PRIVATE PESTICIDE APPLICATOR
TRAINING MANUAL
Revised 1993
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION VIII
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INTRODUCTION
The U.S. Environmental Protection Agency regulates the distribution and use
of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA)
as amended in 1988. Under this law, all pesticide uses are classified as either
general use or Restricted Use. Those classified as Restricted Use can be bought
and used only by persons who are Certified after training. In Colorado private
pesticide applicators - farmers, ranchers and greenhouse growers — are certified
by the EPA Region 8 in Denver.
This Private Pesticide Applicator Training Manual can be used by individuals
as a home study course and is also the basis for training sessions held by Exten-
sion offices and pesticide dealers. Reading the manual, successfully completing
the accompanying questionnaire and sending it to EPA will qualify you for certifi-
cation as a private pesticide applicator. A card will be issued to you which will
allow you to buy and use Restricted Use Pesticides. Keep the manual for a quick
reference whenever you have questions about using pesticides.
Pesticide products are designated as Restricted Use by EPA when they have
been found to be hazardous to people, animals and/or the environment unless
applied by or under the supervision of persons who are qualified to use them in a
safe manner following the label.
EPA is responsible for the registration and regulation of use for pesticides.
The Agency does not endorse or discourage the use of pesticides but strongly
urges the use of alternative methods of pest control as well as integrated pest
management. EPA is in the process of reregistering all pesticides that were
registered before November 1984. Many products are disappearing from the
market in this process. Also, there are new regulations to protect workers,
groundwater and endangered species from the hazards of pesticides. The future
availability of pesticides to support agricultural production depends on responsible
use. This training manual is designed to assist you in that effort.
U.S. EPA Region VIII
Pesticide Section 8ART-TS
999 18th St., Suite 500
Denver, CO 80202
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TABLE OF CONTENTS
Chapter I: Pesticide Laws and Regulations 1
Chapter II: Pests 9
Chapter III: Pest Management Techniques 15
Chapter IV: Pesticides 21
Chapter V: Beware the Hazards of Pesticides 31
Chapter VI: Management of Common Agricultural
Pests in Colorado 45
Chapter VII: Application Equipment 55
Chapter VIII: Calibrating Application Equipment 63
Chapter IX: Protective Equipment 71
Chapter X: Minimizing Pesticide Hazards 77
Chapter XI: Pesticide Storage and Disposal 91
Pesticides Reportable as Hazardous Substances 97
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Chapter I
PESTICIDE LAWS AND REGULATIONS
There are several Federal and state laws and regulations that control the manufacture,
labeling, use, storage and handling of pesticides. These laws enable the appropriate agencies to
manage the safety and effectiveness of pesticides that are put on the market, and to regulate uses
in ways that minimize harmful effects to humans, animals and other life forms.
FIFRA The Federal Insecticide, Fungicide and Rodenticide Act is the most important
of the pesticide laws. Originally enacted in 1910, the act set standards for
labeling of pesticides. It has been updated and amended several times, most
recently in 1988.
RESTRICTED/ An important part of the current law is the classification of pesticides as
GENERAL USE either Restricted Use or General Use. This classification determines who
may purchase and apply the pesticide. This designation appears prominently on the
pesticide label.
The Environmental Protection Agency determines whether a pesticide will be classified for
Restricted Use. This decision is based on its potential for substantial adverse effects to the
applicator or environment. Certification of pesticide applicators, and restricting sale and use
to those applicators, provides a measure of assurance that a product will be used in a safe
manner and in accordance with the label. The restricted use regulation permits the contin-
ued use of many pesticides that might otherwise be subject to cancellation.
When determining the Restricted Use classification for a pesticide, EPA studies information
provided by the manufacturer, research from other sources, and documented accident
information on the chemical. They also study the toxicity of the pesticide to humans and
other life (animals and plants), including potential for causing cancer, reproductive disorders
and allergies. The EPA also considers the effects on nontarget organisms through water
pollution, drift, or buildup in animal tissues.
Some active ingredients of commonly used agricultural pesticides that are currently
classified for Restricted Use are:
Aldicarb (Temik)
aluminum phosphide
azinphosmethyl (Guthion)
amitraz (Baam)
brodifacoum (Talon)
chlorophacinone (Rozol)
cycloheximide
carbofuran (Furadan)
chloropicrin (Chlor-o-Pic)
cypermethrin (Ammo, Cymbush)
diallate (Avadex)
diclofop methyl (Hoelon)
disulfoton (DiSyston)
esfenvalerate (Asana)
ethoprop (Mocap)
ethion
fenvalerate (Pydrin)
fenamiphos (Nemacur)
fonfos (Dyfonate)
methiocarb (Mesurol)
methyl bromide
mevinphos (Phosdrin
oxamyl (Vydate)
paraquat (Gramoxone)
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The Restricted Use classification can be declared at the time pesticides are registered, re-
registered, or when new information indicates a high degree of hazard exists with use of
the pesticide. One pesticide formulation with a high concentration of a highly toxic chemical
may be classified as Restricted Use; whereas, a formulation with a lesser concentration of
the same chemical may be classified as General Use. Also, a pesticide unclassified for
agricultural uses may be restricted for uses in more sensitive environments, such as
indoors, around livestock, near water, etc.
PESTICIDE APPLICATORS: Under the Federal Insecticide, Fungicide and Rodenticide Act
COMMERCIAL/PRIVATE (FIFRA), there are two types of pesticide applicators --
COMMERCIAL AND PRIVATE.
A private applicator is a person who uses, or supervises the use of, restricted use pesticides
in the production of agricultural commodities on land owned or rented by him or his
employer. Farmers, ranchers, orchardists and greenhouse operators are private applicators
in Colorado. A private applicator may also apply restricted use pesticides in production of
agricultural commodities on the property of another person, if the work is done without
compensation. Trading of personal services as a form of compensation is exempted under
this regulation.
DIRECT The pesticide law, FIFRA, says that a Restricted Use pesticide may be applied by a
SUPERVISION Certified Pesticide Applicator or a person under the "direct supervision" of a
Certified Applicator. Environmental Protection Agency policy states that the
Certified Applicator is responsible for the application practices used by the person being
supervised and is liable for any violations that are committed.
In Colorado, a grower/rancher is certified as a private applicator following successful
completion of a Home Study Course administered by the U.S. Environmental Protection
Agency. This manual provides the prescribed training, and successful completion of the
questionnaire enables EPA to determine that a card can be issued that will allow the
applicator to buy and use restricted use pesticides.
A commercial applicator is a person who uses or supervises the use of restricted use pes-
ticides in a situation other than as a private applicator. Commercial applicator groups in
Colorado include agricultural pilots, landscape maintenance personnel, ditch and power
company employees, government workers, grain elevator operators, and other applicators
who apply pesticides as a condition of their employment. Pesticide applications made to
agricultural commodities that have entered commercial channels and are no longer in
production are also commercial applications. Licensing of commercial applicators is by the
Colorado Department of Agriculture.
OTHER LAWS:
ENDANGERED The Endangered Species Act was first passed in 1973 to protect animal and plant
SPECIES ACT species that were threatened or in danger of becoming extinct, and to conserve
their habitats. The latest amendments were passed in 1988, and full implementation
is planned by 1994. Colorado is host to 17 endangered species -- 3 birds, 4 fish, and 10
plants. Some pesticide use practices may be affected where endangered species occur.
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SARA/EPCRA The Superfund Amendments and Reauthorization Act (SARA) regulates storage of
pesticides and handling pesticide spills. One section of this law, the Emergency
Planning and Community Right-to-Know Act (EPCRA), requires that storage of certain
pesticides in amounts above a specified minimum be reported to local and state authorities
so they can respond to any accident at the storage site. Failure to report may result in a
court injunction or fines of up to $25,000 for each day the violation continues. Enforce-
ment of this law is by the Hazardous Materials and Waste Management Division of the
Colorado Department of Health.
PESTICIDE LABELS
A pesticide label includes all the printed information either on the container or included in or
on the package. It provides a description of the product and how it must be used. It is a legal
document that is approved by the U. S. Environmental Protection Agency before the product can
be placed on the market. Use of a pesticide in a manner that is inconsistent with the label
instructions is a violation of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
(Except for four specific exceptions described on Page 7.) The label is the law. Civil penalties can
be levied against private applicators for misuse of any pesticide.
The label of a pesticide includes the actual affixed label and all brochures, flyers, handouts,
and advertising materials distributed by the manufacturer or dealer. These materials must conform
to those approved by EPA during the registration process.
LABEL CONTENT FIFRA requires that all pesticide labels must contain the following information:
1. Brand name, common name, and chemical name
2. Use classification (Restricted or unclassified)
3. Ingredient statement
4. Registered uses
5. Directions for use
6. Safety information, signal words and precautions
7. Net contents
8. Name and address of manufacturer or registrant
9. EPA Registration number and establishment number.
BRAND NAME The brand name is the product name given to the particular pesticide formulation by
the manufacturer or the distributor. It is used for identification and advertising
purposes. Several different brand name products may be identical or nearly identical in
their formulation. The brand name does not necessarily describe the active ingredient(s) in
the product. The active ingredient is listed on the label in the ingredient statement.
COMMON NAME The common name is a shortened generic name of the active ingredient(s)
in a pesticide. For example, glyphosate is the common name of a herbicide
sold under the brand names Roundup, Rodeo and Shackle. An insecticide Disulfoton used
in greenhouses is sold under the name Disyston. And, the fungicide Benomyl used on turf
and ornamentals in Colorado is sold as Benlate. Recommendations for use of a pesticide by
an agricultural consultant or Extension office may give only the common name because
there are so many registered brand name products with the same active ingredient.
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Restricted Use Pesticide
For retail sale to and use ONLY by certified applicators or persons under the direct
supervision of a certified applicator.
Contents: 50 Pounds
Active Ingredients 25.0%
(arthrodie) 1,2,3-benzylchlorofluoromethane 21.0%
(arthrobury) 1,2,3-benzylchlorofluoroethane .4.0%
Inert Ingredients 75.0%
R
Arthrohistory Insecticide (25WP)- A wettable powder insecticide for control of insects
on corn, wheat, strawberries and greenhouse-grown roses.
Always read and follow label directions
„ ...... „ EPA. Est. No. YYYYYYY
R=registered trademark of Arthohistory Co.
.®@IP cDuatl ir©Mlh ®(F ®MMir
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Precautionary Statements
Hazards to Humans and
Domestic Animals
Danger!
Fatal if swallowed, inhaled, or absorbed through the skin. Do not breathe.
Do not get in eyes, on skin, or on clothing.
Signs and symptoms of exposure-Vomiting, headache, difficulty breathing,
pinpoint eye pupils. IN ALL CASES OF SUSPECTED POISONING
CONTACT A PHYSICIAN!
Note to Physician- Arthrohistory insecticide is a cholinesterase inhibitor.
Atropine sulfate is an effective antidote. If ingested, induce vomiting
promptly.
Wear freshly laundered, long-sleeved work clothing. While transfering
from package to equipment, wear a clean cap, rubber gloves, and goggles.
Rubber gloves should be washed with soap and water after each use. Do not
wear the same gloves for other work.
Do Not Breathe Dust
Wear a face mask or other respiratory equipment while emptying bags of product
into a hopper. While emptying bags into equipment, pour downwind and allow
as little free fall as possible. Do not pour at face level and do not allow dust to
reach the breathing zone.
Do Not Contaminate Food or Feed Products
Once a bag has been opened, use it completely. Make sure the hoppers are
emptied completely while still in field.
WARRANTY
USE ONLY ACCORDING TO LABEL DIRECTIONS
Arthrohistory Co. guarantees this product conforms to the
description on this label. It is suited for the purpose sold
when used according to directions. The buyer agrees to assume
all risks in the case of damage from the use of this product
DO NOT EXPOSE TO MOISTURE!
Directions for Use: It is in violation of federal law to use this product in a
manner that is inconsistant with its labeling.
How much to apply-
Crop
Pest
Lbs/100 gal
Days Between Last
Application and
Harvest
Corn
European Corn Borer
Comearworm
11/2-2
10
Do not make more than 3
applications per season
Aphids
Grasshoppers
172-1
Wheat
Aphids
1-2
15
Do not graze treated fields
Grasshoppers
Cutworms
2-3
Strawberries
Aphids
Spider miles
Plant bugs
1-2
3
Do not apply when
temperatures are below 50
degrees (F) or injury may
result
Roses
Aphids
Thrips
Spicier mites
3-5
2
Do not apply to hybrid tea
roses or injury may result
Asrllbmtotetory ImsosMMlQ C®.
ffVQ>. ®®a (6(6<6
Sample side panels of a pesticide label
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CHEMICAL NAME The chemical name of a pesticide ingredient describes the chemical
composition and structure of the active pesticide ingredient. Although they
sound complicated, they are based on standard descriptions used by chemists. For exam-
pie, the insecticide ingredient O-O-diethyl 0-(3,5,6-trichloro-2-pyridyl)phosphorothioate,
common name, Chlorpyrifos, is marketed as brand name Dursban for household products
and Lorsban for agricultural products. The herbicide 2,4-dichloro-phenoxyacetic acid is
commonly known as 2,4-D.
USE CLASSIFICATION The Use Classification statement is required on the front panel of all
pesticides that are classified as RESTRICTED USE. This statement
reads:
"RESTRICTED USE PESTICIDE
For retail sale to and use by certified applicators or persons under their direct
supervision." (For commercial applicators add,"and only for those uses covered by
the certified applicator's certification.")
There may also be a statement of why the pesticide is classified as restricted, such as
"Acute Oral and Dermal Toxicity" or "Avian Hazard"
General Use pesticides do not contain label classification statements.
INGREDIENT STATEMENT The ingredient statement also appears on the front panel of each
pesticide label. It tells the percentage of each active ingredient in
the formulated product. This usually follows the chemical name. For pesticides in liquid for-
mulations (emulsifiable concentrates, flowables, etc.), there is a statement giving the
pounds of active ingredient in a gallon of the formulated product. The concentration of
active ingredient is sometimes indicated in the brand name; for example, Benlate 50W is a
wettable powder containing 50% of the active ingredient benomyl. Methyl Parathion 4E
contains 4 pounds of methyl parathion per gallon of formulation.
The other ingredients in the formulation (adjuvants) are described as "inert ingredients."
The inert ingredients can be used to dilute or boost the effectiveness of the active ingredi-
ent. Adjuvants are emulsifiers, spreaders, stickers and buffering agents. Some can be more
hazardous than the main ingredient; however, since 1987 EPA has required pesticide
manufacturers to reformulate their products to eliminate most of the inerts that were of
greatest toxic concern. Other inerts are being evaluated and new inerts are under more
stringent regulations.
NET CONTENT The net contents statement indicates the amount of formulated pesticide
product in the package. This information is useful in determining the amount to
purchase.
REGISTERED The registered uses of a pesticide are listed in the "Directions for Use" on the label.
USES This portion lists the specific crops, livestock applications, or other uses for the
pesticide. The directions for use portion of the label also tells how much of the
pesticide to use and when, where and how to apply it. Limitations on the use are found in
this section or in a separate statement. It is illegal to use any pesticide in any way that is
not stated on the label.
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SIGNAL WORDS The pesticide label contains various warnings and precautions. On the front
panel of each pesticide there are signal words that indicate the toxicity and/or
hazards associated with its use. The pesticides with the greatest hazard are called
Hazard Category I. Labels of these pesticides carry the signal words DANGER-
POISON and have a red skull and crossbones on them. Moderately hazardous
pesticides are Hazard Category II and carry the signal word WARNING. Less
hazardous pesticides are Hazard Category III and carry the signal word CAUTION.
All pesticide labels must also contain the statement KEEP OUT OF THE REACH OF
CHILDREN. The approximate toxicity to humans of pesticides containing each of
these signal words is:
Approximate oral*
Signal Word Toxicity Category dose lethal to a
human
DANGER-POISON
(Skull/crossbones)
WARNING
CAUTION
I-Highly toxic
II-Moderately toxic
III-Slightly toxic
Taste-teaspoon
Teaspoon-2 table
spoons
Ounce or greater
* Signal words may also be based on dermal toxicity or other hazards associated
with the pesticide.
INCONSISTENT USE The use of a pesticide in a manner inconsistent with the label is a violation
of FIFRA. The original prohibition of "use of any registered pesticide in a
manner inconsistent with its labeling" was modified in 1978 [FIFRA Sec. 2 (ee)] to allow
some deviations. Specifically there are four exceptions which allow applicators to vary
applications from label instructions.
1. Application of a pesticide at dosages, concentrations, or frequencies less than those
specified on the label.
2. Application of a pesticide against a target pest that is not specified on the label ~ if the
crop, animal or site is specified on the label- unless the label prohibits the use.
3. Use application methods not prohibited by the label instructions. (Even more recent
regulations require that certain types of applications, such as chemigation, be specified
on the label.)
4. Use mixtures of pesticides, or pesticides with fertilizers if they are not prohibited by label
instructions.
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Summary Chapter I
FIFRA is the basic law that regulates the use of pesticides.
Restricted Use Pesticides can only be applied by Certified applicators.
Pesticide labels contain all the information needed for determining use of the pesticides.
The label is the law. Read and follow it exactly.
The Superfund Amendments and Reauthorization Act and Endangered Species Act have
provisions that affect the use and handling of pesticides.
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Chapter II
PESTS
In agriculture, various plants, animals and other life forms may impede the raising of crops
and livestock. They are called "pests" in situations where they are not wanted, but a "pest" may
be a desirable plant, animal, or other organism when it exists in a nonthreatening environment.
It is important to identify any pest that conflicts with production, affects human health or
comfort, or destroys property. Then knowledge of the life stages (growth), behavior and potential
for damage to agricultural production are necessary so a pest can be managed effectively.
Common agricultural pests in Colorado can be classified into five main groups:
1. Weeds
2. Plant disease agents (fungi, bacteria, viruses, etc.)
3. Arthropods (insects, mites, ticks, etc.)
4. Slugs and snails
5. Vertebrates (birds, rodents and other animals)
WEEDS
Weeds are defined as "plants out of place"; therefore, it may be difficult to
distinguish between a weed and a desirable plant. Even a widely recognized
agricultural weed such as quack-grass is beneficial when it is growing on a
steep road bank and prevents erosion. Also, a corn plant may be a weed if it
grows as a "volunteer" in a field planted with a different crop.
Unwanted plants assume the role of weeds when they compete for water,
nutrients and light with an agricultural crop. Some "weeds" even secrete
chemical inhibitors from their roots and damage nearby growing plants.
They may also foul harvest machinery or contaminate produce. On range-
land, weeds crowd out needed forage plants and may be poisonous to
livestock. Weeds also may harbor plant disease agents, insects or mites.
Weeds are commonly classified by their life cyles - either annuals (one
year), biennials (two years), or perennials (multi-year).
ANNUAL WEEDS
Annual weeds are plants that germinate from seed, grow, flower, and produce new seed in
less than 12 months. However, among the annual weeds, a variety of life cycles can occur.
Summer annuals are plants that germinate in spring, flower and produce seed during the
summer, then die the same summer or fall. Common summer annual weeds are sunflower,
lambs-quarters, nightshade, pigweed, wild oats, wild proso millet, and Russian thistle.
Summer annual weeds are the greatest problem in crops that are planted in the spring.
Winter annuals germinate in the fall and overwinter as low growing plants, resume growth
in the spring, bloom, and produce seeds shortly thereafter. Common winter annual weeds
are tansy mustard, jointed goatgrass and shepard's purse. They tend to be the greatest
problem in crops that are seeded in the fall and in semi-permanent crops such as alfalfa.
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BIENNIAL WEEDS
Biennial weeds have a two year life cycle. They germinate in spring or early summer and
overwinter as low growing plants (rosette) with a long taproot. The following year these
plants resume growth and produce a flowering spike in late spring or summer. After pro-
ducing seeds, the plants die. Biennial weeds in the region include musk thistle, burdock,
and mullein. They pose the greatest problem in pastures.
Weeds that live for several years are called perennials. They may persist
indefinitely in an area unless they are controlled. Many perennials produce
extensive root systems that prevent them from being destroyed by tillage or
other above ground control practices. Perennials reproduce by seeds, but
once established can spread by underground runners (spreading roots, stolo-
ns, rhizomes), bulbs, or tubers. Perennial weeds that are continual problems
in agriculture are field bindweed, dandelion, Canada thistle, leafy spurge,
and quackgrass.
PLANT DISEASE AGENTS
ABIOTIC DISEASES
An abiotic plant disease is any condition that disturbs the normal and optimal growth and
function of a plant. These can result from adverse environmental conditions such as nutri-
ent imbalance, excessive salinity, oxygen starvation of roots, air pollution, and extreme
temperatures. Abiotic diseases are not caused by living organisms.
PARASITIC DISEASES
Parasitic diseases are caused by infection of a plant by any of a variety of microorganisms
such as fungi, bacteria, mycoplasmas, viruses, and nematodes. Organisms that produce
plant diseases are known as plant pathogens.
Sometimes plant disease agents are spread by other organisms, such as insects, mites or
nematodes. These organisms are called vectors.
FUNGI Fungi are the most important single group of plant pathogens in Colorado. Fungi are a
highly diverse group of organisms with many different types of life cycles. Some feed on
living plant tissues, others primarily on dead plants. Fungi cause rotting/decay, mold, pow-
dery mildew, vascular wilts, and leaf spotting. In Colorado, fungi cause stalk rot of corn,
rusts, Fusarium wilt, Phythophthora root rot, botyrtis neck rot, early blight, damping off
diseases, blue stain diseases of conifers, wood decay fungi, and storage molds.
Fungi reproduce by spores, and an actively growing and fruiting
fungus can release millions of spores. The familiar mushroom is the
spore producing structure of many fungi, while other organisms
produce very small, often microscopic, fruiting bodies. Many fungi
also produce hardened protective structures, known as sclerotia,
that allow the fungus to live for several years in the soil.
PERENNIAL WEEDS
IMd
I
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Most spores are dispersed by the wind, but zoospores can move in water. Spores have
specialized structures that help them penetrate plant tissues, and when they land on a sus-
ceptible plant where warm moist conditions exist the spores germinate.
BACTERIA
Bacteria are very small one-celled organisms. They reproduce by budding and can multiply
rapidly under high moisture conditions. Bacteria that affect plants dissolve plant tissues by
secreting enzymes or by plugging the sap stream of the plant, causing it to wilt. Fire blight
of apples and pears, bacterial ring rot, soft rots, crown gall, and halo blight of beans are
examples of bacterial diseases found in Colorado.
Bacteria rarely are able to move by themselves; most are spread by splashing water,
infected seed, farm equipment, or by insects.
MYCOPLASMAS
Mycoplasmas were recently discovered as plant disease organisms. They have many
characteristics of bacteria but lack a cell wall. They develop in the sap stream of plants and
are spread by insects, primarily leafhoppers. Aster yellows that affect vegetable and flower
crops are caused by these organisms. Pear decline and X-disease of peach are serious my-
coplasma diseases of orchard crops.
VIRUSES
Viruses are extremely small particles that are primarily recognized by the symptoms they
produce in plants. Leaf streaking diseases, known as "mosaics," many "yellows" diseases,
and ring spots are caused by viruses. Viruses multiply by causing the infected cells of their
host plant to form virus particles. By changing the normal function of the plant cells, the
plant is injured.
Many viruses are spread mechanically as plants rub together or by machinery. Others are
spread by specific insects, usually aphids or leafhoppers. Some are spread by mites,
nematodes, or fungi.
Potato leafroll, beet curly top, barley yellow dwarf, tomato spotted wilt, and wheat streak
mosaic are viral disease problems in Colorado agriculture.
NEMATODES
Nematodes, also called roundworms or eelworms, are microscopic organisms of which
thousands of different types occur in healthy soils and water. A few types attack plants
and cause disease.
Nematodes can move short distances on water films, but human movement of infested soil
or plant materials is the most common method of movement. This is particularly true with
nematodes that produce resistant structures, allowing them to survive for several years. In
Colorado, sugarbeet cyst nematodes, alfalfa stem nematodes and various "cyst" and
"sting" nematodes are the most common problems. Nematodes are fairly rare in the arid
West because of dry and heavy soils.
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PARASITIC PLANTS
Some plants live and develop by invading other plants and robbing them of water and nutri-
ents. These "parasitic" plants include dwarf mistletoe which feeds on evergreen trees and
dodder which feeds on alfalfa and other non-woody plants, both of which occur in Colo-
rado.
These parasitic diseases spread by producing small seeds, or in the case of dodder, by
movement of plant fragments. Infected plants can be seriously damaged or killed by the
parasites and have to be destroyed to prevent further development of the problem.
ARTHROPODS
Arthropods, or the "jointed foot" animals, are the most common form of life on earth, with
endless numbers of species.
One group of arthropods - insects ~ contains more than a million species. Other arthropod
groups are mites, ticks, spiders, millipedes, and centipedes. All arthropods have a unique
set of features that distinguishes them from other animals. These features are:
1. Segmented body
2. Jointed appendages (legs, antennae, feet)
3. External skeleton (exoskeleton)
4. Growth involving periodic shedding and replacement of the exoskeleton (molting)
Arthropods also have characteristic internal structures - a tube-like "heart" that runs down
the back and a nerve cord that runs along the lower body.
Insects ~ This is the largest group of arthropods. Characteristics that separate them from
other arthropods are:
1. 3 body regions (head, thorax, abdomen)
2. 3 pairs of legs
3. Adult stage is often winged.
The various groups of insects are recognized by type of wings and mouthparts and the
developmental changes they undergo.
Wing types vary greatly among adult insects. Beetles have a hardened pair of front wings,
while moths and butterflies have wings covered with scales. Flies and mosquitoes have
only one pair of wings, while most insects have two. Some groups of insects never produce
wings.
Beetles
Flies and Mosquitos
True Bugs
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Mouthparts of insects are generally designed to either cut and chew or suck fluids.
Grasshoppers, beetles, caterpillars, bees, and wasps are typical insects with chewing
mouthparts. Insects with sucking mouthparts are aphids, leafhoppers, "true bugs,"
mosquitoes and moths. The mouthparts form a tube to penetrate plants or animals and
suck fluids through a channel. The thrips have a special type of mouthpart that enables
puncturing tissues and sucking fluids with a separate cone-like structure. Insects with
sucking mouthparts can transmit disease organisms to plants or inject toxic substances
while feeding.
