ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF WATER PROGRAMS
THE USE OF PESTICIDES FOR RANGELAND SAGEBRUSH CONTROL
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PESTICIDES STUDY SERIES - 3
THE USE AND EFFECTS
OF PESTICIDES FOR
RANGELAND SAGEBRUSH
CONTROL
This study is the result of Contract No. 68-01-0128
awarded by the OWP, as part of the Pesticides Study
(Section 5(£)(2) P.L. 91-224) to Midwest Research
Institute.
A. R. Hylton, Project Leader
G. R. Savage, Program Coordinator
The EPA Project Officer was Charles D. Reese, Agronomist
ENVIRONMENTAL PROTECTION AGENCY
Office of Water Programs
Applied Technology Division
Rural Wastes Branch
May 1972
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. »«a
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EPA Review Notice
This report has reviewed by the Office of Water
programs of the Environmental Protection Agency
and approved for publication. Approval does not
signify that the contents necessarily reflect the
views and policies of the Environmental Protection
Agency, or does mention of trade names or
commercial products constitute endorsement or
recommendation for use.
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SUMMARY
Sagebrush infests about 270 million acres of land in
the United States. Large areas of this land are potentially
suitable as rangeland for both livestock and various species
of wildlife* Big sagebrush, Artemisa tridentata, is the
most important species of sagebrush,occupyingabout 53
percent of the total sagebrush areas. Aerial treatment of
sagebrush with 2,4-D herbicide has proven to be effective,
economical and practical. The most generally used
formulation is the butyl or isopropyl ester of 2,4-D. Soil
erosion usually is not increased by spraying sagebrush, and
indications are that the control of sagebrush on drainage
areas may increase water flow from those sites. When
properly used, 2,4-D is not considered to-be toxic to man,
domestic animals, game or fish. There are a number of
microorganisms that can degrade 2,4-D and the herbicide does
not accumulate in the soil. Forbs and browse, including
sagebrush, are important as food for various species of
wildlife that inhabit the rangelands. A reduction of
certain forbs on summer ranges could adversely affect
antelope, sage grouse, mule deer, whitetail deer, elk, and
possibly moose. It is highly unlikely that the use of 2,4-D
for controlling sagebrush presents a hazard as a water
contaminant. Analyses of water samples from the Western
United States show the amounts of 2,4-D when present, to be
far below the concentration permissible in public water
supplies. Methods other than herbicide spraying which have
been employed to control sagebrush are more expensive.
Federal and state laws and regulations concerning the use
and sale of pesticides within the study area were evaluated.
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FOREWORD
This Final Report presents the results of a case study of the
effects of herbicide use for rangeland sagebrush control. This project
was a part of a pesticide study authorized by Section 5(1)(2) of P.L. 91-
224 to conduct a series of studies of the impact of different types of
pesticide use on the natural environment.
The work reported covers the period 25 June 1971 to 15 January
1972. Dr. Alvin R. Hylton, Senior Environmental Scientist, served as Project
Leader, and Mr. George R. Savage, S.enior Biologist, was Program Coordinator.
ii
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Appreciation is expressed to the outstanding consultants who
made available their time, knowledge, and experience to this project.
Without the contributions of the following individuals, this report would
not have been possible:
Dr. A. D. Allen, Toxicologist, Consultant to MRI.
Dr. Harold P. Alley, Professor of Weed Control,
University of Wyoming, Laramie, Wyoming.
Mr. John L. Artz, Extension Range Specialist,
University of Nevada, Reno, Nevada.
Dr. Walter L. Gould, Associate Professor of Agronomy,
New Mexico State University, La Cruces, New Mexico.
e
Mr. F. Farrell Higbee, Executive Director, National
Agricultural Aviation Association, Washington, D.C.
Dr. Norman G. P. Krausz, Professor of Agricultural Law,
University of Illinois, Urbana, Illinois.
iii
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TABLE OF CONTENTS
T>aae
SUMMARY i
FOREWORD i:L
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
1. Introduction
11. A General Descrintion of the Sagebrush Growing lands
of the Western United States ............ .
