fly on grapes exported from Chile (Anon., 1990).
Potential alternatives: In-storage fumigation with sulphur dioxide (routinely applied for
fungal control), alone or combined with carbon dioxide (Vota, 1957)., may provide pest
control, although this has received little study. Vail et al, (1992) reported sulphur dioxide
concentrations comparable to those used in routine fumigation of grapes killed a key insect pest
in the United States. This suggests sulphur dioxide has potential to control both fungi and
insects. However, the presence of sulphur residues from sulphites, typically about 10 ppm,
may limit widespread use of sulphur dioxide for disinfestation. The f Jnited States requires
mandatory labelling of products containing > 10 ppm sulphites to warn sulphite-sensitive
people of their presence. Grapes do not tolerate high concentrations of carbon dioxide for
extended periods (Yahia et al., 1983). Gamma radiation using < 1 kGy shows potential for
disinfestation of grapes which are damaged by > 1 kGy (Brarnlage and Couey, 1965; Maxie et
al., 1971). In general the response of grapes to gamma irradiation is variable (Josephson and
Peterson, 1983). Other potential alternatives requiring investigation are heat treatments, and
CAs.
4.3.4.5
Berryfruit
Berryfruit includes strawberry, raspberry, blueberry and blackberry. Exports are economically
important for: Australia, Brazil, Canada, Colombia, Israel, New Zealand, South Africa, the
United States and Zimbabwe.
The main pests of quarantine concern are blueberry maggot and other fruit flies, thrips, aphids,
and mites.
Many countries require a mandatory methyl bromide fumigation for berryfruit imported from
countries with fruit flies. If fruit flies are not an issue, berryfruit are imported upon inspection.
Imports of blueberries into regions in Canada that do not grow blueberries are permitted.
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218
mendax) in blueberries (Miller et al,
Currently, strawberries are 8^n^ "^?cS&SaS other Srts of the United States, a
CA will not be of sufficient duration to kill pests.
4346 Root crops
national econoies of many of the developing countnes.
imorted into the United States and other countnes.
imported into the United States and other countnes.
Existing alternatives: None known.
Potential alternatives: teadiatio, .is Wg^-fJ-*; . and
weevil and the banana moth Opogona sacchan (Sharp, 1994).
may also be feasible.
4.3.4.7 Vegetables
developing countries.
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219
Existing alternatives: Most imports currently rely on inspection and release to the market
if no live pests are intercepted. Asparagus is fumigated with methyl bromide in Japan for
control of lepidoptera and mites, and with hydrogen cyanide when live thrips and aphids are
intercepted. Bell peppers from Okinawa were shipped to other parts of Japan after a vapour
heat treatment to control melon fly which used to infest this island. Tomatoes exported from
Australia to New Zealand are immersed in a dimethoate chemical dip for control of Queensland
fruit fly prior to export (Heather et al., 1987). Moist heated air sufficient to raise the fruit
centre temperature to 44.4°C for 8.75 hours is an approved quarantine treatment for
controlling Ceratitis capitata, Bactrocera dorsalis and B. cucurbitae in bell pepper and tomato
imported into the United States (Anon., 1992).
Potential alternatives: Methyl or ethyl formate fumigants may control pests on leafy
vegetables (Spitler et al., 1985). Unfortunately, effective concentrations are close to their
flashpoints (Aharoni et al., 1979; Stewart and Mon, 1984). Further research is required to
define the tolerance of the pests and commodities to these natural plant products.
Environmental and/or health considerations may restrict registration of these and other
biocides. Heat treatment (vapour or dip) may be feasible for some vegetables (e.g., tomato,
green pod vegetables), and pests (e.g., thrips); research is required to determine the commodity
and pest tolerance. Tomatoes are currently treated commercially with irradiation (Corrigan
1993), a treatment that also appears feasible for asparagus (Markakis and Nicholas, 1972)'
Most leafy vegetables undergo tissue damage at doses of irradiation less than those required-to
kill pests (Markakis and Nicholas, 1972). Cold treatment may control tropical pests such as
fruit fly in tomatoes, particularly if they are picked immature (but capable of ripening under
the specific conditions) when they are more tolerant to cold storage. Cabbages are exported to
Japan from New Zealand under in-transit CA conditions to maintain quality, and this treatment
may have potential for controlling pests. Similarly, CA coldstorage conditions developed to
maintain the quality of vegetables transported in containers from the mainland United States to
Guam by the United States military were observed to kill aphids and thrips (Gay et al., 1994).
4.3.4.8 Cucurbits
Cucurbits include different varieties of cucumbers, melons, and squasih. Exports are
economically important to: Australia, Chile, Israel, Mexico, the Netherlands, New Zealand,
South Africa and the United States. For some developing countries, the sale of cucurbits is
very important for the national economy.
Cucurbits are infested by a wide range of pests particularly fruit fly, lepidoptera, aphids and
thrips.
Most cucurbits are not fumigated with methyl bromide but are imported after inspection and
certification. However, watermelon exported from Tonga to New Zealand is the only example
of an intergovernmental agreement on multiple decrement, based on culling infested fruit in the
field followed by fumigation with methyl bromide.
Existing alternatives: Some countries such as the United States and Japan accept imports
of cucurbits only from pest free zones. Japan accepts melon from Hsingchiang region in China
as this is a pest free zone for melon fly, and squash from Tasmania as this is a pest free zone
for Queensland and Mediterranean fruit flies. Moist heated air sufficient to raise the fruit centre
temperature to 44.4°C and held at this temperature for 8.75 hours is an approved quarantine
treatment for controlling Ceratitis capitata, Bactrocera dorsalis and B. cucurbitae in eggplant
squash and zucchini (Anon., 1992).
Potential alternatives: Some cucurbits such as cucumber and squash are tolerant to heat
(water or moist air), particularly if preconditioned to a temperature slightly less than the final
temperature, and therefore this treatment offers potential for controlling fruit fly and
lepidoptera. Preconditioning increases the tolerance ofDrosophila to heat which may also
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220
and zucchini 0™
under development in Hawaii for eggplant
comm. 1993). It may be possible to
•mauve since some cucurbits are not hosts to some fruit fly
S possible for cucurbits potentially infested by melon fly in
rr r". _. rr«—i.-ir i:r~ of cucumber is extended by
this method requires further
investigation (Shetty etal, 1989; Jang, 1990).
4349 Tropical fruit
ttopS fmit is very important for the national economy.
^icSly exceed the tolerance of the commodity (Arpaia el al, 1992, 1993).
p
Potential alternatives: tradiadon has been tested mainly on tropical fruit and shows the
most potential for these commodities.
Further research is required to determine the i _
University of Hawaii, pen, comm. 1993). Multiple decrement appears promising for
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221
t" I
avocado, based on pest-free zones and periods, host' resistance, and host status. The eerm
plasm of avocado is being screened for resistance to the Caribbean fruit fly using caged adults
™™ S&? ^ng *e devel°Pment of eggs (J-D- Hansen, USDA-ARS MiSni, pers.
comm. 1993) Film wraps to control fruit fly may be feasible for papaya and other tropical
fruit exports (Jang, 1990). A film wrap treatmem for mangoes is Snder irwestigatio^Recent
experiments in Florida have shown Caribbean fruit fly are killed in grapefruit coated with
NatureSeal® coating prior to heat treatments for 60 minutes at 48°C (Mailman pers. comm
1993), and experiments are continuing on other fruit (guava, carambola and mango) and other
treatments such as cold storage, irradiation, and insecticides (Hallman et al., 1994).
4.3.4.10 Cut flowers and ornamentals
Cut flowers such as roses, carnations, chrysanthemums, bird-of-paradise and orchids are
economically important as exports from: Australia, Colombia, Kenya., Malaysia, the
Netherlands, New Zealand, Singapore, South Africa, Thailand, the United States and
Zimbabwe. Ornamental exports include deciduous woody plants, evergreens, and cvcads and
are also economically important as exports from these countries.
infe4Sted ?y a wide ***& of P6518 including external feeders,
™a™ S-' a? ' mitef1an5i ^ msects- Live pests intercepted on cut flowers and
ornamentals on arrival are typically fumigated with methyl bromide (Anon 1992) The
dosage vanes with temperature, target pest, and in the case of ornamentals the physiological
state or the plant e.g., dormancy. 6
Existing alternatives: Methyl bromide is damaging to many types of cut flowers and the
most common alternative to methyl bromide is pre-clearance inspection. Some flowers and
ornamentals are fumigated with hydrogen cyanide to control aphids, thrips and whiteflv but
S>nfe^nt Cajl !,d^imen,tal,t0 SJ?me flowers such as gerbera ** have a high moisture
content. Hawaii and pailand also dip cut flowers in a dilute insecticide solution such as
malathion to control thnps and other pests. The USDA-APHIS approves the use of chemical
dips (for about a 30 second immersion) in lieu of fumigation for those plants known to be
intolerant of fumigants (Anon., 1992). Also permissible is a high-pressure water spray for
Succmea horncola snails followed by a dilute carbaryl insecticide dip, or hand-removal of the
pests where practical followed by immersion in a malathion-carbaryl dip if necessary (Anon
1992). Aerosol formulations of insecticide chemicals (e.g., Hortigas® containing dichlorvos
and Permigas® containing permethrin) are used on cut flower exports from New Zealand to
J3.p3.Il.
Potential alternatives: Irradiation, is being investigated further for cut flowers and their
pests m several countries including the Netherlands, New Zealand, Japan, Malaysia
i!?^-' -^d Tt^d- Van de Vrie d986) showed that cut flowers; in the Netherlands
could be disinfested of key pests without significantly reducing the vase life of cut flowers, and
even increased the vase life of carnation, rose and freesia. Piriyathamrone et al (1986)
reported that irradiation at 1.5 - 2.0 kGy controlled thrips in orchids but the vase'life was about
naivea to o - ID days.
Aerosol formulations of insecticide chemicals and natural products are under investigation in
Thailand and other countries. Results to date show the formulations lack penetration into the
commodity and are therefore not always kill leaf miners and mites.
- shows promise as a disinfestation treatment for tropical cut flowers and
tonage (Hansen et al., 1992). A proposal to control magnolia white scale (Pseudolaucaspis
fro™ ? i?Tc^thurium using 49°C water immersion for 10 minutes will be submitted to
comm " 1993) approval as a
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222
43411 Bulbs
g., narcissi, are infesKd by dry bulb mite, bulb oi. and tulip bulb aphid,
« °f«=n d"5™1' " detect'
bromide, the rate depending on
*"
„
"
water for 1.5 -2 hours
ttves: LiUies
dichWos insec^cide in a
formulation.
4.3.5 Summary table of existing and potential alternatives . methyl bromide for
disinfestation
4 3 5.1. G»l«,ralPraenees(Sys,emSApproach,MultiplePes.Decrement)
(Section 4.3.3.1.1)
Immature banana exported to Japan (fruit fly)
Avocado (fruit fly)
1 uses'
Citrus
Root crops
Some cucurbits
Avocado
• Ginger
4.3.4.9
4.3.4.9
4.3.4.1
4.3.4.2
4.3.4.3
4.3.4.6
4.3.4.6
4.3.4.9
4.3.4.10
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223
4.3.5.2. Pest-free Zones and Periods (Section 4.3.3.1.2)
Existing uses:
• Nectarines from USA to New Zealand (walnut husk fly) 4.3.4.2
• Cucurbits to USA, Japan.and some other countries (fruit fly) ! 4.3.4.8
• Squash from Tasmania to Japan (fruit fly) | 4.3.4.8
• Melons from a region of China to Japan (fruit fly) 4.3.4.8
i
Potential uses:
• Apples and pears from zones that can be certified as pest-free 4.3.4.1
• Citrus 4.3.4.3
• Cucurbits from South America to USA 4.3.4.8
4.3.5.3. Inspection and Certification (Section 4.3.3.1.3)
Existing uses: Section
• Cut flowers from the Netherlands to Japan (many arthropod species) 4.3.3.1.
• Apples from New Zealand and Chile to USA (codling moth and others) 4.3.4.1
• Apricots and nectarines from New Zealand to Australia (thrips) 4.3.4.2
• Curcubits from many countries (fruit fly) 4.3.4.8
• Pineapple (fruit fly) 4.3.4.9
Potential uses:
• Root crops free of soil 4.3.4.6
4.3.5.4. Cold Treatment (Section 4.3.3.2.1.1) -
Existing uses: Section
• Apples and pears from Chile, France, Israel, Italy, Jordan,
Mexico, South Africa, Spain and Uruguay to US A (fruit fly) 4.3.4.1
• Stonefruit, including cherries, from Chile to USA (fruit fly) 4.3.4.2
• Plums from Israel and Morocco to USA (fruit fly) 4.3.4.2
• Apricots and peaches from Morocco to USA (fruit fly) 4.3.4.2
• Citrus from Israel, South Africa, and Florida to Japan (fruit fly) 4.3.4.3
• Citrus varieties from 23 countries to USA (fruit fly) 4.3.4.3
• Grapes from Chile to Japan (fruit fly) 4.3.4.4
• Grapes from 30 countries to USA, in combination with
methyl bromide fumigation (fruit fly, vine moth and other insects) 4.3.4.4
• Kiwifruit from Chile to Japan (fruit fly) 4.3.4.9
Potential uses:
• Berryfruit 4.3.4.5
•Root crops 4.3.4.6
• Some tropical fruit 4.3.4.9
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224
4.3.5.5 Heat Treatments (Section 4.3.3.2.1 .2)
Existin uses:
• Papaya from Hawaii to Japan and mainland USA (fruit fly)
• Mango from Taiwan to Japan (fruit fly)
• Citrus shipped within the USA (fruit fly)
• Tomatoes and bell peppers to USA (fruit fly)
a, zucchini to USA (fruit fly) thrinO
to USA (mite) and Japan (narcissus bulb fly and tnnps)
usesi
• Other stonefruit excluding cherries
• Apples
• Kiwifruit
• Anthurium flowers
• Tropical cut flowers and foliage
• Nectarines
• Bing cherries, combined with refrigeration
• Grapefruit and Valencia oranges
• Grapes
• Berryfruit
• Sweet potato and root crops
• Green pod vegetables
• Tomatoes
• Eggplant and zucchini
• Cucumber and squash
• Mango and lychee
• Banana, guava, carambola and mango
4.3.5.6 Controlled Atmospheres (Section 4.3.3.2.1.3)
uses:
• Apples from Canada to California (scale insects)
Potential usesi
• Apples and pears, if combined with another treatment
• Stonefruit
• Grapes
• Root crops
• Cabbages . . , ,
• Vegetables to Guam (Thnps and aphids)
4.3.5.7 Modified Atmospheres (Section 4.3.3.2.1 .4)
usesi Section
applications:
None
Citrus
Sttawberries from California to other US states
Strawberries
Section
4.3.3.2.1.2
4.3.4.9
4.3.4.3
4.3.4.7
4.3.4.8
4.3.4.11
4.3.3.2.1.2
4.3.3.2.1.2
4.3.3.2.1.2
4.3.4.11
4.3.4.11
4.3.4.2
4.3.4.2
4.3.4.3
4.3.4.4
4.3.4.5
4.3.4.6
4.3.4.7
4.3.4.7
4.3.4.8
4.3.4.8
4.3.4.9
4.3.4.9
Section
4.3.4.1
4.3.3.2.1.3
4.3.4.2
4.3.4.4
4.3.4.6
4.3.4.7
4.3.4.7
4.3.3.2.1.4
4.3.4.2
4.3.4.5
4.3.4.5
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225
• Cucurbits
• Mango
• Tropical fruit such as papaya
4.3.5.8. Irradiation (Section 4.3.3.2.1.5)
Existing uses:
• Plums
• Garlic
Potential uses:
• Apples
• Cherries, nectarines, peaches
• Some varieties of citrus
• Blueberries
• Some root crops
• Tomatoes and asparagus, but not most leafy vegetables
• Tropical fruit excluding avocado
• Some cut flowers
4.3.5.9. Microwaves (Section 4.3.3.2.1.6)
Existing uses:
• None
Potential uses:
• Not yet determined
4.3.5.10 Physical Removal of Pests (Section 4.3.3.2.1.7)
Existing uses:
• Citrus in South Africa (scale insects)
• Root crops such as potatoes, yams, carrots (wide range of soil pests)
Potential uses:
• Citrus in the United States
4.3.5.11. Combined Treatments (Section 4.3.3.2.1.8)
Existing uses:
• Cherimoya from Chile to USA, treated with soapy water and wax (mite)
• Lychee from Taiwan to Japan, treated with vapour heat and
cold treatment (fruit fly) i
• Certain cut flowers to USA, treated with pressurised water spray and
insecticide dip (snails, insects)
• Certain cut flowers to USA, treated with hand-removal of pests
and pesticide dip (thrips, aphids mainly) !
4.3.4.8
4.3.4.9
4.3.4.9
Section
4.3.4.2
4.3.4.11
4.3.4.1
4.3.4.2
4.3.4.3
4.3.4.5
4.3.4.6
4.3.4.7
4.3.4.9
4.3.4.10
Section
4.3.3.2.1.7
4.3.4.6
4.3.4.3
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226
Pn^nrial uses:
• Grapefruit treated with wax coating and heat
• Mango, guava, carambola treated with wax and heat
• Citrus treated with coatings and heat or insecticide
• Rambutan treated with heat and sulphur dioxide
4.3.5.12. Fumigation (Section 4.3.3.2.2.1)
Paring uses;
• Citrus treated with hydrogen cyanide (scale insects)
• Asparagus to Japan/treated with hydrogen cyanide (thnps and aphids)
• Somecut flowers treated with hydrogen cyanide (aphids, thnps, whitefly)
• Cut flowers from New Zealand to Japan, treated with aerosol
formulations of pyrethroids or dichlorvos (mainly thnps)
• Bulbs to Japan, treated with hydrogen cyanide (aphids and thnps)
Potential uses:
• Grapes, treated with sulphur dioxide alone or combined
Some Derryrrun, trcaicu with carbon monoxide or hydrogen cyanide
• Leafy vegetables, treated with ethyl or methyl formate
• Cut flowers, treated with aerosol insecticides
4.3.5.13. Chemical Dips (Section 4.3.3.2.2.2)
F.xisring uses:
• Tomatoes from Australia to New Zealand (fruit fly)
• Cut flowers from Thailand and Hawaii (thnps and other pests)
Potential uses:
• Root crops
• Some tropical fruit
• Lilies, orchids, tulips
4.3.4.9
4.3.4.9
4.3.4.3
4.3.4.9
Section
4.3.4.3
4.3.4.7
4.3.4.10
4.3.4.10
4.3.4.10
4.3.4.4
4.3.4.5
4.3.4.7
4.3.4.10
4.3.4.7
4.3.4.10
4.3.4.6
4.3.4.9
4.3.4.10
436 Commodities without approved quarantine alternatives to methyl bromide
pest is detected, methyl bromide is currently the only approved treatment.