Metamorphosis is the term for the changes in form that all arthropods undergo during
development. Among the insects, two patterns of metamorphosis predominate - simple (or
gradual) and complete. The stages are:
Simple Metamorphosis: Egg -> Nymph (3-7 molts) -> Adult
Aphids, leafhoppers, earwigs, grasshoppers, and true bugs are among the insects that
undergo simple metamorphosis. The immature insects which emerge from eggs are called
nymphs. As the nymphs feed and grow, they periodically shed their skins and transform to
the next stage, a process known as molting. They go through 3-7 molts, emerging from
the final molt as adults. Both the nymphs and adults of insects with simple metamorphosis
feed in the same manner, are often found together, and may look somewhat alike. The
adult insects, however, may be winged and are sexually mature.
Moths, butterflies, beetles, flies, ants and lacewings are examples of the many insects that
undergo complete metamorphosis. The eggs hatch into the immature larval stage. This
stage often causes the most injury to plants and animals since the larvae feed heavily in
order to develop. As they grow, the larvae molt and shed their skin repeatedly. After
reaching full development, they are transformed into a unique developmental stage called
the pupa, during which they appear to be inactive but dramatic internal changes are taking
place. The insects emerge from the pupa stage as adults, which look very different from
the larvae and often have completely different feeding habits and behavior.
A separate group of arthropods called arachnids include the mites and ticks, spiders and
scorpions. The key identifying feature is that they have four pairs of legs. Also, most have
two distinctive body regions (cepahlothorax and abdomen) although in mites and ticks the
separate regions may be hard to distinguish because they have rounded bodies.
Mite and tick eggs hatch into larvae which are tiny and have only three pairs of legs. After
the first molt, they acquire the fourth pair of legs and are called nymphs. There can be
several nymphal stages before transformation to the adult tick or mite.
Complete Metamorphosis: Egg -> Larva (several molts) -> pupa -> adult
' / /
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Arachnids (mites and ticks), stages of metamorphosis:
O
Arthropods as Pests
Insects, mites and ticks are pests in crops, livestock and stored products. They transmit
plant and animal diseases and cause human discomfort. Annually, arthropods do damage in
the billions of dollars in the United States and cause greater losses worldwide.
Many insects, however, are beneficial since they assist in pollination of crops, recycle
nutrients, serve as food for wildlife and other desirable species, and prey upon other pest
species. It is important to distinguish between the pest and beneficial species and those
that are neither.
SLUGS AND SNAILS
Slugs and snails are mollusks and are more closely related to clams or mussels than to
insects and other arthropods. Pesticides used to control arthropods have little effect on
slugs and snails.
Slugs and snails depend on moist conditions to survive and develop. For this reason, they
are relatively infrequent problems in Colorado, except in greenhouses or lush growing
garden areas.
VERTEBRATE PESTS
Mammals and birds can be pests when they interfere with agricultural production but may
be considered "wildlife" in other situations. Examples include deer and elk which damage
vegetables and haystacks in the mountain areas; coyotes which prey on lambs; blackbirds
which damage ripening cherries; voles which injure trees, rodents that infest stored grain,
or prairie dogs that damage pasture land and fields.
Summary Chapter II
Pests include plants, animals, and disease agents.
Plant and animal life that are pests in one place may not be pests in another.
The number of an unwanted plant or animal species determines the need to use pest
control measures.
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Chapter III
PEST MANAGEMENT TECHNIQUES
Pest management can be achieved most effectively through a combination of techniques,
including biological, cultural, mechanical, chemical, and regulatory/legal methods.
BIOLOGICAL All animal and plant species are subject to some degree of natural control, which is
NATURAL commonly known as the "balance of nature." Important natural controls are
CONTROLS temperature, moisture, and wind. In Colorado, cold winter temperatures are
significant in limiting the overwinter survival of many insects and mites. The
germination of weed seeds depends on adequate soil moisture and temperature. Movement
of bacteria, germination of fungus spores, and nematode survival all depend on the exis-
tence of water films. Wind movement of soil particles and water droplets reduces insect
populations. These physical controls are also called abiotic controls.
Other natural controls are animal predators or disease agents that feed on or infect pest
species. These natural enemies ~ predators, parasites or pathogens ~ are called biotic
controls.
BIOTIC CONTROLS
Predators are organisms that live and feed on other organisms. Common predators of
insects in Colorado are ladybird beetles, lacewings, ground beetles and damsel bugs.
Insects and mites can be predators of weeds and plants. Coyotes are predators of rodents.
Nearly all animal and plant life can be both predator and prey.
Parasites are also natural enemies. Parasite often means an organism that is harmful
to desirable plants, animals, and humans, but when it attacks a pest species, a
parasite can be beneficial. Insect parasites consist of other insects which develop
internally (rarely externally) on a host insect. Only a single host insect is killed by a
developing parasite, but often several parasites develop in a single host insect.
Parasitic insects can be highly specific as to the organism on which they develop
and many attack only a single species of insect or a small group of closely related
insects. Parasitic wasps and tachinid flies are common insect parasites. Colorado
potato beetle, forest tent caterpillar, and greenhouse whitefly are examples of local
pests which can be largely controlled by parasites.
Pathogens are various kinds of microorganisms that provide natural controls of pest
species. They can be fungi, bacteria, viruses, and nematodes which attack weeds, insects,
mites and even other pathogens. They are usually specific in the organisms they attack,
and very few attack both plants and animals. For example, none of the numerous fungus
diseases that affect pest insects also attack mammals or birds. Similarly, fungi which attack
plant pathogenic fungi do not attack desirable species of plants.
BIOLOGICAL CONTROL is manipulation of biotic controls in managing pests, including:
- introduction of natural enemies of pests;
- conserving existing natural enemies of pests;
- creating favorable environmental conditions for the natural enemies.
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Several natural enemies have been introduced into Colorado to control new pest species
that have become established in the State. For example, several wasps that attack alfalfa
weevil are now widely established and help reduce losses from weevils. Similarly, weevils
(Rhvnocvllus) that attack the seeds of musk thistle have been established. New natural
enemies of insect pests and weeds in Colorado are continually being introduced through
Colorado Department of Agriculture programs.
Some natural enemies of pests are used as "biological pesticides." The bacterial disease
Bacillus thurinoiensis is effective in controlling most leaf and needle feeding caterpillars
such as the European corn borer. Other strains of the same disease control mosquito larvae
in water or fungus gnats in potting mixes. Several species of predatory mites are used to
control mites and thrips on greenhouse crops. Microorganisms are also used to control
crown gall bacteria in woody plants. Disease agents are also being developed to attack
specific weeds.
The conservation of natural controls can be accomplished by using chemical and cultural
controls in ways that will not damage the natural controls. One method is to use "selec-
tive" insecticides that only kill the insects that are the pests, or timing the application to kill
only the target pest species. For example, use of dormant oils on fruit trees will not harm
predators that do not overwinter on trees. Reducing dusty conditions during planting helps
insect parasites and predators of spider mites.
Improving the performance of natural enemies of pests may require changes in crop
environments. When an insect predator requires nectar, planting suitable nectar producing
plants or applying artificial nectar sprays may improve the predator population.
CULTURAL CONTROLS
Cultural control includes the use of clean planting stocks, resistant varieties, crop siting
techniques, tillage, sanitation, and certain harvesting practices. These may be the most
important means of pest control.
Clean Planting Stock Using high quality seed and other materials that are free of weed seeds and
plant disease agents can prevent serious pest problems.
Resistant Varieties Development and use of plant varieties that are resistant to crop diseases is
essential to production of many crops. The pea-aphid-resistant alfalfa is one
example.
Conditions that favor rapid crop establishment and vigorous plant growth help
reduce pest problems. Weeds can be smothered by a crop that has formed a
thick canopy. Fungus diseases can prosper in crops that are stressed from inade-
quate water, poor fertility or other condition.
Properly locating a crop can be extremely important in preventing pest problems.
Plantings should be not be done in fields where there have been infestations of
weeds or diseases that could adversely affect the crop. Fields can also be isolated from
sources of overwintering insects and diseases, such as in seed potato production.
Crop Rotation Crop rotation is fundamental to controlling plant diseases. Since many plant disease
organisms survive in crop debris, planting non-susceptible crops can prevent further
development of a disease organism and ultimately cause it to die out. For many pathogenic
Plant Vigor -
Crop Siting
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organisms, such as soft rots and Botrytis, a single year of crop rotation can sufficiently
reduce the numbers of a plant disease agent so that it will not be a problem. Other plant
disease agents, such as white mold and sugar beet cyst nematodes, may require multi-year
rotations out of susceptible crops in order to reduce the organism to non-damaging levels.
Crop rotations are also important in controlling difficult weeds. Densely growing crops, such
as small grains, may be used to help smother developing weeds in a field. Suitable crop
rotations also allow control of weeds with herbicides that are not suitable in other crop sys-
tems. For example, wild proso millet may be controlled with post-emergence herbicides in
bean plantings; available pre-emergent herbicides in corn may not achieve adequate control.
Crop rotation is an effective method for controlling insects that overwinter in immobile
(egg, larva) stages. These insects die if the crop planted the following year does not
support the later life stages of the insect. For example, corn rootworms lay eggs around the
base of corn plants in late summer. If corn is not planted within a few feet of the eggs the
following year, the larvae which hatch in June die from starvation. Rotation of greenhouse
crops to allow for "host-free" periods can be effective in managing greenhouse whitefly.
Proper sanitation practices are important to the overall management of many
pests. For example, pest species of flies that breed in livestock manure can
be reduced by proper manure handling. Culled vegetables provide reservoirs
for disease agents unless they are properly disposed. Pruning and disposal
of diseased wood is necessary for management of fire blight. Flower cut-
tings and plant debris under benches promote the growth of leafminers and
fungus gnats in greenhouses. Disinfection is a means of controlling bacterial
ring rot of potatoes, and clean equipment controls the spread of disease
agents and weeds between fields.
Harvest practices are also effective tools for managing pest problems.
Wounds to potatoes or onions during harvest allow plant disease agents to
enter and destroy the crop in storage. Blister beetles in alfalfa hay increase
when the hay is crimped during cutting, trapping the beetles.
Tillage The main purpose of tillage (cultivation) is weed control. During cultivation, roots of
weeds are cut, and young seedlings are buried. Weed seeds, also buried during
plowing, can survive for several years and return to the surface with subsequent plowing.
Eliminating surface debris is necessary before using preemergence herbicides that are
sprayed as a soil barrier.
Tillage also helps speed up the decomposition of crop residues, which can limit the survival
of some plant disease agents. Many fungus disease organisms can overwinter on intact
crop debris but die when decomposition occurs. For example, tan spot of wheat increases
when tillage is reduced.
The effects of plowing on insects are mixed. Many insects which overwinter in crop debris,
such as European corn borer, can be killed during plowing; grasshopper eggs can be
exposed and killed. Highly mobile species, such as potato psyllid and corn earworm, are not
directly affected by tillage. On the other hand, greenbug aphids are less attracted to wheat
that has a lighter surface background created by crop debris.
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MECHANICAL CONTROLS Mechanical control means physically removing, trapping, or
excluding pests from a field, crop or other site. These controls are
usually labor intensive or expensive but can be useful on small acreages, in crops of high
value, or where alternative controls do not exist.
There are various devices and means for excluding insects that are mechanical pest
controls. Screening dairy barns is useful in reducing fly problems. Screens also prevent in-
sects, such as cutworms and thrips, from entering greenhouses. Slugs can be excluded
from a planting by using copper barriers. Insects may be trapped by attraction to lights and
colors. Also hand picking insect pests off a crop would be a simple mechanical control.
Mechanical controls of weeds include hand pulling, hoeing, or mowing. Artificial mulches
are mechanical weed controls, as are ditchbank burning and selective flaming.
REGULATORY CONTROLS Legal controls involve the lawful regulation of areas to eradicate,
prevent or control infestations of pest species.
Quarantines are laws that regulate the movement of plants or animals in commerce to help
prevent the spread of pests. For products to be moved out of areas known to be infested
by certain pests into protected areas, they must be inspected and certified as being pest-
free. Quarantines are critical to preventing many animal diseases, such as foot and mouth
disease and brucellosis. Quarantines have also prevented the movement of uninspected
apples into California from Colorado's Western Slope orchard areas where apple maggot
infestations were suspected. Quarantines also restrict the movement of white fleshed
peaches and nectarines into Mesa County to prevent the introduction of peach mosaic
disease.
Eradication programs are occasionally undertaken to eliminate pest species that have
entered a new area. In Colorado, an attempt has been made to eradicate the gypsy moth, a
serious pest of shade trees. Such efforts are more likely to be successful if initiated shortly
after a pest is found in a region so that its distribution is limited.
Pest control districts are organizations embracing several political jurisdictions, formed to
enable control of pests over a wide area. One type of pest control district is the Weed Con-
trol District empowered by noxious weed laws. In many parts of Colorado, these organiza-
tions are focussing on weed species that are particularly injurious and difficult to control
once established, such as Canada thistle and leafy spurge. The districts can treat infested
areas with herbicides and often have powers to require landowners to control noxious
weeds on their properties. During periods of grasshopper outbreaks, grasshopper control
districts can be formed to coordinate area-wide activities.
CHEMICAL CONTROLS Chemical control typically means use of pesticides. These controls
have been used for centuries, but it is only in the last 40 years that
highly effective formulations have been produced and widely used to protect crops and
livestock. Although chemical pesticides have been central to the control of many pests
during these years, there are risks and hazards that dictate they be used with particular
care. This is discussed more completely in the next chapter.
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INTEGRATED Often, a combination of control techniques is required to manage pest
PEST problems effectively. For example, control of flies in a dairy operation
MANAGEMENT depends on proper manure handling (cultural control), screening of barns to
exclude flies (mechanical control), and selective use of insecticides (chemi-
cal control). None of these techniques alone may be sufficiently effective.
Care must be taken to coordinate the various control techniques so their effects don't
conflict in the overall pest management plan. For example, certain uses of insecticides
against pest species can seriously reduce the effectiveness of biological insect controls.
Mulching used for weed control can increase the prevalence of slugs, particularly in high
moisture conditions. Some tillage and harvest practices may adversely affect beneficial
biological control organisms as well as destroy pests.
Repeated use of a single pest control approach can diminish its value. This has been most
common with the use of pesticides. Many insects, mites, fungi, and even a few weeds
have become resistant to pesticides that had previously been effective. Pesticide use may
also cause shifts in pest problems. For example, nightshade weed has increased in many
fields after use of several commonly used herbicides that were ineffective against night-
shade. Mite problems in fruit and field corn often are aggravated by early season insecticide
use directed against other pests.
Finally, other serious "non-target" effects may result from pesticide uses:
1. Many pesticides are highly toxic to the applicator or to wildlife around a treated
area.
2. Pesticides may move into and pollute ground or surface waters.
3. Pesticide residues may contaminate food or feed.
4. Plants may be inadvertently damaged by pesticides.
These result in hidden costs that are not always considered when making pest control deci-
sions.
Integrated Pest Management (IPM) is a system for making the best pest management
decisions based on both ecological and economic considerations. It is not a particularly
new idea since sound pest management practice has always involved IPM approaches.
Fundamental to Integrated Pest Management are a number of assumptions:
- Optimal pest management is achieved by using a combination of techniques;
- Use of the various pest management techniques should be integrated so their
effects complement each other;
- Since eradication of pests is not often achievable nor desirable, controls should be
applied only when pest populations are large enough to justify their control. Scout-
ing or monitoring fields is used to determine the extent of the infestation.
- In deciding what pest management techniques to use, the long-term costs,
including social and environmental costs, must be considered;
- The success of any pest management practice must be continually evaluated to
determine whether the desired result is being achieved most effectively.
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ECONOMIC THRESHOLD A concept that is basic to the Integrated Pest Management approach
is the economic threshold. This concept recognizes that almost any
pest can occur in numbers that do not cause crop loss or where the cost of control exceeds
the damage. The economic injury level means the lowest number of insect pests that will
cause economic damage. The economic threshold is the density at which control measures
should be used to prevent the pest population from causing economic injury. Use of eco-
nomic thresholds require that fields be scouted regularly to determine the number of pests.
Economic thresholds change with the growth stage of the crop and the crop value.
Several economic thresholds have been calculated for Colorado pests, particularly insect
pests. For example, control of Banks grass mite on corn is recommended when visible
damage occurs on the lower third of the plant and the mites have begun to make colonies
on the middle third of the plant. Treatments for control of greenbug aphids on small grains
are recommended when populations reach 5-15 aphids/stem on seedlings. The threshold
increases to 25 per stem during the boot to heading stages. Greenbug control is not
recommended for small grains that are heading since is is unlikely there would be a net
economic return from an insecticide application at that stage.
Summary Chapter III
Natural pest control factors such as predators, parasites and pathogens keep many
potential pests under control.
Cultural control consists of "housekeeping" measures that keep pests from multiplying in
agricultural crops.
Mechanical control means physically excluding pests from areas where they are not
wanted.
Chemical control means using pesticides to kill unwanted plant or animal life that interferes
with agricultural production.
Integrated Post Managment is the coordinated use of all available control methods to keep
pests from reaching the level that is economically harmful to agricultural producers.
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Chapter IV
PESTICIDES
A pesticide is a chemical or other substance produced and sold for the control of a pest
species. A pesticide may kill the pest or merely inhibit its development. All substances sold to kill,
retard, repel or attract pest species are regulated as pesticides. In the current version of the Federal
Insecticide, Fungicide and Rodertticide Act, the legal definition of a pesticide has further been
expanded to include defoliants, plant growth regulators, and dessicants.
Various types of pesticides are recognized by the types of pests they are used to control.
Although most are chemical substances, some are either natural substances or synthetic versions
of natural substances. Common pesticides include:
Herbicide - a chemical or other substance used to kill undesirable plants.
Insecticide - a chemical or other substance used to kilt undesirable insects.
Fungicide - a chemical or other substance used to kill undesirable fungi.
Miticide (also called acaridde) - a chemical or other substance used to kill mites and ticks.
Bacteriadde - a chemical or other substance used to kill bacteria (sometimes referred to as
sanitizers or disinfectants).
Mollutcicide • a chemical or other substance used to kill pest mollusks such as slugs and
snails.
Nematicide - a chemical or other substance used to kill nematodes.
Rodenticide - a chemical or other substance used to kill rodents.
Plant growth regulator - a chemical or other substance used to desirably alter the growth
processes of crop plants.
Wood preservative - a chemical substance used to protect wood from decay and stain
fungi, insects, and other wood destroying organisms.
Defoliant - a chemical or other substance used to produce leaf drop.
Dessicant - a chemical or other substance used to promote drying as a harvest aid.
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CLASSIFICATIONS OF PESTICIDES
Pesticides are grouped and classified in different ways based on their chemistry, origin, or
mode of action and use.
CHEMISTRY Pesticides and other chemical compounds have either inorganic or organic chemis-
try. Organic means they contain carbon in their molecular structures. These are
overwhelmingly the largest group of currently used pesticides. Inorganic pesticides,
the oldest used pesticides, do not contain carbon. Copper fungicides, lime-sulfur
used to control fungi and mites, boric acid used for cockroach control, and ammoni-
um sulfamate herbicides are examples of inorganic pesticides.
SOURCE Pesticides, particularly insecticides, are also discussed in terms of their source.
Natural organic pesticides are derived from natural sources. Various plant-derived
insecticides, such as pyrethrum, rotenone, and nicotine are examples of natural
organic pesticides. Synthetic oroanic pesticides are man-made. Almost all currently
used pesticides are synthetically produced compounds, although some are based on
naturally occurring chemicals.
SYSTEMIC/CONTACT Pesticides are also be classified as either systemic or contact compounds.
Systemic pesticides can be picked up through the leaves or roots of a plant and move
within the plant. Applied to herbicides, the term translocated may be used to describe these
pesticides. Systemic pesticides vary in how readily they move in a plant, and movement
depends on environmental factors, such as heat and moisture, as well. Some systemic
herbicides move widely in plants. For example, glyphosate, the active ingredient in many
herbicide products, when applied to leaves may move into and kill the plant roots. Alter-
natively, the insecticide, aldicarb, applied to roots moves upwards in the plant and concen-
trates in actively growing foliage. Some insecticides used for control of livestock pests are
also systemic after being fed or injected into an animal.
MODE OF ENTRY Insecticides are also described in terms of how they enter the insect.
Stomach poisons, such as Bacillus thurinoiensis. must be ingested by the
insect to be effective. Contact insecticides penetrate through the external
skeleton (cuticle) of the insect. Insecticides which primarily enter through
the breathing openings (spiracles) are called fumioants.
HERBICIDE Herbicides can be selective or nonselective. pf9-p|ant> ore-emergence, or Doat-
TERMS emergence, in their mode of action.
Selective herbicides can kill one type of plant but cause little or no injury to another. For
example, 2,4-D is considered to be selective since it is more active against broadleaved
weeds than against grasses. However, if it is used at an excessive rate or at the improper
time, selectivity is reduced and injury can occur to normally tolerant crops. Selective herbi-
cides applied to actively growing weeds may act as either contact or translocated herbi-
cides.
Non-selective herbicides are toxic to both crop and weed plants. Dessicant herbicides such
as paraquat and diquat are examples of non-selective herbicides.
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Soil sterilants are non-selective herbicides used as soil treatment and which can kill actively
growing plants and prevent growth of new plants for as long as the compound remains
active, often several years. Soil sterilants are used in maintaining rights-of-way or in other
areas where no vegetation is desired. Serious damage can be done to desirable plants, such
a* tree* and shrubs, if toil sterilants are applied near landscape plantings.
Pre-plant herbicides are applied to the soil before planting a crop. Pre-emergence herbicides
are applied after planting but before weeda or the crop emerges. Post-emergence applica-
tions are made after weeds and the crop have emerged.
FUNGICIDE TERMS Fungicides are often classified as being either orotectanta or eradicants.
Protectants, such as maneb and chlorothalonil, must be applied to the sur-
face of the plant before the fungus attacks the plant in order to protect the
plant against infection. On the other hand, eradicants such as benomyl can
move within the plant and kill developing fungi.
CHEMICAL FAMILIES
Among the various kinds of pesticides, chemical familiaa are recognized based upon
similarities in chemical structure and pesticidal activity. Some of the common families of pesticides
are discussed below:
FAMILIES OF HERBICIDES
TrinhB The triazine herbicides are used to kill weed seedlings. Atrazine, simazine, and
cyanazine are commonly used members of this herbicide family. Plants are killed by
triazine herbicides through interference with photosynthesis used by the plants to
produce food. Broadleaf weeds are particulary susceptible to these herbicides.
Some triazine herbicides may persist for several months or even years and injure
suceptible plents in following growing seasons. Some triazine herbicides leach into
groundwater or move laterally through the soil, injuring desirable plants.
Phtnoxy The phenoxv herbicides are widely used in agriculture to control broadleaf weeds.
2,4-D and MCPB are examples of phenoxy herbicides. This group of herbicides acts
like many plant hormones and primarily affects the actively growing tissue of the
plants. Most often these herbicides are sprayed onto plants, although they can also
be picked up by plant roots. Phenoxy herbicides can cause unwanted plant injuries
if applied when conditions allow drift onto susceptible plants.
Add Amino Acid amide herbicides are usually used to control seedling weeds prior to, or
immediately following, emergence. Alachlor and propachlor are examples. Acid
amide herbicides are absorbed into the shoots or roots of plants and affect various
growth processes in susceptible plants. Many broadleaved and grass weeds are
vulnerable to acid amide herbicides. Persistence of these herbicides is generally
fairly short; however, many of them are susceptible to leaching and have been
found as contaminants in groundwater.
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DinitroanJBne Dinitroaniline herbicides are used to control germinating weeds. Trifluralin and oryz-
alin are examples of this family of herbicides. The dinitroaniline herbicides prevent
cells in roots and shoots from dividing and developing. Many annual grass and
broadleaf weeds are susceptible to these herbicides. Dinitroaniline herbicides are
yellow in color and must be incorporated into the soil to provide weed control.
TNocarbamat» Thiocarbamate herbicides are used to control germinating seedlings and young
weeds, primarily grasses. EPTC, cycloate, and butylate are examples. The thiocar-
bamate herbicides change to a gaseous form (volatilize) readily when exposed to
moisture, and they often must be incorporated into the soil to maintain their effec-
tiveness. Thiocarbamate herbicides degrade rapidly in warm moist soils.
SuHony1 Urea Sulfonvl urea herbicides are a fairly new group of herbicides, having very diverse
characteristics, that are being used to control weeds in dry-land wheat. New com-
pounds are being developed continually, some of which can be used after weeds
have germinated (post-emergence). The sulfonyl ureas are used at extremely low
rates, sometimes less than an ounce per acre. A drawback is they can be highly
persistent in alkaline soils.
FAMILIES OF INSECTICIDES AND MITICIDES
Chlorinated Chlorinated hydrocarbon insecticides, such as DDT, toxaphene, and dieldrin were
Hydrocarbons the main family of insecticides used following their introduction after World War
II. However, environmental and health related concerns have caused most of the
chlorinated hydrocarbon insecticides to be discontinued or banned in recent years. Some
were extremely persistent in the environment. Problems with many chlorinated hydrocar-
bons also involved their tendency to concentrate in the fatty tissues of humans, livestock,
and wildlife. This latter phenomena, called bio-accumulation, had severe adverse effects on
many forms of wildlife. Chlorinated hydrocarbon insecticides still being used include me-
thoxychlor, dicofol, and endosulfan. Chlorinated hydrocarbons tend to be more active at
cool temperatures.
Organophosphates Most chlorinated hydrocarbon insecticides were replaced by various insecti-
cides in the organophosphate family. Parathion, disulfoton, phorate, and
chlorpyrifos are examples. Some of these insecticides are systemic when applied to foliage
or roots of plants; others are not. Organophosphate insecticides do not persist in the
environment as long as the chlorinated hydrocarbon products but tend to be more toxic to
applicators and wildlife. The organophosphate insecticides are nerve poisons which inhibit
cholinesterase vital to transmission of nerve impulses. These effects are cumulative, so
repeated exposures result in increased poisoning. Most of the serious human pesticide poi-
sonings have involved organophosphate insecticides. Most uses of ethyl parathion were
cancelled because of extreme hazard to applicators, mixers, loaders, and field workers.
Carbamates Carbamate (or n-methyl carbamate) insecticides are nerve poisons in insects and
other animals, as are organophosphate insecticides. Carbaryl, methomyl, and
aldicarb are examples of carbamate insecticides. The effects of carbamate poisoning are
more readily reversible (are not cumulative) than organophosphate poisoning. Carbamates
tend to be quite soluble in water and some are systemic in plants. Because of their water
solubility, several carbamates are susceptible to leaching into groundwater.
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Pynthrok/s The fastest growing family of insecticides in recent years has been the pvrethroid
insecticides. Chemically, these are related to naturally occurring insecticides (pyreth-
rins) found in certain flowers. Examples include esfenvalerate, bifenthrin, and permethrin.
The pyrethroid insecticides are highly effective against susceptible insects (for example,
caterpillars and leaf beetles) and are typically used at rates of active ingredient that are sev-
eral times lower than organophosphate and carbamate insecticides. Most pyrethroids exhibit
low mammalian toxicity, although some formulations have been associated with human irri-
tation and allergic reactions. Most pyrethroids are highly toxic to fish.
FAMILIES OF FUNGICIDES
Organic Sulfur The most important family of fungicides in current use is the organic sulfur
(carbamate) compounds derived from dithiocarbamic acid. Ferbam, metiram, and
thiram are examples of this fungicide family. The organic sulfur fungicides must be applied
in a preventive manner and will not control existing infections in a plant.
Benzene The benzene fungicides, such as chlorothalonil and PCNB, are used as protectants.
BenzknMazoh The benzimidazole fungicides have been the most important group of fungicides
with systemic activity. Benomyl, thiabendazole, and thiophanate methyl are
examples of this fungicide class. Because of their systemic activity, they can help to
control some diaeases after infection. Benzimidazole fungicides are also used to pre-
vent post-harvest rots and as soil-drench treatments.
Sterol Inhibitor Sterol inhibitor fungicides are one of the newer fungicide families. Bayleton
and Banol are examples of sterol inhibitor fungicides. The sterol inhibitors
are systemic in the plant and have eradicant activity.
WOOD PRESERVATIVES
Creosote Creosote and creosote solutions are oily byproducts of making coke from bitumi-
nous coal. They have been widely used as preservatives for such products as rail-
road ties, large timbers, fence posts, poles, and pilings. Creosote based preservatives are
toxic to wood-destroying fungi, insects, and some marine borers. They are easy to apply
and are insoluble in water. Creosote has low volatility and does not readily produce fumes.
However, creosote treatment of wood results in a dark color and strong oidor. Creosote
tends to "bleed" and the wood surface remains oily and unpaintable. Creosote-treated
wood cannot be used in homes or other living areas.
Pentachforophenol Oil-borne preservatives include wood preservatives such as pentachloro-
phenol (penta). These chemicals are generally insoluble in water and must
usually be dissolved in organic solvents in order to penetrate wood. The oil-borne preserva-
tives are toxic to fungi (including mold) and insects as welt as to plants, animals and hu-
mans. However, for some applications, these preservatives provide less physical protection
than creosote. Wood treated with penta can have an unpaintable surface (depending on the
carrier) and produces toxic fumes. It should not be used in homes or other living areas.
Metallic Salts Water-borne preservatives include various metallic salts and other compounds. The
principal compounds are combinations of copper, chromium, arsenic, and fluoride.
Waterborne preservatives have gained increasingly wider usage for lumber, plywood, fence
posts, poles, pilings and timbers. The treated wood surface is clean, paintable, and free of
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26
objectionable odors. The waterborne preservatives also resist leaching and can be used in
living areas or for playground equipment. The preservative copper-8-quinolinolate also has
been approved for food contact uses such as for boxes, crates, and pallets used during
harvesting, storage, and transportation of food. Water-borne preservatives, however, do
not protect the wood from excessive weathering, and the wood must be redried after
treatment to prevent warping and checking.
ANTIBIOTICS
Antibiotics are substances produced by one organism that are toxic to another organism.
Most antibiotics in current use are products of bacteria-like soil organisms known as
actinomycetes. Antibiotics are used in medicine as well as in pest management. Examples
include streptomycin, tetracyclines, and avermectins. Control of the bacterial fruit tree
disease fire blight with streptomycin is one of the greatest non-veterinary uses of antibiotics
in agriculture. Avermectins are also available for control of spider mites and leafminers on
greenhouse crops, and for control of livestock parasites.
FUMIGANTS
Pesticides used primarily as toxic gases are known as fumioants. Methyl bromide, alumi-
num phosphide, and paradichlorobenzene are examples. Most fumigants kill susceptible
pests that breathe the gases into lungs (mammals) or spiracles (insects, mites). Some fumi-
gants may also enter through the skin and be corrosive to the eyes. Many fumigants,
particularly those used to control insects in stored grain and for rodent control, are
extremely toxic and hazardous to applicators. Fumigants are also used to control nema-
todes, soil-borne fungus diseases, and weeds in crop land. Uses of fumigants in forestry
have declined sharply since the banning of ethylene dibromide (EDB).
Some pesticides applied to soil or foliage may also have some fumigant activity. For
example, some of the parathion applied to a crop will volatilize into a gaseous state and act
in a fumigant manner. Several soil applied herbicides move through the soil in a gaseous
state; however, these pesticides are not true fumigants since they are not designed for that
use.
Special training is required in order to apply the more hazardous fumigants. Special
protective equipment and supervision are required during application. In addition, use of
fumigants for prairie dog control requires a pre-treatment survey to determine that the
highly endangered black-footed ferret is not present. Fumigant properties and applications
are covered in a separate chapter.
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27
PESTICIDE FORMULATIONS
There are a variety of formulations for pesticides used in agriculture. Each formulation
contains the active pesticide ingredient plus various "inert ingredients." Inerts are used to improve
the performance of the pesticide by affecting such characteristics as handling, persistence on
foliage, safety, ease of application, and ability to mix with water. Some of the more common
formulations follow:
EMULSIFIABLE Emulsifiable concentrates (EC or E) are common liquid formulations with
CONCENTRATES active ingredients that are insoluble in water. The addition of an "emulsifier"
allows the pesticide to mix with water. This mixture is called an emulsion.
Emulsifiable concentrates penetrate skin more readily than other formulations, and many of
the inert ingredients are harmful to the eyes, so special handling is necessary. Inadvertent
injury to plants is also possible with emulsifiable concentrates. These formulations are easily
damaged by exposure to extreme temperatures.
WETTABLE Wettable powders are pesticides formulated on a dry particle and contain ingre-
POWDERS dients that allow the particles to mix with water. The resulting mixture is referred to
as a suspension. Continuous agitation is required when using wettable powders to prevent
them from settling in the spray tank. Wettable powders may also cause increased wear on
spraying equipment. Because they occur as dust-like particles, they can be easily inhaled
during mixing if protective equipment is not used. However, wettable powder formulations
often are quite safe to use on plants. They are used extensively in greenhouse and fruit
production where plant injury is of great concern.
FLOWABLES Dry flowables/water dispersible granules are the fastest growing new pesticide
formulations and are replacing many wettable powders. Ease of handling and
reducing the hazards from blowing dusts during mixing are two reasons for the adaptation
of dry flowable formulations. They form a suspension when mixed with water and require
less agitation than wettable powders. A further advantage of flowables over wettable
powder formulations is that they cause less wear on equipment.
Flowables are formulations of pesticides which can only be produced in solid or semi-solid
form. They are often ground into a fine powder and suspended into a liquid. Flowables are
produced for uses where they are more easily handled and mixed than wettable powders.
SOLUBLE Soluble powders are dry formulations of pesticides that go into true solution when
POWDERS mixed with water. Because of this characteristic, soluble powders do not require
agitation after mixing. Relatively few pesticides are water soluble. These pesti-
cides may also be formulated as liquids.
DUSTS Dusts are formulations of pesticides on dry particles that are applied dry. Formerly
widely used, few dust formulations are currently being produced because of difficul-
ties in application with current equipment, excessive drift, increased hazards to honeybees,
and applicator inhalation hazard. Currently, dust formulations are most often found in
gardening products and for applications to livestock, pets, and poultry. Dusts used as
"tracking powders" are also used for rodent control.
GRANULES Granules are dry formulations mixed onto fairly large particles of clay, ground corn
cob or walnut hulls, or manufactured granules. Until wetted, most of the pesticide
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28
remains attached to the granule, making this a less hazardous formulation to handle than a
liquid. Due to their heavy weight, granules have the advantage of being able to sift down
into plant parts such as corn whorls or grass and are minimally susceptible to drift.
MICROENCAP- Microencapsulated pesticides are impregnated into tiny, slow release plastic
SULATION beads and mixed into a liquid. Pesticides formulated in this manner are
often much safer to humans than other liquids and may have somewhat longer residual life.
However they are often somewhat more expensive and can increase hazards to honeybees.
Numerous other formulations can be found for specialized purposes, primarily for ease of
application and effectiveness. Ultra-low volume (ULV), aerosol, smoke bomb, paints and bait
formulations are among these other specialty products.
ADJUVANTS
Adjuvants are added ingredients which increase the effectiveness of the active ingredient
and make application easier. When added by the user, these products are exempt from the food
crop tolerance requirements that apply to pesticides used on food crops. Some common types of
adjuvants are:
- Wetting aoents or surfactants are used to improve spread of a spray mixture on foliage.
Surfactants are most commonly used to apply pesticides on plants that have waxy or hairy
leaves;
- Stickers improve the weatherability of a spray deposit, particularly from washing by
rainfall or irrigation;
- Synergists greatly increase the activity of insecticides by blocking the ability of the insect
to break down the insecticide;
- Penetrants are used to increase uptake of herbicides into a plant;
- Buffers are used in spray tanks to decrease breakdown of a pesticide caused by exposure
to alkaline water conditions.
INERT INGREDIENTS
Essentially no pesticides offered for sale to growers contain 100% active ingredient.
Instead pesticides are "formulated" by the manufacturer. During this process, various diluents or
adjuvants are added. The resulting formulation may greatly change the active ingredient's
performance and use; therefore, each formulated pesticide is individually registered by the U.S.
Environmental Protection Agency under the FIFRA law. The percentage of adjuvants is given on the
pesticide label as inert ingredients.
Despite the implied meaning of the term inert, these ajuvants can have some biological
activity, and certain inert ingredients are associated with increased pesticide hazards. As with the
active ingredients, many inert ingredients are being reviewed by the Environmental Protection
Agency.
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MIXTURES OF PESTICIDES
It is often desirable to mix two or more pesticides during application or to mix pesticides
with fertilizers. When a mixture can be made without reducing safety or effectiveness, the mixture
is said to be compatible. Otherwise it is incompatible. Incompatible mixtures can increase the
toxicity or hazard of the pesticides to the applicator or the environment. Also incompatible
mixtures may greatly reduce the effectiveness of the pesticides or cause crop injury.
PhyM/eai Incompatibilty can involve undesirable physical changes in the mixture. For example,
IncompatibOfty a mixture cause material to precipitate as a solid and deposit on the bottom of the
spray tank. Physical incompatibility may also cause the components to form sepa-
rate layers following agitation. Large aggregates may form, or curdling of the mixture may
occur. These types of physical incompatibilities may result in an unsprayable mixture or
cause fluctuations in the amount of pesticide being applied.
Chemical Chemical chances may occur when pesticides are mixed together or when
ktcompatibHty pesticides and fertilizers are mixed. This is particularly common where highly
acidic or alkaline materials are used. Reactions in the tank may form compounds
that increase environmental hazards, reduce the amounts of active ingredients, or
cause plant injury.
Increasingly, tank mixes of two or more compounds are specified on pesticide labels.
Compatability problems should be minimal with these previously tested and registered
combinations. Where combinations are not specifically labeled, private pesticide applicators
may make tank mixtures unless the label prohibits them. However, where specific tank
mixes have not been extensively tested, caution is advised. Often testing procedures for
determining incompatibility are given on the product label.
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Summary Chapter IV
Pesticides are classified according to the type of pests they are used to control. They
include herbicides, insecticides, fungicides, and others.
Pesticides are classified by their chemistry, origin, mode of action and use. They are
organic or inorganic; systemic or contact; selective or nonselective, pro-plant, pre-emer-
gence, post-emergence. These all determine how they are to be used.
Pesticides are classified by their chemical families, such as chlorinated hydrocarbons,
organophosphates, carbamates, etc. This classification may indicate how toxic they ere.
Pesticides are classified according to how they are formulated, whether liquid, dry, dust,
granules, etc. This affects how they are applied.
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Chapter V
BEWARE THE HAZARDS OF PESTICIDES!
Since pesticides are poisons designed to destroy pest species, there are many hazards
associated with their use. Pesticides can be poisonous to the applicator or other people in the area.
They can harm beneficial species such as bees that pollinate crops. They can injure crops and
wildlife and contaminate surface or ground water.
HARM TO HUMANS
Pesticides vary in their toxicity (potential for harm) to humans. During application, or other
exposure, pesticides can be taken into the body through the skin, mouth, eyes or lungs.
DERMAL EXPOSURE Dermal exposure occurs when pesticides touch the skin. The skin can
absorb pesticides, particularly the liquid formulations such as emulsifiable
concentrates. Contact with the skin is a hazard during mixing of concentrated pesticides
when they can be spilled or splashed. Also, during spraying operations pesticide drift may
settle on exposed skin or clothing. The degree to which pesticides are absorbed by the skin
depends on the type and formulation of the pesticide and the location on the body. Areas
around the genitals and the thinner areas of skin, such as the forehead, absorb the
pesticides faster. Also wounded areas such as burns, abrasions and rashes are more
susceptible to pesticide penetration.
Pesticides splashed into the eyes can be extremely damaging, particularly the more
corrosive ones such as lime sulfur, or formulations containing corrosive solvents such as
xylene.
ORAL EXPOSURE Oral exposure is when pesticides enter through the mouth. This may occur
from splashing, from drift or dust, or when an applicator smokes or eats
with pesticides on the hands. Oral exposure is a hazard when a person cleans nozzles by
blowing into them. Accidental poisonings often occur when children drink pesticides from
containers that are not kept out of their reach.
INHALATION EXPOSURE Inhalation exposure (through the lungs) occurs from breathing dusts,
spray mists or fumigant gases. Fine particles from pressure spraying
and aerosols are particularly hazardous to lungs. Pesticide exposure to the lungs is highly
dangerous because of the thin lining of air sacs in the lungs which are easily damaged and
which allow rapid movement into the blood stream.
Manuring The toxicity of a pesticide is determined by laboratory testing on animals such as
Toxldty/LDSO rats, mice and rabbits. The measuring method, LD50 (Lethal dose, 50%), describes
the dose of a pesticide that will kill half of a group of test animals from a single
exposure by either the dermal (skin) or inhalation (breathing) route. A lower LD50 number
means the pesticide is more toxic than a higher number since it takes less of the pesticide
to kill half of the animals.
LC60 The toxicity of fumigant pesticides is described in terms of the concentration of the
pesticide in the air -- LCSO. A similar system is used to test the potential effects of
chemicals against aquatic organisms in water.
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These methods for measuring toxicity give only approximate indications of how poisonous
a pesticide is because the tests are conducted on animals other than humans. Also, they
give indications of effects on the average animal and not the most resistant or most
susceptible individuals. The numbers, however, can be used to assess the relative risks
when comparing different chemicals.
Acute Toxicity Acute Toxicity of a pesticide means the poisoning that occurs after a single
exposure such as an accident during mixing or applying pesticides. There are
various signs and symptoms associated with acute poisonings. Symptoms (feelings noticed
by the person who has been exposed) may include nausea, headache, weakness, dizziness,
etc. A sign of poisoning is a result which can be seen by others, such as vomiting. Anyone
who works with pesticides should learn what these signs and symptoms are to prevent
serious injury and allow prompt treatment.
Poisoning Symptoms Pesticides in the same related chemical family tend to cause the same kinds
of poisoning sickness, and follow the same illness pattern, which helps in
diagnosis. Organophosphate and carbamate insecticides depress the levels of the enzyme
cholinesterase which affects nerve transmission. Signs and symptoms of poisoning by
these insecticides are:
Symptoms Associated with Organophosphate and Carbamate Poisoning
Mild Doisonino
Moderate Doisonino
Severe Doisonino
Fatique
Inability to walk
Unconsciousness
Headache
Weakness
Severe constriction
Dizziness
Chest discomfort
of the eye pupil
Excessive sweating
Muscle twitching
Muscle twitching
Salivation
Constriction of the
Secretions from
Nausea, vomiting
eye pupil
mouth and nose
Stomach cramps
Increase in earlier
Breathing
Diarrhea
symptoms, signs
difficulty
Death, if untreated
NOTE: There is extensive overlap of symptoms between various described stages of
poisoning. If poisoning symptoms are suspected seek medical attention.
Chlorinated hydrocarbon and pyrethroid insecticides are less likely to cause acute poisoning.
Early signs and symptoms of poisoning are headache, nausea, vomiting, general discomfort and
dizziness. Later symptoms can include excitability or irritability, convulsions, and occasionally coma
and death.
BipyridyKum herbicides, such as paraquat and diquat are among the most hazardous
pesticides since poisoning effects can be irreversible. Exposed cells can be killed so that perma-
nent damage occurs, producing problems such as lung fibrosis. Skin contact can produce severe
irritations.
Phenoxy herbicides, such as 2,4-D and MCPA, cause skin irritation or a local burning sensa-
tion when inhaled. Dizziness or chest pain may result from prolonged inhalation. When large
quantitities of the pesticide are absorbed, muscle twitching, muscle tenderness, and muscle
stiffness may occur.
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Wood preservatives have been associated with a variety of acute and chronic hazards;
therefore, they have been classified as Restricted Use pesticides. Creosote exposure can cause skin
irritation, and prolonged exposure may lead to dermatitis. Vapors and fumes of creosote are
irritating to the eyes and repiratory tract. PentacMorophanol is also irritating to the eyes, skin, and
respiratory tract, with prolonged exposure sometimes leading to an acne-like skin condition.
Ingestion of penta solutions, excessive skin contact, or inhalation of concentrated vapors may
cause fever, headache, weakness, dizziness, nausea, and profuse sweating. Extreme cases can
induce loss of coordination and convulsions. Pentachlorophenol poisoning can be fatal. Arsenical
wood preservatives can cause nausea, headache, diarrhea, and abdominal pain (if swallowed).
Extreme symptoms can progress to dizziness, muscle spasms, delirium and convulsion. Prolonged
exposure to arsenical wood preservatives can result in persistent headache, abdominal distress,
salivation, low grade fever, and upper respiratory irritation.
Fumigant pesticides can be extremely hazardous to applicators. Methyl bromide and
phosphine (released by the exposure of aluminum phosphide to water) damages the cells that line
the air sacs in the lungs, causing fluids to accumulate. This is a major cause of deaths from
fumigant exposure. Fumigants such as methyl bromide may also irritate heart muscles, leading to
heart attack. Liver and kidney damage may also result from exposure to fumigant pesticides.
Signs and symptoms of fumigant poisoning often resemble those associated with drunken-
ness (alcohol poisoning). These include poor coordination, slurring of speech, confusion, and
sleepiness.
Among the botanical insecticides, nicotine, has a high degree of associated hazards when
used as a spray or a fumigant to control greenhouse insect pests. Nicotine is very rapidly absorbed
through the skin as well as through inhalation during these applications. Skin burning and irritation
can occur from mild exposure. Stimulation and excitability, followed by extreme depression, are
common advanced poisoning symptoms. Nicotine poisoning can be serious, and even fatal, causing
death by paralysis of muscles used in breathing.
Chronic Toxicity Chronic toxicity means the effects of long term or repeated low level
exposures to a toxic substance. The effects of chronic exposure do not appear
immediately after first exposure and may take years to produce signs and symp-
toms. Examples of chronic poisoning effects include:
Carcinogenicitv - ability to produce cancer or to assist carcinogenic chemicals;
Mutagenicity - ability to cause genetic changes;
Teratooenicitv - ability to cause birth defects;
Oncogenicity - ability to induce tumor growth (not necessarily cancers);
Liver damage:
Reproductive disorders (reduced sperm count, sterility, miscarriage);
Nerve damage (including accumulative effects on cholinesterase depression associ-
ated with organophosphate insecticides);
Allergenic sensitization (development of allergies to pesticides or chemicals used in
formulation of pesticides).
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34
The effects of chronic toxicity, as with acute toxicity, are dose-related. In other words,
low-level exposure to chemicals that have potential to cause long term effects may not cause
injury, but repeated exposures through careless handling or misuse (failure to follow label instruc-
tions) can greatly increase the risk of chronic effects.
Decisions by the Environmental Protection Agency (EPA) to continue registrations of
pesticides with known or suspected risks of chronic effects are complicated. Among factors
considered are:
- Weight of the evidence that the pesticide is capable of causing long-term injuries such as
cancer, birth defects, or organ injuries;
- Amount of exposure possible during use of the pesticide, (hazard associated with its use);
- The number of people exposed to the pesticide at levels which may cause chronic effects.
Label Restrictions The probability of exposure to a pesticide when it is used according
to label directions is an important consideration. Methods of reducing this exposure
by changing methods of using the pesticide (including protective clothing require-
ments, restricted entry intervals, etc.) are evaluated. Pesticides with hazards for
chronic effects have warning statements on the labels to the effect that applicators,
in using these pesticides, understand the hazards and agree to follow all label
precautions to prevent injury. (A consent agreement.) Evidence of repeated appli-
cator failure to use a pesticide in accordance with the label (the label is the law) can
lead to the pesticide being banned or more strictly regulated.
Haxard The hazard of a pesticide means the degree of danger from a pesticide considering
the conditions of its use. Hazard can vary; whereas, toxicity is a constant. The
hazard can be reduced by taking precautions that minimize exposure, such as using
a less dangerous formulation or method of application, or using protective clothing
and equipment that reduces the potential for exposure.
RESISTANCE OF PESTS TO PESTICIDES
It is possible for pests to develop resistance to a pesticide, making the pesticide ineffective.
Pesticide resistance develops from the survival of preadapted, genetically resistant individuals.
When pesticides are applied, susceptible pests are killed and resistant ones survive. Subsequent
generations carry on the resistance. Once established in a population, pesticide resistance is perma-
nent. Pesticide resistance does not involve a single generation of the pest developing tolerance to
the pesticide following repeated small exposure.
Resistance has led to the loss of use of many pesticides that formerly were effective for
pest control in Colorado. This loss has been most severe in industries where pesticide use is most
intensive, such as greenhouse, tree fruits, livestock, and vegetables. In Colorado, resistance has
been found in insect and mite pests such as pear psylla, two-spotted spider mite, green peach
aphid, onion thrips, horn fly, and house fly. Resistance to fungicides has been developed in certain
Fusarium diseases. Weeds such as lambsquarters and kochia have become resistant to herbicides.
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aldtcarb (Tamm)
disulfoton (DtSyston)
•thyl parathlon
carbofuran (Furadan)
azinphosmathyl (Guthion)
andosulfan (Thlodan)
asranvaiwata (Asana)
malathlon
chlorpyrifos (Lorsban)
dtmathoata (Cygon)
carbaryl (Savtn)
2,4,0
acaphate(Orthana)
dlcamba (Banvtl)
atrazina
alachlor (Lasso)
sethoxydtm (Poast)
permethrln (Pounce, Ambush)
glyphosate (Round-up)
chlorsulfuron (61ean)
plcloram (Tordon)
chlorothalonti (Bravo)
Oral Toxicity of Some
Selected Pesticides
Nota: Tha shorter ths bar, tha mora toxic th« chamtcal
10000 +
0
500
1000
1500 2000 10000
LD 50 value
mg pesticide/kg body weight
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CO
03
dlsulfoton (DtSyston)
aldtcarb (Tamlk)
phorate (Thimtt, Rampart)
•thyI parathlon
azlnphoamathyl (Guthlon)
•ndosulfan (Thiodan)
glyphosate(Round-up)
malathton
dimathoate(Cygon)
trlphanyltln hydroxide (Outer)
dtcamba (Banval)
cuprlc hydroxide (Koclda)
chlorpyrtros (LorsDan)
permethrin (Pounce. Ambush)
asfanvalarata (Asana)
matalaxll (Ridomil)
chlorsulfuron (Glean)
sathoxydlm (Poast)
chlorothalonll (Bravo)
carbofuran (Furadan)
acaphate(Orthana)
metribuzln (Sancor)
Dermal Toxicity of Some
Selected Pesticides
Note: The shorter the bar, the more toxtc the chemical
10000 +
10200
10250 +
20000 +
0 1000 2000 3000 4000 5000 10000 20000
LD 50 value
mg pesticide/kg body weight
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37
ENHANCED DEGRADATION
Enhanced degradation occurs when there is an increase in soil microorganisms that break
down a pesticide, causing it to become ineffective. This happens after a pesticide has been
used too many times in the same location, and it has caused the loss of use for some
pesticides. Once developed, the results are permanent.
Development of any new pesticide is a long and costly procedure. It is in the agricultural
producer's own best interests to reduce the probability of pesticide resistance and en-
hanced degradation through proper pesticide management. The best practice is to use pesti-
cides only when needed, thereby reducing the selective pressure that produces resistant
pests. Also, it is desirable to switch between classes of pesticides to preserve their
effectiveness.
DAMAGE TO BIOLOGICAL CONTROL ORGANISMS
Use of pesticides can severely diminish the performance of biological control organisms
such as natural predators and parasites. Specifically, the use of insecticides reduces organ-
isms that prey on insect and mite pests. Fungicides are also known to kill certain predators
of spider mites and inhibit naturally occurring fungus diseases of insect pests.
Secondary One of the consequences of the disruption and destruction of biological control
Pests organisms is when pest species that are normally not economically harmful increase
and reach a level of significance. These are called secondary pests. Many of the problems
with spider mites in fruit and field corn are secondary pest problems; pea aphids in alfalfa
have increased after alfalfa weevil treatment.
Post When a pest species is reduced by pesticide application, and their natural enemies
Resurgonco are also reduced, the pest may increase rapidly after pesticide residues diminish.
This is called pest resurgence or rebound.