Apple exports potentially infested with codling moth to countries free of codling moth.
This is important for New Zealand and the United States exports to Japan.
Stonefruit (peaches, plums, cherries, apricots, nectarines) exports potentially infested
with codling moth to countries free of codling moth.
Grapes from Chile potentially infested with Brevipalpis Mlensis mite on exports to the
United States.
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227
• Berryfruit (strawberry, raspberry, blueberry and blackberry). Exports are
economically important for the United States, New Zealand, Colombia, Australia, Israel,
Brazil, South Africa, Canada, and Zimbabwe.
• Root crops (carrot, cassava, garlic, ginger, onion, potato, sweet potato, taro, and
yams). Some of these crops are exported in minor (but often economically significant)
volumes from developing countries to ethnic groups in developed countries.
4.3.7 Opportunities to reduce emissions
Postharvest disinfestation of perishable commodities using methyl bromide is carried out in
fixed-wall structures such as a fumigation chambers, or under gastight tarpaulins.
i
Controlled conditions allow manipulation of the key fumigation parameters: dosage,
temperature and time. Greater control is potentially more achievable in an enclosed structure.
The dosage can be reduced by increasing either the temperature or the time, or both. Forced air
circulation could also allow reduction of the dosage. Methyl bromide could be conserved by
developing high temperature schedules with or without longer fumigation durations, providing
the marketability of the produce is acceptable.
Improving the gas tightness of fumigation facilities will prevent unwarranted leakage of methyl
bromide into the atmosphere. Simple test criteria have been provided to the industry for
determining the gas tightness of chambers (Bond, 1984, see also Section 3.5).
More accurate measuring equipment (weighing scales, and measuring cylinder with dispenser)
will minimise excessive use of methyl bromide. This equipment could also be attached for
fumigation from small cylinders (e.g., 5 kg) which would avoid the use of small cans (about
1 kg).
A combination of gases e.g., methyl bromide with carbon dioxide and phosphine, allows a
reduction in methyl bromide, is less phytotoxic to cut flowers and ornamentals than methyl
bromide or phosphine alone, and has the same insecticidal activity (Anon., 1994).
Currently, most fumigation chambers release methyl bromide into the atmosphere at'the end of
the fumigation period. Equipment currently under development to recover methyl bromide
could be attached to the fumigation chamber, making up to about 80% of the gas available for
the next fumigation depending on commodity adsorption and losses to the facility (see
Section 3). However, the use of such systems will depend mainly upon the level of emission
reduction required, and, in the absence of legislation, to some extent on the cost-benefit of
methyl bromide recovery and recycling.
4.3.8 Research priorities
The research priorities for alternatives to methyl bromide are different for developing and
developed countries because each has different market requirements and economic constraints.
4.3.8.1
Developing countries
Developing countries are largely dependent on technology tested arid available in other
countries. Assistance should be provided by developed countries for the implementation of
specific alternatives. For example, a heat treatment for papaya was, developed in the United
States (Armstrong el al., 1989) and modified by New Zealand for use in the South Pacific
(Waddell et al., 1993). This process is now used on Cook Island papaya exports, replacing
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228
ethylene dibromide which was recently banned. The project was financed by a consortium of
government and private organisations.
The choice of alternatives will be determined largely by the commodity tolerance, the target
pest, and the potential for success based on previous research findings. Most research in
developing countries currently involves heat treatments. There is also some research on
irradiation for high value fruit exports because most tropical commodities have been shown to
tolerate these treatments.
Currently, grapes exported from Chile to the USA, and cut flowers (roses, carnations and
statice) exported to Europe, USA, Scandinavia and Japan are the only examples of
commodities from a developing country with no alternative treatment
4.3.8.2
Developed countries
Most research involves the development of heat, cold, CA, MA and combinations of these
alternatives in the short term because these have shown the most potential for many
commodities. Treatments based on preharvest procedures (inspection, pest-free zones and
periods, and multiple decrement) are also high priority, but are longer term since considerable
documentation on pest security is required by regulatory agencies. Irradiation research is
usually given medium priority as scientific information on the effects on the commodity and the
pest is generally recognised as sufficient, although high priority is given if other alternatives are
less promising.
Those commodities with ho potential alternative treatment currently available are apples and
stonefruit exports to Japan, and rootcrops with unacceptable pest levels upon importation into
many countries. Therefore these commodities should have a high priority for research.
4.3.9 Transfer of knowledge, and training in improvements and alternatives
Funds are required for key personnel to attend conferences, workshops and training courses.
Information on postharyest alternatives must be written in the appropriate technical language
and published in scientific journals and bulletins.
Developing countries should request clear guidelines for the development of disinfestation
treatments. A technical expert from the developed country may be necessary to assist with
experimental design (including equipment, lifestages, commodity quality) and report
documentation necessary for demonstrating quarantine security. Ongoing exchange visits to
developing countries by scientists and technicians are essential for effective collaboration in
projects that test and implement alternatives.
To ensure continuity of skilled personnel, quarantine officers and students should be
encouraged to undertake courses essential to the development and implementation of
alternatives, particularly those related to plant physiology, entomology, engineering and related
areas. International companies with facilities in developing countries should be encouraged to
increase their technology transfer expenditures.
4.3.10
Developing country issues
Postharvest treatments using methyl bromide are more common for perishable commodities
exported from developing countries in Asia and Latin America than Africa which, apart from
Kenya and Zimbabwe, has relatively few such exports. Methyl bromide is mainly used to
disinfest cut flowers, vegetables and fruit in Asia and Latin America.
-------
229
Despite this varying usage, developing countries have similar requirements that include:
• Obtaining the appropriate disinfestation technology;
• Transferring this technology to the local environment;
• Training personnel to carry out new disinfestation treatments;
• Obtaining sufficient funds to allow completion of the research to demonstrate efficacy;
and -)
• Training in the commercial use of alternatives.
Ideally, any alternative treatment to methyl bromide must be appropriate to the local conditions,
i.e., cost-effective, safe to apply, environmentally sound, simple to use, and require minimal
maintenance. Promising technologies must be tested in the developing countries. Highly
skilled personnel are required to adapt the technology to the local conditions, train local staff in
its effective use, and develop treatment and operational manuals in collaboration with technical
staff. .
The first priority must be to replace methyl bromide with an alternative treatment. However, if
this is not possible, an interim strategy must be to reduce the amount of methyl bromide
released to the atmosphere. This could be achieved by fitting fumigation facilities with
recovery equipment as soon as it becomes commercially available. Equipment for recovering
and recycling methyl bromide requires further technological development before it can be
adopted widely, and it is likely to be expensive.
4.3.11
References
Aharoni, Y., Stewart, J.K., Hartsell, P.L., and D.K. Young. 1979. Acetaldehyde - a potential
fumigant for control of the green peach aphid on harvested head lettuce. Journal of
Economic Entomology, 72,493-495.
Anonymous. 1972. MAFF-Japan notification number 798.
I
Anonymous. 1980. MAFF-Japan notification number 437.
Anonymous. 1986. Irradiation in the production, processing and handling of food; final rule.
CFR 21(179), 13376-13390.
Anonymous. 1987. Food Irradiation Newsletter, IAEA, Supplementuo Vol. 11 (1).
Anonymous. 1988. The Manual for the Operation of the Plant Quarantine Treatment. Theory
and application of fumigation. Japan Technical Fumigation Association. Takeo Mori,
ed. Japan Ministry of Agriculture and Fisheries, Plant Protection Division. 190 pp.
Anonymous. 1988b. MAFF-Japan notification number 183.
j .
Anonymous. 1988c. MAFF-Japan notification number 944.
Anonymous. 1988d. MAFF-Japan notification number 326.
Anonymous. 1989. MAFF-Japan notification number 47. i
I
Anonymous. 1990. MAFF-Japan notification number 439.
-------
230
Anonymous. 1991. MAFF-Japan notification number 947.
Anonymous, 1992. USDA Animal and Plant Health Inspection Services. 1992. Plant
Protection and Quarantine Treatment Manual. Interim Edition. 30 November 1992,
386 p.
Anonymous. 1994. MAFF-Japan notification number 917.
Armstrong J W, Hansen, J.D., Hu, B.K.S., and S.A. Brown. 1989. High-temperature,
forced-air quarantine treatment for papaya infested with tephritid fruit flies (Diptera:
Tephritidae). Journal of Economic Entomology, 82, 1667-1674.
Armstrong, J.W. 1994. Heat and cold treatments. In: Paull, R.E. and Armstrong J.W eds.,
Insect Pests and Fresh Horticultural Products, Treatments and Responses. Part in:
Physiological and Biochemical Responses of Insects to Possible Dismfestation
Procedures. Wallingford, Oxon, CAB International, 103-120.
Armstrong, J.W., Mitchell, W.C. and Farias, G.J. 1983. Resistance of 'Sharwil' avocados at
hardest maturity to infestation by three fruit fly species in Hawaii. Journal of Economic
Entomology, 76, 119-121.
Arpaia, M.L., Houck, L.G., Hartsell, P, Ontai, S.H. and Reints, J.S. 1992 Response of
'Hass1 avocado to methyl bromide fumigation. HortScience, Z7(o), o/s.
Arpaia, M.L., Houck, L.G., Hartsell, P, Ontai, S.H. and Reints, J.S. 1993. The influence of
methyl bromide fumigation on the storage life of 'Hass' avocado. HortScience, 28(5),
580.
Baker A C 1939 The basis for treatment of products where fruit flies are involved as a
' condition for entry into the United States. USDA Circular No. 551.
Baker R T Cowley, J.M., Harte, D.S. and Frampton, E.R. 1990. Development of
mk^um peS limit for fruit flies (Diptera: Tephritidae) in produce imported into New
Zealand. Journal of Economic Entomology, 83, 13-17.
Batchelor, T.A, O'Donnell, R.L. and Rpby, J.J. 1985.The , efficacy -of '™"^
coolstorage in controlling leafroller species. Proceedings of the 38th NZ Weed
Control Conference, 13-15 August, Rdtorua, 53-56
Benshoter, C.A. 1987. Effects of modified atmospheres and refrigeration tempe ratures oni the
surVival of eggs and larvae of the Caribbean fruit fly (Diptera: Tephritidae) in laboratory
diet. Journal of Economic Entomology, 80(6), 1223-1225.
Bond, EJ. 1984. Manual of fumigation for insect control. FAO Plant Production and
Protection Paper No. 54, 432 p.
Bramlage, WJ. and M.H. Couey. 1965. Gamma radiation of fruits to extend market life.
Marketing Research Report No. 717, 27 p.
Burditt A J and H.R. Moffitt. 1985. Irradiation as a quarantine treatment for fruit subject to
infestation by codling moth larvae. In: Moy, J.H., ed., Radiation Dismfestation of
Food and Agricultural Products: Proceedings of an International Symposium on Food
Irradiation, 14-18 November, 1983, University of Hawaii, Honolulu, 87-97.
Carpenter, A. and A. Stocker. 1992. Envirosols as postharvest fumigants for asparagus and
cutflowers. Proceedings New Zealand Plant Protection Conference, 21-26
-------
231
Codex. 1993. Report of the second session of the Codex Committee on food import and export
inspection and certification systems, 29 November - 3 December 1993, Canberra,
Australia. Codex Alimentarius Commission (FAO/WHO). ALINORM 95/30.
Corrigan, J.P. 1993. Experiences in selling irradiated foods at the retail level. In: Proceedings
of an International Symposium on Food Irradiation Processing, 1-5 March 1993, Aix-
en-Provence, France. lAEA/FAQ/WHO.
Couey, H.M. and V. Chew. 1986. Confidence limits and sample size in quarantine research.
Journal of Economic Entomology, 79, 887-890.
Couey, M. 1989. Heat treatment for control of postharvest diseases and insect pests of fruits.
HortScience, 24, 198-202.
Curtis, C.E., Clark, J.D. and Tebbets, J.S. 1991. Incidence of codling moth (Lepidoptera:
Tortricidae) in packed nectarines. Journal of Economic Entomology, 84, 1686-1690.
Dickler, E. 1975. Influence of standard coldstorage and controlled atmosphere storage on
apples from Italy on the mortality and fecundity of the San Jose scale (Quadraspidiotus
perniciosus Comst.). Redia, 56, 401-416.
Drake, S.H., Moffitt and Eakin, D. 1994. Low dose radiation of 'Rainier' sweet cherries as a
quarantine treatment. Journal of Food Processing and Preservation, 18, 393-399.
i
Gay, R., Brecht, P. and K. Rodde. 1994. Pacific surface initiative and produce shipment
losses to Guam. DSRPAC Report: Defense Logistics Agency, Defense Subsistence
Region Pacific, Alameda, California. 219 p.
Gould, W.P. and J.L. Sharp. 1992. Hot-water immersion quarantine treatment for guavas
infested with Caribbean fruit fly (Diptera: Tephritidae). Journal of Economic
Entomology, 85, 1235-1239.
Hallman, G.J., Nisperos-Carriedo, M.O., Baldwin, E.A. and Campbell, C.A. 1994. Mortality
of Caribbean fruit fly (Diptera: Tephritidae) immatures in coated fruits. Journal of
Economic Entomology, 87,752-757.
Hansen, J.D., Hara, A.H. and Tenbrink, V.T. 1992. Insecticidal dips for disinfesting tropical
cut-flowers and foliage. Tropical Pest Management, 38, 245-249.
Hata, T.Y., Hara, A.H., Jang, E.B., Inaino, L.S., Hu, B.K.S. and Teinbrink, V.L. 1992.
Pest management before harvest and insecticidal dip after harvest as a systems approach
to quarantine security for red ginger. Journal of Economic Entomology, 85,2310-
2316.
Heather, N.W., Hargreaves, P.A., Corcoran, R.J. and Melksham, K.J. 1987. Dimethoate and
fenthion as packing line treatments for tomatoes against Daais tryoni (Froggatt).
Australian Journal of Experimental Agriculture, 27,465-469.
Honiball, F., Giliomee, J.H. and Randall, J.H. 1979. Mechanical control of red scale
Aonidiella aurantii (Mask.) on harvested oranges. Citrus and. Sub-tropical Fruit Journal,
519, 17-18. ;
Houck, L.G. 1967. Hot water treatments for control of Penicilliwn digitatum green mold of
Eureka lemons. Phytopathology, 57,99.
Houck, L.G. and J.W. Snider. 1969. Limitation of modified atmospheres for decay control of
citrus fruit. Phytopathology, 59,1031-1032.
-------
232
Houck, L.G., Tenner, J.F. and B.E. Mackey. 1990a. Seasonal variability of the response of
desert lemons to rind injury and decay caused by quarantine cold treatments. Journal ot
Horticultrual Science, 65, 611-617.
Houck, L.G., Jenner, J.F. and Bianchi, J. 1990b. Holding lemon fruit at 5 or 15°C before
cold treatment reduces chilling injury. HortScience, 25(9), 1174.
International Atomic Energy Agency. 1991. Facts about food irradiation. A series of fact sheets
from the International Consultative Group on Food Irradiation. International Atomic
Energy Agency document No. IAEA/PI/A33E.
International Consultative Group on Food Irradiation (ICGFT). 1988. Provisional guideline for
the irradiation of fresh fruits for insect disinfestation as a quarantine treatment. Joint
FAO/IAEA publication No. 1648.
International Consultative Group on Food Irradiation (ICGFI). 1992. Inventory of product
clearances. Joint FAO/IAEA/WHO publication as a result of the ninth meeting of the
ICGFI 28-30 October 1992, Orlando, Florida.
Jang, E.B. 1990. Fruit fly disinfestation of tropical fruits using semi-permeable shrinkwrap
films. Acta Horticultural 269, 453-458.
Johnson, J.A., Soderstrom, E.L., Brandl, D.G., Houck, L.G. and Wofford, P.A. 1990.
Gamma radiation as a quarantine treatment for Fuller rose beetle eggs (Coleoptera:
Curculionidae) on citrus fruit Journal of Economic Entomology, 83(3), 905-909.
Josephson, E.S. and Peterson, M.S., eds. 1983. Preservation of Food by Ionising Radiation.
Baton Rouge, CRC Press, volume 1-3.
Kader A A 1985 A summary of CA requirements and recommendations for fruits other than
' pome fruits. In: Blakenship, S.M., ed., Controlled atmospheres for storage and
transport of perishable agricultural commodities: Proceedings of the Fourth National
Controlled Atmosphere Research Conference, 23-26 July 1985, Raleigh, N.C., p. 445-
492.
Kader, A.A. 1986. Potential applications of ionising radiation in postharvest handling of fresh
fruits and vegetables. Food Technology, 40,117-121.
Kitagawa H., Matsui, T. and Kawada, K. 1988. Some problems of marketing citrus in Japan.
In- Goren, N., ed., Citriculture: Proceedings of the Sixth International Citrus
Congress, 6-11 March, Tel Aviv, Israel. Rehovot, Israel, Balaban Pub., 1852 p.
Kok, I.B. 1979. Control of mango seed weevil by trapping and irradiation. Citrus and Sub-
tropical Fruit Journal, 552, 14-16.