DAMAGE TO POLLINATING INSECTS
Pollinating insects, such as honeybees and leafcutter bees, are vital to the production of
fruit and seed crops. Crop yields and quality depend on and are improved by the activities
of these pollinators.
Industries surrounding the culture of honeybees are an important part of Colorado agricul-
ture. Millions of dollars worth of honey, wax, and other honeybee products originate here.
Income derived from these products is either a primary, or important secondary, source of
farm income.
Often, pesticide use conflicts with pollinating insects, especially when pesticides that are
hazardous to honeybees are applied to areas where worker bees are gathering pollen or
when harmful pesticides drift onto bees that are clustered on the outside of hives. Protec-
tion of honeybees must be an important consideration of pesticide applicators, since the
success of their crops may depend on bees.
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PHYTOTOXICITY
Inadvertent crop injury can result from certain pesticide applications. This is known as
phvtotoxicitv and is most likely when using "selective" herbicides that are selective only
because they are less toxic to the crop than to the weed. Phytotoxicity can also occur
when certain insecticides and fungicides are used on sensitive greenhouse crops. Many
corn rootworm insecticides are phytotoxic if placed in contact with the seed. Occasionally,
damage can be done when two pesticides are applied to a crop and there would have been
no damage if only one pesticide had been used. Usually, phytotoxicity hazards are recog-
nized when pesticides are being developed. Warning statements then are placed on the
pesticide label giving directions on how to avoid such damage.
HAZARDS TO WILDLIFE AND ENDANGERED SPECIES
Many pesticides have the potential to seriously damage wildlife. The use of pesticides has
largely caused the elimination or sharp reduction in numbers of birds, certain mammals, and other
species in areas of intensive agriculture in Colorado. In some cases, pesticide use has caused
wildlife species to be in danger of extinction.
Damage to Pesticides can affect wildlife populations in a number of ways, including:
WHdSfe
- pesticides directly applied to wildlife habitats can directly kill plants and animals.
- pesticides can run-off a site and contaminate water that is ingested or inhabited by
wildlife.
- pesticides can eliminate food used by wildlife.
- pesticides can accumulate in predators that feed upon plants or animals that have
been exposed to pesticides.
- pesticides can damage or elminate habitat required for the survival of wildlife.
Endangered Among the species that have been most directly affected by pesticides in Colorado
Species are the black-footed ferret and the peregrine falcon. The poisoning of prairie
dogs eliminated the black-footed ferret from much of its original range, where its principal
food source was the prairie dog. It is now the rarest mammal in North America. Peregrine
falcons and many other birds of prey were severely affected by the accumulation of DDT
and persistent industrial chemicals (PCBs) in their bodies, which interfered with their ability
to reproduce. Other endangered species have been greatly reduced through loss of habitat,
water pollution, and hunting.
Bald E«gl«
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39
ENDANGERED SPECIES IN COLORADO
The following species of plants and animals found in Colorado are recognized nationally as
being either endangered or threatened. Endangered species are in danger of extinction and are the
subjects of the greatest measures of protection.
COUNTY
Boulder, Clear Creek, Custer
Delta
Douglas
El Paso
Garfield
Grand
Huerfano
Jackson
Jefferson
La Plata
Lake
Larimer
Mesa
Moffat
Montezuma
Montrose
Park
Rio Blanco
San Miguel
Teller
SPECIES
Greenback Cutthroat Trout
Mesa Verde Cactus
Spineless Hedgehog Cactus
Uinta Basin Hookless Cactus
Clay-Loving Wild Buckwheat
Colorado Squawfish
Pawnee Montane Skipper (insect)
Greenback Cutthroat Trout
Greenback Cutthroat Trout
Uinta Basin Hookless Cactus
Colorado Squawfish
Penland Beardtongue (plant)
Osterhout Milk-vetch (plant)
Greenback Cutthroat Trout
North Park Phacelia (plant)
Pawnee Montane Skipper
Knowlton Cactus
Greenback Cutthroat Trout
Greenback Cutthroat Trout
Spineless Hedgehog Cactus
Uinta Basin Hookless Cactus
Bonytail Chub
Colorado Squawfish
Bonytail Chub
Humpback Chub
Colorado Squawfish
Mesa Verde Cactus
Mancos Milk-vetch (plant)
Colorado Squawfish
Mesa Verde Cactus
Spineless Hedgehog Cactus
Uinta Basin Hookless Cactus
Clay-loving Wild Buckwheat
Pawnee Montane Skipper
Greenback Cutthroat Trout
Dudley Bluffs Bladderpod (plant)
Dudley Bluffs Twinpod (plant)
Colorado Squawfish
Spineless Hedgehog Cactus
Clay-loving Wild Buckwheat
Pawnee Montane Skipper
The Bald Eagle has been identified in 46 of the 63 counties, the Whooping Crane in 17 counties,
and the American Peregrine Falcon in 15 counties; however, their range is difficult to map.
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The Endangered Species Protection Program, which has been voluntary to date (1992), is a
cooperative effort by the U.S. Fish and Wildlife Service, the U.S. Department of Agriculture, and
the U.S. Environmental Protection Agency. EPA has contributed by requiring pesticide manufac-
turers to include warning statements regarding the potential for harming endangered species on
their product labels. When the program becomes enforceable (planned for 1993), there may be
restrictions on the use of certain pesticides in areas where susceptible endangered species are
found.
PESTICIDE DRIFT
Pesticide drift is the movement of a pesticide to areas other than the intended area of
application. Some drift is expected during applications, and short-range drift can aid in crop cover-
age; however, small spray droplets or dust particles can be carried by air movement for great
distances. Pesticides may also drift when they evaporate from the crop and travel as fumes. The
effectiveness of pesticides at the application site can be reduced by drift, and damage can be done
where it is not intended.
Sensitive crops, gardens, landscape and shelterbelt plantings may be damaged by pesticides
that are not intentionally applied. Illegal residues can also occur on crops from these sources, and
livestock, honeybees, and wildlife can be affected. Humans may also be exposed to pesticides
because of drift.
Several factors influence the drift potential. Some important ones include the natural drift
hazard of a pesticide, the formulation, droplet sizes produced during application, height at which
the pesticide is released, temperature and air movements. Management of drift is critical to the
successful use of pesticides. Failure to take proper precautions can cause damage to your own
property and people there, as well as "chemical trespass" on neighboring properties.
POLLUTION OF WATER RESOURCES
Contamination of surface waters is always a hazard of using pesticides, either directly from
drift or by accidental application of pesticides into streams, rivers, or lakes. Extreme care must
always be taken when applying pesticides near waterways.
Erosion Water may be contaminated by pesticides during runoff from irrigation or rainfall.
Wind blown soil contaminated by pesticides may also enter surface waters. The
potential for contamination from these sources is greater if there is rain or strong wind
shortly after a pesticide application. Site conditions that promote erosion (steep slopes,
exposed soil, etc.) greatly increase the probability of unwanted pesticide movement from
erosion.
Groundwater Attention is now focused on groundwater contamination from pesticides and
various industrial chemicals. Groundwater is the source of water for wells and
springs which serve about half of the population of the United States for drinking water. In
rural areas 90 percent of drinking water is from groundwater sources. Until recently, this
resource was believed to be relatively free from pollution, but discoveries of contamination
have raised serious concerns regarding pesticide use over major aquifers. In addition there is
increased awareness that groundwater and surface water resources are often intercon-
nected.
Groundwater is stored In an aquifer, a saturated zone of soil, sand, gravel, or fractured
bedrock. The top of the aquifer Is called the water table. These underground water
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41
reserves are supplied by water from the surface (recharge) that percolates downward
through soil into the water table. The percolating water picks up chemicals from the soil, a
process known as leaching. Leaching of soil salts can result from poor irrigation practices,
and can be of great concern in areas of high salt content.
Groundwater becomes contaminated when recharge water carries pollutants, such as
pesticides, with it to the water table. Once in the aquifer, water travels in a more horizontal
direction. The pollutants move with the groundwater, forming a region of contaminated
water known as a plume.
Once groundwater is contaminated, it may be
too expensive or impossible to clean it up.
Since pesticides degrade very slowly in
groundwater, contamination may last for
years. Clearly, the best solution is to keep
pesticides and other chemicals out of ground-
water through careful application, storage,
and disposal.
A number of factors contribute to potential
groundwater contamination. These include
site conditions, characteristics of the pesti-
cide, the method of application, and envi-
ronmental conditions following application.
Site Conditions Site conditions associated with groundwater contamination potential include:
Soil texture: Texture is determined by the relative proportion of sand, silt, and clay. Soils
with more clay and organic matter tend to hold water and dissolved chemicals longer than
soils with low clay and organic matter content. Soils that are more sandy allow con-
taminated water to move more readily into groundwater. Many Colorado agricultural areas,
such as the northeast, have very sandy soils;
Soil permeability: Permeability is a measure of how rapidly water can percolate through a
soil. Highly permeable soils allow greater downward movement of water-borne contami-
nants. Many Colorado areas (for example, the San Luis Valley) have highly permeable soils;
Soil organic matter: Organic matter, such as plant residue or manure, in a soil influences
how much water it can hold and how well it can adsorb chemicals, including pesticides.
Low organic matter soils are common in Colorado probably because of lack of moisture to
degrade organic matter;
Soil pH: The relative acidity or alkalinity of soil can be important in the degradation of the
pesticides. Most pesticides degrade more rapidly under alkaline conditions.
Depth of water table: How deep the water table is below the surface influences the speed
with which dissolved chemcials can reach the underlying aquifer. In areas of high water ta-
bles, such as parts of the San Luis Valley, the risk of groundwater contamination is greater.
Areas along streams and rivers also pose a high risk for contaminating groundwater supplies
when pesticides are applied there. Pesticides degrade slowly in groundwater since few
microorganisms occur to break down the pesticide.
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42
Pesticide
Characteristics
Characteristics of the pesticide that can influence hazards to ground-
water include:
Water solubility: If a pesticide is easily dissolved in water, it will move more freely with the
water. Among the highly soluble pesticides are many carbamate insecticides and triazine
herbicides
Environmental persistence: Persistence means a pesticide's ability to resist degradation. If
a pesticide is persistent (lasts a long time without breaking down), it has a greater potential
for entering groundwater.
Electrical charge: The charge, or speciation, of a chemical determines how readily it binds
to soil particles (adsorbs). Since clay and organic matter tend to be negatively charged,
chemicals with a positive charge will cling to the soil and resist leaching. Negatively
charged pesticides, or soils with few negatively charged clay and organic matter particles,
increase leaching potential.
Application The manner in which a pesticide is applied, and what it is used to control can
increase or decrease the risk of groundwater contamination.
High use rates: If a high dose rate of a pesticide is applied to a crop or other location, the
potential for leaching and contaminating groundwater is greater.
Over-irrigation: If too much water is applied to a crop, there is more likelihood of percolating
water carrying pesticides into the groundwater.
Chemigation: The techniques for applying pesticides through irrigation systems present
special hazards to groundwater. If a power failure occurs during application, there is a
potential for back siphoning of chemicals, thereby drawing large amounts of pesticides
directly into the well. Appropriate protective devices, such as check valves, are now
required by law and pesticide labels carry instructions on how to prevent accidental back
siphoning pollution of wells.
Leachers Several pesticides have been found as contaminants in groundwater supplies
throughout the United States. These compounds, or those with similar chemical
characteristics, are sometimes classified as "leachers" by the Environmental Protection
Agency. Extra precautions should be used with these products to prevent groundwater
contamination. Pesticides that have been found in groundwater include:
acifluorfen
dicamba
diuron
alachlor
aldicarb
ametryn
atrazine
bromacil
methomyl
metolachlor
oxamyl
propachlor
carbofuran
cyanazine
propazine
simazine
terbacil
trifluralin
2,4-D
dalapon
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Summary Chapter V
Pesticide exposure to humans can be by dermal, oral or inhalation routes.
Hazard to humans can be either acute (immediate) or chronic (long term) toxicity.
A pest can become resistant to a pesticide over time, making the pesticide useless for
controlling that pest. Pests that have a built-in resistance to a pesticide survive its use and
their offspring are resistant, eventually making a large part of the pest population resistant.
Pesticides can kill insects that are needed to pollinate crops.
A side effect of using pesticides is damage to wildlife or wHdltfe habitat.
A side effect of using pesticides is pollution of ground and surface water.
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Chapter VI
MANAGEMENT OF COMMON AGRICULTURAL PESTS IN COLORADO
Essentially all crops grown in Colorado are subject to competition and attack by certain pest
species. Information on the management of these pests is available from various sources, such as
the Colorado State University Cooperative Extension Service, agricultural chemical dealers, and
consultants. Some examples of pest management techniques follow.
CANADA THISTLE
Canada thistle is a noxious weed under Colorado law. This aggressive and
serious pest of pasture and cultivated crops usually starts in disturbed
ground, such as overgrazed pastures, tilled fields and waste areas. Once es-
tablished, Canada thistle spreads by means of underground rhizomes,
creating circular patches. Root pieces cut by cultivation may regrow and
spread the weed. In addition, large numbers of seeds which are produced
during late spring and early summer are blown to new areas, spreading the
weed.
In cropland, best control of the weed is achieved by persistent cultivation.
Use of a duck-foot cultivator which cuts the plant no deeper than 4 inches
below the surface is suggested for this operation. Plants are particularly
susceptible to cultivation shortly before flowering, when root food reserves
are lowest.
Planting cropland to highly competitive crops, such as small grains and alfalfa can
help reduce Canada thistle infestations. In grain crops, rangeland, and pasture, a
few selective herbicides can be used. Herbicides are more effective when applied in
the fall, shortly before a killing frost when they are most likely to reach and kill the
root system.
LEAFY SPURGE
Leafy spurge is the most damaging weed in Colorado's pasture lands.
Cattle do not graze leafy spurge because it produces an irritating milky sap,
and since it is highly aggressive, it can rapidly outcompete desirable forages.
A relative newcomer to Colorado, leafy spurge has ruined large areas of
rangeland in more northern states which spend millions of dollars to control
it. Leafy spurge is recognized as a noxious weed.
The seed is spread primarily by birds, humans and water. It has taken hold
along ditchbanks and streams in Colorado. Once established, an extensive
creeping root system that produces numerous new plants enables it to reach
into new areas. The root system contains large nutrient reserves which help
the plant survive control measures.
Intensive cultivation is an effective means to control leafy spurge. In rough
terrain where this is not practical, specialized equipment can be used to lift
and damage the roots and expose them to disease organisms. This is most
effective if done at flowering. Herbicides applied at the proper time, depend-
ing on the product, can be effective in leafy spurge control.
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JOINTED GOATGRASS Jointed goatgrass is a serious weed of winter wheat. It has a winter
annual life cycle, similar to that of the crop, germinating primarily in
fall. The plants resume growth in spring, usually flowering and setting seed shortly before
the wheat. Occasionally, jointed goatgrass will hybridize with wheat. Jointed goatgrass has
been classed as a noxious weed in Colorado since 1978.
The seeds are small cylinders which look like half inch pieces of wheat stem. Because of
this similarity, many farmers have unkowingly planted the weed and contributed to its
spread. Once established in a winter wheat field, jointed goatgrass is extremely difficult to
control since it is so similar to the crop that selective herbicides are not available. Seeds
may also remain viable for several years, particularly if buried deeply during plowing.
Farmers can prevent the spread of jointed goatgrass by learning to recognize the weed
seeds and inspecting all seed for presence of the weed. Since infestations in fields can
originate from roadsides, these areas should also be surveyed and treated for the weed.
When jointed goatgrass has become a problem in a field, rotation to a spring crop should be
considered as more effective herbicidal control is then possible.
MUSK THISTLE Musk thistle is a biennial weed found in pastures and rangeland. The musk
thistle plant is usually large and has long spines; therefore, it is avoided by
livestock.
Although musk thistle can become a problem even on good pastureland, it has more
difficulty becoming established in vigorously growing grass. Herbicides are often used for
controlling musk thistle. It is most sensitive to herbicide treatment while in the rosette
stage, before it produces a seed spike.
A species of weevil which feeds on the developing seeds of musk thistle has been intro-
duced into Colorado as a control technique.
LARKSPURS Larkspur is a major weed of Colorado ranges because it is poisonous to cattle,
occasionally causing death. Horses are also susceptible to the effects of the weed but
usually do not consume enough foliage to cause poisoning. Sheep are generally not
poisoned by larkspur.
There are two groups of larkspurs. The tall variety is usually found in moist meadows or
woodlands at high elevations; the low variety in the foothills at lower elevations and drier
environments. Larkspurs are perennial and reproduce both by seeds and by tubers or
rhizomes.
The plants produce a rosette of green growth early in the season, often before suitable
forage plants have begun to grow. Animals then feed on the larkspur because other green
plants are not present. Delaying use of the infested range or pasture until the grass begins
to grow is a means of preventing animals from eating larkspur. Sheep may be run earlier to
consume the larkspur, which also helps to save grass for cattle.
Broadleaf herbicides can be used to control larkspur in rangeland.
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BOTRYTIS Botrytis neck rot and purple blotch are harmful fungus diseases of onions in storage.
NECK ROT Under conditions favorable to the disease, near total losses from rotting are
OF ONIONS possible. Bulbs may become infected in the field or in storage since the spores are
spread by wind, water, equipment, workers, or insects. Botrytis enters onions
through wounds. Common sources of these wounds include hail, harvest injuries, foliage tip
burns, topping, and inadequate curing of neck areas. Late planting and excessive use of
nitrogen fertilizers contribute to problems by delaying maturity of the crop.
There are several ways to reduce losses from botrytis neck rot in onions. Cull piles should
be covered with soil to prevent production of spores that can infect the crop. Fields should
be rotated, preferably on a 3-4 year cycle, to allow elimination of infected crop debris. Neck
areas should be allowed to cure properly before topping. Late season applications of
fungicides may also help to protect the neck area from infections.
During harvest, bulbs should be carefully lifted and handled to avoid bruising, and only
undamaged bulbs should be stored. Then stored onions should not be exposed to direct
sunlight or freezing temperatures. Good air circulation can help prevent disease develop-
ment in storage facilities.
PHYTOPHTHORA Root rot caused by Phytophthora fungi can seriously damage vegetable
ROOT ROT crops such as tomatoes, peppers, squash and melons. Phytophthora fungi
also cause root rot and crown rot in orchards. Most plant damage results when the fungus
infects and girdles plants at or below the crown area. Vegetable plants may wilt and die.
Infected fruit trees show symptoms of reduced vigor, such as poor growth and discolor-
ation of leaves.
Phytophthora root rots are likely to develop when soils are poorly drained or when the soil
is a heavy clay type. Growing vegetables in raised plant beds can help improve drainage
and prevent infections. When irrigating fruit trees, avoid prolonged wetting of the crown
area. Resistant varieties of vegetables and rootstocks help prevent root rots. In vegetables,
crop rotations to non-susceptible crops, such as corn and grain, should be used to eliminate
sources of the disease.
Some of the new systemic fungicides (metalaxyl) can effectively control Phytophthora;
however, the County Cooperative Extension office should be consulted for information on
the use of these products in Colorado.
CORN STALK ROTS Corn stalk rots result from various types of fungi. Lodging is common with
this disease, or infected plants may die. The fungi may also produce toxins
that are injurious to livestock.
Infection may occur through invasion of the roots or at nodes. Invasion of the roots is
particularly common if there are cool, moist conditions after planting. Infection may also
enter through insect wounds such as are produced by corn rootworm larvae.
Unfavorable growing conditions create stresses on the corn plant and promote corn stalk
rot. By correcting fertility imbalances, maintaining optimal plant populations, and providing
adequate moisture, the likelihood of corn stalk rot developing can be minimized. Favorable
growing conditions are particularly important after pollination and during early grain fill
when the plants are most susceptible to infection. Although no varieties are immune to the
disease, some varieties are more resistant than others.
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Crop rotations and plowing can help reduce the amount of infected plant debris in a field.
COMMON Common bacterial blight and halo blight are two bacterial diseases of beans in
BACTERIAL Colorado. The amount of damage they do depends on what plant tissues are
BLIGHT OF infected. Infections on leaves kill areas of plant tissues and if extensive can
BEANS reduce yields. Infections on stems can form watersoaked cankers and cause plants
to break. If pods are infected, seeds become shriveled, discolored or rot.
The disease organism overwinters on infected plant debris and in seeds. Use of certified,
disease-free seed is important in minimizing the disease. Fields should also be rotated,
preferably in a minimum 3-year rotation. (This practice also helps reduce other common
bean problems such as white mold and root rots.) Some varieties of beans have resistance
to this organism.
Like most bacterial diseases, common bean blight is favored by warm moist conditions.
Overhead irrigation, as opposed to furrow irrigation, promotes this plant disease. Use of
certain copper fungicides can help manage the disease.
FIRE Fire blight is the most serious disease of pear, apple and other plants of the rose
BLIGHT family. The disease organism kills the inner bark of trees, causing terminal shoots
and foliage to suddenly wilt and die. As the disease progresses, extensive areas of
the tree can be killed.
The bacteria enter the plant through wounds, flowers, and during pruning. Spread can be
from splashing water, human activities and by pollinating insects. Once inside the tree, the
bacteria can develop rapidly if warm, moist conditions exist. During active periods of
disease development, the bacteria ooze from the damaged cankers that they produce on
trunks and branches.
Pruning at least 15-18 inches below visible cankers is the only means to manage the
disease in infected trees. Pruning should be done during the dormant season. Carefully
sterilize pruning tools between cuts, and remove and destroy the infected wood. Preventive
sprays of fixed copper or the antibiotic streptomycin can be used during periods when new
infections can develop.
BARLEY Barley yellow dwarf is a virus disease of cereal crops in Colorado, including wheat
YELLOW and barley. Infected plants are stunted, generally discolored yellow, and yield poorly
DWARF if at all. Young plants may die.
Barley yellow dwarf is spread by aphids. Greenbug, bird cherry oat aphid, English grain
aphid, and corn leaf aphid are common species of aphids in Colorado which transmit the
various strains of the disease organism. There is often an increase in the disease where
Russian wheat aphid occurs. The disease occurs in corn, on perennial grasses, and other
grassy weeds as well as in grain crops.
Barley yellow dwarf control can be difficult. Insecticides to control aphids that transmit the
disease may be useful but are generally not economical. Planting crops far from infection
sources and delaying fall planting can also help reduce disease incidence.
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RUSSIAN
WHEAT APHID
The Russian wheat aphid was first identified in Colorado during 1986. It has
spread extensively throughout the state and has caused severe losses to
wheat and barley.
Unlike most other aphids found on small grains, the Russian wheat aphid produces saliva
that is toxic to the plant, causing the chlorophyll to be destroyed, and producing symptoms
of leaf streaking. Infected leaves often curl tightly, preventing normal seed heads from
emerging. The leaf curling also protects the aphids from predatory insects such as ladybird
beetles. Surveys of the insect are most easily made by watching for the symptoms.
The biology and habits of the Russian wheat aphid as a pest in Colorado are still poorly
understood. Damage to winter wheat seems to be greatest on drought stressed plants. Dry
winter conditions appear to favor overwintering of the insect. Among spring seeded small
grains, barley is the plant that most favors development of the aphid.
Economic levels for treating the insect vary depending upon the growth stage of the crop.
Because of continuous new research developments with this insect, grain growers should
check with county Cooperative Extension offices regarding latest recommendations for
control.
Insecticide treatment of the Russian wheat aphid is known to cause extensive bird kills.
POTATO The potato psyllid damages potato and tomato plants by injecting a toxic saliva
PSYLLID during feeding. This toxin apparently moves systemically in the plant and has
properties similar to plant growth regulators. Foliar symptoms in infested plants
include stunting, erectness of new growth, and color changes. Potato tuber set can be
disrupted causing the plant to produce numerous rough tubers that fail to grow. Alterna-
tively, tubers may sprout prematurely. Tomatoes can be greatly reduced in size and quality.
Following control of the insect there is some recovery of infested plants.
The potato psyllid does not overwinter in Colorado; infestations result from annual migra-
tions. Once in a field the insect reproduces continuously, completing its life cycle in 3-4
weeks. Infestations are irregular but more common in eastern Colorado than other areas of
the state. Fields should be surveyed regularly with a sweep net to detect adult insects as
they first arrive.
ALFALFA Alfalfa weevil is the most serious insect pest of alfalfa in Colorado. Damage is
WEEVIL caused by the immature "grubs" (or larvae) which chew on first cutting hay,
reducing yields and quality. To a lesser extent, grubs may be present in sufficient
numbers to damage second cutting hay.
Alfalfa weevils overwinter in the adult stage in protected areas around field edges. They
return to the field in spring and deposit their eggs in developing shoots. The larvae feed for
several weeks before becoming full-grown, at which time they drop from the plant and
pupate. The emerging adults feed some but do not cause yield reductions. There is only one
generation per year.
Pesticides used to control alfalfa weevils have caused extensive losses of honeybees. Also,
pea aphids can increase after use of pesticides to control alfalfa weevils. The Colorado
Department of Agriculture has released numerous parasites of the alfalfa weevil, several of
which have become established, to control the pest naturally.
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TWO-SPOTTED The two spotted spider mite affects a wide variety of Colorado crops
SPIDER MITE including greenhouse, fruit, bean and field corn. The mites damage the
plants by sucking the cell contents from leaves causing areas of the leaf to die. During
heavy infestations leaves can look scorched and die or drop prematurely.
Outdoors, two-spotted spider mites overwinter as full-grown females and often take on a
red color. Populations indoors cycle continuously. During warm temperatures, particularly
when dry conditions exist, mites can complete their growth cycle in as little as a week.
Because of rapid growth and reproduction, mite populations can explode in a short time.
Two-spotted spider mites can be difficult to manage since they have developed resistance
to most pesticides used to control them. Some natural controls can be effective on outdoor
crops if they are not disrupted by pesticides used to control other pests such as codling
moth and European corn borer. Indoors, some introduced predators of the two-spotted
spider mite have been used successfully.
Water management can also be used in a mite control plan. Overhead watering can wash
off and destroy many mites. Preventing drought stress on plants can also reduce develop-
ment of the mites.
CODLING Codling moth is generally the most critically damaging insect pest of apples and
MOTH pears in Colorado. Damage is produced by the larval stage (common "apple worm")
which tunnels into the fruit. The adult stage is a small, grey moth with a copper
spot on the wing tips.
The insect overwinters in a cocoon on the bark of the tree or on
debris in the vicinity of the trees. The adult moths emerge shortly
after petal fall, mate, and the females lay eggs on leaves. The
young larvae may feed upon leaves but then move to developing
fruit, usually entering the calyx end. After feeding, they drop from
the fruit and pupate.
Moths of the second generation fly in July and lay eggs directly on the fruit.
The larvae tunnel into the fruit shortly after hatch. Most fruit damage is
done by these second generation larvae. A third generation may occur in
August.
Codling moth control is achieved primarily through the use of protective cover sprays of
insecticides applied when moths are laying eggs and eggs are hatching. Pheromone traps,
containing the sex attractant of the insect, can indicate timing for codling moth sprays.
GREENHOUSE Greenhouse whitefly damages many greenhouse crops and occasionally infests
WHITEFLY vegetables transplanted outdoors. Damage is caused when the insect removes sap
during feeding and excretes a sticky honeydew onto lower leaves.
The greenhouse whitefly cannot overwinter outdoors in Colorado and the pest survives on
indoor plants. Continuous, overlapping generations of the the insect are completed in about
a month, and egg laying adult insects can live for a month or more.
By scheduling greenhouse plantings to provide for host-free periods of 2-3 weeks, the life
cycle of the insect can be broken. When new plants are introduced into clean greenhouses,
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quarantine. The immature stages of this insect are particularly difficult to see, being pale
colored and scale-like on lower leaf surfaces.
Insecticides, primarily those in the pyrethroid family, are used for managing the whitefly.
Repeated applications are required since the egg and non-feeding "pupal" stages are
resistant to control. Yellow sticky traps can be used to monitor and even control the
greenhouse whitefly, which is attracted to yellow. In warm temperature greenhouses, ex-
ceeding average temperatures of 75 degrees, an introduced parasite (Encarsia formosa)
may help control the insect.
COMMON The common cattle grub, or "heel fly" is the most destructive insect pest of cattle
CATTLE in Colorado. Immature stages of the insect develop as parasites inside the animal,
GRUB diminishing weight gains and milk production. In slaughtered animals, cattle grubs
cause serious losses because carcasses must be trimmed and hides are damaged.
Adult flies lay eggs on the legs and lower areas of the animal in the spring. The buzzing of
the "heel flies" is often disturbing to cattle and they may run wildly trying to escape.
Disrupted feeding and disturbed behavior of the cattle is an indirect hazard of the common
cattle grub.
Larvae of the grubs hatch from eggs in 3 to 5 days, migrate down the hair of cattle and
penetrate the skin. Then they move through the animal and lodge underneath the skin on
the back where they form a cyst. When full grown, they emerge through the skin, drop to
the ground and pupate. There is one generation per year.
Cattle grubs can be controlled by using insecticides that can enter the animal systemically
and kill the developing grubs. These treatments are sprayed, poured on the back of the
animal, or used in dips. The timing of the treatments is critical since harm can be done if
grubs die in sensitive areas such as the esophagous or spinal cord. Lactating dairy cows
and animals that will be slaughtered before the required minimum post-treatment interval
has elapsed cannot be treated with systemic insecticides.
RICHARDSON Richardson ground squirrels occur over most of Colorado, including the higher
GROUND elevations. They are usually seen close to their mounded burrow openings and tend
SQUIRRELS to occur in small family or colony groups. When there is plentiful feed, ground
squirrels may increase rapidly; they can produce annual litters of a dozen or more.
Planted or growing grain and forage crops are all food for Richardson ground squirrels.
Where they are numerous, crops can be extensively damaged. Burrows may also be a
hazard in irrigated areas such as pastures.
Populations of Richardson ground squirrels fluctuate rapidly and may be virtually wiped out
by disease. Natural enemies also include hawks, weasels, badgers, and man. Four methods
of control have been practiced success-fully: poisoning, trapping, shooting and fumigation.
Poisoned grain is the most common and effective means of control
on farms and ranches. On large areas with numerous animals, it is
the only practical one. Poisoned oats or barley are cheap and effec-
tive; oats are favored. Grass seed and cracked wheat should not be
used since seed-eating birds may feed on them. Timing is important;
treatment should not be applied at the first sign of activity in spring
nor in late summer when the squirrels start
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to disappear into burrows. Also there are periods when the squirrels may feed selectively
on individual grains, eating kernals after removing the treated hull. The best time to use
poisoned grain is when the entire colony is active and grain baits are being readily accept-
ed, particularly when squirrels are "pouching" (gathering seeds for winter storage).
Poisoned grain should be scattered on the hard bare ground dose to the cleared surface of
squirrel runways, not piled or placed in the burrow. Bait stations can be built which make
the bait inaccessible to other species of wildife. Poisoned grain should be handled and
placed with care at all times to avoid poisoning seed-eating birds, pets, livestock, and
young children. DO NOT REMOVE POISONED BAIT FROM ORIGINAL CONTAINERS WHEN
STORING.
PRAIRIE DOGS Prairie dog species found in Colorado include the black tailed prairie dog of
The eastern plains, the Gunnison prairie dog in the southwest, and the
white tailed prairie dog in the northwest. Prairie dogs are considered by many people to be
pests since they reduce vegetation in the area around the colony. The holes and mounding
produced by prairie dogs also can be a hazard to livestock and equipment. Prairie dogs, and
many other rodents, may also harbor fleas that transmit bubonic plague.
Prairie dogs, however, are an important part of the short-grass prairie ecosystem, providing
food for many wildlife species, including some which are threatened or endangered. Also,
other animals sometimes use their burrows for protection. Colonies of prairie dogs range
from 5-20 individuals per acre, increasing in April or May after the pups are born.
Prairie dog control is necessary in some situations, but precautions must be taken to
protect threatened, endangered, and some non-target wildlife during control operations.
Because of the hazards associated with poisons used for prairie dog control, to both the
applicator and non-target wildlife, regulations have become increasingly restrictive. The
Colorado Division of Wildlife, county Cooperative Extension offices, or the Colorado
Department of Agriculture's Bureau of Rodent Control can provide information on regula-
tions.
To protect the black-footed ferret, an important prairie dog predator and one of North
America's most endangered mammals, special precautions must be taken. These may
include surveys prior to controlling prairie dogs. The U.S. Fish and Wildlife Service has
declared some areas as unlikely to support black-footed ferrets. Such "ferret free" areas no
longer require ferret surveys before a fumigant (aluminum or magnesium phosphide or gas
cartridges) or poison grain bait (zinc phosphide, effective 1993) is used to control prairie
dogs. Follow label restrictions in areas not yet declared "ferret free,"
To reduce harm and/or protect wildlife, read and follow all pesticide label directions.
Fumigants will kill any wildlife in the burrows. Poison grain bait has to be eaten to cause
death. It is used outside burrows, and any grain-eating wildlife can be killed by it.
Carcasses found above ground should be properly disposed of to eliminate any risk of
secondary poisoning. Proper control techniques and timing can prevent inadvertent death
to non-target wildlife species.
Use of poison oat baits for prairie dog control is most effective when green food is not
available. Late summer, fall or early winter are usually the best times for a poisoning
program. Prebaiting the area with untreated oats 2-3 days before actual baiting will increase
later acceptance of the poison bait by the prairie dogs. When doing the actual baiting, treat
the entire colony at one time. Repeat the application 7-10 days later.
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Poison baits (about 1 Tbsp/hole) should ba thinly scatter ad at tha edga of tha mound whare
tha soil and grass maat. By scattering the grain, there is less liklihood that desirable wildlife
or livestock will eat the grain. Whenever possible, livestock should be removed from the
treatment area.
Fumigants may be used when additional control is required. Because fumigants are
expensive and highly hazardous, their use should be limited to small acreages and only after
use of poison baits. Swift/kit foxes, burrowing owls, badgers, rabbits, reptiles and amphibi-
ans inhabit the burrows of prairie dogs and will be killed by fumigants. Rabbits are at risk
from zinc phosphide but zinc phosphide is less hazar-dous to foxes. Zinc phosphide is toxic
to grain-eating birds.
Prairie dogs don't use burrows occupied by owls. Owl burrows often have white droppings,
owl pellets, feathers or shredded cow and horse manure around the opening. Do not use
fumigants in owl burrows between March 1 and October 31, especially during the critical
May-June nesting period.
STORED Insects that infest stored grain are both primary pests, which attack intact kemals,
GRAIN and secondary pests, which feed on broken or cracked grain. In addition, there are
INSECTS several insects that feed on fungi associated with grain molds. The most common
primary pests include the lesser grain borer, granary weevil, and Indianmeal moth. The
sawtoothed grain beetle, flat grain beetle, and flour beetles are secondary pests.
Insects can damage stored grain in several ways. Direct feeding results in lower weight
and nutritional value, and reduced germination. Insect feeding can help create conditions
favorable for storage molds to develop. Sometimes the greatest injury is the mere presence
of the insect, contamination of the grain, which can result in serious dockage. This latter
issue has become increasingly important as strict standards for insect infestation have
recently been enacted.
Fortunately, winters in Colorado are sufficiently cold to prevent serious losses during the
first storage season. Further losses can be prevented if the proper precautions are taken
when storing grain. These may include:
1. Keep storage bins and grain handling equipment clean;
2. Maintain the storage area in good repair;
3. Use residual sprays on bin surfaces after cleaning and before storing new grain;
4. Store clean, dry grain only;
5. Properly aerate the grain to maintain uniform temperatures and prevent conden
sation;
6. Use grain protectants as the grain is being moved into storage;
7. Inspect grain regularly to detect developing infestations.
When insect problems are detected, the following alternative methods may be considered:
1. Grain can be removed and retreated with a protectant insecticide.
2. When the grain is removed during very cold periods, some insects may also be
killed by the handling and temperature.
3. Infested grain may also be fed to livestock.
4. A final option is to fumigate the grain.
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54
Grain fumigation involves the use of highly toxic gases. Fumigation of stored grain requires
the use of specialized equipment (discussed later) and special protective measures for the appli-
cator. All entrances of grain storages being fumigated must be placarded. Furthermore, fumigated
grain must be aerated and handled carefully to insure dispersal of residues. It is safer and often
easier to allow fumigation professionals to do the job rather than attempting on-farm fumigation.
Summary Chapter VI
Troublesome weeds in Colorado crop and rangelands are Canada Thistle. Leafy Spurge,
Jointed Goatgrass, Musk Thistle and Larkspurs.
Fungal and bacterial diseases do serious damage to com, wheat, vegetable and fruit crops.
Russian Wheat Aphid. Potato PsyMd, Alfalfa Weevil, Two Spotted Spider Mite and Coddling
Moth all can reduce agricultural production in Colorado.
Managing Colorado's most troublesome pests involves the use of mechanical, cultural and
chemical controls, in a coordinated effort known as Integrated Pest Management.
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Chapter VII
APPLICATION EQUIPMENT
The successful application of pesticides depends on use of appropriate equipment and its
careful maintenance. The amount of pesticide applied, how efficiently it controls the pest species,
and the safety of its use to both the environment and applicator all depend on the equipment.
There is a wide variety of equipment available, each with advantages and limitations for the
particular situation. It is important to choose the equipment best suited to the use.
SPRAYERS
Tanks Tanks used to apply pesticides should be constructed with materials that resist
corrosion. Fiberglass and stainless steel resist corrosion caused by most chemicals,
as do plastic coatings; however, durability of these materials is reduced if cracks or chips in
the coating develop and expose the base metal to corrosive forces. Untreated metal can be
used for applying non-corrosive pesticide solutions but precautions should be taken to
prevent rust and scale. All tanks should be constructed to prevent leaking and rupture.
Regardless of their construction, sprayer tanks should be of a design that allows for ease in
inspection, filling, and cleaning. A drain plug should be located at the bottom to permit
complete drainage when cleaning.
Agitators Sprayer systems should include adequate agitation in the sprayer tank to provide
uniform mixing of the pesticide during application. Proper agitation is particularly
important when wettable powder formulations are used or they will settle to the bottom.
There are various agitation systems: By-pass agitation involves pumping excess spray
material back into the tank under pressure. This system is good for stirring solutions and
emulsions, but may not adequately mix wettable powders. Mechanical agitation uses
paddles or other devices to mechanically agitate the spray solution. Mechanical agitators
provide excellent mixing but are expensive and difficult to maintain. Jet agitation uses
liquids from the sprayer's pressure system. The line to the agitator in this system should be
connected between the pump and any cut-off valves so that agitation continues when
spraying has stopped.
Pumps Any pump used to apply pesticides must supply the spray volumes at the pressures
required for application. The selection of a pump is usually influenced by cost and
durability for the intended use.
Piston pumps are among those most commonly used for applying agricultural chemicals.
These are positive displacement pumps that can be used for both corrosive and abrasive
materials. The two types of piston pumps are for different application purposes: high
pressure-low volume-high speed, and low pressure-high volume-low speed applications.
Roller or roller impeller pumps are also used in many agricultural spray systems. These
pumps are adaptable to a wide range of pressures, volumes, and materials. They are accu-
rate in the amount of spray material applied because they maintain constant pressure and
flow.
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56
Centrifugal pumps are designed for use with abrasive and coarse materials. Pumping action
is achieved by use of a high speed impeller that throws the material out of the pump.
These pumps are used to spray high volumes, but the maximum spraying pressures are
limited to 50-60 pounds per square inch (psi).
Gear pumps are semi-positive pumps that develop uniform, moderate pressures but output
volume is limited. They cannot be used with abrasive materials.
Nozzles Nozzles should be chosen to give the proper particle size, spray pattern, and
application rate for the pressures used during application. Each nozzle is rated as to
the amount of fluid that will be applied at a specified pressure and ground speed. Nozzles
also are rated by the angle at which the sprayed material is discharged.
Nozzles are generally classified as to the pattern of spray they deliver. The more common
types of nozzles are:
1. The flat spray nozzle produces a rather coarse spray in a fan-shaped pattern.
Even coverage is achieved when spray areas overlap in boom sprayer applications.
Flat-spray nozzles are suitable for most insect and weed control applications where
penetration of the foliage is not necessary. A wide angle nozzle with a flat spray
pattern can be operated close to the ground to minimize drift.
2. Even spray nozzles apply a more uniform spray than flat spray nozzles. Even
spray nozzles are useful for band applications where there is no overlap of spray
patterns from different nozzles.
3. Solid and hollow cone nozzles produce a sheet of spray in a cone shape. These
nozzles are frequently used for insect or disease control because the spray pattern
penetrates foliage well and from many directions.
4. The flooding jet nozzle is most commonly used to apply herbicides. It uses a
fairly wide opening which can help reduce wear from abrasive materials such as
wettable powder formulations. This type of nozzle also operates at a low pressure,
reducing the amount of drift.
Hollow Cone
Flooding Flat Fan
(Front)
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57
Nozzle Nozzles are constructed from many different materials, each with different
Construction characteristics in terms of resistance to corrosion, abrasion, or reaction
with spray mixtures. Selection of nozzle types should be made by balancing the character-
istics of the construction materials against the cost of the different nozzles.
For example, brass nozzles are relatively inexpensive but wear quickly if exposed to abra-
sive materials. Aluminum nozzles resist corrosion by some pesticide spray mixtures but are
readily corroded by some fertilizers. Stainless steel nozzles will not readily corrode and
resist abrasion but cost substantially more than brass nozzles. Plastic nozzles may resist
both corrosion and abrasion but may swell when exposed to certain solvents in pesticide
formulations. Tungsten carbide and ceramic nozzles are most highly resistant to abrasion
and corrosion but are usually the most expensive.
Strainers Strainers or screens are placed at various points in the sprayer system to exclude
foreign material that would wear out precision parts or clog the system. Screens are
normally placed at the entrance to the pump intake line, in the line from the pressure
regulator to the boom, and in each nozzle. Usually 25- to 50- mesh screens are used in the
intake hose, 50- to 100- mesh screens in the boom supply, and screens the size of the
nozzle tip opening for the nozzle. For spraying wettable powders, all screens should be 50-
mesh or coarser to prevent clogging.
Pressure The pressure regulator, or relief valve, maintains regulator required pressure in the
Regulator system. This is a spring loaded valve that opens to prevent excess pressure in the
line and allows some of the solution to return to the tank. Most pressure regulators are
adjustable to permit changes in the working pressure of the system.
Types of Low-pressure sprayers are normally designed to deliver low to moderate volumes at
Sprayers 15-80 pounds of pressure per square inch (psi). Application is usually made through
a boom equipped with nozzles. Low-pressure sprayers are used primarily for weed and
insect control on row crops, pasture, and forage lands where pressures of 80 psi provide
sufficient crop coverage. Low-pressure sprayers are also used to apply liquid fertilizers or
fertilizer-pesticide mixtures.
Low-pressure sprayers requiring low flow rates often are equipped with roller-impeller
pumps. Centrifugal pumps are generally required where high flow rates are needed and
when agitation of the spray mixture is required.
High-pressure sprayers are designed to deliver large volumes at high pressure. They are
often similar to low-pressure sprayer systems but have a piston pump which can deliver
high volume {up to 50 gallons/minute) at high pressure (up to 800 psi). Application rates of
high-pressure systems are typically 200-600 gallons per acre. Sprays are usually applied
with either a boom or a handgun. All components of a high pressure system must be
designed and selected to withstand the high pressures.
High pressure systems are used primarily on fruit crops, vegetables, and trees for insect and
disease control. High pressure systems may also be designed for washing equipment.
Air-blast sprayers use a blast of air, instead of large volumes of water, to propel the spray
mixture. Nozzles deliver the spray into a high-velocity airstream generated by a powerful
fan which breaks the spray into fine droplets. Air-blast sprayers are typically used on fruit
trees, shade trees and for fly or mosquito control.
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Air-blast sprayers provide good coverage of foliage, are lighter weight, use lower pressures,
and are easier to operate than high-pressure sprayers. However, they are often expensive
and produce fine particle sprays which drift readily. Because of this drift potential, use of
these sprayers is more limited by weather conditions. Since relatively low water volumes
are used, calibration is particularly critical with air-blast sprayers.
Special air-blast sprayers which have higher air velocities (120-200 mph) and lower air
volumes are known as mist blower*. These sprayers produce a very fine spray.
Small-capacity sprayers are designed for spot treatments, home and garden pest control,
small tree and nursery spraying, and for restricted areas unsuitable for larger units. Most
are hand sprayers which use compressed air to pressurize the supply tank, forcing the air
through a nozzle. Several types of small power sprayers are available that deliver 1 -3
gallons per minute at pressures up to 300 psi; adjustable handguns are usually used with
these units, but spray booms are available on some models. Small-capacity sprayers are
relatively inexpensive, simple to operate and maneuver, and easy to clean and store.
Adequate agitation and screening for wettable powders, however, is necessary. Since there
is a direct reliance on the operator for movement across the treated area, there can be
substantial variability in application rates.
Maintaining Proper maintenance of sprayer equipment is essential to its proper performance.
Sprayer Several steps are involved in maintaining sprayers:
Equipment
1. Use only clean water during application and cleaning.
2. Keep proper screens in place.
3. Never use a metal object for cleaning nozzles.
4. Do not lock a pump solidly to a tractor.
5. Lubricate the pump properly and fill with antifreeze or a light oil when not in use.
6. Flush a new sprayer before use.
7. Clean sprayers thoroughly after each use, when changing chemicals, or before
storage. After using potent herbicides, such as 2,4-D, more extensive cleaning
procedures are required to prevent possible crop injury from residue in the tank
during subsequent applications of different pesticides. These are:
a. Remove and clean all screens and nozzles with kerosene;
b. Pump kerosene or fuel oil through the sprayer;
c. Circulate a cleaning solution (1 lb detergent in 40 gal of water) through the
bypass for 30 min. Flush part through the sprayer. Empty the remainder;
d. Fill the tank with water and ammonia (1 quart ammonia per 25 gallons of
water). Pump enough to fill the hoses and nozzles, then leave for 24 hours.
e. Empty the sprayer and rinse with clean water.
8. For extended periods of storage, exposed metal parts should be coated with a
light oil to prevent rusting.
GRANULAR APPLICATORS
Granular applicators are designed primarily for soil applications. They range from crank-
operated, spinning disc backpack units which broadcast granules, to field equipment
designed for broadcast, band or drill applications of granular pesticides. Granules are
normally applied before or at planting and worked into the soil. Post-plant side dress
applications made during cultivation through drop tubes and fertilizer shoes are another
common method of granular application. Granules are also applied by air, such as for
control of first generation European corn borer, which develops within whorl leaves of corn.
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Construction Most granular applicators consist of a hopper for the pesticide, with a mechanical-
type agitator at its base to provide efficient and continuous feeding. Some type of
metering device, usually a slit-type gate, is used to regulate the flow of the granules.
Metering devices typically consist of a dial with a set-screw, or an adjustable lever with a
large dial. The granules flow out with gravity feed.
Spreader Drop-through spreaders attached to the ends of drop tubes are available in relatively
narrow widths (1 1/2-3 feet). On band applicators, the height of the spreader also
can be used to change the width of the band. Rotary spreaders, which distribute the
granules to the front and sides of the spreader, can be used to cover a wider swath.
In selecting a granular applicator, choose a unit that is easy to clean and fill. Be certain
that it has good agitation over the outlet holes. Banders should spread the granules
uniformly, even on side slopes of 10-15%. Chain drives should have sprockets of eight or
more teeth to keep drive speed uniform. Design should be so that granule flow stops when
the drive stops, even if outlets are not closed.
Maintenance Granular applicators should be cleaned thoroughly after each job. Corrosion on
feeder plates or the agitator can be removed with a wire brush. All fasteners should
be checked regularly. Equipment should be lubricated in accordance with manufacturer
specifications.
CHEMIGATION SYSTEMS
The application of both water and agricultural chemicals through irrigation systems is called
chemigation. As with other methods of applying agricultural chemicals, there are both benefits and
risks associated with chemigation. The most significant risk is potential contamination of the water
supply; therefore, to minimize risks, an irrigation system used to apply agricultural chemicals must
be properly equipped and operated. Equipment required to apply chemicals through an irrigation
system includes:
a chemical supply tank with agitator
an injection pump
a calibration tube
proper safety and anti-pollution devices
to prevent potential contamination of
the water source.
Cheek valve
(anti-
backflow
valve)
Irrigation
pipeline
Electric motor
yr fepump
Discharge
line
Chemical
tank
Suction line
¦trainer
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Chemical The supply tank should be constructed of noncorrosive materials such as stainless
Suppiy steel, fiberglass, nylon, or polyethylene. Agitation should be provided to allow mix-
Tank ing of wettable powder, dry flowable, and flowable formulations and when tank
mixes or other suspended formulations are used. For hard-to-mix formulations, mechanical
agitators are needed.
Since some agricultural chemicals are flammable, the supply tank should be separated from
any source of sparks or potential explosions. This includes use of explosion-proof electric
motors and wiring, or placing electrical motors far from the supply tank. Wiring must
conform with the National Electrical Code for hazardous area applications.
Pumps The proper functioning of the chemical injection pumn is critical to performance of
any chemigation system. Throughout the operating range of the pump, an accuracy
of delivery plus or minus one percent is desirable. The pump should be easily adjustable for
different injection rates. Mechanical design should be rugged and construction of non-
corrosive materials.
The injection pump capacity should be consistent with pesticide/fertilizer application rates.
This can range from 1 pint or less/acre for certain insecticides and herbicides to 30
gallon/acre for liquid fertilizer applications. With such a range, no single pump can be used
for all jobs. The most efficient and consistent operation of a pump is in the broad middle
capacities. Avoid operating a pump at or near the maximum output to avoid damage to the
pump and inaccurate pumping rates. Several types of pumps are available for chemigation.
Diaphragm pumps, although often more expensive than other pumps, have some important
advantages in use and maintenance. These include: 1) a small number of moving parts; 2)
a limited area of exposure of pump components to the injected chemicals; and 3) design
which allows for easy adjustment of injection rate.
Piston pumps were among the first used in chemigation systems. Calibration of these units
requires that stroke length be adjusted mechanically, often while the pump is stopped. As
such, calibration of equipment can take more time than with diaphragm pumps. Piston
pump seals may also wear faster, increasing risks of leakage and requiring more mainte-
nance. There are, however, various designs of piston pumps, some of which help limit
these problems.
The relatively low cost venturi "pumps" draw the chemical by creating differential pressure
or vacuum across a venturi device. It may be difficult to obtain accurate and consistent
chemical injection rates with a venturi device. Variation in the flow rate of the chemical can
cause pressures to vary, altering the rate of chemical injection.
CaKbration A calibration tube should be located in the line between the supply tank and the
Tuba chemical injection pump. It is used to measure output of the injection unit during
calibration. The calibration tube should be clear, resistant to breakage, and graduated in
units of volume (pints, ounces, milliliters, etc.). To properly calibrate an injection system, it
is necessary to monitor chemical injection for at least five minutes. Calibration tubes must
be large enough to hold the amounts of chemical injected over that time.
Safety Irrigation line check valves and vacuum relief valvan are required in irrigation
Devices pipelines. They keep the chemical-water mixture from draining or siphoning back
into the water supply. Both of these valves need to be located between the injection site
and the discharge site.
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The check valve must have a positive closing action and water-tight seal, and be easy to
repair and maintain. The vacuum relief valve allows air into the pipeline when the water
flow stops, preventing back-siphoning of the chemical-water mixture into the water source.
This back-flow prevention system must meet regulatory requirements. The valves should
also be inspected before each chemigation operation. Other safety equipment includes:
an inspection port to permit visual inspection of the check valve for leaks;
a low-pressure drain located at the lowest point of the irrigation pipeline to allow the
chemical solution to drain away from the water-source(well) in stances (?) where the main-
line check valve leaks slowly;
one-wav interlockino between the irrigation pump and injection pump to ensure that the
injection pump will stop with the irrigation pump;
a chemical injection ]jQ£ check valve with a minimum opening (cracking) pressure of 10 psi
to prevent flow of liquids into the supply tank, or from the supply tank into the irrigation
line during unexpected shut-down;
a solenoid valve, normally closed, that provides a positive shutoff of chemical in the
injection line if the chemical injection pump is stopped;
a chemical suction Uqs strainer placed on the inlet end of the chemical suction line to
prevent clogging of the injection pump, check valve, or other equipment.
fumigation of stored grain
Fumigation of stored grain is a highly specialized pest control practice. Because fumigants
are extremmely hazardous, special precautions must be taken for their application. Furthermore, a
thorough understanding of fumigation is critical to effective pest control. It is usually safer and less
expensive as well as more effective to hire a professional fumigator.