Landolt P.J., Chambers, D.L. and Chew, V. 1984. Alternative to the use of probit 9 mortality
as a criterion for quarantine treatment of fruit fly (Dipera: Tephritidae) infested fruit.
Journal of Economic Entomology, 77, 285-287.
Lay-Yee, M. and Rose, K.J. 1994. Effect of forced-air treatments for insect disinfestation on
the quality of 'Fantasia1 nectarines. HortScience, 29, 663-666.
Lay-Yee, M., Waddell, B.C., McLaren, G.F., Rose, K.J., Jones, V.M., Fraser, J.A. and
Batchelor,T.A. 1993. Disinfestation treatments to control pests of summerfruit. In:
Muggleston, S., ed., Summerfruit Research. HortResearch Technical Report 93/3,14-
19.
-------
233
Lipton, W.J. Harvey, J.M. and Couey, H.M. 1967. Conclusions about radiation. United
Fresh Fruit and Vegetable Association Yearbook, 173-174,176,178, 181.
Luckman, W.H. and Metcalf, R.L. 1982. The pest management concept In: Metcalf, R.L. and
Luckman, W.H., eds., Introduction to Insect Pest Management. Second edition. New
York, John Wiley, 12.
Mangan, R.L. and Ingle, S.J. 1994. Force hot-air quarantine treatment for grapefruit infested
with Mexican fruit fly (Diptera: Tephritidae). Journal of Economic Entomology, in
press.
Marcotte, M. 1992. Irradiated strawberries enter US market Food Technology, (May), 80-86.
Markakis, P. and Nicholas, R. 1972. Irradiation of fruits and vegetables - 1966 to 1970.
Isotopes and Radiation Technology, 9, 472-474.
Maxie, E.G., Sommer, N.F. and Eaks, I.L. 1969. Effect of gamma radiation on citrus fruits.
In: Chapman, H.D., ed., Proceedings First International Citrus Symposium,
University of California, Riverside, Vol 3,1375-1387.
Maxie, E.G., Sommer, N.F. and Mitchell, F.G. 1971. Infeasibility of irradiating fresh fruits
and vegetables. HortScience, 6, 202-204.
Meheriuk, M. and Gaunce, A.P. 1994. Temperate Pests. In: Paull, R.E. and Armstrong,
J.W., eds., Insect Pests and Fresh Horticultural Products. Treatments and Responses.
Wallingford, Oxon, CAB International, 291-307.
Miller, W.R., McDonald, R.E., McCollum, T.G. and Smittle, B.J. 1994. Quality of "Climax"
blueberries after low-dose electron-beam irradiation. Journal of Food Quality, 17 71-
79. .
Moffitt, H.R. 1990. A systems approach to meeting quarantine requirements for insect pests of
deciduous pests. Proceedings. Washington State Horticultural Association, 85,223-
225.
Moffitt, H.R., Drake, S.R. and Sell, C.R. 1988. A two-component treatment for postharvest
control of the'codling moth on 'Red Delicious' and 'Golden Delicious' apples. USDA-
ARS Report 8, April 1988,71 p.
Moffitt, H.R., Hathaway, D.O., Albano, D.J., Mantey, K.D. and Heidi:, M.H. 1994. A two-
component treatment for postharvest control of the codling moth on 'Red Delicious' and
'Golden Delicious1 apples: Confirmatory tests of efficacy (Results). USDA-ARS
Report 3, January 1994, 84 p.
Mori, T., ed. 1988. The Manual for the Operation of the Plant Quarantine Treatment Theory
and application of fumigation. Japan Technical Fumigation Association. Japan Ministry
of Agriculture and Fisheries, Plant Protection Division, 190 p.
Neven, L.G. 1994. Effects of combined heat treatments and cold storage on fifth instar codling
moth (Lepidoptera: Tortricidae) mortality. Journal of Economic Entomology, in press.
Olsen, K.L., Hungate, F.P., Drake, S.R. and Eakin, D.E. 1989. 'R
-------
234
Agricultural Products, 222-225.
363-376.
Sharp, J.L. 1990. Mortality of Caribbean fruit fly immatures in shrinkwrapped grapefruit.
' Florida Entomologist, 72, 662-664.
fruit fly
Sharp, J.L. 1992. Hot air quarantine treatment to mango *
(Diptera: Tephritidae). Journal of Economic Entomology,
Sham I L 1993 Hot air quarantine treatment for 'March' white grapefruit infested with
^' Caribbean fiSt^iptoa: Tephritidae). Journal of Economic Entomology, 85, 168-
171.
Sham JL 1994 Mortality of sweet potato weevil (Coleoptera: Curculionidae) stages
^' foiiowkig garrima Ladiation. Journal of Economic Entomology, in press.
Sham JL andHallman GJ. 1992. Hot-ak quarantine treatment for carambolas infested with
^' MbbeaB fSy CDiptera: Tephritidae). Journal of Economic Entomology, 85, 168-
171.
a
D C 1989. Quality of nectarines stored in insecticidal low-O2
'. Journal ofte American Society for Horticultural Science,
114, 431-436.
on film-wrapped lettuce. Journal of Economic Entomology, 77, 569-573.
Nutrition, 24, 53-89.
Protection Service of Japan, 9, 6-18.
Vail P V Tebbets, SJ. and Smilanick, J. 1991. Sulphur dioxide control of omnivorous
' learroUerln me laboratory. Insecticide and Acaricide Tests 17: 37 1.
V T»KK^tc T«J andMackev BE 1993. Quarantine treatments: A biological
-Zg^^^z^
tortricidae). Journal of Economic Entomology,
-------
Van de Vrie, M. 1986. Studies on the use of gammas radiation as a ix>st-harvest treatment for
disinfestation of cut flowers. Food Irradiation Newsletter. Joint FAO/IAEA Division of
Isotope and Radiation applications of Atomic Energy for Food and Agricultural
Development
Vota, M. 1957. Preliminary study on storage of Emperor grapes in controlled atmospheres
with and without sulfur dioxide fumigation. Proceedings. American Society of
Horticultural Science, 69,250-253.
Waddell, B.C. 1993. Japanese market access for New Zealand apples. Development of a
postharvest disinfestation treatment for codling moth. The Oichardist of New Zealand
66, 25. '
Waddell, B.C., Clare, O.K., Maindonald, J.H. and Petty, R.J. 1993. Postharvest
disinfestation ofBactrocera melanotus and B. xanthodes in the Cook Islands- Report 3
HortResearch Client Report No. 93/270. F
Whiting, D.C., Foster, S.P. and Maindonald, J.H. 1991. The effects of oxygen, carbon
dioxide and temperature on the mortality responses of Epiphyas postvittana
(Lepidoptera: Tortricidae). Journal of Economic Entomology, 84,1544-1549
Woutersen, R.A., Appelman, L.M., Feren, V.J. and Vander Heijden, C.A. 1984. Inhalation
toxicity of acetaldehyde in rats, JJ. Carcinogenicity study interim results after 15
Xu, Z., Cai, D., He, F. and Zhao, D. Radiation Preservation and test marketing of fruits and
vegetables. Radiation Physics and Chemistry, 42,253-257.
Yahia, E.M., Nelson, K.E. and Kader, A.A. 1983. Postharvest quality and storage life of
grapes as influenced by adding carbon monoxide to air or controlled atmospheres
Journal of the American Society for Horticultural Science, 108, 1067-1071.
Yokohama, V.Y. and Miller, G.T. 1988. Laboratory evaluations of codling moth (Lepidoptera-
Tortricidae) opposition on three species of stone fruit grown In California. Journal of
Economic Entomology, 81, 568-572.
Yokohama, V.Y., Miller, G.T. and Hartsell, P.L. 1987. Methyl bromide fumigation for
quarantine control of codling moth (Lepidoptera: Tortricidae) on nectarine. Journal of
Economic Entomology, 80, 840-842.
Yokohama, V.Y., Miller, G.T. and Hartsell, P.L. 1992. Pest-free period and methyl bromide
fumigation for control of walnut husk fly in stone fruits exported to New Zealand
Journal of Economic Entomology, 85,150-156.
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236
Case History 4.3.1: Heat Disinfection Treatments for Papaya in Hawaii
Commodity: Papaya, Carica papaya L.
Pests.
PeStS*
Melon fly,
Oriental fruit fly, Bac
2. History
Quarantine disinfestatioiii tteatments
of the presence of tephnttd fruit flie
1984, interest in heat treatments resw»~... -^z^M
s,v -*«t"2'j«!sssrSvg)i
-water immersion, vapour
hot.water immenaoi
stm in use today. HTFA and
,
heat (VH), and high-temperature forced-^
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237
8. Is the effect of this treatment on other crops being determined?
Yes. HTFA and/or VH disinfestatipn,treatments are in use or being researched for atemoya,
avocado, carambola, capsicums, citrus, cucumber, eggplant, green beans, guava, mango, and
zucchini. Hot-water immersion treatments are in use or being researched for carambola, guava,
litchi, mango, and sapote.
-------
I
238
Annex 4.3.1
Table 4.3.1 List Of Countries That Were Sent Forms to Determine the Postharvest Use of
Methyl Bromide on Perishable Commodities
Argentina
Australia
Belgium
Bolivia
Brazil
Canada
Chile
China
Colombia
Costa Rica
Cuba
Denmark
Dominican Republic
Ecuador
Egypt
Fiji
France
Germany
Greece
Guatemala
Honduras
Hungary
India
Indonesia
Israel
Italy
Ivory Coast
Japan
Republic of Korea
Malaysia
Mexico
Morocco
New Zealand
Panama
Philippines
Poland
Saudi Arabia
Singapore
South Africa
Spain
Sweden
Switzerland
Thailand
The Netherlands
Turkey
United Kingdom
United States of America
Uruguay
Venezuela
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Annex 4.3.2
239
United Nations Environment Programme
Methyl Bromide Technical Options
Committee
«DATA MBTOC Disk #l:Info on world MB use:MB Form addresses*
File H2/5/11/6
May 20,1993 . i '
'
«address» ;
Dear «IF name»«name»«ELSE»Sir/Madam«ENDIF»,
Re: 1993 United Nations Environment Programme (UNEP) Methyl Bromide Technical Options
Committee (MBTOC)
Methyl bromide is a gas of world-wide economic importance. Its use as a postharvest fumigant to
control pests on fresh fruit, vegetables and cut flowers is often essential for export earnings from
horticulture for many countries.
This fumigant was recently identified as a substance that depletes the stratospheric ozone layer.
Depletion of the ozone layer causes skin cancer, cataracts, suppression 6f the human immune system,
damage to agricultural crops, as well as other adverse environmental effects.
The United Nations Environment Programme (UNEP) has recently established a Methyl Bromide
Technical Options Committee (MBTOC) to evaluate the technical and economic feasibility of
reducing and phasing out the world wide production of methyl bromide. The MBTOC is chaired by
Dr H. Jonathon Banks, CSIRO Canberra, Australia.
Prior to the meeting of the Open-ended Working Group of the Parties to the Montreal Protocol, and
the Seventh Meeting of the Parties to the Montreal Protocol, the MBTOC must submit a report to the
Secretariat evaluating the technical and economic feasibility of reducing and phasing out the world-
wide production of methyl bromide. The Montreal Protocol on substances that Deplete the Ozone
Layer is the international agreement that controls the production and consumption of ozone-depleting
substances such as chlorofluorocarbons (CFC's) used as refrigerants
The Protocol list of controlled substances was recently amended to include methyl bromide. This
amendment was based in part on a "Methyl Bromide Science Workshop" (Washington DC June 2-3
1992) which was a scientific assessment of the atmospheric impact of methyl bromide, and the results
of an "International Workshop on Alternatives and Substitutes for Methyl Bromide" (Washington DC,
16-18 June 1992).
This first MBTOC meeting was held in the Hague, Netherlands, 25-29 March 1993. It was mainly
organisational and discussed the report structure, subcommittee involvement, work programmes, and
timetable. At this meeting, a subcommittee on "Perishable Commodities" was formed to determine the
postharvest use of methyl bromide on perishable commodities.
-------
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countries in early July, and present ^ &ble
However,
hearing from you.
Yours sincerely,
Thomas A. Batchelor
Science Manager
AkioTateya
oTli—ng and CoordinaUon Secuoa
1- Fumigation of Imports
esh ftuit commodities
Form
Form 2.
IS I Methyl bromidejunugat
^ssassssssiw
country
List of cut flowers and ornamentals
List of bulbs and tubers
List of nursery plants
-------
r
FORM i: FUMIGATION OF IMPORTS 241
Country:
Contact person:
Address:
Telephone
Number:
Facsimile
Number:
Please list the fresh
commodities fumigated with
methyl bromide at the port
sea, air) of entry in you
country (see attached list)
e.g.,
Asparagus
\
Methyl bromide
lose, duration and
temperature
48gm-3/2hrs/15-
25°C
•
Target
pestfs)1
lass e.g.,
mites,
epidoptera,
ruit fly etc
^epidoptera
Origin by
country
percent) in
1992, as a
iroportion
of total
imports for
this
commodity
Australia
(30%),
USA
(40%),
Tainwan
(10%)
Volume
imported
1992) as
lieces, Kg,
ons, or
tonnes
2,000 tons
this
commodity
fumigated
with methyl
bromide2
30%
Approximate
amount of
MB used
(tons,
tonnes, Kg)
for this
commodity
in 1992
3,500 Kg
1
1
i
i
i ,
1
:
:
|
{
:
:
1
i
j
j
:
alue of I
commodity
treated with
methyl
iromidein
1992
(US$)
$200,000
1 Target pests are described as major pests for their class
2 If this is not available for individual commodity, please list the amount as a group e.g., fresh fruits and vegetables
-------
FORM 1: FUMIGATION OF IMPORTS
242
Please list the fissil
commodities fumigated with
methyl bromide at the port
sea, air) of entry in you
country (see attached list)
Methyl bromide
lose, duration and
temperature
Target
pest(s)3
lass e.g.,
mites,
epidoptera,
ruit fly etc
Origin by
country
percent) in
1992, as a
jroportion
of total
imports for
his
commodity
•
Volume
imported
1992) as
>ieces, Kg,
ons, or
tonnes
Percentage of Approximate
iis amount of
commodity MB used
umigated (tons,
with methyl tonnes, Kg)
bromide4 for this
commodity
in 1992
1
i
:
1
:
1
j
I
|
]
1
]
:
i
I
1
1
1
Estimated
alueof
commodity
treated with
methyl
iromidein
992
(US$)
•
3 Target pests are described as major pests for their class
4 If this is not available for individual commodity, please list the amount as a group e.g., fresh fruits and vegetables
-------
FORM 2: FUMIGATION OF EXPORTS 243
Methyl bromide use on fcgsll EXPORT products after harvest by vour country
COuilUy.
Contact person:
Address:
Telephone
Number:
Facsimile
Number:
commodities fumigated with
methyl bromide after harvest
in your country (see attached
list)
Onions
dose, duration anc
temperature
48gnr3/2 hrs/15-
25°C
pestfs)1
class e.g.,
mites,
lepidoptera,
fruit fly etc
Lepidoptera
Export
destination
by country
in 1992
Australia
(30%),
USA
(40%),
Tainwan
(10%)
Volume
exported
(1992) as
pieces, Kg,
tons, or
tonnes
2,000 tons
Percentage of
income from
horticultural
exports for
your country
for this
commodity
30%
i
Estimated
volume to
be exported
in year
2000 from
your
country
3,500 tons
Quantity o:
MB used
(tons,
tonnes, Kg
for this
commodity
in 1992
2 tons
1 Target pests are described as major pests for their class
-------
FORM 2: FUMIGATION OF EXPORTS
244
Quantity of
MB used
(tons,
tonnes. Kg)
for this
commodity
in 1992
Estimated
volume to
be exported
in year
2000 from
your
country
Percentage of
income from
horticultural
exports for
your country
for this
commodity
Volume
exported
(1992) as
pieces, Kg
tons, or
tonnes
Export
destination
by country
in 1992
Methyl bromide larget
dose, duration and p.*
ated With
class e.g.,
mites,
lepidoptera,
fruit fly etc
country (see attached list)
-------
245
FORM 3: Methyl bromide use on fcssfc commodities alter harvest and! shipped within your country
MI i • -fTss^^^^s^aa^^asaa;
Country:
Contact person:
commodities fumigated with
methyl bromide after harvest
and shipped within your
country (see attached list)
Onions
!
'SSI^S^^^^SSS^^SS^
Address:
Methyl bromide
dose, duration an
temperature
48gnr3/2 hrs/15-
25°C
=====================3=
^^^— '^'•'^^''^^g^^^^^ggggg^™— ^^-^-••-^—
Target
pes^s)1
class e.g.,
mites,
lepidoptera,
fruit fly etc
Lepidoptera
Shipped
from.. .to..
e.g.,
name the
regions or
states
Region 'A1
to Region
B1
Volume
shipped
(1992) as
pieces, Kg
tons, or
tonnes
2,000 tons
lelepnone
Number:
Facsimile
Number:
—
Value of this Estimated
commodity volume to
as a be shipped
percentage of in year
total 2000
horticultual within your
products for country
your country
|
1
5% { 3,500 tons
:
:
:
1 :
:
i •
. ! 1
:
:
; i
{
! :
i i
1 :-
1 :
:
| ;
! !
:
i
:
i |
, :
1 |
I :
:
•1 I
l i
i :
i
•i i
i !