Safety Two people should always work together when fumigating. Never fumigate nor enter a
fumigated storage alone.
Proper safety equipment is essential. A self-contained breathing apparatus must be used.
These are expensive (typically $1500 or more) and require special training for use. How-
ever, simpler chemical cartridge-type gas masks do not provide adequate protection when
high concentrations of toxic gases exist.
Mark the treated area with warning signs at ail entrances. The signs should be in place
during the fumigation and remain there until the stored grain has been thoroughly aerated to
reduce the fumigant to safe levels. Do not enter a fumigated storage until it has been
aerated, and be sure aeration equipment is operating during any inspection of a fumigated
grain storage facility.
Temperature Grain temperature is extremely important to the effectiveness of fumigation because
it determines the speed with which a fumigant vaporizes and pentrates through the
grain. Low grain temperatures (less than 50 degrees F.) greatly slow the vaporization rate
and movement of lethal gas concentrations to the pest insects. Insect activity is also
decreased during low temperatures, resulting in reduced kill. Longer time is required for
fumigating when the temperature is cool.
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Moisture Atmospheric moisture is used to release the phosgene gas from aluminum and
magnesium phosphide tablets; however, high moisture grain retards the movement
of the fumigant. High moisture grain also absorbs more fumigant than dry grain, reducing
the concentrations in the air around the kernals. Non-uniform gas concentrations can
caused reduced effectiveness.
Dockage Dockage (trash) in grain is very important in determining the effectivenss of
fumigation. The ability of the grain mass to absorb the fumigant will increase with
the amount of dockage. As grain is loaded into bins, the light dockage (chaff, dust, etc.)
settles around the outside of the grain mass and the heavier dockage around the spoutline
area. This uneven distribution causes fumigants to flow through areas of least resistance. In
addition, insects often concentrate in areas of high dockage and therefore escape the
effects of the fumigant.
Storage The shape and depth of the grain in a bin affects how well the fumigant works.
Upright storages present a minimum of grain surface from which the fumigant can
escape. Peaks in the top of the grain surface often have lower concentrations of gas
allowing insects to escape; therefore, grain should be leveled before fumigation. Also,
remove or break up any crust that has formed on the grain surface.
Fumigated storage bins must be tightly sealed to allow concentrations of the gas to build up
and persist. Use of a gas-tight cover over the grain can improve fumigant performance,
particularly when a bin is only partially filled.
Vmnutation Fumigants are heavier than air and sink down through the grain. Penetration
through the entire grain mass, especially in deep bins, can be improved by using
aeration. However, during the actual fumigation, the aeration system should be sealed off.
Aeration should also be used to remove the fumigant after the recommended exposure
time.
Summary Chapter VII
Equipment to apply pesticides includes sprayers of various kinds, granular applicators,
chemigation equipment and fumigation equipment.
Equipment should be exclusive to the type of pesticides applied. Herbicides should not be
applied using equipment previously used for insecticides, for example. Contamination of
one by the other can do serious damage.
Meticulous maintenance of equipment it critical to effective use of pesticides.
Fumigation of stored grain is hazardous and should never be attempted by one person
alone.
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Chapter VIII
CALIBRATING APPLICATION EQUIPMENT
Proper calibration of application equipment is essential to proper pesticide performance.
Inadequate amounts of a pesticide may not control the target pest; too much pesticide can cause
plant injury or excessive residues on the crop, contribute to environmental contamination, and cost
money.
The objective of calibration is to apply the correct amount of pesticide. Calibration is
relatively simple but takes time, some equipment, and accurate calculations. Because conditions at
worksites vary and application system performance changes as a result of use, calibration should
be done regularly. It is also necessary to recalculate whenever any components of application
equipment are replaced.
CALIBRATING The application rate of pesticide mixtures used in field sprayers (including air blast
FIELD sprayers) is usually given in gallons per acre (GPA). The speed at which the sprayer
SPRAYERS moves over the ground is given in miles per hour (MPH), the output of nozzles is
listed in gallons per minute (GPM), and the pressure is given in pounds per square
inch (psi). Ground speed, pressure, and nozzle size can all be varied to change the
application rate.
www b CAPACITY CHART
Tip no. pfm. In PSI Cap. In OPM G»Mon» pw «cr»
3
4
5
7.5
10
mph
mph
mph
mph
mph
28
21
16.8
11.2
8.4
31
24
18.7
12.5
9.4
34
•26
21
13.7
10.3
40
44
30
24
15.8
11.9
33
27
17.7
13.3
49
36
29
19.4
14.5
20 .28 43
8004 26 .32 47
(*26 GPA) 30 .35 81
ISO Math) 40 .40 59
50 .45 66
60 .49 73
Method 1. The easiest method of calibrating the sprayer is to run it across a known
area of the field or orchard to be sprayed and to measure the sprayer
output. The steps are:
1. Determine the distance the sprayer must travel to cover one acre. This is
accomplished by dividing the spraying width (in feet) into 43,560 (the
square feet in an acre). For example, a sprayer with a boom that is set to
apply spray to a 20 foot swath would travel 2178 feet to cover an acre
(43,560/20 = 2178).
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64
2. Mark off this distance in the field to be sprayed. (Note: a fraction of this
distance may be used to equal a fractional part of an acre.)
3. Prepare the sprayer and set the pressure to the level that will be used
during spraying.
4. Fill the tank with a measurable amount of water.
5. Select a ground speed that will be used during spraying and not the
throttle setting so that it can be duplicated.
6. Spray over the marked course. Be precise in turning the sprayer on and
off at the start and end of the course. Maintain a uniform speed.
7. Measure the amount of water that has been applied. This may be done
by measuring the amount remaining in the tank or by determining the
amount of water needed to refill the tank to the original level.
If a shorter (or longer) course was used representing a fraction (or multiple) of an
acre, determine the refill amount in the same proportion.
If an oil solution is to be applied, and water was used during calibration, add 10%
to the measured volume.
Method 2. Calibration of sprayers can also be determined by measuring the various
factors involved in application rates. These include:
- gallons per minute (GPM) discharge from each nozzle;
- ground speed (MPH) of the sprayer during application;
- nozzle spacing on the boom (in inches).
With these factors, application rates can then be determined using the formula:
5940 X Gallons per minute
Gallons per acre =
MMes par hour X Nozzle spacing (inches)
Where width of spray coverage by the boom is known this formula can be modified as:
49S X Gallons per minute
Gallons per acre =
Miles par hour X Total width sprayed (feat)
Discharge from nozzles can be determined by measuring the amount of liquid sprayed from
nozzles during a known period of time. Fill the sprayer with water and set the sprayer
pressure at the level to be used in field application. Place a collection container under the
nozzle. The number of cupfuls of liquid collected in 3 3/4 minutes is equivalent to the
gallons par hour (GPH) output of the nozzle.
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65
All nozzles should be checked during this calibration to make sure they are discharging the
same rates of liquid. Where there are substantial deviations in nozzle output (greater than
5%), they should be checked for wear and replaced as needed. Inconsistent output will
cause streaks in application pattern.
Ground speed (MPH) determinations can be made by running the sprayer along a course of
known distance and using the formula:
Distance traveled in feet
Miles per hour (MPH) =
1.47 X Seconds required to travel distance
Changing sprayer pressure is oqi a good means of changing sprayer output because sprayer
output only increases as the square root of the pressure increase. For example, doubling the
sprayer pressure would only result in increasing output 1.4 times. Furthermore, increased
sprayer pressures may cause increased drift.
CALIBRATING Several factors affect application rates of granular applicators. No applicator
GRANULAR units are identical, and even seemingly minor differences can affect
APPLICATORS application rates. Wear of granular applicators can be substantial because
many of the products are abrasive. Furthermore, each pesticide and each
formulation of the pesticide has different flow characteristics which affect application rates.
Although manufacturers may provide guidelines for typical applicator settings, it is impor-
tant to check these settings by calibration.
Recommended granular application rates for formulated pesticides are expressed in pounds
per acre or ounces per thousand row feet. Herbicide and insecticide calibrations may differ
slightly. Herbicides are typically applied at a constant rate per unit area (acre), so band
width is critical to proper calibration. Most granular insecticides used at planting in Colorado
are applied at a constant rate per length of row (dz/1000 row-ft).
To calibrate a granular applicator:
1. Set each applicator at the setting suggested by the manufacturer or at the
setting determined by previous calibrations;
2. Fill the hoppers at least 1/2 full and run them until they all begin to feed;
3. Remove the feed tubes and attach a container, calibration bag, or premarked
calibration tube to each hopper output unit;
4. Travel a measured distance at planting speed. Since ground speed and field
conditions can substantially affect granular application rates, it is recom-
mended that calibration be conducted in a worked field over a considerable dis-
tance;
5. Weigh and record the amount of pesticide collected in each container using an
accurate scale. (Remember to subtract empty container weight.);
6. Calculate the application rate for each row.
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The application rate is determined by various formulae. Insecticides, applied at rates
indicated by ounces per 1000 row-feet, are calculated by:
1000 X ounces collected
= ounces/1000 row-feet
distance traveled (feet)
Where labelled insecticide application rates are given as pounds per acre, this formula
changes to:
43560 X pounds collected
= pounds/Acre
distance traveled (feet) X row width (feet)
Granular herbicides are often applied as bands over the row. Where labelled application
rates are expressed as ounces per 1000 row-ft the formula used is:
1000 X ounces collected
= oz/1000 row-feet
distance traveled (feat) X band width (feet)
Herbicide application rates indicated by pounds of formulation per acre use the formula:
43560 X pounds collected
= lbs/A
distance traveled (feet) X row width (feet) X band width (feat)
If the application rate of any unit is not within 5% of the recommended rata, adiust the rate
setting gauge and repeat the calibration.
To roughly check an application rate, place a vertical strip of tape in each hopper. Fill the
hopper one pound at a time. After each pound is added, level the pesticide by shaking the
hopper and mark the new level. Using this method, the application rate can be checked
quickly by reading the level before and after treating a known acreage.
HANDGUN AND Handgun and knapsack spraying equipment, such as that used in green-
KNAPSACK house operations, are difficult to calibrate because "ground speed" is
SPRAYERS difficult to judge. One method is to calculate the time it takes to cover a
measured area. By timing the spray, gallons-per-hour (GPH) can be determined. As with
other sprayers, gallons-per-hour can be determined by collecting the liquid from the nozzle
for 3 3/4 minutes. The number of cupfuls collected in this time equals the gallons per hour
(GPH) output of the sprayer.
With this information, the formula to determine
1.38 X Gallons per Acre
minutes needed to cover 1,000 square feet =
Gallons per Hour
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CALIBRATING CHEMIGATION SYSTEMS:
Calibration of sprinkler chemigation equipment involves 5 basic steps:
1. determine the area (in acres) to be irrigated;
2. determine the amount of material desired per acre;
3. determine the total amount of material required for application (step 1 X step 2);
4. determine the time (in hours) that injection will require;
5. determine the injection rate in gallons per hour (step 3/step 4).
The calibration process is based on the measurements of the irrigation system (length, end
gun wetting area, etc.), some common mathematical constants and conversions, and the
desired rate of chemical injection. The following calculations must be made: a) area
irrigated; b) amount of chemical required; c) travel speed; d) revolution time; and e)
chemical application rate.
The area irrigated is calculated with one of several formulas, depending on the shape of the
field. Where fields are square or rectangular in form the area is simply determined by:
length (feet) X width (feat)
. = area (acres)
43,560 (square feet/acre)
Where a complete circle is involved, as with center pivot irrigation systems, the calculation
for determining area is:
3.1416 (pi) X radius (feat) X radius (faet)
= area (acres)
43,560
Determining the area irrigated becomes increasingly more complex with partial circles, and
other irregular areas. In many situations involving center pivot equipment, it may be wise to
leave off the end gun during chemigation and when making calibration estimations. Water
patterns from end guns are easily distorted by wind, and end guns may cause off-target
applications.
The amount of chemical to use per acre is indicated on product labels. By multiplying this
figure by the number of acres, the amount of chemical required for the chemigation
operation is determined.
For moving systems, travel speed is critical to calibration. When calculating the irrigation
system speed, the system should be running "wet" and at the speed and pressure that will
be used while chemigating. Two measurements, time and distance are required to
determine travel speed. These can be made in either of two ways:
a) record the time it takes for the outer pivot tower to travel a premeasured
distance (minimum of 50 feet); or
b) measure the distance traveled by the outer pivot tower in a preselected time
(minimum 10 minutes).
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The result of either method is a rotational travel spaed measurement in feet per minute. A
measurement error of only a few feet or few minutes can create a significant error in the
entire calibration process. If the terrain is rolling, check rotational travel speed at several
locations and determine an average value.
Rotational speed should be checked periodically throughout the season to account for
differences in wheel track resistance due to cover, soil compaction, track depth, etc.
Always recalibrate when changing speed settings.
In center pivot systems, revolution time must be calculated. This is done by measuring
rotational travel speed (above) and circumference of the last wheel track. Circumference is
calculated by the formula:
Circumference (feat) = 2 X 3.1416 (pi) X radius (feet).
Revolution time is calculated by dividing the circumference (in feet) by the rate of travel
(feet per minute).
The chemical application rate (gaRons per hour-GPH), is the amount of chemical to be
applied per hour of chemigation. This amount is calculated by determining the total amount
of pesticide to be applied to the field (amount of pesticide applied per acre X number of
acres). Divide this figure by the number of hours required to complete a full revolution of a
center pivot irrigation system.
Example of calibration measurement - canter pivot chemigalion-
The field to be chemigated has a wetted radius (length of pivot) of 1300 feet. (Note: A
decision must be made whether chemigation is going to include the end gun throw distance
or to shut-off the end gun during application). The area would be equivalent to:
3.1416 X 1300 X 1300
= 122 acres
43,560
The pesticide is to be applied at the rate of 1 quart/acre. The total amount of chemical
required for the chemigation will be:
122 (acres) X 1 quart (use rate/acre) *= 122 quarts (30.5 gallons)
Measurements to determine the travel speed indicate that the outer pivot tower moved 130
feet during 20 minutes. The travel speed is
130 (feet)
= 6.5 feet/minute
20 (minutes)
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To determine revolution time, a calculation first has to be made to determine the circumfer-
ence travelled by the last wheel track. Assuming the radius of the last wheel track to the
tower is 1280 feet (does not include overhang), the circumference is:
2 X 3.1416 X 1280 = 8042 feet.
The revolution time is then determined by:
8042 (feet)
= 1247 minutes per revolution (20.6 hours/revolution)
6.5 feet/minute
The chemical application rate would thus be:
30.5 gallons (amount of pesticide for field application)
____ = 1.48 gallons/hour
20.6 hours (revolution time)
The use of the calibration tube is now needed to determine at what injection pump setting
this amount of chemical is being applied. By setting the pump at this setting, the calibra-
tion is completed.
Summary Chapter VIII
Accurate calibration of application equipment is critical to economical and affective pest
control.
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Chapter IX
PROTECTIVE EQUIPMENT
Because pesticides can enter your body through various routes it is necessary to wear
protective clothing and/or use protective equipment to prevent exposure. No safety recommenda-
tions cover all situations; use common sense and remember that more protective measures are
called for as the hazard increases. Always read and follow the pesticide label for directions on use
of protective clothing or devices.
Gloves The most common location on the body for pesticide exposure is the hands.
Therefore, the single most important protective equipment for most pesticide applications is
a pair of protective gloves. Use of liquidproof gloves (such as rubber or neoprene) when
handling pesticides or contaminated equipment greatly reduces the likelihood of pesticide
exposure. Qfil use gloves with fabric linings because pesticides cannot easily be
removed from fabrics. Never use cotton or leather gloves when handling liquid formulations
or when working with pesticides diluted with water because these materials absorb
pesticides and do not provide adequate protection. Some granular pesticides may be
handled with cotton gloves, if the gloves are washed or discarded after every use. Always
COPWlt Ibfi Pesticide label for directions on protective clothing.
Always wear your shirt sleeves outside the gloves to prevent pesticides from getting into
the gloves. Gloves used to handle pesticides should never be used for other purposes.
Boots Wear lightweight rubber boots when handling or spraying pesticides. Do not use
leather or canvas footgear since they absorb and retain pesticides. Do not tuck pants legs
into boots since that may funnel pesticide sprays or chemicals into the boot.
Covering Shield yourself with some form of protective body covering. Wear a long sleeved
shirt and long legged trousers or a coverall type garment of closely woven fabric. An outer
layer of spunbonded olefin or fabric with a soil-repellent finish offers more protection than
durable press or untreated fabrics. Soil-repellent finishes can be applied by clothing
manufacturers or by consumers. Alternatively, use a disposable suit designed for protection
when handling hazardous materials. A second layer of clothing, made with smooth T-shirt
fabric, can further help to prevent pesticides from touching the skin. Wettable powder
formulations of pesticides are easier to keep off the skin than liquid formulations.
Wear pants legs outside your boots to prevent pesticides from getting inside. When
handling pesticide concentrates or highly toxic chemicals, also wear a lightweight raincoat
or rubber apron for added protection.
When applying pesticides use a wide-brimmed, waterproof hat to protect your neck as well
as your eyes, mouth, and face. The hat should not have a cloth or leather sweatband,
since these materials retain pesticide residues and are difficult to clean.
Eye Protection Many pesticides are highly corrosive to eyes, and eyes readily absorb pesticides
into the body. Wear goggles or a face shield when there is risk of pesticides coming
in contact with eyes during mixing or application. Goggles may be worn separately or in
combination with a respirator.
Respirators Respiratory protection is essential in some pesticide handling situations since the
lungs readily absorb pesticides, and inhalation risks are high when handling highly
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toxic pesticides with volatile fumes or fumigants. Always follow the instructions on the
pesticide label regarding use of respiratory protection equipment. It is vital that the
appropriate equipment be used for the particular product and its application. It is also
essential that the respirator fit your face properly to insure a good seal. Long sideburns, a
beard, or glasses may prevent an adequate seal.
Chemical cartridge respirators draw air through activated charcoal or a dust filter. Most
harmful gases, vapors, and particulate matter are removed by the filter. This type of
respirator is lightweight and easy to use but does not provide eye and face protection.
Chemical cartridge respirators are not suitable protection where toxic fumigants are being
used, such as in grain storages.
Gas mask respirators cover and protect the entire face. They contain larger filters with more
absorbent material than do chemical cartridge respirators. Gas mask respirators should be
used when mixing or applying pesticides in poorly ventilated areas. Neither gas mask nor
chemical cartridge respirators give sufficient protection in low-oxygen environments.
Gas mask respirators which have a self-contained oxygen supply should be used where the
application site is deficient in oxygen or where high concentrations of toxic gases are
present (such as fumigants).
Wearing a respirator does not eliminate the need for protecting other parts of the bodyl
Respirator Respirators should be inspected regularly for defects, cleaned and disinfected,
Maintenance repaired and stored in a clean dry place away from pesticides or other contami-
nants. An inspection check includes: tightness of connections and condition of the face
piece, head bands, valves, connecting tube, and canister. Clean all respiratory devices after
each day's use. Prior to cleaning, remove any filter, cartridge, or canister. Wash the face
piece and breathing tube with warm soapy water and rinse with fresh water to remove all
f "N traces of soap; sanitize if necessary, and air dry in a clean place away from possible
v - J\ pesticide contamination.
When using a respirator, change the cloth filter twice a day, or more
often if breathing becomes difficult. Change the cartridges after
eight hours of actual use, or more often if an odor of pesticide is
detected.
Periodically, test the fit of a respirator by removing the cartridges
and blocking the intake while wearing the respirator.
Several factors affect the service life of respiratory protective devic-
es. These include: the type and amount of chemical fill in a cartridge
or canister, the concentration of the contaminants in the air, the
breathing rate of the wearer, and the temperature and humidity. It is
essential to read carefully the manufacturer's instructions on use and
maintenance of any respirator and its parts before using it. Use
respirators approved by either the National Institute of Occupational
Safety and Health, the U.S. Bureau of Mines, or the U.S. Depart-
ment of Agriculture.
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WASHING PESTICIDE-CONTAMINATED CLOTHES
Handling If liquid concentrates of pesticides are spilled on clothing, other than rubber
Clothing or neoprene gloves and unlined boots, discard the clothing. Washing will not
remove enough of the pesticide to make the clothing safe to wear. Wear rubber gloves
when handling highly contaminated clothes. (Research has shown that clothing contaminat-
ed by undiluted pesticides can still contain high amounts of pesticides after 10 washings;
diluted pesticides were largely removed after 3 washings.)
Outdoors, empty any pesticide granules from cuffs and pockets. If left in clothing, granules
will dissolve in the wash water and may not be removed from the clothing in the remainder
of the wash cycle.
Keep clothing worn while applying pesticides separate from other clothing. Always wear
rubber gloves when handling the contaminated clothing.
Wash pesticide contaminated clothing immediately after use. The longer the clothing is
stored, the harder it is to remove pesticide residues.
Washing Prerinse or presoak the clothing in a bucket or tub or by agitating in a
Procedures washer and spinning out before running them through the regular wash
cycle. Prerinsing followed by a regular wash cycle has been found to be much more
effective in removing pesticides, especially wettable powders, than washing without
prerinsing.
Use hot water for washing, never cold. Cool water (86 degrees F) removes much less
pesticide than does warm (120 degrees F) or hot (140 degrees F) water. Heavy duty liquid
detergents should be used to wash pesticides from contaminated clothing. In hard water
areas, use higher rates of detergent to get adequate cleaning action. Pre-wash cleaners help
remove pesticides from clothing; however, ammonia and bleach do not. Wash a small
number of items at a time, using the highest water level and longest wash time available.
Do not drv clean clothing contaminated with pesticides. Dry cleaning solutions are
routinely recycled. Including pesticide contaminated clothing contaminates other clothes.
Laundry After washing clothes contaminated by pesticides, run the empty washing
Equipment machine through a complete cycle using detergent. Line dry pesticide
Care contaminated clothing to avoid contaminating the dryer.
Always wash clothing immediately after mixing and applying pesticidesi
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FIRST AID FOR PESTICIDE POISONING
Pesticide poisoning can result from exposure during handling or applying pesticides, from
spills, from accidental spraying, ingestion or inhalation, from misuse, or illegal residues on
commodities. Pesticide poisoning can also be the result of inadequate safety precautions. The
rapid and appropriate administration of first aid may save the life of a person exposed to pesticides.
Symptoms It is important to recognize symptoms of pesticide poisoning so that prompt
medical treatment can be administered before more serious injury occurs. Although
symptoms of pesticide poisoning vary, some typical symptoms of mild poisoning, or early
symptoms of acute poisoning, can include: headache, fatigue, weakness, dizziness,
restlessness, nervousness, perspiration, nausea, diarrhea, loss of appetite, thirst, soreness
in joints, skin irritation, eye irritation, or irritation of the nose and throat. More advanced
poisoning symptoms can involve: stomach cramps, nausea, diarrhea, trembling, reduced
muscle coordination, extreme weakness, mental confusion, blurred vision, difficulty in
breathing, rapid pulse, flushed or yellow skin, excessive perspiration, and weeping. WHEN
PESTICIDE POISONING IS SUSPECTED, SEEK IMMEDIATE MEDICAL ATTENTION!
First aid procedures may be followed while waiting for a physician or while transporting a
victim to medical facilities. The first action to take with any poisoning is to remove the
victim from the source of exposure. Then administer basic first aid procedures.
Inhalation If a pesticide has been inhaled, immediately move the victim to fresh air. When the
Exposure poisoning occurs in an enclosed space, such as a fumigated storage, DO NOT GO IN
WITHOUT AN AIR-SUPPLIED RESPIRATOR. Not using the proper equipment may
result in the rescuers being poisoned also. Loosen all the victim's tight clothing and keep
the victim as quiet as possible. Apply artificial respiration if breathing has stopped or is
irregular. If the patient is convulsing, watch the breathing and keep the chin up to keep the
air passage free. Prevent the victim from chilling by using blankets, but do not overheat.
Skin Exposure Where dermal (skin) exposure of pesticides occurs, immediately remove all
contaminated clothing. The victim should be drenched with water (shower, hose,
faucet, pond, etc.) and washed thoroughly with detergent or soap, then dried with a towel
and wrapped in a blanket for warmth while being transported to a doctor or medical facility.
Eye Exposure Damage to the eyes from exposure to pesticides can be very serious, especially if
corrosive pesticides are involved. It is critical to flush the eye out as quickly aa
possible with a gentle stream of running water. Continue washing the eye for 15 minutes
or more. Do not use chemicals or drugs in the rinse water since that may increase the
damage.
Ingestion If a person has swallowed pesticides, a decision has to be made whether to induce
vomiting. Where highly toxic pesticides are involved, vomiting is almost always the
better course of action. However, vomiting should never be induced in a person who is
unconscious or in convulsions. When corrosive poisons (strong acid or alkali) or petroleum
products (kerosene, emulsified pesticides, oil, etc.) are involved in the poisoning, first aid
decisions are more complex. Highly corrosive materials severely burn the mouth, throat,
and esophagous and vomiting will cause additional injury. These poisons should be treated
by attempting to neutralize the poison. Petroleum products also can cause burns.
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Ingested pesticides should be diluted or absorbed as quickly as possible. If the patient is
conscious, administer milk or water. Activated charcoal is very effective in absorbing many
poisons and can be mixed with water as a thick soup. A mixture of 4 tablespoons of toast
(burned black), two tablespoons of strong tea (instant ice tea will do), and two tablespoons
of milk of magnesia is a good home remedy. This mixture will not only absorb but also help
neutralize most poisons.