:
:
j :
1 :
:
1
:
:
Quantity of i
MB used I
(tons, 1
tonnes, Kg)l
for this 1
commodity |
in 1992 i
2 tons 1
:or their class
-------
246
FORMS: Methyl bromide use on flash commodities^
harvest and shipped silHift your country
Target
I and shipped within your
I country (see attached list)
class e.g.,
mites,
lepidoptera,
fruit fly etc
Shipped
from...to...
e.g.,
name the
regions or
states
Volume
shaped
(1992) as
pieces, Kg,
tons, or
tonnes
Value of this
commodity
asa
percentage of
total
horticultual
products for
your country
Estimated
volume to
be shipped
in year
2000
within your
country
Quantity of |
MB used
(tons,
tonnes, Kg)J
for this
commodity |
in 1992
^Target pests are described as major pests for their class
-------
247
Annex 4.3.3
Perishable commodities treated with methyl bromide, at least on some
occasions, for disinfestation and pest control
FRESH FRUIT
Apple
Apricot
Banana
Blackberry
Blueberry
Cactus pear (prickly pear)
Cerimoya
Cherry
Citrus
Orange
Grapefruit
Lemon
Lime
Others
Coconut
Durian
Feijoa
Grape
Guava
Kiwifruit
Longsat
Loquat
Lychee (Litchi)
Mango
Melons
Cantaloupe
Honeydew
Muskmelon
Watermelon
Others
Nectarine
Olive
Papaya
Passionfruit
Peach
Pear
Persimmon
Pineapple
Plum
Pomegranate
Quince
Raspberry
Sapodilla
Starfruit
Strawberry
Tamarind
-------
248
Annex 4.3.3 (cont.)
Perishable commodities treated with methyl bromide, at least on some
occasions, for disinfestation and pest control
VEGETABLES
Arrowhead
Artichoke
Asparagus
Basil
Beet
Bell pepper
Broccoli
Brussel sprout
Cabbage
Carrot
Cassava
Cauliflower
Celery
Celtuce
Chayote
Chervil
Chicory
Chinese cabbage
Chinese leek
Chrysanthemum (edible leafy vegetable)
Coriander
Corn (fresh)
Cress (garland, garden, winter)
Cucumber
Dandelion
Dasheen
Dill
Edible burdock
Eggplant
Endive
Fennel
Garlic
Ginger
Green pod vegetables
Broad bean
Kidney bean
Soybean
Pea
Others
Horseradish
Indian rice (wild rice)
Leek
Lettuce
Lotus
Okra
Onion
Parsley
Parsnip
Peppermint
Plantain
Potato
Pumpkin
Purslane
Rhubarb
Sorrel
Spinach
Squash
Sweet potato
Swiss chard
Tomato
Yam
Zucchini
-------
249
Annex 4.3.3 (cont.)
Perishable commodities treated with methyl bromide, at least on some
occasions, for disinfestation and pest control
Acacia
Adenanthos
Agapanthus
Alstroemeria
Anigozanthus
Banksia
Berzelia
Boronia
Brunia
Butcher's Broom
Calathea
Calla
Canada Tree
Carnation
Chrysanthemum
Coco Palm
Douglas Fir
Dracaena
Eryngium
Eurya
E-verDssting
Fern
Club-moss.
Davallia
Nephrolepsis
Polystichopsis
Rumohra
Fir
Freesia
Galax
Gladiolus
Galingale
Gypsophila
Heath
Heliconias
Japanese Cleyera
Juniper
Larkspur
Leucosperumum
Lily
Nerine
Orchid
Ornithogalum
Phaenocoma
Prairie Gentian
Protea
Sandersonia
Scholtzia
Screw-Pine
CUT FLOWERS and ORNAMENTALS
Acacia spp.
Adenanthos spp.
Agapanthus spp.
Alstroemeria spp.
Anigozanthus spp.
Banksia spp.
Berzelia spp.
Boronia spp.
Brunia spp.
Ruscus spp.
Calthea spp.
Zantedeschia spp.
Gaultheria spp.
Dianthus caryophyllus
Chrysanthemum spp.
Cocos spp.
Pseudotsuga spp.
Cordyline spp.
Dracaena spp.
Eryngium spp.
Eunyaispp.
Helichrysum spp.
Lycopodium
Davallia spp.
Nephrolepsis spp.
Polystichopsis spp.
Rumohra spp.
Abies spp.
Freesia spp.
Galax spp.
Gladiolus spp.
Cyperus spp.
Gypsophila spp.
Er/ca spp.
Heliconia spp.
Cleyera spp.
Juniperus spp.
Delphinium spp.
Leucospermufj. spp.
Lilium spp.
Nerine spp.
Orchidaceae
Ornithogalum spp.
Phaenocoma spp.
Eustoma spp.
Protea spp.
Sandersonia spp.
Scholtzia spp.
Pandanus spp.
-------
250
Annex 4.3.3 (cont.)
Perishable commodities treated with methyl bromide, at least on some
occasions, for disinfestation and pest control
CUT FLOWERS and ORNAMENTALS (cont.)
Sea-Pink
Shell Ginger
Silver Tree
Summer Cypress
Tail Flower
Verticordia
Waxflower
Limonium spp.
Alpinia spp.
Leucadendron spp.
Kochia spp.
Anthuriwn spp.
Verticordia spp.
Chamelauciwn spp.
BULBS, TUBERS, etc.
African com lily
Amaryllis
Calla
Christmas bell
Crocus
Freesia
Fritillary
Giganteum
Garlic
Gladiolus
Hyacinth
Iris
Lily
Lycoris
Narcissus
Shallot
Tufted Stone Leek
Tulip
Unifolium
Ixia spp.
Hippeastrum spp.
Zantedeschia spp.
Sandersonia spp.
Crocus spp.
Freesia spp.
Fritillaris spp.
Allium giganteum
Allium sativum
Gladiolus spp.
Hyacintus
Iris spp.
Lilliwn spp.
Lycoris spp.
Narcissum spp.
Allium ascalonicum
Allium fistuloswn var. caepitosum
Tulipa spp.
Allium unifolium
-------
251
Annex 4.3.3 (cont.)
I
Perishable commodities treated with methyl bromide, at least: on some
occasions, for disinfestation and pest control
NURSERY PLANTS
Aechmea
Alchemilla
Alstroemeria
Anigozanthus
Asarum
Bermuda Grass
Billbergia
Carnation
Cherimoya
Chrysanthemum
Cinquefoil
Coco Palm
Croton
Cryptanthus
Cucumber Tree
Day-Lily
Dogwood
Dracaena
Evening Primrose
Fauwort
Fig-Tree
Geranium
Guzmania
Hawthorn
Holly
Honeysuckle .
Hydrangea
Ivy
Ivy-Arum
Juniper
Lilac
Maidenhair Fern
Maple
Michelia
Neoregelia
New Jersey-Tea
Orchid
Pachira
Pampas Grass
Polygonum
Polyscias
Aechmea spp.
Alchemilla spp.
Alstroemeria spp.
Anigozanthus spp.
Asarum spp.
Cynodon dactylon
Billbergia spp.
Dianthus caryophyllus
Annona cherimoya
Chrysanthemum spp.
Potentilla spp.
Cocos spp.
Croton spp.
Cryptanthus spp.
Magnolia spp.
Hemerocallis spp.
Cornus spp.
Cordyline spp.
Dracaena spp.
Oenother spp.
Cabomba spp.
Ficus spp.
Geranium spp.
Guzmania spp.
Crataegus spp.
Ilex spp.
Lonicera spp.
Hydrangea spp.
Hedera spp.
Scindapsus spp.
Juniperus spp.
Syringa spp.
Adiantum spp.
Acer spp.
Michelia spp.
Neoregelia spp.
Ceanothus spp.
Orchidaceae
Pachira spp.
Cortaderia spp.
Polygonum spp.
Polyscias spp.
-------
252
Annex 4.3.3 (cont.)
Perishable commodities treated with methyl bromide, at least on some
occasions, for disinfestation and pest control
Rose
Snapweed
Spleenwort
Spurge
Stevia
Syngonium
Tillandsia
Virburnum
Vriesea
Wonnwood
Yellow Poplar
Yucca
NURSERY PLANTS
(cont.)
Rosa spp.
Impatiens spp.
Aspleniwn spp.
Euphorbia spp.
Stevia spp.
Syngonium spp.
Tillandsia spp.
Virburnum spp.
Vriesea spp.
Artemisia spp.
Liriodendron spp.
Yucca spp.
-------
253
Annex 4.3.4
Table 4.3.2 Examples of Fumigation of IMPORTS as a Condition of Entry.
Country
importing
the
commodity
Canada
Commodity
Pears
Mixed vegetables
Durian
Target
pest(s)
Lepidoptera
Diptera and
Coleoptera
Lepidoptera
Apricots and peaches Lepidoptera
Chile
Costa Rica
Denmark
Egypt
Germany
Hungary
Other fresh fruit
Ya pears
None reported
No data are collected
on the use of methyl
bromide
No fumigation of
perishable
commodities
Apple
Coconut
Pear
Two out of 16 states
reported no
fumigation of
perishable
commodities
No fumigation of
perishable
commodities
Homoptera
Homoptera
Hemiptera
Homoptera
Coleoptera
Hemiptera
Diptera
Homoptera
Quantity Methyl
imported bromide used
100 1 15 kg
2.5 t 1 ke
o
4 1 .0.3 kg
3.4 t 1.8 kg
2 1 1.2 kg
? 1.8 kg
1354 t 270.6 t
759 t 74 kg
- 35 1 8kg
-------
254
Annex 4.3.4 (cont.)
Tab,e 4.3.2 (con,., Exan-p.es of Fun^on of SPORTS as a Condon of Entty.
Country
importing
the
commodity
•i "••
Japan
Kenya
•••^•"
Commodity
Fresh fruit
Fresh vegetables
Cutflowers and
ornamentals
Fresh bulbs and
tubers
Nursery plants
Target
pest(s)
Quantity Methyl
imported bromide used
Malaysia
————
Morocco
i
Norway
_
Poland
—
Singapore
•
South Africa
Stem cuttings,
budwood, rooted
plants, bulbs, cut
flowers and
miscellaneous fruit
.————
Willow
•
None reported
. —
No fumigation of
perishable
commodities
.—• •
No postharvest uses
•
None reported
i —-
None reported
Acarina
Lepidoptera
Coleoptera
Hemiptera
Acarina,
Lepidoptera
Coleoptera
Hemiptera
Acarina,
Lepidoptera
Coleoptera
Hemiptera
Acarina,
Lepidoptera,
Coleoptera
Hemiptera
Acarina,
Lepidoptera
Coleoptera
Hemiptera
,
Miscellaneous
injurious pests
and diseases
1582181t
2699961
329,467,000
pieces
277,559,000
pieces
71,273,000
pieces
•——^
Not reported
Insects
^
Not available
42.3 t
96.5 t
11.6 t
163kg
2.1 t
3.7 t
<15t
-------
255
Annex 4.3.4 (cont.)
Table 4.3.2 (cont.) Examples of Fumigation of IMPORTS as a Condition of Entry.
Country
importing
the
commodity
South Korea
Spain
Sweden
Switzerland
Thailand
Commodity
Pineapple
Grapefruit
Chicory
Roses
Orchids
Ornamental fir
Nursery stock
Rhododendron
Lily bulb
Fig tree
Garlic
Coconut
Quince
No fumigation of
perishable
commodities
None reported
None reported
Target
pest(s)
Homoptera
Homoptera
Homoptera
Lepidoptera
Lepidoptera
Coleoptera
Homoptera
Nematode
Nematode
Nematode
Lepidoptera
Mites
Diptera
Quantity
imported
4848 t
5118t
1.3 t
2.1 t
182 t
3.2 t
300309 pieces
2126 pieces
230,000 pieces
152,999 jpieces
969 t
1.2 t
2.1 t
Methyl
bromide used
85 1
3t
0.3 t
1.2 t
1.8 t
0.7 t
0.3 t
0.2 t
It
0.1 t
Not reported
Not reported
Not reported
United States
Fruit (16 types) &
vegetables (13 types)
Various
6,100 t
1091
-------
256
Annex 4.3.5
Table 4.3.3 Examples of Fumigation of EXPORTS as a Condition of Entry.
Country
exporting
the
commodity
Canada
Chile
Costa Rica
Denmark
Egypt
Japan
__ — - i—i— — — — — —
Commodity
Nursery stock
(Malus spp.)
Grapes
Plums
Peaches
Nectarines
Apricots
Tomatoes
No data are
collected on the
use of methyl
bromide
No fumigation of
perishable
commodities
None reported
Unshu oranges
Bonsai trees,
Cornus spp,
Cotoneaster spp,
Rosa spp.
Main
target
pest(s)
Homoptera
Lepidoptera
Acarina
Various
Various
Various
Various
Diptera and
Lepidoptera
Mealybug
Scale insects
Exported
to...
USA and
France
USA
USA
USA
USA
USA
Argentina
USA
UK
Quantity
exported
2900 pieces
Million cases
10,800
310
217
183
5
168
692 1
958 pieces
altogether
Methyl
bromide
used
2.7kg
Not reported
Not reported
41.6 kg
Not reported
Not reported
680kg
2.46kg
2.5kg
Finland No fumigation of
perishable
commodities
-------
257
Annex 4.3.S (cont.)
!
Table 4.3.3 (cont.) Examples of Fumigation of EXPORTS as a Condition of Entry,
Country
exporting
the
commodity
Germany
Hungary
Iceland
Malaysia
Morocco
Norway
Poland
Singapore
South Africa
Commodity
Two out of 16
states reported no
fumigation of
perishable
commodities
No fumigation of
perishable
commodities
No fumigation of
perishable
commodities
Orchids
Roses
Potatoes
No fumigation of
perishable
commodities
No postharvest
uses
Orchids
Pineapple
Carnation
Chrysanthemum
Main
target
pest(s)
Thrips,
mites
Thrips,
mites
Photorimea
opercullela
Lepidoptera
Acarina
Acarina
Acarina and
nematodes
Exported Quantity
to... exported
Japan 1,000,000
'pieces
Japan 20,000 pieces
France and 24.7 t
other European
countries
Japan, USA 30,000,000
pieces
Europe, Japan 5080 1
Europe, Japan 2 t
Europe, Japan, \ 10 1
USA
Methyl
bromide
used
?
?
12kg
7
4t
0.1 t
0.75 t
-------
258
Annex 4.3.5 (cont.)
Table 4.3.3 (con,.) Examples of Fumigation of EXPORTS as a Condition of Ettry.
Country
exporting
the
commodity
^
Commodity
Main Exported Quantity
target to... exported
pest(s)
_—.
South Korea Chestnut
_
Coleoptera Japan, USA,
Canada
Spain
•-
Sweden
Cabbage Homoptera Japan
Chinese cabbage Homoptera Japan and
China
—
None reported
__———————
No fumigation of
perishable
commodities
3421
1901
1351
Switzerland None reported
• •
Thailand Orchids
Asparagus
_^____ -i
United States Cherries
Peaches
Nectarines
Strawberries
Thrips Japan, USA, 118 million
Australia pieces
Thrips and Japan
Lepidoptera
__————
Lepidoptera Japan,
Korea
Lepidoptera Chile, Israel,
Morocco,
Tunisia
Lepidoptera Chile, Israel
Thrips ?
18641
16,400 t
?
9
Methyl
bromide
used
17 t
15.4 t
4t
5.5 t
1.7t
•——
7.3 t
7
9
^Million cases
-------
259
Annex 4.3.6
Table 4.3.4 Examples of Fumigation for SHIPMENT WITHIN THE SAME COUNTRY.
Country
Canada
Chile
Japan0
Commodity
Nursery stock
(Malus spp.)
Fruit trees -
rootstocks
Tomatoes
Kidney bean
Target
pest(s)
Grapholitha
molesta
Grapholitha
molesta
Ceratitis capitata
fruit fly
(Diptera)
Melon fly
Shipped
from. ..to.
* •
Ontario to
British
Columbia
Ontario to
British
Columbia
Arica region
in north of
Chile to
Central
Region
Yaeyama
Islands to
other regions
Quantity
shipped
16,000
pieces
50,000
pieces
30,000 t
38 t
Methyl
bromide
used
14kg
15kg
2.5 t
114kg
1993, melon fly (Bactrocera cucurbitae) has been completely eradicated from the south
west regions of Japan including the Yaeyama Islands removing the need to fumigate
commodities with methyl bromide prior to shipment to other regions in Japan.
-------
260
4.4 Alternatives for treatment of structures
and transportation
Executive Summary
other inaccessible areas.
spiders; wood destroying insects (termites, beetles); and rodents.
methyl bromide.
as alternatives.
withstand the increased temperatures.
diox?d!2,d/or heat has been used to control these pests in some situations.
ability to locate the site(s) of infestation.
rodent and insect elimination aboard aircraft.
-------
261
There are opportunities to reduce methyl bromide emissions through better containment and
monitoring, which has the additional benefit decreasing treatment time. The use of methyl
bromide in combination with carbon dioxide can reduce use by 50% or more. Certain
structures, such as aircraft, lend themselves to developing strategies for recapture, recycling
and/or destruction of methyl bromide.
Research is needed in many areas before alternative strategies can be adopted. In particular
more data are needed on critical temperatures for heat treatment, biological controls, modified
atmospheres, combination treatments, and potential fumigants.
As these new technologies are developed there is a continuing need for technology transfer, and
this will be one of the major problems confronting developing countries. Programs for the
transfer of knowledge and training must be developed to bring about a successful transition to
reductions of methyl bromide use and emissions and/or to replace methyl bromide with
alternatives and substitutes for structural pest control. Particularly crucial is training in pest
identification, biology and habits, monitoring and use of new technologies. The success of this
training is dependent on economic, social and cultural conditions in developing countries.
Various constraints exist which affect the adoption of substitutes and alternatives. At the present
time there are situations where there are no feasible alternatives for food processing structures
or in conveyances containing sensitive metals, particularly aircraft, when pest eradication is the
goal. A critical element in determining the use and effectiveness of alternatives is the
establishment of economic thresholds for the various pests. Differing regulatory requirements
and use constraints throughout the world will determine the availability of alternative pesticide
products and fumigants.
The economic constraints of substitute and alternative strategies must also be considered. For
example, the use of sulphuryl fluoride is not allowed where food is exposed; and phosphine
has some limitations on its use. High demurrage rates for ships, nonoperational time for aircraft
and extended closure time for mills can significantly increase pest management costs and the
cost of goods sold.
4.4.1
Introduction
Structural pest control is used to prevent or control pests in either an entire structure or a portion
of a structure. The structures may contain raw agricultural commodities, raw products in
process or finished food products awaiting delivery to distribution points, non-agricultural
materials, or may be empty. In this context, pests include insects and other arthropods, as well
as rodents and other vertebrate pests.
The types of structural facilities which are treated are conveniently grouped into three
categories:
• Food production and storage facilities - buildings primarily used, for the production or
storage of food, e.g., mills, food processing plant, distribution warehouse, and others.
Nonfood facilities - buildings not primarily used for the production or storage of food,
e.g., residences and museums.
Transport vehicles - conveyances that are empty but may be infested and need to be
treated, and can be considered mobile storage areas. If loaded with foods, the treatment is
normally classified as a commodity treatment since the commodity would be the primary
source of an infestation.
-------
262
f
Infestations
as insects move from the
-
goods.
consume
induction of allergic responses (Wirtz, 1991).
consumers and wortcers, including
nuc
inmany ca Js by mL sustainable
react with nonfood materials in the structure.
.
the ability of the fumigant gas to
ability to penetrate through
structural fumigation.
^en
W inadequate, and a
-------
263
1
5
§
u
n.
2
3
u
o
1
I
*3
2
a
:§
I
o
o
I
I
I
9-
S
o O H — o
m ->oo
s
o
>».«
S
B
I
u1
5,
? '
9-s-
oQ
§•§
is
:0-
^1
fel
x*-> °
u y
la.a
^=a
5 -
_o"
I
03
-------
264
4.4.2 Existing uses of methyl bromide in structural fumigation
Many conditions and pests exist which require structural pest control; only | some , of tose are
Sed primarily by nETthyl bromide fumigation. There are teee main apphcattons: 1) control
ofdirect structural damage by dry wood termites and wood-bonng beetles to domestic,
' for ™™**
buildings, 2) control of pests, facilities
cockroaches, mites, and rodents, in food processing or storage facilities and non-food fecilmes,
and?) control of pests, for example moths, beetles, cockroaches and rodents, in transport
vehicles, including ships, trucks, aircraft and freight containers.
The following list contains many of the current uses of methyl bromide for structural
tiorald is followed by adiscussion of substitutes and alternatives that have either been
verif die viabilit
mgao
used or ones that might be utilised. Additionally, research is needed to verify die viability,
Salons and conditions of some alternatives and to develop others that are still experimental
or in the planning stage.
4.4.2. 1 Pests Other Than Wood Destroying Insects. Methyl bromide is currently used in
many countries for this category of structural fumigation.
Description
Food Production and Storage
Facilities
Food processing plants
Flour and feed mills
Bulk commodity storage (e.g. silos)
Warehouse
Bakeries
Ham smoke houses
Cheese plants
Refrigerated storage
Restaurants
Examples of Pests
Stored product insects, rodents,
cockroaches, psocids, mites, silverfish,
beetles
Nonfood Facilities
Seed warehouses
Museums
Poultry houses
Mushroom houses
Condemned housing or public health
compliance
Rodents, stored product insects
Dermestid beetles, clothes moths, cigarette
beetles, drugstore beetles
Lesser meal worm, mites, rodents
Mushroom flies, mites
Rodents, cockroaches, venomous spiders
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265
4.4.2.2 Wood Destroying Insects. Methyl bromide is used for this category of structural
fumigation only in the USA and in a small number of other countries.
Dwellings including apartments,
condominiums, trailer homes, historical
buildings
Structural elements before building or in
place, e.g., beams
Museums
Antique vehicles
Drywood termites, furniture beetles,
powder post beetles, long horned beetles
Powder post beetles, long horned beetles
Wood boring beetles
Powder post beetles
4.4.2.3 Transport Vehicles
Trucks, truck trailers, vans (empty)
Ships, shipholds, galley & quarters
(empty)
Railcars (freight or commodity)
Buses
Aircraft
Beetles and moths
i
Insects & rodents
I
j
Insects & rodents
i.
Insects i
Cockroaches & other insects, rodents
Methyl bromide can be used on an entire structure or a portion of a structure. Treatment
duration is dependent upon the time taken to achieve a set cf-product. Ideally sufficient gas to
kill the pests is released into the space and then maintained at the toxic level for a defined period
of time. Methyl bromide is a highly volatile gas that requires containment: for at least several
hours so the fumigant can reach pests. The current practice in many countries is to fumigate
with methyl bromide during a three day weekend when operations are typically suspended.
When a structural fumigation with methyl bromide is completed, the gas is currently ventilated
into the atmosphere. Structural components and materials can absorb the fumigant and release
it slowly into the interior of the structure for a period between a few hours and several days
after aeration has been actively terminated; the length of time needed to safely aerate a structure
depends on the materials which compose and are contained in the structure, and the method of
aeration employed (CA-EPA/DPR. Fumigation Study Data, Methyl Bromide Treated Houses
March 1992. CA. USA). Low lying areas may be particularly difficult to clear of fumigant.
There is no data available to indicate that methyl bromide breaks dowin to nonvolatile
components during structural fumigation. It is assumed that most (>95%, TEAP Report 1994)
methyl bromide used for structural pest control ultimately is emitted directly into the atmosphere
(U.S.A. Department of Health and Human Services, ASTDR. Toxicological Profile for
Bromomethane. September 1992. WA, DC. U.S.A; Hazardous Substances Data Bank Nat
Toxicology Information Programme. 1989. U.S.A).
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266
4.4.3 Substitutes and alternatives to methyl bromide
4431 Substitutes and alternatives for pests other than wood destroying insects
should be to achieve the desired level of pest control by:
- Using no or minimum amounts of pesticides;
- Minimising disruption to the mill or plant;
- Maximising cost effective techniques; and
- Minimising health and environmental effects.
following should be included in the pest management program:
Sound construction and maintenance practices. These
liminary step in most IPM programs for the management
tructural pests regaroiess 01 any other procedures used. Sanitation reduces pest food
anuSSges and cL enhance other alternative strategies by cleaning up waste and
debris that pests can eat, and where they can breed and live.
Detection and monitoring. Suitable detection devices should be installed, maintained
?nd™Tarlv ctecfad toprovide early evidence of insect, rodent and other pest activity.
; of sanitation, construction, and maintenance, tnat neea
S'emtiof to prS ^sts from becoming established .This sometimes requires close
liaison between pest control professionals and site stall.
Preventive treatments. A program of preventive treatments shoul ^be instigated that
are designed to prevent pest infestation from developing in relevant areas. These are
l^ely to^within the wdls of the structure (where, for example, inert dusts may be
used), and within the milling or processing equipment (where for example it may be
necessary to strip down and clean machinery at regular intervals).
situation.
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267
• Full site treatments. Full site treatments are used to eradicate an infestation that cannot
otherwise be adequately controlled. Due to the particular difficulties in achieving pest
control in flour mills and similar food processing sites, it has usually proved necessary
for a complete site treatment to be carried out at various intervals.
Some IPM programs in countries with relatively cold.climates have avoided the necessity for
complete site treatments for several years. When an infestation becomes established within the
walls, floors, machinery and other inaccessible areas, the site will neai treating in a way which
will ensure penetration and eradication or to stop production in that building and move to
another site. In full site treatments, eradication of pests is the objective, rather than control by
reducing the population to a more manageable level. This is because if the population is
reduced but not eradicated, it will more quickly revert to a population level that again requires
full site treatment Secondly, partial control rather than eradication can often encourage
resistance to develop (this may apply to both chemical and nonchemical methods). If this
happens it will make future full site treatments and IPM programs less effective. IPM because
of its multi-technique approach can delay the onset of resistance.
Alternative full site treatment options to methyl bromide include:
Carbon dioxide
Cold I
Controlled atmospheres
Heat
Hydrogen cyanide
Phosphine
or combinations of these options.
The choice is determined by regulatory approvals, the prevailing weather conditions, the type
and condition of the building, contents, the time available, the relative costs, health and
environmental risks and the species of pest present.
There is no one method or material to replace methyl bromide for structural fumigation for all
situations in which it is currently used (Watson et al., 1992). IPM approaches employing site
specific detection, physical remedies, other pesticides and monitoring and appropriate training
of pest control workers will provide a framework for alternatives to some methyl bromide
applications.
It is theoretically possible that if new structures are constructed to minimise pest harbourage,
and maximise the effect of sanitation then it will be possible to reduce ifurther the necessity for
complete site treatments. In cold climates it may be possible to avoid the necessity for complete
site treatments altogether. In suitable buildings heat treatment can be eiffectively used in many
situations to achieve pest eradication.
Meanwhile, most existing mills and similar processing sites using the most sophisticated IPM
programs will, based on present evidence, continue to require a complete site treatment within
the IPM program from time to time. Future development of these programs should therefore
include specific attention to integrating strategies (for example building design, construction,
and alterations) that will allow alternatives to methyl bromide to be used for complete site
treatments.
Although methyl bromide is often used to treat for pests other than wood destroying insects
within structures, other methods have been used for many years in specific cases.
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These alternatives can be grouped into three categories:
• Fumigants
• Nonfumigant pesticides
• Nonchemical methods
understood.
e is often used in grain fumigation and can be used in some structural situations. It
^od penetration and its efficfcy against some pests is well researched and
badearyingy conditions. TT.e use of phosphine is not recommended
Phosphine Idlls most stored product pests but does not provide adequate control of several mite
SS tfiatare important stored grain pests. Resistance of some insect species to phosphine
oc^STvarioSSrls of the world. There is a high degree of intra-specific
^oSce^with eggs and pupae being much more tolerant than larvae and adults
1 §5 S c?egxp?sure was morl critical than dosage for both susceptible and
ttains Control of resistant populations requires high dosage and long periods of
s (Wee SdSs 1988). Alternating phosphine use with other furmgants is one
potential way of slowing development of resistance.
TfeA«» ic a Hanrer of fire or even explosion, when phosphine formulations are misused or
presenting a disposal problem and further potential hazard.
established. The manufacturer does not intend to pursue this registration (DowElanco,
communication to MBTOC).
It is verv effective against all life stages of wood destroying insects. The efficacy of tius
.
^l^SSnded SelcoSmcsyof plant down time must be considered when detemnmng the
exposure period. It must be applied by skilled operators.
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Hydrogen cyanide (HCN) has been used as a fumigant for almost a century and still has
some uses in a few countries. It is the only fumigant gas that is lighter than air. This product
acts very rapidly in suitable locations, particularly against rodents. It is easy to apply and has
very little residue if used correctly.
HCN is no longer used in most countries for a variety of reasons including the fact that it is
extremely toxic to humans and skin absorption alone can cause death at (the concentrations
normally used. During normal fumigations inadequate distribution can occur and localised
concentrations can be explosive. It is very water soluble. This property can interfere with
penetration and cause exposed water to become toxic. Its reaction with some foods produces
toxic compounds. There are severe restrictions imposed on its transport
4.4.3.1.2. Controlled Atmospheres
Considerable research has been conducted on disinfestation of stored commodities with
controlled atmospheres (see Sections 4.2.3.1.10 and 4.2.4.3.2) and data obtained in those
studies may be pertinent to structures.
Controlled atmospheres can be characterised as ones which either deficient in oxygen or rich in
carbon dioxide Carbon dioxide acts as a toxic gas on insects, whereas atmospheres made with
nitrogen act solely through lack of oxygen to support life. These techniques offer the advantage
that no toxic residues remain on food contents in the structure.
Presently, there are few flour mills or other food manufacturing plants that are well sealed
enough to hold the required concentrations for the required amount of time, usually more than
10 days, without excessive use of gas. Structural modifications for older food production
facilities or new construction could be expensive. This technology can be incorporated into
new construction Accidental tearing of the seal during long exposure periods, which can cause
failures, is more likely than with shorter duration fumigations. Heat exchangers and other
specialised equipment are often needed for treatment of large structures for distribution and
circulation of the gas. There is active research in generation of gases for modified atmospheres
tor insect control. Machines capable of generating such gases on site have already been trailed
for treatment of grain pests in large silos (Cassells et al., 1994).
4.4.3.1.3 Combinations
Fumigant + carbon dioxide
Fumigant + heat
Fumigant + carbon dioxide + heat
Fumigant + fumigant
The most significant advantage of using combinations is the reduced amount of fumigant
required for effective treatment. This also can reduce costs. These procedures have the
potential to reduce risks of human and environmental exposure, and aeration time.
Phosphine (0.09 - 0.14 g m-3) combined with heat at 32 - 37°C and CO2 (4 - 6%) has proven
to provide good penetration and a rapid treatment time, similar to that for methyl bromide
(Mueller, 1994). Additional data is needed on efficacy and the advantages and limitations of
these techniques, particularly damage to sensitive metals in equipment.
4.4.3.1.4 Nonfumigant Pesticides
Space Sprays (fogging, misting) usually involve dispersal of small particles below
50 microns in size dispersed in the air at a rate of 0.5 to 1.0 g nr3. The small particles stay
suspended in the air for a period of time and contact and kill exposed insects. It can supplement
other control methods as part of an IPM program, but is seldom a complete control itself, since
space sprays are not assumed to have penetrating ability and therefore cannot move between
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These space sprays can also contribute to IPM programs.
So ™nfood ^aVjnd its toxiciv may lead to tether restriction and unavauabtbty.
sSSS^ss^
44.3.1.5 Nonchemical Treatments
washing, and can enhance other alternative strategies.
pesticide application.
high humidities, greater th£n about 80%. They adhere weakly to surfaces and are easily
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removed from the site of application. Silica gel and diatomaceous earths can be applied as a
slurry. They can be unsightly and are usually used in areas such as wall voids that are not
visible. ,.. !
Diatomaceous earth formulations are relatively non-toxic, provided they do not contain
crystalline silica.
Heating above 52°C (125°F) has been used to control insects in flour mills for almost
100 years. It is still used extensively by a number of major food processors as an important
part of their pest control program. Food plants that can be successfully heat treated rarely
require fumigation. It is also advantageous in that there are no residues. Although expansion
of use of this technique is expected, there are some important limitations. For example, some
structures cannot tolerate the stresses caused by extreme changes in temperature and differential
expansion of structural components, e.g. of concrete and steel. Insects cart sometimes migrate
temporarily to outer walls or floor drains and successfully escape the effect of heat treatment.
Some life stages may tolerate elevated temperatures for extended periods of time, a factor that
requires further research. Heat dissipation is often slow, and may delay resumption of normal
activities. Some equipment must be modified or removed to avoid damage. Some greases may
liquefy and must be reapplied after heat treatment Some products cannot withstand the required
temperatures and may have to be removed and treated separately to prevent the reintroduction of
pests. Some buildings are not constructed so that they can be uniformly heated to the required
temperatures. Certain aspects of this technique are discussed in the attached case history (case
history 4.4.1).
Trapping Devices can be used to monitor pest populations and as a technique for limited
control (case history 4.4.2). Both the monitoring function and the function of limited control
are valuable as part of an IPM program. These devices include glue-board traps, glue-board and
electrocuting light traps and other devices such as pitfall traps. Trapping may be enhanced by
the use of baits and/or pheromones. Mechanical traps for rodents can be effective;
understanding feeding and nesting requirements of different kinds of rodents allows traps to be
utilised most effectively. Traps can also deter the entrance of pests into a facility and they can
be used for the early detection of pest populations.
Traps should be properly placed to avoid attracting pests into the structure or an internal area
where they would not normally be found. In addition, insects living in closed structures such
as machinery may be unable to reach traps.
Rodent traps include snap, glue and live trapping devices. They are particularly effective in
reducing rodent populations within structures. They can be labour-intensive because they
require frequent inspection and maintenance. Glue boards are considered inhumane in some
countries. Rodent eradication by trapping may require an extended period of time in contrast to
the rapid action of fumigation.
4.4.3.2 Substitutes and alternatives for wood destroying insects
Although methyl bromide is often used to treat wood destroying insects, such as powder post
beetles, long-horned beetles, dry wood termites and carpenter ants within structures, other
methods have been available for many years.
These alternatives can be grouped into three categories:
• Fumigants ;
• Nonfumigant pesticides •
• Nonchemical methods
Detection of wood destroying insects involves identifying and finding the specific location of
pests so that control measures can be applied to the infested area when possible and practical.
Monitoring pests is an on-going process of assessment of continuing pest presence where
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treatment procedures have been utilised. Several tools are used to supplement visual inspections
as spot treatments.
i^thvl bromide fumigation is particularly used to eradicate drywood termites from structures.
ch kSes that termites are very heat and cold sensitive. When seasonal changes
Sd TtSmftfcolonies move significantly within the structure. During warmer times,
firom exterior wall areas and attic spaces to other locations deeper into the structure
^rare cooler. Conversely when colder temperatures exist, the opposite
urf This may make detection and spot treatment of an entire colony more
fficuho e. Additional research indicates that when an entire colony is not eradicated it
wf produc^new reproductive and survive. Subsequently, eggs will be produced and a
colony can recover and potentially continue to damage the structure.
4.4.3.2.1 Fumigants
Siilnhurvl fluoride is a substitute for methyl bromide in several countries where it is
La5aWeyiX re^stered for use. In the USA (California) this substitution has led to virrn^y
riOO%1eduction fimethyl bromide use in the fumigation of dwellings now. Usage fell from
about 2300 1 in 1990 to 430 1 in 1992. The efficacy of this product is well researched and
understood ^provides good penetration, requires a short fumigation period of approximately
24 hSSid haPs a 6 - 8 hour aeration period. It is effective against all life ^«™£.
HpQrrnvina insects However, the egg stage of many insects requires up to a lOx increase in
dosaS when compSo u^e norm!! rate for adult control. The economics of the higher dosage
a?e a coSeration in evaluating this treatment. If good sealing techniques, which enhance
rSgrcoSment are achieved, lower dosages may be made more efficacious by extendmg
dieelposure period. Sulphuryl fluoride is nonreacnve and thus can be the preferred fumigant
for libraries and museums.
At the present time, sulphuryl fluoride is only available in the United States Germany, Japan,
Swedehand some parts of the Caribbean. It must be applied by skilled operators.
Phosohine is often used in grain fumigation and can be used in some structural situations.