First-aid Kit A well equipped first-aid kit which is always readily available is important
in handling emergencies. One can be made easily and maintained in a lunch pail,
tool box, or sturdy wooden box. It should contain such items as:
1. a small plastic bottle of detergent to help wash pesticides off skin;
2. a small plastic container of salt to help induce vomiting;
3. a container of baking soda or a bottle of milk of magnesia to neutralize acidic
chemicals that have been swallowed;
4. a plastic bottle of lemon juice or vinegar to neutralize alkaline chemicals that
have been swallowed;
5. a small package of activated charcoal to act as a pesticide absorber;
6. a bottle (at least one pint) of dean watar;
7. bandages and tape to cover cuts and scrapes to keep pesticides out of the body;
8. a blanket;
9. a quarter to help place an emergency phone call;
10. a plastic jar to use as a drinking glass to induce vomiting or feed activated
charcoal;
11. a card with emergency phone numbers including doctor, hospital, and Poison
Control Center.
After administering first-aid to a poisoning victim, immediately seek medical attention.
Take the label of the pesticide to the doctor or medical facility to assist in treatment. When the the
poison is unkown, a sample of the vomit can help medical personnel determine the type of poison.
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Summary Chapter IX
Always raad and follow the pesticide label regarding protective clothing. Preventing
exposure can save your health and your life.
Keep protective clothing and equipment dean and in good repair, and easily accessible.
In the event of accidental exposure, remove the exposed person immediately from the
source of exposure.
In case of accident, always have a first aid kit immediately available with the essential
elements listed in this chapter.
Dispose of clothing that has been saturated with pesticides.
Always wash pesticide contaminated clothing separately with hot water and heavy
detergent and hang to dry outdoors.
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Chapter X
MINIMIZING PESTICIDE HAZARDS
WORKER PROTECTION
New rules for protecting agricultural workers from pesticide exposure were issued August
21, 1992. The new requirements for employers on farms, forests, nurseries and greenhouses are
designed to reduce the risks of illness or injury resulting from pesticide handlers' and agricultural
workers' occupational and accidental exposures during production operations.
The regulations apply to plant production and not to livestock, pasture/rangeland pesticide
uses or control of vertebrate pests or post-harvest applications.
The agricultural enterprise's owner and immediate family are exempt from the required
training, notification, decontamination, and emergency assistance provisions; however use of
personal protective equipment and observation of restricted-entry intervals do apply.
Employers are responsible for protecting their workers; they are barred from preventing or
discouraging any worker or handler from the benefits of the regulations.
An agricultural employer is one who hires or contracts for the services of agricultural
workers OR who owns or is responsible for the management and condition of an agricultural estab-
lishment that uses such workers.
A handler is one who mixes, loads, transfers or applies, pesticides, disposes of pesticides or
containers; flags; cleans, adjusts, handles or repairs contaminated equipment; assists with
application, any worker who enters any enclosed area after use of airborne pesticde before Permis-
sible Exposure Level or ventilation, who enters an area treated with a soil fumigant to adjust or
remove tarps; or who performs tasks as a crop advisor during application or restricted entry
interval.
A worker is one who performs other tasks related to production of agricultural plants in an
agricultural establishment.
There are specific worker protection requirements for all employees and additional ones for
"workers" and "handlers."
PROTECTION REQUIRED FOR ALL EMPLOYEES:
Centrally Located Information - a poster containing information specified in the EPA Worker
Protection Standards, the location of the nearest emergency medical facility, location of
pesticide applications on the property and the product name, EPA registration number and
active ingredient(s), time and date of application and restricted entry interval for the
pesticide. This must remain posted until 30 days after the restricted entry interval expires.
The employer must inform all workers/handlers of the poster's location and allow access.
Emergency Assistance - Prompt transportation to an appropriate medical facility if pesticide
poisoning is suspected. Information from the pesticide label and how the exposure occurred
must be provided to the employee and medical personnel who treat the exposed worker/
handler.
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Decontamination -- A decontamination site must be provided at the location during
application, and the restricted entry interval plus 30 days. Supplies for washing pesticides
from the skin and eyes must be provided within 1/4 mile of all workers/ handlers. This
includes sufficient quantities of water, soap and single-use towels. Clean coveralls must be
provided at the handler site. Eyeflush water must be made immediately available to handlers
and early-entry workers if they are required to wear protective eyewear.
Information Exchange -- A commercial handler must provide an agricultural employer with
the information that must be posted and deliver oral warnings as well as post treated areas,
and provide other protection requirements on the label for workers or other people.
WORKER SPECIFIC REGULATIONS
Application Restrictions — The employer must keep workers other than trained and
protected pesticide handlers out of an area being treated. Under some application condi-
tions, employers must keep nursery or greenhouse workers out of locations that are near an
area being treated.
Entry Restrictions - If contact with pesticides is possible, the employer must keep workers
from entering a treated area until the Restricted Entry Interval expires. No entry for the first
4 hours after the application and until any label-specified inhalation exposure level or the
ventilation criteria have been met.
Workers must be informed of health effects and safety information from the pesticide
labeling.
Personal Protective Equipment must be provided, cleaned, and maintained for the worker,
the worker must be instructed in its proper use, maintenance and storage. Workers must
be instructed that washing thoroughly after removing personal protective equipment is
necessary. A clean place must be provided to put on and take off protective clothing and
equipment, and to store personal clothing. Water, soap and towels must be provided. The
employer is responsible for making sure no contaminated protective equipment or clothing
is taken home. These provisions also apply to handlers.
Employers must make sure that workers and handlers are not subject to heat related illness
while wearing personal protective equipment.
Unless the worker is a certified applicator or trained handler, any early-entry worker must
be trained through written or audiovisual materials that the worker can understand. Training
is to be by a certified applicator, a trainer of certified applicators, or other approved trainer.
The training program must contain the general pesticide safety information specified in the
Worker Protection Standards.
Notice of Applications - On farms, nurseries and forests, each worker who might enter a
treated area or walk within 1 /4 mile of a treated area either during application or a restrict-
ed entry interval must be warned orally or by posting warning signs at the treated area. At
a greenhouse, each worker who might enter a greenhouse during an application or a
restricted entry interval must be warned by posted warning signs at entrances to treated
areas. Some pesticide labels require both methods of notice.
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The posted warning sign must include the words "Pesticides/Pesticidas - Danger/Peligro -
Keep Out/No Entre" and must contain the warning symbol (stern face and upraised hand),
meet size and color requirements, and be visible at all usual entrances to the treated area.
The oral warning must give location and description of the treated area, the time span of
restricted entry and instruct workers to not enter until the restricted entry interval is over.
HANDLER SPECIFIC REGULATIONS
Application Restrictions: The employer and the handler must make sure that no pesticide is
applied so as to contact, either directly or through drift, any person other than a trained and
protected handler. The employer must make sure that any handler who is working with a
pesticide having a skull and crossbones symbol on the label is monitored visually or by
voice contact at least every two hours. The employer must make sure that any handler
who is working with a fumigant in a greenhouse maintains continuous visual or voice
contact with another handler.
Knowledge of Pesticide Labeling: The employer must make sure that each handler has
either read the pesticide labeling or been informed of its contents. The labeling must be
accessible to the handler while working with the pesticide.
Safe Operation of Equipment: The employer must make sure that each handler is instructed
in the safe operation of handling equipment and that all equipment is inspected and in good
operating condition before each use.
Training: Unless already a certified applicator or trained to use restricted-use pesticides,
handlers must be trained before performing handler tasks. The training must include
written or audiovisual materials and be presented in a manner the handler can understand.
The trainer must be a certified applicator, trainer of certified applicators, or other approved
trainer. The training program must contain the general pesticide safety and correct handling
practice information specified in the Worker Protection Standards.
Cleaning and Maintaining Personal Protective Equipment: The employer must make sure
that anyone who cleans personal protective equipment is informed that the equipment may
be contaminated with pesticides and the correct procedures for handling it, and that it is
properly cleaned, dried and stored according to manufacturer's instructions. In addition,
the employer must make sure that the equipment is inspected and repaired before each use
and that filters, cartridges and canisters are replaced as required. The employer must make
sure that equipment which cannot be cleaned or is severely contaminated is disposed of.
SUBSTITUTIONS AND EXCEPTIONS
Pilots in open cockpits are exempted from any chemical-resistant footwear requirement; a
helmet may be substituted for chemical-resistant headgear and a visor may be substituted
for protective eyewear.
Pilots in closed cockpits are exempted from all personal protective equipment requirements,
but long-sleeved shirt, long pants, shoes and socks are required.
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Handlers using closed systems for mixing and loading are exempted from all personal
protective equipment requirements except chemical resistant gloves and apron; long
sleeved shirt, long pants, shoes and socks are required. If the closed system is pressurized,
protective eyewear is also required.
Handlers using enclosed cabs are exempted from all personal protective equipment
requirements except respirator requirement; long sleeved shirt, long pants, shoes and socks
are required. Respirators are waived if the enclosed cab offers respiratory protection equal
to or greater than the type of respirator specified.
Handlers or early entry workers who are working with plants that have sharp thorns may
wear leather gloves over chemical-resistant glove liners.
Handlers or early entry workers who are working in rough terrain may wear leather boots
instead of chemical resistant footwear.
REQUESTS FOR EXCEPTION
Affected parties may request an exception to the restricted entry interval; however the
process takes approximately one year from the time of application.
WOOD PRESERVATIVES LIMITATIONS
A number of health-related concerns have been identified with pesticides used as wood
preservatives. As a result, the Environmental Protection Agency has classified the three
major wood preservatives (creosote, pentachlorophenol, inorganic arsenicals) as Restricted
Use Pesticides. This restriction is based on studies that link creosote, arsenic, and a dioxin
contaminant of pentachlorophenol to cancer in humans. In addition, these products have
caused gene defects (mutagenicity) in laboratory animals. Continued use of these wood
preservatives is currently based on regulations that limit how these materials can be
applied, where treated wood can be used, and on new labeling directed at consumers.
APPLICATOR Special precautions for workers who apply pentachlorophenol require that a closed
PROTECTION system be used for powdered, flaked, and prilled formulations. Spray applications
of pentachlorophenol must be done in a manner to minimize overspray. Where
visible mist occurs, workers are required to wear goggles and protective clothing through
which the pesticide cannot penetrate. Pregnant women should avoid exposure to penta-
chlorophenol.
Workers who treat wood with arsenical wood preservatives are required to wear a respira-
tor if the level of arsenic is unknown or exceeds a level of 10 micrograms/cubic meter of air
during an 8 hour day (the Permissible Exposure Limit established by the Occupational
Safety and Health Administration). Applications cannot leave visible surface deposits of the
preservative on the wood.
USE RESTRICTIONS Wood treated with creosote and pentachlorophenol can no longer be used
indoors or where there may be contamination of feed, food, drinking or
irrigation water. In barns, stables, and similar sites, wood that is in contact with the soil
can be treated with creosote or pentachlorophenol if K is covered with a sealer (at least 1
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sealer coat for pentachlorophenol, 2 coats for creosote). Sealants must also be applied if
wood is likely to be exposed to body contact. Logs treated with pentachlorophenol can no
longer be used for log homes.
All uses of inorganic arsenical wood preservatives are Restricted Use except for brush-on
treatment for commercial construction purposes (not household construction).
The treated wood industry agreed to develop and distribute Consumer Information Sheets
to provide information to consumers about treated wood uses and restrictions.
LIMITING PESTICIDE RESIDUES IN CROPS
The public is greatly concerned about pesticide residues in crops; however, regulations limit
these residues to what studies show to be safe levels. Preventing excessive residues in harvested
crops is essential to keeping these pesticides on the market for use in agriculture. Pesticide
residues can be limited by:
- following pre-harvest interval requirements;
- applying a pesticide only to crops listed on the label;
- applying a pesticide only by methods listed on the label;
- applying a pesticide only at the rate specified on the label.
PREHARVEST The pre-harvest interval is vital to reducing the hazards of pesticide use. It is the
INTERVAL minimum amount of time that must elapse between the last pesticide application
and harvest. Pre-harvest intervals are established for all pesticide uses on food and
feed crops. Required intervals also exist for many ornamental crops. The length of the pre-
harvest interval is determined after studies are done on the degradation of the pesticide
under labeled use conditions.
The length of the pre-harvest interval varies with different pesticides. Also, intervals for any
individual pesticide may vary on different crops on which it is used. Carbaryl (Sevin)
applied to apples requires that 1 day elapse between application and harvest; a 14 day pre-
harvest interval exists for carbaryl on head lettuce. Pre-harvest interval requirements are
listed on the pesticide label. Failure to follow these requirements by harvesting prematurely
can allow excessive pesticide residues to appear on the crop.
SITE Pesticides can be applied to only those crops that are specifically listed on
RESTRICTIONS the label. Since pesticides degrade at different rates depending on how the
crop is grown, use of a pesticide on a crop may depend on how the crop is
produced as well as what is grown. For example, pesticide registrations for greenhouse
grown tomatoes differ from field grown tomatoes since they are considered as separate
crops. Pesticide uses for ornamental plants grown in greenhouses differ when the plants
are moved to interior landscaping.
APPLICATION The methods that can be used to apply a pesticide are also specified on the label.
METHOD Complying with these instructions helps reduce the possibility of excess residues
on harvested produce. For example, a pesticide may be applied to the root system
of the crop but not to the foliar portion (and vice versa). Aerial application may be allowed
but not chemigation. Chemigation is typically allowed for overhead irrigation systems but
not trickle irrigation.
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APPLICATION Use of a larger amount of a pesticide than the label specifies is a violation of FIFRA
RATES and can also cause harmful residues on a crop. Use only the amount equal to or
less than that indicated on the label. With some pesticides, there are also restrictions on
how many times they can be applied during a season and the frequency.
Ensuring that excess residues do not occur in harvested crops is a major concern when
pesticide labels are written. It is violation of the law to use a pesticide in a manner that is
inconsistent with its labeling.
MANAGING PESTICIDE DRIFT
Drift control is vital during every pesticide application. Several techniques can be used to
reduce the possibility of drift:
- use pesticides that have low volatility;
- use formulations that resist drift and volatility;
- use low pressures during spraying;
- use nozzles which reduce formation of small spray particles;
- use high water volumes during application;
- apply pesticides close to the crop or soil surface;
- avoid applying pesticides when the temperature is high;
- avoid applying pesticides during windy conditions;
- use drift reducing adjuvants.
Certain formulations of pesticides can help reduce drift. For example, low-volatile acid and
amine 2,4-D formulations have less potential for drift than ester formulations. Dust
formulations drift much more readily than most sprays. Granular formulations are relatively
less likely to drift.
Droplet size of pesticides during application is extremely important in determining the
potential for drift. The ability of particles to drift increases greatly as the particle size
decreases (below).
Distance water droplets drift while falling 10 feet in winds of 3 miles per hour.
Droplet diameter Particle
(microns) classification Drift distance (ft)
30 Cloud 500
100 Mist 50
200 Drizzle 16
500 Light rain 7
The various spray nozzles and application equipment produce a wide range of droplet sizes.
There are several techniques that will reduce the number of the smallest particles while still
giving effective coverage.
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Application pressures are important in determining the sizes of droplets that are formed. As
pressure increases, the number of fine particles also increases. Drift can be reduced by
reducing sprayer pressures during application.
Nozzle construction can also affect the number of small particles that are formed during
spraying. Nozzle tips that produce larger droplet sizes help reduce drift. For example, larger
nozzles can be used at lower pressures to get the same volume (Gallons per acre, or GPA)
as smaller nozzles operated at higher pressures. Use of higher GPA applications are an
alternate means of achieving adequate crop coverage with minimal pressures.
"Thickening" or "drift control" adjuvants can be added to the spray mixture to reduce drift.
These compounds can increase the percentage of larger droplets which are formed but do
not completely eliminate small droplets.
The weather conditions during application have a great effect on pesticide drift. Air
movements, both horizontal and vertical, cause pesticides to move away from where you
are spraying. The higher the wind speed, the larger the amount of pesticide that will be
carried away. Pesticides should never be applied during high wind conditions (greater than
10 mph). This is particularly important when wind direction is likely to move drifted
pesticides onto nearby sensitive crops or other sensitive areas. Drift to sensitive areas often
can be avoided by spraying when the air is moving away from these areas.
Drift may also increase when warming air near the soil rises. Applications should be done
at times when air and soil temperatures are most similar, often during early morning and
late evening. At this time, vertical air movements are lowest.
If the air near the soil surface is cooler than the air above, an "inversion" exists. Small
spray particles remain suspended in the cool air during temperature inversions, and the
particles do not settle readily onto soil or plants. Later the suspended particles move out of
the crop on winds and drift. Pesticide applications should be avoided during inversions.
Temperature and humidity can affect pesticide drift. When the temperature is high and
humidity low, particles evaporate most rapidly. This evaporation causes droplet sizes to
decrease and drift more readily. Volatile pesticides also evaporate more rapidly with high
temperatures. Pesticides should be applied when the temperature is cool.
Height and orientation of sprayer nozzles can also affect drift. Distance and time for spray
droplets to reach plants or soil is directly related to the height at which a pesticide is
released. Sprays should be released as near the target as will permit adequate coverage.
Sprays should also be directed so droplets are propelled downward to reduce the distance
of droplet fall.
Vapor drift of soil-applied pesticides can be reduced by properly sealing the soil after
application. This often involves proper soil incorporation of the pesticides during applica-
tion.
AVOIDING POLLUTION OF GROUND AND SURFACE WATERS
Contamination of ground and surface waters is an imminent hazard of using pesticides in
agriculture. This potential must be a major consideration in planning for pest control on cropland
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and other agricultural areas. Elements that enter into water pollution by pesticides are:
- proximity of the treated area to surface waters;
- proximity of the treated area to drinking water wells or aquifers;
- depth of the water table at the treated site;
- soil conditions that increase the potential for the pesticide to leach into groundwater;
the hazard of the pesticide as potential contaminant of groundwaters;
- conditions during application that affect pesticide drift into surface waters;
- crop managment practices that minimize pesticide leaching;
- precautions during application to avoid leaching or direct groundwater contamination.
The potential for ground and surface water contamination should be evaluated whenever
determining the need, method and frequency of pesticide use. Pesticides should only be used
when and where necessary and only in amounts adequate to control the pests. When there are
alternative pest controls available with less water pollution hazard, they should be considered.
Treatment of fields near rivers, streams, and other surface waters are most likely to result
in contamination of surface waters. Treatment of fields where there are high water tables, or areas
near drinking water wells may result in groundwater contamination. Pesticides should never be
applied in a location or in a manner that could contaminate water resources.
In determining whether to use a pesticide or which one to use, the likelihood of leaching
should be evaluated. Lighter soils and soils low in organic matter are most commonly associated
with leaching of pesticides into groundwater. Soil pH (acidity or alkalinity) may also affect the
breakdown and leaching potential of a pesticide. In fields where a high potential for leaching
exists, pesticides should be avoided or use limited to chemicals that do not readily leach into
groundwater. Some chemicals known to be "teachers" are highly water soluble and are weakly
bound to soil particles. At sensitive sites where other conditions favor leaching, these pesticides
should not be used.
Proper precautions should be taken during application to reduce potential contamination
hazards. Application equipment should always be properly calibrated and maintained. Excessive
application rates or spills due to poorly maintained equipment can result in high concentrations of
pesticides on crops or land. Pesticides should always be applied in a manner that reduces drift.
Application equipment should include safety devices to minimize problems with spills and back-
siphoning. This includes the installation of backflow control equipment (check valves or air gaps)
on filling pipes and in chemigation systems.
Irrigate in a manner that reduces pesticide movement. High rates of irrigation can increase
the amount of pesticide leaching. Excessive irrigation can also cause run-off and erosion.
Particular care should be given when irrigating shortly after a pesticide application, since the
pesticide is in the highest concentration at this time.
. A,w»y» *°llow directions on the pesticide label. Application safety instructions and any
:er;crs °n Jhe pesticide's use are on the label. It is the responsibility of the applicator to read
o ow ate instructions. The pesticide label is a legal document, and the content of the label
may change as manufacturers and the EPA evaluate uses and hazards. Don't take it for granted
/.ri« «n|C8 v.ou hfve us®d a Product that the directions for use will remain the same. There are
c iminai and civil penalties for using pesticides in a manner that conflict with the label instructions.
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REDUCING HAZARDS TO WILDLIFE
Destruction of wildlife is an unfortunate offshoot of pesticide use. In some cases, such as
DDT, the devastating effects have resulted in cancellation of the pesticide registration.
Threats to endangered species have become important considerations in registering
pesticides for use. Damage to wildlife from pesticide use can be reduced by:
- avoiding pesticides that are highly toxic to wildlife;
- using pesticide formulations that are less hazardous to wildlife;
• applying pesticides in a manner that minimizes damage to wildlife.
TOXICITY Pesticides vary widely in their toxicity to wildlife. For example, many organophos-
phate insecticides are quite toxic to birds and mammals. Fish tend to be more
susceptible to synthetic pyrethroid insecticides. Often, several effective pesticides may be
available and the less hazardous materials can be selected.
FORMULATIONS The formulation of a pesticide can make a chemical more or less
hazardous to wildlife. Bait formulations for grasshopper control are less
harmful to birds than broadcast sprays. Systemic insecticides applied to the soil can be
less hazardous to wildlife than sprayed applications. Granules tend to be relatively safe to
many types of wildlife; however, granules exposed on the soil surface, particularly colored
granules, may be eaten by some animals. Surface exposed granular pesticides and pesti-
cide treated seed have been involved in some serious bird kills. The pesticide, Diazinon,
was banned for use on golf courses and sod farms because of its toxicity to birds.
APPLICATION There are several application practices that can be used to protect wildlife.
Pesticides should not be applied to known habitats of desirable wildlife. In some
cases, such as prairie dog poisoning, pre-treatment surveys for wildlife are required. Also,
there are restrictions under the Endangered Species Act on some pesticide uses in areas
known to be frequented by threatened or endangered species.
Pesticide applications can be timed to reduce the hazards to wildlife. It may be possible to
apply pesticides during periods when migrating wildlife is not present. Delays in treatments
may also be considered to allow breeding birds to rear young and disperse from the area.
During application, care should be taken to reduce potential exposure of wildlife to pesti-
cides. Pesticides applied to soil or pesticide-treated seed should always be covered with
soil. When lifting equipment during field turns, it is possible for granules and seed to spill
and pile. Spills or puddling of insecticide spray mixtures can be hazardous since water may
attract birds and animals. Steps should also be taken to reduce pesticide drift into areas of
wildlife habitat.
REDUCING LOSSES OF HONEYBEES
Honeybees visit fields and orchards to collect pollen, nectar, water and other materials
needed to maintain their hives. For many fruit and seed crops, the pollination by bees is essential
to crop production. In addition, the honeybee industry and honeybee byproducts provide a major
source of income to full and part-time beekeepers, and contributes millions of dollars in value to
Colorado agriculture.
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Unfortunately, activities of pollinating insects such as honeybees often
conflict with crop protection practices. Pesticides, particularly certain
insecticides, kill large numbers of honeybees in Colorado annually, destroy-
ing or weakening colonies. For example, pesticides used to control alfalfa
weevil and sweet corn insects can cause extensive honeybee losses. Steps
to avoid these problems include:
- communication and coordination with area beekeepers;
- avoid treatments to crops in bloom;
- control flowering weeds in crops;
- avoid drift;
- use pesticides that are least hazardous to honeybees;
• treat fields during times when honeybees are not active.
COMMUNICATION Regular communication between pesticide applicators and beekeepers is a
two-way process that can help protect honeybees. If applicators are aware
of the location of bee colonies, they can warn beekeepers of planned applications so that
colonies can be moved or temporarily covered. Also, beekeepers can block the main hive
entrance and open a new entrance which disrupts honeybee foraging for several hours.
HAZARD There is a wide range of hazard to honeybees among the various pesticides. In
general, relatively slow acting pesticides can be among the more hazardous since
they may be carried to the hive and fed to many other bees. Pesticides which are readily
collected by foraging bees, such as certain micro-encapsulated insecticides, are also most
commonly associated with honeybee poisonings. However, formulation of pesticides can
also reduce these hazards. For example, most carbaryl (Sevin) insecticides are considered
highly hazardous to bees, but the Sevin XLR formulation is much less hazardous since bees
do not easily pick up the insecticide during foraging.
Flowering crops in bloom should not be treated with pesticides that are toxic to honeybees.
Indeed, some pesticide labels prohibit the use of the pesticide on crops in bloom. This is
often relatively easy when bloom occurs over a limited time, such as with orchard crops;
however, the presence of flowering weeds in nearby fields or orchards may attract bees for
longer periods. Weed control can therefore be an important factor in reducing honeybee
poisoning.
Sometimes crops must be treated when they are blooming because it is critical to crop
protection. For example, the sunflower moth lays eggs during bloom and is most easily
controlled by applying pesticides at that time. Less hazardous pesticides should be used for
these applications. In addition, pesticides can cause less honeybee poisoning if they are
applied during periods when honeybees are not active. Early evening is a particularly good
time to make these treatments since the spray deposits will have settled and dried before
honeybees resume foraging in the morning.
DRIFT Serious honeybee poisonings can be caused by pesticide drift. During warm periods, large
numbers of honeybees may mass on the outside of the hive to help control hive tempera-
tures. These exposed bees can be destroyed easily by drifting pesticides.
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INTEGRATING CHEMICAL AND BIOLOGICAL CONTROLS
Biological controls are important to controlling insects, mites, weeds and diseases of crops.
But, they can be eliminated by use of pesticides, causing an even greater dependency on chemic-
als. Whenever possible, it is wise to integrate chemical and biological controls by practices such as:
- recognition of existing biological controls and evaluating their value before applying any
pesticides;
- using pesticides that are less harmful to beneficial organisms;
- timing pesticide applications so they are less harmful to beneficial organisms.
Scouting Biological control organisms may be effectively controlling pests even though they
are not recognized. Even pests that occur regularly, such as spider mites on field
corn or greenbugs on sorghum, may be effectively controlled under some conditions.
Before applying pesticides, fields should be examined for the activity of natural enemies. If
large numbers are present, pesticide use may be deferred or avoided.
Selective When several different pesticides are available, selection of pesticides with less
Pesticides impact on natural enemies can be made. For example, "selective" insecticides {for
example. Bacillus thurinaiensis for first generation European corn borer or miticides
such as Vendex for control of spider mites on fruit trees) can conserve most other biological
control organisms.
Insecticides that are relatively short-lived may also be used selectively since resistant
stages of the biological controls (eggs, pupae) may survive, allowing fields to be rapidly
recolonized. The formulation may also be important in determining selectivity. Formula-
tions of soil-applied systemic insecticides, such as Disyston 15G, can be more selective
than the same insecticide used in a sprayed application, such as Disyston 8E.