The* -is Umited efficacy datffor wood destroying insects; this requkes further research or
d^TmenSrfto determine the feasibility of using this product in dwellings. It was effective
against wood-boring insects in Norwegian churches (case history 4.4.3).
The use of nhosohine in dwellings may be limited due to its corrosive properties, particularly
2 copper or y£S& silver alloys under high humidity conditions^ ^S^ST "
extended fumigation time, 72 hours or more, against some pests and at low temperatures
(<20°C).
Hvdrosen cyanide has been used as a fumigant for almost a century and still has some uses
in V few cSSes Historically it has been used for long-horned beetles and other wood
destroying insects.
HCN is no
in most countries because it is extremely toxic to people. Skin
at concentrations currently used. During fumigations inadequate
cyanide.
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Combinations
Fumigant + carbon dioxide '
Fumigant + heat
Fumigant + carbon dioxide + heat
Fumigant + fumigant
most significant advantage of using combinations of techniques is the reduced amount of
fumigant required while still achieving an effective treatment. These treatments have the
potential to reduce exposure and aeration time. The efficacy of reduced sulphuryl fluoride
concentrations and carbon dioxide has been demonstrated by Scheffran and Su (In press) This
technology requires further study in operational settings. Further research is needed on the
errect of the combination of phosphine, heat and carbon dioxide which has been used asainst
stored product insects. «sa"«»
Chloropicrin has been used in combination with other fumigants (principally as a warnine
Sfi to ™ntrol wood destroying insects in dwellings. It is highly toxic to various insecls but
is difficult o remove from sorptive materials and considerably more toxic on a weight for
weight basis to humans than methyl bromide. 8
4.4.3.2.2 Nonfumigant Pesticides
Surface application/injection of liquid residuals is used for spot application to
accessible wood. The products used for this application include organophosphates (e g
chlorpynfos), pyrethroids (e.g., permethrin), and borates (e.g., sodium octaborate
tetrahydrate).
These products are applied as sprays, fogs, brush-ons and/or injections for treating accessible
components The efficacy of organophosphates and the pyrethroids against wood destroying
insects is well documented. The efficacy of borates for drywood tenmils is promising and is
undergoing further study. 6
r ncludef tive ingredients such as boric acid, pyrethroids, silica gel, diatomaceous earth,
and sodium octaborate tetrahydrate. These products are applied as spot treatments or into
cavities created by insects m the wood. Dusts are efficacious against some wood destroying
pests, e.g., carpenter ants and termites, and have long lasting residual activity when dry
Application of dusts can be labour intensive and require boring into the wood in the structure
Further work is needed to determine the efficacy of these products for other wood destroying
llloClf-Lo*
Wood Preservative Treatment is a method of preventing wood destroying insect problems
by applying a pesticide or preservative to wood pre-construction.
Some materials used for wood impregnation have been discontinued because of environmental
effects. Pentachlorophenol was broadly used at one time, but is only in use in a few countries
i
A wide range of preservatives are available for vacuum or pressure creating wood, for example
borates and copper containing compounds. Preservative treated wood is useful in new
construction and renovations to prevent infestations.
Sodium octaborate tetrahydrate has proven effective, when adequate penetration of the wood
can be achieved, for some wood destroying pests for which methyl bromide is currently used
Tests are being undertaken to quantify the efficacy of borate with drywood termites, the pest '
historically responsible for most of methyl bromide use in dwellings,.
The use of arsenic and chromic compounds for pressure impregnation has several effects on the
environment and human health, regarded as unacceptable in some countries.
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4 4 3 2.3 Nonchemical
Construe*,,, and Removai.
prevention as a priority so pests n™l a situations constructng
provide inaccess,bl? tabo^eJefcEe^0Jt°rthe™?od from humidity, destroying the
wooden structures m a manner jhich protects me woo substituted for the
attacks.
replaced with pre-treated wood.
Heat. Heating to greyer than ^^^^^
temperatures are likely f &ve more rap ia mor ^ temperature are attained
treatment time is expected to be the rate ^wn^em | ine what speclflc
^ *
C.,d can be used as
has been
^^
mUtechnioue recommendable.
«
is recommended and may be only
applicable to accessible wood.
4433 Ships, Aircraft and Other Transport Vehicles
These are included here on the basis that any treatment required is likely to require many
of the same considerations as buildings.
-4.4.3.3.1 Ships
Methyl bromide is currently used for ship fumigation for:
Quarantine treatment of holds and/or accommodation for rodent control.
Quarantine treatment of holds either empty or Ml of cargo for insect control.
Treatment of cargo after loading and prior to sailing, either with ventilation
before sailing or during the voyage.
Methyl bromide is currently the only fumigant allowed for many quarantine treatments on
ships in many countries.
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Containment, recovery and recycling. Studies on MeBr recapture have been initiated in
German flour mills, and may provide methods of using methyl bromide, while minimising
emissions (see Section 3.7.2). This, and similar techniques, should be tested for applicability
to other types of structures.
4.4.6.2 Substitutes and Alternatives
Phosphine. Methods of using phosphine which reduce or eliminate damage to copper and
noble metals require further investigation. Detailed research is needed on methods of using
shorter treatment times while at the same time retaining and improving efficacy to ensure
resistance problems are not increased.
Biological control. These techniques currently have limited application for controlling pests
in structures. Research on pheromones, parasites, predators and microorganisms is needed to
expand their role.
Carbonyl sulphide. This gas is currently being researched as a fumigant for stored grain and
structures. Efficacy has been demonstrated in laboratory studies (Desmtarctielier, 1994) but
field trials have not been reported. Potential problems with residual odours caused by the
hydrolysis of carbonyl sulphide to H2S or by its reaction to form other sulphur compounds,
toxicity, corrosion and flammability must be addressed. Registration has not yet been obtained.
Sulphury! fluoride. Studies are needed to assess the feasibility of extending the use of this
product to structures in which food is present.
Modified atmospheres. These techniques warrant further studies on efficacy and treatment
strategies that would achieve the same purpose as fumigation, i.e., pest eradication. Research
should investigate shorter treatment times, while maintaining and increasing efficacy, protecting
health and the environment. Demonstration trials are needed to show applicability to aircraft for
rodent eradication.
Temperature modifications. The use of heat shows considerable promise and is already in
use in some mills and for domestic premises (Ebeling, 1994), but further research is needed to
develop data on efficacious treatments, mitigation for effects of heat on construction, and the
construction or modification designs of facilities to permit the effective use of this technique.
Combinations. Research is needed on treatments using combinations of fumigants, modified
atmospheres, and physical changes, (e.g., heat) to shorten treatment times by utilising the
potential synergistic effects of combinations with lower dosage rates, e.g., combined low
dose treatments of phosphine, heat and carbon dioxide. Likewise combinations of approaches
for prevention of pest infestations (e.g., construction of warehouses, careful storage of
commodities) should receive site relevant research priority.
4.4.7.
Uses without alternatives
At the present time there are situations where there are no feasible alternatives for food
processing structures or conveyances containing phosphine-sensitive metals, particularly
aircraft, when immediate insect pest eradication is the goal.
4.4.8 Feasible reduction in methyl bromide use
The subcommittee of MBTOC involved in considering methyl bromide use and alternatives in
structures estimated that a 49% reduction in usage was feasible in structures by 1998 and 53%
by 2003, subject to the constraints listed in Table 4.4.2.
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278
449 Constraints
increased costs.
through effective fumigation.
not available or registered globally.
4 4. 10. Developing country issues
avaUabili* of methyl b—dehas » beoonsiden a
technical expertise to introduce and utilise alternatives.
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275
The alternatives currently available are HCN for rodents in Singapore, phosphine for insects
and rodents, rodenticides and traps. HCN could be used in empty vessels alone where there is
no water in the bilges, rodenticides and traps could be used more widely if maintained carefully
and consistently or where the infestation is low and time is not a constraint. HCN has some
advantages in the control of rodents because it rapidly kills them and their ectoparasites,
principally fleas. Availability of HCN may be limited by regulations on its transportation and
handling.
Phosphine appears potentially to be suitable as an alternative to methyl bromide for treatment of
empty ships and barges for rodent and insect control prior to loading commodity. Some
developing countries currently use methyl bromide for this purpose. While phosphine is rapidly
lethal to rodents, its slow action against insect pests, and consequent demurrage costs, may
limit its usefulness. Where ships contain cargo, in-transit fumigation with phosphine or
modified atmosphere treatments may be feasible (see Section 4.2.4.3.1).
4.4.3.3.2 Aircraft
Methyl bromide is currently used to fumigate aircraft for rodents and sometimes insects;
however attempts are typically made to control insects through residual or aerosol insecticide
applications. Methyl bromide provides a rapid and guaranteed kill which is essential in the
context of the cost of grounding aircraft and the risks to the aircraft if the rodents are not killed.
There are at present no well researched and acceptable alternatives. Phosphine is not
recommended because of the corrosion risk, but could presumably be used in extreme
circumstances, though at risk of affecting the aircraft controls and other electrical systems.
Controlled atmospheres have been shown to be promising for rodent control, but require
research.
4.4.3.3.3 Other Vehicles (freight trucks, railcars, etc.)
These vehicles may require treatment to meet quarantine requirements when empty and prior to
loading. In some countries methyl bromide treatment is currently mandatory. Phosphine could
be an alternative treatment. Nitrogen-based controlled atmosphere treatments are being
considered for quarantine rodent control between Barrow Island and mainland Australia for
treatment of trucks and containers.
4.4.4 Containment/methods for reducing current methyl bromide use
4.4.4.1 Improved Containment
The objective of containment in the use of methyl bromide for the fumigation of structures is-to
enable reduced dosages to be effective, and to reduce emissions to the atmosphere.
Containment alone would not normally be considered as a viable possibility to reduce emissions
to the atmosphere without effective recovery technology. However, improved containment
and monitoring may in fact be considered as a strategy for reducing emissions from structures
while maintaining efficacy.
Containment and emission reduction strategies for structures involve: leakage control;
extending the fumigation period, while ensuring adequate cr-products are achieved; and
pressure testing. This aspect of fumigation can be enhanced by improved monitoring of
fumigant concentrations and adjusting dosages where found to be excessive. Recovery and
recycling are under development to further reduce emissions (see Section 3).
Reduced emissions can also be achieved as discussed earlier by using reduced methyl bromide
dosages in combination with carbon dioxide and/or heat.
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4.4.4.2 Methyl Bromide and Carbon Dioxide
The MAKR system is an alternative treatment
"
4443 Volume Displacement Techniques
circulation of the gas.
445 Transfer of knowledge and training
disseminated through industry journals and conferences.
• i * i ^;nn or Alimimtinc methvl bromide for structural pest control is
human health and environmental protection in each region.
Research Requirements
Emission reduction for methyl bromide
4.4.6
4.4.6.1
Monitoring fumigant levels. Data is needed on the percentage decomposition of the
rfedmefhvl bromide as used currently in structures, to improve estimates of emissions
to atmosDhere from current practice in structures. The losses from well sealed and
Se^reSed sutures need to be determined. This data would be useful for calculation
oflower dose longer exposure regimens that would produce effective ct-products while
reducing quantity of MeBr applied, and consequent emissions.
Combinations. Further evaluation of application methods of combinations such ^carbon
dioxide MeBr mixtures, which with increased exposure time, may lower the methyl
bromide dosage.
Leakage control. Research is needed to develop improved methods to detect and reduce
leakage during fumigation, to permit use of lower MeBr dosages.
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279
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280
4.4.11 References
r««ells J Banks HJ and Allanson. R. 1994. Application of pressure-swing absorption
(PSA) anfnquSI ntaogen as methods for providing controlled atmospheres m gram
^n^ In Hiehley E et al, eds, Stored Product Protection: Proceedmgs of the
^^o^r^Co^^ on Stored-product Protection, 17-23 April,
1994, Canberra, Australia, 56-63.
Desmarchelier, J.M. (1994) Carbonyl sulphide as a fumigant for control of insects and
mites In: HigWey, E. et al., eds, Stored-Product Protection: Proceedings of the 6th
mSiatLal Wording Conference on Stored-product Protection, 17-23 April,
Canberra, Australia, 78-82.
Ebeling, W. 1994. The thermal pest elimination system for structural pest control. The IPM
Practitioner, 16(2), 1-7.
Hallas T.E., Gyldenkaerne, S., Nehr Rassmussen, A. and Jakobsen, J. 1993. Methyl
bromide in the Nordic Countries - Current Uses and Alternatives. Ihc Nordic
Councol, Stockholm, 51p.
Mills K A Clifton, A.L., Chakrabarti, B. and Sawidou, N. 1990 The impact of
pho^hine resistance on the control of insects in stored gram by phosphine
. fumigation. Proceedings of the BCPC Crop Protection Conference, Brighton, 1181-
1187.
Mueller, D. K. 1994. A new method of using low levels of phosphine in combination with
heat and carbon dioxide. Fumigants and Pheromones, 33, 1-4.
Price, L. A. and Mills, K. A. 1988. The toxicity of phosphine to the immature stages of
resistant and susceptible strains of some common stored product beetles and
implications for their control. Journal of Stored Products Research, 24, 51-59.
Scheffran, R.H. and Su, N.Y. (in press). J. Econ. Entomol.
Watson RT Albritton, D.L., Andersen, S.O. and Lee-Bapty, L. 1992. Methyl bromide:
°S atoospheric science, technology and economics. United Nations Environment
Programme, Nairobi, 42p.
Wirtz, R A 1991. Food pests as disease agents. In: Gorham, J.R, «L, Ecology and
Management of Food Industry Pests. FDA Technical Bulletin 4. Arlington, VA,
Association of Official Analytical Chemists, 469-476.
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281
Case History 4.4.1: Heat Treatment of Flour Mill and Cleaning House
A flour mill and a cleaning house located on the Kansas State University campus. These
facilities are connected to other structures on the campus by a common heat tunnel.
Flooding in the midwest USA in the spring of 1993 led to the development of a heating and
dehumidification system that proved successful in the disinfection of two flour mills. This
system did not require capital investment in plant heating capacity. This procedure was tested
because the common connection between university faculties was a deterrent to traditional
fumigation.
This test was designed to determine the efficacy of heat treatment against stored products pests
in these facilities. The buildings were sealed and eleven 50-kilowatt heaters were placed
throughout the facilities and heat ducts were used as necessary. Tempieratare was monitored
with thermocouples and bioassays (48 units) were used to determine efficacy.
The amount of methyl bromide replaced using this method could not be estimated because the
sizes of the facilities were not indicated, other than the mill had five floors and the cleaning
house had four.
This procedure was documented as early as 1911 and is being tested and used with increased
frequency, particularly in the United States. The use of this technology is not regulated by any
governmental agency since it does not involve the use of a pesticide, and quality assurance is a
matter of company policy and is rarely formalised by regulation.
Heat treatment is used as a pest management strategy by some of the larger mills and food
processors in the United States, when pest eradication is not required. Companies that are
anticipating restrictions on products traditionally used in these facilities, i.e., methyl bromide
and dichlorvos, and as an alternative to fumigation and/or space treatments are adopting heat
treatments as alternatives. There is no data to document the number of facilities and the amount
of commodity protected with this treatment.
The procedure based on the report did not appear difficult to research. The most difficult
problem appeared to be the installation of the heaters and the necessity of posting a fire guard
because the sprinkler system had to be inactivated.
To avoid damage, heat sensitive materials, such as plastic pipes and equipment, must be
removed prior to treatment. To effect treatment the building must be sealed virtually to the same
degree necessary for standard fumigation.
This treatment has been used for food production and storage facilities, as well as nonfood
facilities. However, it is not known to have been used for transport vehicles.
The overall assessment of insect control was that it provided very good results, however a few
adults and larvae survived the treatment at the floor level, at the lower levels in the structure and
around windows. It took 15 -18 hours to reach the target ambient temperature range of 52-
54°C and 20 hours to reach this temperature in commodity samples.
Source: Manuscript in press. Dr. John R. Pedersen, Department of Grain Science and
Industry, Kansas State University, Manhattan, KS 66506.
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282
Case HU,.. 4A* _*£ C-J.• Jj --MjHs JJ-..M- Trapping,
of food through the mill.
The treatment of this problem has previously entailed the use of two MeBr fumigations and
several other applications of insecticide per year.
investigated:
first year.
occur with broader applications of insecticides.
Source- Trematerra P 1994. Control of Ephestia kuehniella Zell. by sex Pheromones in the
'fOr Schadlingskunde, Pflanzenschutz und Umweltschutz 67:74-77.
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283
Case History 4.4.3: Fumigation of Three Stave Churches in Norway,
August - September 1984
Three 900 year old wooden churches located in the Sognefjord area of Norway were
fumigated. Some were decorated with original illuminated carvings and paintings. Some of
these had been painted directly onto the wooden walls and had been damaged by the House
Longhorn Beetle (Hylotrupes bajulus).
The infestation was probably present for many years and some control had been achieved in the
past by spot treatments. During detailed surveys, serious infestations wen; found in the roof
timbers and behind hidden panels. Wooden timbers could not be treated using conventional
methods, therefore, tent fumigation was the selected method. The preferred fumigant, methyl
bromide, was not selected because it posed a potential risk to the paintings due to its solvent
action, the high relative humidity (up to 95%), which might cause formation of hydrobromic
acid and a colour change in sensitive pigments. Hydrogen cyanide was dismissed for similar
reasons. Sulphuryl fluoride was considered, but rejected because there, was no registration in
Norway, it has poor ovicidal activity and is expensive.
This was one of the first uses of magnesium phosphide formulated in a plastic matrix. This
formulation does not liberate ammonia which can cause damage. Extensive laboratory trials
using simulated ingredients used by the original artists established that phosphine had the
lowest risk. Despite this, considerable time was spent covering all silver and gilt coatings to
prevent exposure to phosphine.
Had methyl bromide been selected, 300 kg would have been required.
Phosphine has been accepted for many years as an alternative to methyl bromide for structural
fumigations where prolonged exposure times are possible, there is no risk of damage, and
appropriate precautions can be taken to minimise risk.