Timing Pesticide use may also be timed so the effects on natural enemies will be low. For
example, use of dormant sprays on fruit trees before flowering can control pest
species on the plant at that time. Biological control organisms typically move to
orchards later in the season so would not be affected by dormant applications.
MANAGING PHYTOTOXICITY HAZARDS
Plant damage resulting from a pesticide application to a desirable plant is known as
phytotoxicity. Some burn of leaves, flowers, or growing tips will be seen. Yellowing, leaf
distortions, abnormal growth and stunting are other signs of phytotoxicity. This is a
particular concern where appearance is critical to marketing a crop (tree fruits, flowers,
ornamentals).
Phytotoxicity is regularly associated with the use of specific pesticides or formulations on
susceptible plants; however, phytotoxicity may be irregular. Problems can be avoided by:
- avoiding use of pesticides on plants known to be susceptible;
- using formulations that have reduced phytotoxcity hazard;
- applying pesticides under the best environmental conditions;
- following label directions on application rates or frequencies;
- avoiding pesticide mixtures;
• never using equipment that has been used for herbicides to apply insecticides
or fungicides.
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Careful reading of the pesticide label can help identify plants that are sensitive to the
pesticide. Warnings may be in the label section that discusses crop uses or in a separate
section. They may indicate that only certain varieties are susceptible to injury. Pesticides
broadly labeled for use on flowers or ornamentals may not include warning statements for
some susceptible plants.
Formulation Wettable powder and other dry formulations tend to be safer to use on sensitive
plants than emulsifiable concentrate liquids. This is because the various "inert"
ingredients in some emulsifiable concentrates (xylene, for example) can be harmful to
plants. Almost all aerosol formulations of pesticides for use on ornamental plants can cause
injury if the spray nozzel is too close to the plant. It should be 18-20 inches or more from
the plant.
Weather Avoid spraying plants during extremely hot sunny conditions. Temperatures
above 90 degrees can increase injury by many insecticides. During sunny condi-
tions, leaf and flower temperatures may be considerably higher than the air, allowing for
injury at lower air temperatures. Cool temperatures increase the plant injury of other pesti-
cides.
Pesticides should not be applied when they will not dry. Plants sprayed when the weather
is cool and humid will remain wet for long periods, and there will be increased likelihood of
injury. Wet foliage is also more likely to be injured by aerosol formulations. Slow drying is
one reason greenhouse grown plants are more sensitive to spray injuries.
Never spray plants that need water. Wilted or dry plants are extremely sensitive to spray
injury. Slow growing or diseased plants may also be injured more frequently than vigorous-
ly growing plants.
Mixtures/Rates Excessive rates of pesticides can cause injury. Plants may also be
injured by repeated applications made at short intervals.
Certain mixtures of two or more pesticides can cause plant injury. For example, the use of
any sulfur based pesticide will cause increased injury if combined with oils. Compatibility
charts that can help avoid many mixtures known to cause phtyotoxicity.
Sprayer equipment used for applying herbicides should never be used for spraying insecti-
cides and fungicides. Minute amounts of herbicide residues in such equipment can cause
damage to desirable plants.
Testing An important precaution for use of pesticides on flowers and ornamentals is to test
the spray mixture on a few plants. Several (3-4) preliminary applications should be
made, at short intervals (3-7 days) under normal growing and spraying conditions. Plant
damage by some pesticides may appear within 18 hours; with others it may take 3 days. It
•s useful to compare sprayed plants with adjacent non-sprayed plants receiving identical
cultural care.
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Summary Chapter X
Be sura that each person who applies pesticides understands how to use them and follows
the label precautions. A supervisor is responsible for everyone under his/her direction.
Observe Restricted Entry Intervals required by the product label. Never enter a treated field
unless trained to do so using required protective equipment.
The Pre-harvest Interval is the length of time that must pass after e pesticide is applied
before harvest of the crop can begin. If not observed, Megal residues may appear on
commodities.
Make sure that pesticides do not drift into areas where other crops, animals, or people will
be harmed. Never epply pesticides when there is a wind, or when it is too hot.
Some pesticides have greater potential for contaminating groundwater than others. Soil,
the water table, irrigation practices, and the pesticide's characteristics all contri-bute to the
likelihood of water pollution.
An undesirable side effect of using pesticides is damage to wMHfe and its habitat. Use
pesticides in e manner that is least likely to damage wildlife or the environment.
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Chapter XI
PESTICIDE STORAGE AND DISPOSAL
STORAGE Storage facilities that protect the pesticides and keep them away from other
FACILITIES materials, people and animals are essential. The effectiveness of pesticides
is lowered by freezing, extreme high or low temperatures, or exposure to moisture.
Proper storage reduces the chance of pesticide-related accidents and allows for easier
handling of accidents if they do occur.
The structure should have a concrete floor which is impermeable and easy to wash. The
structure should be fire resistant and located away from other buildings. Adequate
ventilation is needed to prevent exposure of the pesticides to extreme heat and reduce the
concentration of toxic or flammable vapors in the building. Insulation and a heating system
to protect pesticides from freezing during cold temperatures are essential in Colorado.
Many pesticides, particularly liquid emulsifiable concentrates, separate and degrade at low
temperatures. Lighting in storage facilities must be sufficient to allow easy identification of
stored materials.
Pesticide storage areas should not be used for other purposes. Pesticides should never be
stored with food, feed, seed, planting stock, fertilizers, or veterinary supplies. Pesticides
should also be stored separately from protective equipment such as respirators, goggles,
and protective clothing. Since total decontamination of pesticide storage areas is often not
possible, designated pesticide storages should not be planned for subsequent uses.
Running water and materials for safely handling small-scale pesticide accidents should be
located near storage facilities.
Placement of pesticides in a storage area is important. Dry formulated pesticides should be
stored on wooden pallets or metal shelves so they will not be in contact with damp floors.
Dry materials should be stored above liquid formulations so they will not be contaminated
from leaking containers.
If metal containers are to be stored for long periods, they should also be placed on pallets
to prevent corrosion caused by dampness. If a container is corroded, it should be either
repaired or the contents transferred to another container which has held exactly the same
product and which has an intact label.
Pesticide storage areas should always be kept locked when unattended. They must be
clearly marked as to contents with warning signs that conform with standards for marking
hazardous storage areas. This will assist emergency response personnel in case of acci-
dents or fires.
EMERGENCY PLANNING AND COMMUNITY RIGHT-TO-KNOW ACT
A federal law, the Emergency Planning and Community Right-to-Know Act (EPCRA), sets
regulations for pesticide storage. Certain pesticides have been designated as "Extremely
Hazardous Substances." These include most Restricted Use pesticides and some materials
considered hazardous, such as ammonia. If the amount of these chemicals in storage
exceeds the "Threshold Planning Quantity" for that pesticide, this regulation applies. The
amount varies from 10-10000 pounds of active ingredient, depending on the pesticide.
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Notification must be given to both state and county agencies when pesticides more than
the Threshold Planning Quantity are stored. State notification should be given to the
Colorado Emergency Planning Commission, c/o Colorado Department of Health, 4210 E.
11th Ave., Denver CO 80220. (Phone number 303-331-4858). Local Fire and Police
officials will have information on whom to contact within the county. Most County
Cooperative Extension offices also have information on the Threshold Planning Quantities of
various pesticides.
To notify the State and local authorities, send a letter such as the following:
"This is to notify you that I am/we are storing one or more of the Extremely Hazardous
Substances at or exceeding the "Threshold Planning Quantity" at my/our (farm, ranch, or
greenhouse) which is located at (p^ress)—. •
The contact for my (farm/ranch/greenhouse) is (name) ¦ He/she can be
contacted by calling (phone number) or by writing (address) ¦'
CONTAINER Pesticide containers come in many shapes and sizes and are made of paP®r'
DISPOSAL plastic, or metal. They must be disposed of in a manner to protect peop ,
and the environment, in accordance with the Federal Insecticide, Fungici e .J*
Act and appropriate label direction. Proper methods for disposal of pestici e c
include:
1. Paper bags must be completely emptied and either buried on your propertyin asafe
location away from water, susceptible animals or plants, or placed wit ot er ra
for sanitary landfill disposal.
2. Rigid containers must be triple rinsed and then either buried or placed with solidI waste
destined for a sanitary landfill. Do not let "empty" pesticide containers set for mo
12 hours before triple rinsing. Pesticide residues may solidify and stick to the insi e
container and not be rinsed away adequately. Mark "triple rinsed" on containers es i
for landfills to identify them as non-hazardous waste.
The Triple Rinse Procedure
- Empty your pesticide container into the spray tank and allow the container to drain for 30
seconds;
- Add rinse water to the container until it is 1 /4 full; . __
- Rinse the container thoroughly. Pour the rinse water into the spray tank and drain tor
seconds. Repeat 3 times.
- Recycle, or puncture and dispose of the triple rinsed container properly.
3. Plastic containers (bottles and jugs) should be triple-rinsed, punctured, and then either
buried or added to other solid waste for sanitary landfilling.
4. Metal containers, other than pressurized containers, must be triple-rinsed, punctured, and
either buried, recycled, or added to other solid waste for sanitary landfilling. Flattening
metal containers after they have been triple rinsed reduces landfill space requirements and
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facilitates recycling as well. Properly rinsed metal drum containers may be accepted by
some reconditioners and manufacturers.
Promptly store used pesticide containers in proper pesticide storage facilities pending
disposal. Improperly stored containers are a potential poisoning hazard to children, pets,
and wildlife.
DO NOT send pesticide containers that have not been triple rinsed to sanitary
landfills, reconditioners, or recyclers.
DO NOT discard pesticide containers in unapproved locations.
DO NOT reuse pesticide containers for other purposes.
DO NOT dispose of any pesticide container in a manner that is inconsistent with its
label directions.
PESTICIDE WASTE When pesticides are used there may be some excess pesticide or waste.
Proper disposal of these wastes can be difficult and expensive; however,
improper disposal can result in serious pollution or poisoning hazards. Improper disposal also
subjects the applicator to substantial fines, clean-up and disposal costs. Good planning for
pesticide needs can keep waste to a minimum and reduce disposal needs. The beet way to
avoid the need for pesticide waste disposal is to avoid creating pesticide waste. Some ways
to reduce your wastes are:
1. Purchase only the amount of pesticide needed for the intended pest control task
or for a season's use.
2. Prepare only the amount of the pesticide needed for the application after calculat-
ing how much is needed to cover the intended site.
3. Protect pesticides from damage and contamination so they remain useful and
have legible labels. Store pesticides in a cool place out of the sun in locked
storages. In the winter, protect liquid formulations from freezing. Protect dry
formulations from moisture.
4. Always try to use pesticides while they are still effective for the intended
purpose, using older products first.
Even planning may not eliminate all the needs for pesticide disposal. When disposal is
necessary, methods include:
1. Use as much of the pesticide according to label directions as possible. This will
not always be feasible, especially when use is on a food crop or animal or when the
label limits the frequency of application to a site. Read the label to be sure that this
method of disposal is appropriate for the pesticide in question.
2. Acutely hazardous wastes (Toxicity Category I, LDM of 50 mg/kg or less) in
quantities greater than 2.2 pounds must be disposed of in an approved hazardous
waste site. Failure to properly dispose of these highly hazardous materials is
considered a pesticide spill and is subject to regulations covering spilled pesticides.
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3. Smaller quantities of hazardous pesticide waste (or pesticides not classified as
being highly hazardous) generated by an agricultural producer can be disposed of on
the property of the producer. Such disposal must be done in a manner that
prevents potential environmental damage, away from waterways, wells, wildlife
habitats and sites that may erode or aNow leaching.
PESTICIDE Pesticide spills can threaten human health and cause significant environmental con-
SPILLS tamination. Knowing what to do in the event of a spill will help you minimize ad-
verse effects and save you expensive clean-up costs. Always be prepared to handle spills
before they occur. Contamination can be much more serious if response to a pesticide spill
is delayed.
Spills may be relatively minor, involving one or a few leaking containers. However major
spills, such as when a truck or sprayer overturns and the contents are spilled, can occur.
Regardless of the magnitude of the spill, the proper response is the same. First, control the
spill; second, contain the spill; third, clean it up. These three steps are called the "Three C"
program of spill management.
Control Immediately after a spill has occurred, control the flow of leaking pesticide. Do
everything possible to stop the leak or spill immediately at its sourcel Leaking con-
tainers can be repacked. Leaking sprayers should be turned off immediately. Stopping
large leaks or spills often is very difficult. When trying to control the flow of the chemical,
do not expose yourself unnecessarily. Always carry protective clothing and equipment
when transporting pesticides and use it whenever there is a pesticide emergency.
Contain After the leak has been stopped as much as the possible, contain the spilled
material in as small an area as possible. If the spill is liquid, build a dam to prevent
the chemical from spreading. it '« particularly important to prevent anv chemical from
getting into anv body of water, or storm sewer. Do not hose down the erea; this will cause
further spread of the chemical.
Liquid spills can be further contained by spreading absorbent materials such as fine sand,
vermiculite, sawdust, or clay over the entire spill. For absorbing small spills and minor
leaks, kitty litter is particularly useful. (Note: Do not use sawdust or sweeping compounds
if the pesticide is a strong oxidizer. Such a combination is a fire hazard.)
Reporting Spills on public property and all spills involving pesticides that are considered to be
highly hazardous must be reported immediately to the local and state emergency
planning agencies. Police or fire officials are the usual local contacts for reporting such
spills. Contact the State Emergency Planning Commission at 303-331-4858 or 303-331-
4830. These agencies will advise as to proper procedures for cleaning and disposing of
spilled pesticides. Failure to report such spills is a violation of the Emergency Planning and
Community Right-to-Know Act (EPCRA), and can result in fines of up to $25,000 for each
day the violation continues.
Accidents involving some pesticides and hazardous materials are also regulated by Compre-
hensive Environmental Response, Compensation, and Liability Act (CERCLA) (1980). Spills
involving CERCLA-regulated materials (see below) require that the National Response Center
also be notified (1-800-424-8802). If you are not sure whether a spill is covered by this
law, report it.
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During a mqjor spill, someone must remain at the site at all times until it has been effective-
ly contained and cleaned up. The contaminated area should be isolated, preferably by
roping it off. Keep people (and animals) at least 30 feet from the spill. Avoid coming into
contact with drift or fumes from the spill. Depending on the circumstances, it may be
necessary to evacuate people downwind from the spill. Do not use road flares if you
suspect the material to be flammable.
Clean-up When cleaning up the spill, spread absorbent material over the contaminated area,
if not already done. Sweep up the saturated material and put it in a heavy duty plastic bag.
Continue to add absorbent and pick up the saturated material until all the liquid has been
soaked up. It may then be necessary to decontaminate and neutralize the area, particularly
if highly hazardous pesticides are involved. Use a mixture of full-strength bleach and
hydrated lime. Work the solution into the spill area with a coarse broom, then add absor-
bent material to soak up the cleaning solution. Sweep and place the contaminated material
in a heavy duty plastic bag. Repeat the procedure until the area is thoroughly decontami-
nated.
When large amounts of pesticides are spilled on soils, effective decontamination is often
not possible. In these instances, the top 2-3 inches of soil should be removed. Cover the
contaminated soil with at least 2 inches of lime, then cover with fresh topsoil.
Where there are minor spills on soil, activated charcoal can be used in clean up. The
charcoal may absorb and tie-up enough chemical to avoid significant long-term injury.
STORAGE FIRES Pesticides (also fertilizers) should be stored in separate, locked buildings,
away from other structures on the farm or ranch. Such things as ammonium nitrate
fertilizers can become become highly flammable when contaminated by fats, oils, acids,
finely divided metals, or sulfur.
Should the storage facility be involved in a fire, the local fire authorities should be allowed
the clear option of allowing the facility to burn. In many cases, extensive contaminated run-
off would result from fire-fighting activities or incomplete combustion would produce toxic
compounds in the air. Allowing the pesticide facility to burn completely may be the best
option in these instances.
Pesticide storage facilities must be marked with appropriate warning signs showing the
contents. This is an essential safety regulation designed to protect individuals who respond
to fires, spills, and other emergencies at a pesticide storage facility. Growers are also
required to pre-notify local fire authorities of pesticide storage contents as regulated by the
Emergency Planning and Community Right-to-Know Act, discussed before.
Should fires occur in pesticide storage facilities, persons involved in the firefighting and
cleanup should follow personal precautions:
1. Wear rubber footgear during clean-up operations. Leather or cloth footware will absorb
and retain pesticides;
2. Wash and shower using large amounts of soap and water to remove any trace of toxic
chemicals;
3. Put on clean clothes ;
4. Wash all personal clothing, protective clothing, and respirators. Wash separately from
clothing that is not contaminated with pesticides.
5. Watch for pesticide poisoning symptoms.
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Decontamination and disposal of fire damaged pesticide storage facilities is complex. This
task should be undertaken in conjunction with state and local emergency reponse person-
nel.
Summary Chapter XI
Store pesticides in a dry building with heat source for winter and ventilation for summer,
separate from other buildings on the farm or ranch. Keep ft locked and marked as to
contents.
Running water is needed in or adjacent to the storage facility in case of accident.
State and local authorities must be advised if certain hazardous chemicals are in a storage.
Plan the needed amount of pesticide for each use or season to reduce the need to dispose
of waste.
Dispose of wastes in an approved manner: Triple rinse rigid containers before disposal.
In case of spills. CONTROL. CONTAIN, CLEAN UP, REPORT
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PESTICIDES REPORTABLE AS HAZARDOUS SUBSTANCES
Storage of a number of pesticides on farm or ranch properties or greenhouse premises must
be reported under the Superfund Amendments and Reauthorization Act (SARA), Title III Emergency
Planning and Community Right-to-Know Act of 1986. The pesticides that are most likely to be
reportable in Colorado are shown in the chart.
Definitions and Explanations:
The abbreviations R.Q. and T.P.Q. are used in the two columns on the right. R.Q. means
"Reportable Quantity" of the chemical in pounds of active ingredient. Reporting is required in case
of an accidental release or spill of any of these chemicals at, or in excess of, the quantities
indicated. T.P.Q. means "Threshold Planning Quantity" of the active ingredient. Any chemicals
stored at or in excess of the amounts listed must be reported to the State Health Department, the
local county emergency planning committee, and the local fire department. A material safety data
sheet (MSDS) pertaining to each chemical must accompany the T.P.Q. Some chemicals in this
column have two different numbers: The lower figure denotes the solid or liquid formulation of the
product (example, Furadan 4F), the larger number denotes the granular formulation of the product
(example, Furadan 15G). Both are in pounds of active ingredient. To make T.P.Q. determinations
easier, the percentages and/or pounds of active ingredient per gallon for each pesticide are given.
Reporting Requirements SARA (Title III):
The Superfund Amendments and Reauthoriztion Act (SARA) has a number of reporting
requirements. They are: Emergency Planning (Section 302), Emergency Notification/Accident
Release (Section 304), Material Safety Data Sheets/Chemical List (Sections 311 and 312), and
Toxic Chemical Release Reporting (Section 313). Considerable confusion exists about to whom
these reports should be submitted.
Section 302 - Emergency planning (storage information) and Section 304 - Emergency
Notification/Accidental Release or Spills are the most common for farmers to be concerned with.
SARA mandates that reports on storage or spills be submitted to:
1. State Emergency Reponse Commission
2. Local Emergency Planning Committee
3. Local Fire Department
In Colorado report to or obtain information from:
Colorado Emergency Planning Commission
Colorado Department of Health
4300 Cherry Creek Dr. S.
Denver, CO 80222
Phone (303) 692-3300
Jody Waddill or Winifred Bromley
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Emergency notification must include the following information:
1. Name of chemical.
2. Indication of the acute and chronic health risks of the substance.
3. Estimate of the quantity of the chemical released.
4. Location of the release.
5. Time and duration of the release.
6. Environmental medium into which the release occurred (air, water, soil, etc.).
7. Indication of whether the substance is extremely hazardous.
8. Proper precautions; for example, is evacuation necessary.
9. Name and telephone number of the contact person.
A written follow-up report is required and must include information about:
1. Update information included in the initial report.
2. Actual response actions taken.
3. Any known or anticipated data about the health risks associated with the releasi
4. Any advice provided regarding medical attention for persons exposed to the
chemical.
Reportable Quantities and Threshold Planning Quantities for Hazardous Substance Pesticides
Common Name Trade Name Type of R.Q. T.P.Q.
Pesticide (Ibs.ai) (Ibs.ai)
aldicarb
aluminum phosphide
ammonia
azinphos-ethyl
azinphos-methyl
carbofuran
carbon disulfide
carbophenothion
chlorophacinone
chlorouron
coumafuryl
coumaphos
coumatetralyl
crimidine
cycloheximide
demeton
Temik 10 & 15%G
Insecticide
1
100/10,000
Phostoxin, Fumitoxin
Fumigant
100
500
etc. (pellets & tablets)
anhydrous ammonia
Fertilizer
100
500
Ethyl Guthion 2 lb.EC,
Insecticide
1
100/10,000
25 & 50% WP
Guthion 25 & 40% EC,WP
Insecticide
1
10/10,000
25 & 50% WP
Furadan 4 lb. flowable.
Insecticide
10
10/10,000
15% G
several
Fumigant
100
10,000
Trithion 25% WP. 4 & 8 lb
CP
Insecticide
1
500
CI*
Rozol baits & powders
Rodenticide
1
100/10,000
Tenoran 50% WP
Herbicide
1
500/10,000
Fumarin 5% EC, bait,
Rodenticide
1
10,000
crystals
Co-Ral, 1 lb. EC, 4%
Insecticide
10
100/10,000
pour-on, 25% WP
Racumin powder, bait.
Rodenticide
1
500/10,000
liquid
Castrix liquid
Rodenticide
1
100/10,000
Actidione 0.027%-2.26%
Fungicide
1
100/10,000
WP
Systox 2 & 6 lb. EC
Insecticide
1
500
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dichlorvos
Vapona (many formulations)
Insecticide
10
1,000
dicrotophos
Bidrin 8 lb sol. conc.
Insecticide
1
100
and 40-50% EC
dimethoate
Cygon, De-Fend 2 & 4 lb. EC
Insecticide
10
500/10,000
dioxathion
Delnav, Deltec 4 & 8 lb. EC
Insecticide
1
500
diphacin one
Ramik, Diphacin .005.01
Rodenticide
1
10/10,000
baits & 1.25% tablet
disulfoton
Di-Syston 8 lb. EC, 15% G
Insecticide
1
500
endosulfan
Thiodan 2 & 3 lb. EC,
Insecticide
1
10/10,000
EPN
EPN 2 &4 lb. EC, 15% G
Insecticide
1
100/10,000
ethion
Ethion 4 & 8 lb. EC, 25% WP
Insecticide/
10
1,000
Acaricide
ethoprophos
Mocap 15% G, 61b. EC
Insecticide
1
1,000
ethylene oxide
ETO 10-20% mix with COST
Fumigant
1
1,000
fenamiphos
Nemacur 3 lb. EC, 15% G
Nematicide
1
10/10,000
fenitrothion
Sumithion (many formu-
Insecticide
1
500
lations
fensulfothion
Dasanit 6 lb. EC, 10 &
Insecticide
1
500
15% G
fonofos
Dyfonate 4 lb. EC, 10 &
Insecticide
1
500
20% G
lindane
Lindane 1.7 lb. EC 25 & 95%
Insecticide
1
1000/10,000
WP, seed treatments
mercuric chloride
Calo-Chlor, Calo-Gran 30%,
Fungicide
1
500/10,000
0.9%
methamidophos
Monitor 4 & 6 lb. EC,
Insecticide
1
100/10,000
25% WP
methiadathion
Supracide 2 lb. EC, 20% &
Insecticide
1
500/10,000
40% WP
methiocarb
Mesurol 50 & 75% WP, 2%
Insecticide
10
500/10,000
bait, 3% dust
Molluscide
methomyl
Lannate, Nudrin 90% SP,
Insecticide
100
500/10,000
1.8 lbs. L
methyl bromide
Meth-O-Gas 26, 69, 98,
Fumigant
1,000
1,000
100%L
methylmercuric
Panogen 15,42 Pandrinox
Fungicide
1
500/10,000
dicyanamide
(seed treatment)
mevinphos
Phosdrin 2 & 4 lb. EC
Insecticide
10
500
mexacarbate
Zectran 2 lb. EC
Insecticide
1000
500/10,000
monocrotophos
Azodrin 3.2 % 4.8 lb. EC
Insecticide
1
10/10,000
nicotine sulfate
Black Leaf 40
Insecticide
1
100/10,000
oxamyl
Vydate 2 lb. EC, 10% G
Insecticide
1
100/10,000
paraquat
Ortho Paraquat, Gramoxone
Herbicide
1
10/10,000
Cyclone 1.5 lb. EC & 2 lb. EC
methyl parathion
Methyl parathion 4, 6, 8 lb
Insecticide
100
100/10,000
EC & Penncap-M 2 lb. EC
pentachlorophenol
PCP, Penta
Wood Preserv. 10
10,000
phenylmercury
Mist-O-Matic 3.5%
Fungicide
100
500/10,000
acetate
Panomatic 10%, PMAS 10%
phorate
Phorate 15% G, Thimet
Insecticide
10
10
20% G
phosmet
Imidan, Prolate 50% WP
Insecticide
1
10/10,000
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100
phosphamidon
Dimecron 20 & 50% EC &
8 lb. EC
Insecticide
1
100
pirimiphos-ethyl
Primicid 4 lb. EC, 20% WP
5 & 10% G
Insecticide
1
1,000
sodium arsenite
Penite, Atlas "A"
Insecticide
1,000
1,000/10,000
sodium fluoroacetate
Compound 1080
90% powder
Rodenticide
10
10/10,000
TEPP
TEPP
Insecticide
10
100
terbufos
Counter 15% G
Insecticide
1
100
trichlorphon
Dipterex, Oylox, Neguvon
(numerous formulations)
Insecticide
100
10,000
warfarin
Warf, D-Con, Ratorex
(numerous formulations)
Rodenticide
100
500/10,000
zinc phosphide
Mous-Con, Gopha-Rid, Kilrat
(numerous formulations)
Rodenticide
100
500
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