This technique is rarely used in the Northern Hemisphere for commercial locations because the
required exposure time of 8 - 15 days is not acceptable. In the case of mon-commercial
structures, time is not a major problem, permitting the use of phosphine. Had there been
commercial pressures and time restraints, phosphine would not have been considered.
A considerable amount of laboratory and site time was spent testing the pigments and
developing methods to isolate the various gilt materials from the effects of phosphine. Those
gilt and silver items which were movable, were removed from the church prior to the
fumigation. Only after extensive trials did the fumigators feel confident to undertake this work.
The location of the churches presented a significant logistic problem: moving personnel and
equipment to isolated parts of Norway. Treatments were time consuming as each building had
to be completely wrapped in fumigation sheeting, and all sensitive materials in the churches had
to be protected from phosphine.
The fumigations were very successful. The churches have been monitored since the
fumigations and there have been no reports of any insect activity. The paintings and carvings
show no signs of change or deterioration.
Sources:
Anon. 1985: Hausbockbekamfung in einer Stabkirche Debkmalpflege durch Begasung sichert
schonende Behandlung. Holz-Zentralblatt, Stuttgart, p. 1020.
The fumigation of the three churches is recorded in a confidential Rentokil document
"Preservation of Stave Churches Norway, August - September 1984."
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284
5 . 0 DEVELOPING COUNTRY ISSUES
Executive Summary
5 counts currenuy use *« 18% of*e
and dependence on methyl
Side varies widely between Article 5 countries.
Where methy, taon.de is
and disease control in
cut flowers,
A
for fumigation of nursery and seed
ion 5 staple foodstuffs. Where
fordisinfSmdonof imported and exported cereal grams.
countries.
Atpresen, u,ere is no single **
are currently no
technically feasible alternatives.
Whileitnwbeposs^^^^^
alternatives be appropnately adapted .to *e f gg^ondi^ns p w ^ used for
resource availability >^S«^^J^J^SSytoiSolvc significant effort toward
different crops, commodities .and ^^-^VS °sting technology transfer, user
selecting appropriate ^^niaiivcs.^wna^lwwtM ^ ^^ ft .g ^.^
education, institutional capacity JjJJ^LSwl b?3e receive technical and financial assistance
^^^^^^^ t0 —^ ^ ^ CUffently
controUed by methyl bromide.
5.1
Introduction
in Article 5
environmental
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285
kinds of issues to be assessed in developing and appraising research and technology transfer
projects for introducing or developing country-specific alternatives for Article 5 countries.
In light of possible future restrictions on methyl bromide, this chapter describes Article 5
country-specific issues with regard to the implementation of alternatives. In comparison to
developed countries, Article 5 countries have, in general, characteristics that may affect the
economic and technical feasibility of the implementation of alternatives to methyl bromide.
Resources such as technological capacity and infrastnictural attributes in Article 5 countries tend
to be less developed. Article 5 countries may also have more urgent social needs and are more
dependent on the agricultural sector than developed countries.
Several Article 5 countries have become dependent on the use of methyl bromide for some
important aspects of their economies. Issues, such as short-term agricultural development,
poverty, global inequalities, and external debts, are often closely linked to the revenue
generated by the export of crops which have become dependent on methyl bromide, both for
viability of production in economic terms, as well as for export quality. These issues should be
considered carefully during any phase out of methyl bromide, especially as specific alternatives
are introduced or developed and implemented in Article 5 countries.
In addition, in many Article 5 countries government regulatory and advisory staff are typically
few in number, with technical assistance for pesticide use often provided mostly by pesticide
manufacturers and distributors. Furthermore, since regulatory controls for pesticide use in
Article 5 countries may often be inadequate, the implementation of chemical, alternatives to
methyl bromide will need to include provision for local extension services and training of local
pest control personnel in the technology program so as to ensure safe and effective use.
Implementation of non-chemical alternatives, some of which may require considerable skill for
effective use, will also require good local services and training.
The financial mechanism of the Montreal Protocol makes explicit provision for the incremental
costs associated with adoption of non-ozone depleting technologies in place of substances
controlled under the Protocol. The fourth meeting of the Parties approved the indicative list of
those incremental costs to be financed. However, this list will need modification to reflect the
specific incremental costs of methyl bromide replacement, if phase out is agreed, as the present
list is only relevant for substances of Annexes A, B, and C of the Protocol and the technologies
relevant to these substances. The committee suggests the Parties prepare and approve the
relevant additions to the indicative list if methyl bromide is further controlled arid when
considering extending these control measures to Article 5 countries.
!
There is concern that potential trade conditions which may be imposed by importing countries
upon Article 5 countries that utilise methyl bromide in the production or disinfestation of export
commodities may render a grace period ineffective. Furthermore, the international FAO Code of
Conduct for Procedures of Pesticides states that pesticides which are severely restricted or
prohibited in the producing country cannot be exported to developing countries. This could
apply to methyl bromide in case of a ban in the developed countries or regions. Developed
countries or regions may wish to consider adjusting their legislation in a manner which will
enable Article 5 countries to use methyl bromide and to export commodities produced or treated
with methyl bromide without restrictions during a grace period.
5.2
Methyl bromide use in Article 5 countries
Methyl bromide is a broad spectrum pesticide which is used as a fumigant in the control of
insects, nematodes, weeds, pathogens, and rodents. Methyl bromide usage in developing
countries in 1992 was about (18%) of global consumption of methyl bromide for agricultural
and related uses. Breakdown of usage by Article 5 country is given in Table 5.1.
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286
TableS
.1 Consumption of methyl bromide by some Article 5 countries (1992)
Territory
Country
MeBr
consumption
(t)
(% of Total)
Commodities
ASIA
Bangladesh
China
India
Indonesia
£an (Islamic Republic of)
Jordan
Lebanon
Malaysia
Myanmar
Pakistan
Philippines
Republic of Korea
Saudia Arabia
Singapore
Sri Lanka
Syria
Thailand
Turkey
United Arab Emirates
Vietnam
20
1,000
141
260
100
900
30
69
100
60
70
1,400
100
110
6
10
1,200
800
50
100
IA
AMERICA
AND
CARRIBEAN
Bahamas
Barbados
Costa Rica
Cuba
Dominican Republic
El Salvador
Guatemala
Honduras
Mexico
Trinidad
1
400
300
40
95
60
200
1,000
2
0%
0%
100%
100%
0%
50%
100%
0%
5%
100%
100%
50%
0%
100%
95%
0%
100%
100%
100%
100%
100%
0%
0%
0%
AMERICA
Argentina
Brazil
Chile
Colombia
Ecuador
Peru
Uruguay
Venezuela
1,400
319
130
70
20
20
100
90%
70%
100%
100%
100%
5%
30%
0%
0%
0%
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287
Table 5.1 (conk) Consumption of methyl bromide by some Article 5 countries (1992)
Territory
Country
MeBr
consumption
(t)
(% of Total)
Soil
Commodities
AFRICA
SUBTOTAL
EUROPE
SUBTOTAL
TOTAL
Algeria
Cameroon
Cote d'lvoire
Egypt
Ethiopia
Gabon
Ghana
Kenya
Libyan Arab Jamahiriya
Malawi
Morocco
Mozambique
Namibia
Nigeria
Senegal
Tanzania
(United Republic of)
Zambia
Zimbabwe
Albania
Cyprus
Malta
50
60
70
750
1
50
100
250
150
207
450
15
2
40
40
20
330
660
3,245
40
100
40
180
14,510
100%
100%
,50%
70%
80%
0%
55%
90%
80%
90%
80%
100%
100%
0%
0%
50%
20%
20%
10%
20%
0%
0%
10%
20%
0%
0%
Data source: Bromine Compounds Ltd. and MBTOC survey.
Notes:
(1) Commodity fumigation includes treatment of durables, perishables and structures.
(2) Usage of methyl bromide in Central and Southern Africa was considerably lower than
normal in 1992 due to a very severe drought and reduced harvests. This may have not
only affected the quantity used, but also the relative proportion used on soils and,
particularly, on durables, particularly food grain stocks.
(3) Article 5 countries not shown in this table are assumed to have little or no consumption
of methyl bromide.
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288
importance of methyl bromide in particular sectors.
to Ae other sources as some users did not respond to the survey.
Table 5.2 Consumption of methyl bromide (t) in developing countries in three regions
(1992)
Region0
Africa
"N. Africa"
S. America
™«—••———^^—
TOTALS
1594
1651
2459
•B^^MHBB^""
5704
MBGCC
996d
1363
2300
4659
MBTOC Survey
1463
1000
1252
^^™«^^™^—
3715
a Countries classified into regions according to MBGC system (Table 2.2).
b Bromine Compounds Ltd. data (used in Table 5.1).
c Methyl Bromide Global Coalition data (from Table 2.2).
d South Africa consumption (est. 701 1) subtracted from MBGC estimate.
In many but not all Article 5 countries, little or no methyl bromide is usedfor the production of
' consumption. None is used for production of staple foodstuffs.
Pmsentlv there is no single alternative chemical treatment or combination of treatments that can
substitute for the pest control uses of methyl bromide in many situations.
S°me
The most critical use of this pesticide is on cash-crop exports (e.g.
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289
country. It is essential that alternatives to the use of methyl bromide For perishable commodities
admiSbl y C°ntt°l ^ "^ ^ effectively> but ^ ** accep*ed by the importing country as
Agricultural systems which rely on methyl bromide are currently being developed and expanded
in a number of Article 5 countries as one important method of producing certain high value
crops for export. In addition, a significant portion of the population in several Article 5
countries (e.g. Kenya, Colombia, Zimbabwe) is employed in production of these high value
crops*
Important specific Article 5 country uses include:
Soil fumigation (nursery and seed bed) for production of certain export commodities to
developed country markets. This may include vegetables, strawberries, cut flowers and
tobacco, among other crops.
1 °f some durable commodities (such as timber, tea, cocoa beans) for export
Methyl bromide is used primarily as a quarantine treatment specified by the importing
country. J ^ &
Fumigation of perishable commodities (e.g. some fresh fruit, vegetables, cut flowers) for
export to meet quarantine, phytosanitary, and commercial requirements of certain
importing countries.
Disinfestation of in-country food stocks, particularly cereal grains held in long-term
storage and against the Larger grain borer in Africa.
Specific treatments required by importing countries against pests of quarantine
significance (e.g. Khapra beetle, African giant snail, Larger grain borer).
Disinfestation of ships, aircraft, and other transport vehicles for rodent control or to
prevent the cross-contamination of exports.
Disinfestation of imported grain, notably as food aid. This may be in transit to a third
country.
Potential alternatives in specific use areas are as described in other sections of this report Thev
include cultural practices, IPM, other pesticides, heat or cold treatments, controlled
atmospheres, and irradiation. The choice of alternatives will be determined largely by the
commodity tolerance and the target pest, and the potential success based upon research findings
or experience elsewhere. Since many exported commodities are perishable, and will lose quality
under prolonged storage, it is essential that an effective treatment be accomplished within a
short period prior to shipment, as well as having a high degree of pest efficacy. Research needs
to locus on specific cash-crop exports for each particular situation, commodity, and pest
Country-specific infrastructural limitations and needs should be defined and delineated earlv to
assure lasting technology transfer.
5.3
Soil fumigation
In Article 5 countries, about 70% of the total imported methyl bromide is used for pre-plant soil
fumigation, controlling soil-borne pests, such as diseases, nematodes and weeds. This
pesticide is used particularly during nursery-bed preparation for some tobacco, flower
vegetable and strawberry seedling production. The chemical is also used to a limited amount to
fumigate soil to control replant problems associated with perennial fruit trees such as apples
pears, citrus and guava, among others, as well as on established recreational areas, such as golf
®?Znh * addltlon'a sma11 amount, depending on the country, is used for general fumigation
ot helds for vegetable crops. Almost all methyl bromide use on soils is related to export crops
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290
rth very Httie (less than 2%) used for the production of food for in-country consumption, and
none for production of staple foodstuffs.
Progress on development and adoption of alternatives to methyl bromide use
in soil fumigation
5.3. 1
There are several potential
Serange of pests now controlled using methyl bromide.
both methyl bromide and alternatives in many Article 5 countries.
5 4 Fumigation of durables
Memyibromideisusedi^— ^^
^SS$£SZ£Sf£3£ oS&d- may also be fumigated with methyl
bromide prior to import or export, as a quarantine requirement.
In eastern and southern Aftica,
commodities such as toed sp, ces ti
wheat, beans, peanuts, soya bean, sorghum and timber.
*<> Latin
Salvador and Uruguay,
' cotton- maize>
On an annual basis of A.
meliyl bromide, primarily by the importing countries.
fcsomecircumstance,
developing countries. For example,
barked, sawed, dried
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5.4.1
291
Progress on development and adoption of alternatives to methyl bromide in durable
commodity pest control
Phosphine is an effective alternative fumigant which, when used and applied properly, can
directly substitute for methyl bromide in many durable commodity applications. In most Article
5 countries it is the fumigant of choice for protection of stored grains and tobacco. Methyl
bromide is used largely because of a tradition of effective use, not because of specific
advantages of the material. While phosphine can be used as an alternative to existing uses of
methyl bromide, there are constraints, which need to be considered:
Insect pest resistance has been identified in several Article 5 countries.
• Phosphine requires a longer fumigation period than with methyl bromide for full
effectiveness. This may slow importation or exportation processes to a level where it
may be difficult to accommodate logistically.
• The potential of fire hazard during application if the material is handled improperly or
carelessly.
i
• Currently available formulations of phosphine are not suitable ifor very dry conditions,
the gas taking much longer to be released than normally. It is not generally recommended
where grain moistures are below 9%.
A systems approach or other single technologies are currently used in many Article 5 countries
for disinfestation of durables where methyl bromide could be used. For instance, fumigation of
rice with carbon dioxide is routinely used in Indonesia on a large scale for protection of stored
rice and has been used experimentally in Papua New Guinea for protection of stored coffee.
Controlled atmosphere treatments have been used to replace methyl bromide for disinfesting
coffee and cocoa beans.
Available alternative technologies for durables include sulphuryl fluoride (for wood), carbon
dioxide, hot air treatments, steam treatments, hot water dips, hermetically sealed storage,
controlled atmospheres, irradiation and combined treatments such as protein coating with steam
(for spices), and vacuum steam flow processes (for leaf tobacco). However, these technologies
may be appropriate for some commodities only and may require additional research and capital
to adequately replace methyl bromide where rapid disinfestation is neisded. Additionally, they
may not have local registration for use.
5.5
Fumigation of perishables
Methyl bromide is sometimes used to fumigate perishable agricultural products, such as cut
flowers, stem cuttings, bud-wood, rooted plants, bulbs, corms, rhizomes, fresh fruits,
including grapes, bananas, and vegetables prior to export. This is a critical area of use to some
Article 5 countries, with an estimated annual usage of about 7% (667 tonnes) of total. The
majority of this usage is due to quarantine and other phytosanitary requirements of the
importing countries.
Examples of perishable commodities, some of which are currently treated with methyl bromide,
and their economic importance include:
• cut flowers in Kenya, which accounts for 13% of the total foreign exchange earning
(US$42 million in 1992);
• cut flowers, fruit and vegetables from Colombia which between 1988 and 1992, provided
3.9% of the total foreign exchange earnings;
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292
cut flowers in Thailand, which accounts for an annual US$20 million;
. grapes exported from Chile to USA which in 1993 accounted for 3% of total exports
(value US$293 million).
Note that the need for treatment is usually driven by the requirements of the importing country
fflflSpSSSw of the pests. Only a proportion of this trade (but all Chilean grapes to USA)
is treated currently with methyl bromide.
5.5. 1 Progress on development and adoption of alternatives to methyl bromide in
perishable fumigation
Alternative quarantine treatments or procedures already approved by certain countties include
nSrinment inspection, pest-free zones or periods, cultural practices, cold and/or hea
?elS controlled atmospheres, physical removal of pests or soil. For example cold
treatments are used for apples from Chile, Jordan, Mexico, and Uruguay to the USA, for
pS and apricots from Morocco to the USA; and for kiwifruit from Chile to Japan. Hea
Sments are used to disinfest papaya, mango, citrus, eggplant, zucchini, squash and bell
peppers, and could be developed for a wide range of perishables. In "J^^ff^*
treatments are necessary, such as soapy water with wax for chenmoya from Chile, and vapour
heat with cold treatment for lychee from Taiwan.
Each treatment is dependent upon the commodity, the target pest, and the geographical area.
Some of these treatments are already in operation to a limited extent in specific ™™™*-
Limitations and constraints can include capital costs, operational costs, lack of c0™
resarch, technical capabilities and especially, quarantine acceptance by the
Sid inconsistent results of a particular alternate treatment However, some alternative treatments
of quality in transport and storage compared with methyl bromide
may
use.
5.6 Structural fumigation
Small quantities of methyl bromide, less than 1% of Article 5
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293
5.7 Recycling, Recovery and Reclamation
Presently the Article 5 countries do not recycle, recover or reclaim methyl bromide. Once the
technology is developed and feasible, the Article 5 countries are likely to benefit by adoption of
these technologies in order to recover methyl bromide applied to fumigation chambers,
structures and buildings. Some Article 5 countries are currently investigating application of this
technology (e.g. Chile). Better containment and recycling of methyl bromide may improve the
reliability of fumigation and thus help to maintain and expand export markets. However, most
recovery technologies, and all the recycling technologies, are likely to have high capital and
running costs. They may also be energy intensive. Many would require a level of technical
expertise not normally found currently at fumigation facilities.
5.8 Replacement of methyl bromide
The complete replacement of methyl bromide will involve not only site-sp<;cir!c agricultural
research, but also social and economic processes such as:
• The creation of awareness in regard to the Montreal Protocol and ensuring that adequate
technical information is made available at all relevant levels.
• The determination of the capacity of various developing countries in terms of
technological capabilities, manpower resource base, and the availability of funds to
implement alternative pest control methods.
• The development and production of training and public information materials for
distribution to the relevant authorities and personnel such as technical staff, local farmers,
and the public sector.
• The implementation of sound programs to ensure a quick field adoption of alternatives.
Among the technical strategies necessary for developing alternatives to methyl bromide use,
there is a need for the following specific research priorities:
• implementation of IPM practices, which include non-chemical technologies (e.g. using
healthy stocks for propagation, preventative - quarantine, crop rotation, biological •
control, etc.), and including chemical pesticides when needed;
• research to find, adapt and implement alternatives that are effective, environmentally
sound, easy to apply, safe to users and affordable, and specific to local conditions, crops
and target pests;
• technology transfer to enable developing countries to evaluate and implement the use of
alternatives;
• training of local technical staff as part of the process of technology transfer.
5.9 Conclusion
Methyl bromide is currently used in many Article 5 countries for certain economically important
products of agriculture. It is important that alternatives to methyl bromide for use in Article 5
countries allow the continued economic gains from agricultural and horticultural production.
Article 5 countries using methyl bromide will require some assistance to implement alternative
pest control methods which are affordable, environmentally sound, and safe to users.
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294
Alternatives need to be country-specific, crop-specific, and pest-specific, and wiU require
substantial programs involving research, technology transfer, training and infrastructure
strengthening.
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295
APPENDIX: UNEP METHYL BROMIDE
TECHNICAL OPTIONS COMMITTEE
Address list as at 1 December 1994
Mr Joel arap-Lelei
First Secretary/Environment
Embassy of the Republic of Kenya
Nieuwe Parklaan 21
2597 LA The Hague
NETHERLANDS
Ph:+31 70 350 4215
Fax:+3170 3553594
Mr Mohd. Azmi Ab Rahim
Ministry of Agriculture, ASEAN PLANTI
P.O. Bag 209, UPM Post
Serdang
MALAYSIA
Ph: +60 3 948 6010
Fax:+60 3 948 6023
Dr HJ. Banks
Head
Stored Grain Research Laboratory
CSIRO Division of Entomology
G.P.O. Box 1700
Canberra ACT 2601
AUSTRALIA
Ph: +61 6 246 4207
Fax: +61 6 246 4202
*Dr Thomas A. Batchelor
Technical Manager (Market Access)
ENZA New Zealand (International)
P.O.Box 1101
Hastings
NEW ZEALAND
Ph: +64 6 878 1865
Fax: +64 6 876 8597
Email: 100035.3402@compuserve.com
Dr Antonio Bello
Centro de Ciencias Medioambientales
Consejo Superior de Investigaciones Cientificas
Serrano 115 apdo.
28006 Madrid
SPAIN
Ph: +34 1 56 25020
Fax:+34 156 40800
Dr Barry Blair/Mr John Shepherd (alternate)
Assistant Director & Research Coordinator
Tobacco Research Board
P.O. Box 1909
Harare
ZIMBABWE
Ph: +263 4 575289/94
Fax:+2634575288
Indicates government nominee to MBTOC
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296
Mr Richard C Bruno/Mr Ed Ruckert (alternate)
Director, Technical Administration
Sun Diamond Growers of California
1050 South Diamond Street
P.O. Box 1727
Stockton CA 95201
UNITED STATES OF AMERICA
Ph: +1 209 467 6266
Fax: +1 209 467 6249
*Dr Adrian Carter
Agriculture Canada
Plant Industry Directorate
Ottawa, Ontario
K1AOC6
CANADA
Ph: +1 613 993 4544
Fax: +1 613 998 1312
DrVicentCebolla
Ingeniero Agr6nomp Investigador
Plant Pathology (Micology)
Institute) Valenciana de Investigaciones Agranas
Carretera de Moncada a Naquera Km 5
Aptdo Oficial 46113 Moncada (Valencia)
SPAIN
Ph: +34 6 139 1000
Fax: +34 6 139 0240
*MrBishu Chakrabarti
Central Science Laboratory
London Road
Slough, Berkshire SL3 7HJ
UNITED KINGDOM
Ph: +44 7 53 534626
Fax: +44 7 53 824058
%Mr Chamlong Chettanachitara
Agricultural Regulatory Division
Department of Agriculture
Chatuchak, Bangkok
THAILAND
Ph: +66 2 579 2145
Fax: +66 2 579 4129
Ms Patricia Clary
CATS (Califomians for Alternatives to Toxics)
860 1/2 Eleventh Street
Arcata,CA 95521
UNITED STATES OF AMERICA
Ph: +1 707 822 8497
Fax:+1707 822 7136
Email: cats@igc.apc.org
*Mr Jorge Corona
Canarintra
Cto. Misioneros G-8, 501
CD. Satelite 53100
MEXICO
Ph: +52 5 3933649
Fax: +52 5 5729346
Indicates government nominee to MBTOC
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*Dr Miguel Costilla
Investigador Principal
Estacion Experimental
Agro-Industrial Obispo Colombres
Casilla Correo No. 9
4101 Las Talitas Tucuman
ARGENTINA
Ph: +54 81 266 561
Fax:+54 81 311462
*Ms Jennifer Curtis
Natural Resources Defense Council
71 Stevenson Street
San Francisco, California 94105
UNTIED STATES OF AMERICA
Ph: +1 415 777 0220
Fax: +1 415 495 5996
Dr Tom Duafala/Mr Dean Storkan (alternate)
TriCal
P.O. Box 1327
Hollister, California 95024
UNITED STATES OF AMERICA
Ph: +1 408 637 0195
Fax:+1 408 637 0273
Mr P. Ducom
Ministere de 1'Agriculture et de la Peche
Laboratoire National d'etude des Techniques
de Fumigation et de Protection
Des Denrees Stockees
Chemin d'Artigues 33150 CENON
FRANCE
Ph: +33 56 32 62 20
Fax:+33 56 86 5150
Dr J.E. Eger
Senior Scientist
North American Crop Production Field TS&D
DowElanco
Suite 780, One Metro Center
4010 W. Boy Scout Boulevard
Tampa, FL 33607-5728
UNITED STATES OF AMERICA
Ph: +1 813 874 1200
Fax:+l 813877 1326
*Mr Juan Francisco Fernandez
Chief of the Department of Sustainable Development
Office of Studies and Agricultural Policies of Chile
Environmental Unit
Ministerio de Agriculture
Teatinos 40, Santiago
CHILE
Ph: +56 2 696 3241
Fax:+56 2 6716500
Indicates government nominee to MBTOC
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*Dr Michael Graber
Head, Air Quality Division
Ministry of the Environment
P.O. Box 6234
Jerusalem 91061
ISRAEL
Ph:+972 2 251977/251936
Fax:+9722251830
DrAviGrinstein .
Laboratory for Pesticide Application, State of Israel ^ ^^ ^ %g
P.O. Box 6 Fax. +972 3 960 4704
Email:
DrDougGubler
Department of Plant Pathology
University of California
Davis CA 95616
UNITED STATES OF AMERICA
Ph:+1916 752 0304
Fax:+1916 752 5674
*Mr Thorkil E. Hallas
Department of Biotechnology
Danish Technological Institute
Gregersensvej
P.O. Box 141
DK-2630 Taastrup
DENMARK
Ph: +45 43 504680
Fax: +45 43 993414
Email: TEH@svane.dti.dk
Dr Toshihiro Kajiwara
Director General
Japan Plant Protection Association
(Nippon Shokubutsu Boeki Kyokai)
1-43-11 Komagome Toshima-ku
Tokyo 170
JAPAN
Ph: +81 3 3944 1561
Fax: +81 3 3944 2103
Dr Jaacov Katan
Hebrew University
Rehovot76100
ISRAEL
Ph: +972 848 1217
Fax: +972 846 6794
Dr Richard Kramer
National Pest Control Association
8100 Oak Street
Dunn Loring, Virginia 22027
UNITED STATES OF AMERICA
Ph:+1 703 573 8330
Fax:+1703 573 4116
* Indicates government nominee to MBTOC
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Mr Laurent Lenoir
UCBSA
Avenue Louise, 326
B-1050 Brussels
BELGIUM
Ph: •*-32 2 641 1712
Fax: + 32 2 640 7412
Prof. Maria Ludovica Gullino
DI.VA.P.R.A. - Patologia Vegetale
Via Giuria 15
10126 Torino
ITALY
Ph:+39 11 6505236
Fax; +39 11 6502139
Ms Michelle Marcotte
Nordion International Inc.
447 March Road
Kanata, Ontario
CANADA K2K 1X8
Ph:-H 613 592 2790
Fax: +1 613 592 0440
Email: Internet! Marcott:e@Attmail.com.ca
Dr Melanie Miller
Sustainable Agriculture Alliance
P.O. Box 665
Napier
NEW ZEALAND
Ph/fax no.: +64 6 835 3501
Email: Melanie.MiHer@green2.dat.de
Mr Takamitsu Muraoka
Sanko Chemical Co. Ltd.
No. 6, 2, 3-Chome, Kasumigaseki
Chiyoda-Ku, Tokyo
JAPAN
Ph:+813 3580 0861
Faxi +81 3 3593 3406
*Ms Maria Nolan
Department of the Environment
Room B259
Romney House
43 Marsham Street
London SW1P 3PY
UNITED KINGDOM
Ph:+44 71276 8284
Fax:+44 71276 8285
Dr Joe Noling
Citrus Research and Education Center
University of Florida
700 Experiment Station Road
Lake Alfred, Florida 33850
UNITED STATES OF AMERICA
Ph:+1813 956 1151
Fax:+1813 956 4631
Mr Henk Nuyten
Experimental Garden Breda
Heilaarstraat 230
Breda
NETHERLANDS
Ph:+31 76 144382
Fax:+3176 202711
Indicates government nominee to MBTOC
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Mr Gary L. Obenauf
Consultant
Agricultural Research Consulting
P.O. Box 5377
Fresno CA 93755
UNTIED STATES OF AMERICA
Ph:+1209 244 4710
Fax: +1 209 224 2610
*Dr Mary O'Brien .
Pesticide Action Network, North America Regional Center
P n ROY 11056
Eueene OR 97440
UNTIED STATES OF AMERICA
1 503 485 7429
Email: mob@darkwing.uoregon.edu
Dr David M.Okioga
Kenya Agricultural Research Institute
Division of Plant Quarantine Services, Muguga
P.O. Box 30148
Nairobi
KENYA
Ph: +254 154 32880
Fax: +254 2 521930
Email: Elizabeth.Agle@unep.no
*Dr William Olkowski/Ms Sheila Daar (alternate)
Project Director
BIRC Inc. (Bio-Integral Resource Center)
1307 Acton Street
Berkeley, California 94706
UNITED STATES OF AMERICA
Ph:+1510 524 2567
Fax:+1510 524 1758
*Mr Sergio Oxman
Ozone Operations Coordinator - Latin America
Global Environment Coordination Division
Environment Department Q
The World Bank, 1818 H Street, N.W. Ph: +1 202 458 9028
Washington DC 20433 Fax: +1 202 522 3 5°
UNTIED STATES OF AMERICA Email: Soxman@WORLD BANK.ORG
Mr Santiago Pocino
FMC Foret S.A.
C6rcega293
08008 Barcelona
SPAIN
Ph:+34 3 416 7517
Fax: +34 3 416 7403
*Mr Michael Host Rasmussen/Mr J. Jacobsen (alternate)
Ministry of Environment
Danish EPA
Strangade 29 DK-1401
Conenhaeen K
DENMARK ' '
Email: michael@mst.mst.min.dk
Indicates government nominee to MBTOC
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*Dr. A. Nathan Reed
Director of Research & Development
Stemilt Growers Inc.
P.O. Box 2779
Wenatchee WA 98807-2779
UNITED STATES OF AMERICA
Ph: +1 509 662 3602
Fax: +1 509 663 2914
*Dr Christoph Reichmuth
Federal Biological Research Centre
for Agriculture & Forestry
Ko'nigin-Luise-Strasse 19
14195 Berlin
GERMANY
Ph: +49 30 8304 261
Fax: +49 30 8304 284
Dr Rodrigo Rodriguez-Kabana
Department of Plant Pathology
Auburn University
Auburn, Alabama 36849-5409
UNITED STATES OF AMERICA
*Dr Ralph T. Ross
Special Assistant
Animal and Plant Health Inspection Service
Office of the Administrator
United States Department of Agriculture
P.O. Box 96464
Washington DC 20250
UNITED STATES OF AMERICA
Mr Tsuneo Sakurai
Chemical Technology Department
Teijin Chemicals Ltd.
Daiwa Bank Toranomon Building
6-21, Nishi-shinbashi 1-Chome
Minato-Ku, Tokyo 105
JAPAN
Mr John Sansone
SCC Products
1152N Knollwood Circle
Anaheim CA 92801
UNITED STATES OF AMERICA
Mr Colin Smith
Rentokil Ltd.
Felcourt
East Grinstead
Sussex RH19 2JY
UNITED KINGDOM
Ph: +1 205 844 4714
Fax: +1 205 844 1948
Ph: +1 202 720 5015
Fax: +1 202 690 4265
Ph: +81 3 35064714
Fax: +81 3 525 17179
Ph: +1 714 761 3292
Fax: +1 714 761 2095
Ph: +44 342 833 022
Fax: +44 342 326 229
Email: GBR-RTK@immedia.ca
Indicates government nominee to MBTOC
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*Dr Don K.W. Smith
Industrial Research Limited
P.O. Box 31-310
Lower Hurt
NEW ZEALAND
Ph:+64 4 569 0000
Fax: +64 4 566 6004
Email: D.smith@irl.cri.nz
Dr Michael Spiegelstein/Dr David Shapiro (alternate)
Bromine Compounds Ltd.
P O Box 180 ph: +972 '
R^heva 84101 Fax: +972 7 297832
ISRAEL Email: 100274,235 l@CompuServe.COM
*Mr M.R. Steyn
The Director General
Department of National Health and Population Development
Private Bag X828
Pretoria 0001
SOUTH AFRICA
Ph: +27 12 3120215
Fax: +27 12 215392
Dr Robert Suber
Director of Health & Environmental Sciences
RJR Nabisco
Bowman Gray Technical Center
Winston-Salem, NC 27102
UNITED STATES OF AMERICA
Ph: +1 910 741 5544
Fax:+1910 741 7472
*MrAkioTateya
Agricultural Chemicals Inspection Station MAFF
Nouyaku Kensasho
2-772 Suzukichou Kodairashi
Tokyo 187
JAPAN
Ph:+81 423 83 2151
Fax: +81 423 85 3361
*Mr Robert Taylor
Natural Resources Institute
Chatham Maritime
Chatham
KentME4 4TB
UNITED KINGDOM
Ph: +44 634 883778
Fax: +44 634 880066/77
*Mr Bill Thomas/Dr Janet Andersen (alternate)
U.S. Environmental Protection Agency
401M Street, SW
Mail Code 6205J
Washington DC 20460
UNITED STATES OF AMERICA
Ph: +1 202 233 9179
Fax:+1202 233 9577
Email: thomas.bill@epamail.epa.gov
Indicates government nominee to MBTOC
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Mr Gary Thompson
Quaker Oats
2811 South llth
P.O. Box 28
St. Joseph MO 64502-0028
UNTIED STATES OF AMERICA
Ph:+1816 279 1651
Fax: +1816 279 8355
Mr Jom Tidow
Product Management Fungicides
BASF
APM/FB Li 555
P.O. Box 220 D-6703
Limburgerhof
GERMANY
Ph: +49 62 36 68 27 70
Fax: +49 62 36 682014
*Dr loop van Haasteren
Ministry of Housing, Physical Planning and Environment
RijnstraatS
Den Haag
THE NETHERLANDS
Ph: +31 70 339 4879
Fax:+3170 339 1293
Dr Patrick V. Vail/Mr Preston Hartsell
Laboratory Director/Research Entomologist
USDA-ARS
Horticultural Crops Research Laboratory
2021 South Peach Avenue
Fresno, California 93727
UNITED STATES OF AMERICA
Ph: +1 209 453 3002/3033
Fax: +1 209 453 3088
Dr Etienne van Wambeke
Katholieke Universiteit Leuven
Laboratory of Phytopathology and Plant Protection
Willem de Croylaan 42
-
: +32 16
BGIUM
j «
Fax: +32 16 322 y°y
Email: ANNITA=ERAETS%FYT%AGR@CC3.KU1.EUVEN.AC.BE
Dr Kenneth Vick
United States Department of Agriculture
Agricultural Research Service
National Program Staff
Beltsville MD 20705
UNITED STATES OF AMERICA
Ph: +1 301 504 5321
Fax: +1 301 504 5467
Mr Chris Watson
IGROX Ltd.
White Hall Farm
Worlingworth, Woodbridge
IP13 7HW Suffolk
UNITED KINGDOM
Ph: +44 72 876 424
Fax: +'14728 628247
Indicates government nominee to MBTOC
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Mr Robert Webb
Driscoll Strawberry Associates Inc.
Research Division
404 San Juan Road
Watsonville, California 95076
UNITED STATES OF AMERICA
Ph:+1408 722 7126
Fax: +1 408 724 3022
Mr Rene Weber/Mr David Mac Alister (alternate)
Great Lakes Chemical Corporation
P.O. Box 2200
West Lafayette IN 47906
UNITED STATES OF AMERICA
Ph: +1 317 4976100
Fax:+1317 4637176
Mr James Wells
California Environmental Protection Agency
Department of Pesticide Regulation
Executive Office
1020 N Street, Room 100
Sacramento CA 95814
UNTIED STATES OF AMERICA
Ph: +1 916 445 4000
Fax:+1916 324 1452
*Mr Wang Wenliang
Engineer
Zhejiang Chemical Industry Research Institute
Ying Menkou, Liu Xia
Hangzhou
Zhejiang Province 310023
PEOPLE'S REPUBLIC OF CHINA
Ph: +86 571 5129414
Fax:+86 5715129 858
Dr Frank V. Westerlund
Research Specialist
California Strawberry Commission
41 Hangar Way
P.O. Box 269
Watsonville, California 95077-0269
UNTIED STATES OF AMERICA
Ph: +1 408 724 1301
Fax: +1 408 724 5973
Indicates government nominee to MBTOC
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