A. General ........................ • ..... ........ 4
B. The Plains of Eastern Montana, Wvominq, Colorado
and New Mexico ...... . ....... ...... ........... 4
C. Rocky Mountains and Intermountain Basins ..... 7
D. Current and Potential Sagebriish Areas ........ 11
111. The History of Herbicide Use in the Studv Area ...... 2?,
IV. Inventory and Current Herbicide Use.... .............. 33
V. Apnlication Techniques and Herbicide ^ormtilations Used
to Control Sagebrush ................ . ..... • .......... 35
A. 2, 4-D Formulations ........................... 35
B. Carriers Used ........... . ......... . .......... 37
C. Time of Application .......................... 3<>
D. Method of Annlication ........................ 40
vi. Abiotic Factors in Sagebrush Control ........ . ........ 43
A. Soil Erosion ................................. 43
B. Effects on Watershed Areas, Moisture Trtention
Snow Holding Canacities ......... ... .......... 43
C. Comments on Soil Moisture Retention and Snow
Holding Canacit" as Affected bv the Chemical
Control of Bier Sagebrush. ... ................. 40
D. General Comments ............................. 51
Vll. Effects of Herbicide Use on the Biotic ^actors
(Flora and ^auna) .... ........................ 53
A. Direct Effects of 2, 4-D on Animals ........... 53
B. The Effect of 2, 4-D on Microorganisms.. ...... 53
C. The Response of Sagebrush and Other Shrubs
to Treatment With 2, 4-D ...................... 55
D. Resnonse of ""orbs to 2,4-n in Sagebrush
Treatment Areas .............................. 57
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TABLE OF CONTENTS (Concluded)
Page
E. Response of Grasses to 2,4-D. 60
F. Effects of Sagebrush Control on Certain Game Species. 63
G. Comments 84
VIII. Herbicides in Aquatic Environments 96
A. Sources of Herbicides 96
B. Entry Into Aquatic Environments 97
C. Impact of 2,4-D Pollution on the Water Environment. . 100
D. Degradation of 2,4-D in an Aquatic Environment. . . . 103
E. 2,4-D Content of Water in Western States 104
t
IX. Toxicity and Hazard of 2,4-D to Animals and Man 110
A. Introduction 110
B. Toxicity and Hazard to Animals 110
C. Toxicity and Hazard of 2,4-D to Man 117
D. Teratogenic Effects 118
X. Alternate Methods of Sagebrush Control (Other Than With
Herbicides) 123
A. Introduction 123
B. Selection of a Method of Sagebrush Control. ..... 123
C. Methods 125
XI. Applicable Laws and Regulations Governing Pesticide Use . . 134
A. Federal Laws and Regulations Relating to the Sale
and Use of Herbicides on Rangeland Sagebrush. . . . 134
B. State Laws and Regulations on the Sale and Use of
Herbicides on Rangeland Sagebrush . . 138
C. Litigation Relating to the Use of Herbicides 146
D. Effects of Herbicide Laws on the Environment 151
E. Changes in Laws Recommended for Adequate Environ-
mental Protection 152
XII. Conclusions and Recommendations 157
A. Conclusions 157
B. Recommendations
Index
v
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I. INTRODUCTION
It has been estimated that sagebrush occupies about 270 million
acres of land in the United States.I/ Since most of this land lies within
the Western Range, vast areas of potentially productive rangelands are
relatively useless because of sagebrush infestations. These woody plants
compete with more desirable vegetation, prevent growing and grazing of
grasses, and hamper the movement of livestock. Because of these large
concentrations of sagebrush, lambs and calves often stray and become lost,—I
since heavy sagebrush stands provide excellent cover for predators (e.g.,
coyotes). Because of these factors, western rangelands now support con-
siderably smaller numbers of livestock than they would otherwise be able
to support.
These sagebrush-infested grasslands an'd rangelands of the western
United States are dominated by a cover of undesirable species of plants.
It is well known that one of these plants, big sagebrush, is a very inefficient
user of water and highly drough-resistant; it produces a minimum of palatable
forage for livestock and game animals. It is abundant in watersheds in
every state in the West. Until recent years, it was believed impractical
to superimpose any management practice on sagebrush lands because costs of
improvement were prohibitive in relation to the possible gains in return.
With the advent of selective herbicides, chemical removal of sagebrush has
revolutionized the management procedures which can be applied to sagebrush-
dominated lands.
Many methods have been used to eliminate sagebrush and to clear
land, but in recent years the application of 2,4-dichlorophenoxyacetic
acid (2,4-D) herbicide has emerged as the control method of choice. Spraying
of 2,4-D has proven to be an effective, economical, and practical sagebrush
control measure.d^®.' However, there has been concern about possible adverse
environmental effects resulting from the large-scale use of this herbicide.
Detrimental effects that have been suggested include disruption of faunal
habitats, endangennent of certain species, modification of food chains,
promotion of soil erosion, laterization and siltation, and increased
turbidity of streams and lakes.6"13/ The purpose of this report, then,
is to present factual information on these and other effects, both adverse
and beneficial, which may be caused by the use of herbicides in controlling
sagebrush.
A general description of the sagebrush-growing areas of the
western United States, the history of herbicide use in the study area,
application techniques, herbicide formulations, and alternate methods of
sagebrush control are presented in the first five sections of this report.
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In the following sections, a discussion and analysis of the broad
environmental effects of 2,4-D are given. Areas included are the consequences
of 2,4-D use on biotic factors (flora and fauna), abiotic factors, the aquatic
environment, and the toxicity and hazard of 2,4-D to animals and man. A
discussion of the legal aspects concerning the use of herbicides also is
given. Finally, conclusions and recommendations are made about the use of
this herbicide to control sagebrush.
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REFERENCES
1. Alley, H. P., "Chemical Control of Big Sagebrush and Its Effects Upon
Production and Utilization of Native Grass Species," Weeds. 4(2), 164-
172 (1956).
2. Pechanec, J. F., Sagebrush Control on Rangelands. Handbook No. 277, U.S.
Department of Agriculture, February 1965.
3. Matthews, J., and C. W. McMillon, "Statement Before the House Committee
on Agriculture," Hearings on Pesticides (H.R. 4152 and H.R. 26),
March 18, 1971.
4. Echart, R. E., Jr., and R. A. Evans, J. Range Management, 21(5), 325-328
(1968).
5. Tabler, R. D., J. Range Management. 21(1), 12-15 (1968).
6. Pimental, P.. Bio. Science. 21(3), 109 (1971).
7. Courtney, K. D., et al., Science. IbQ, 864-866, May 15, 1970.
8. Johnson, J. R., and G. F. Payne, Jr., J. Range Management. 21(4), 209-
213 (1968). ~~
9. Stoddard, L. A., and A. D. Smith, Range Management. McGraw-Hill Book
Company, Inc. (1943).
10. Klebenow, A. J., J. Range Management. 23(6), 396-400 (1970).
11. Blaisdell, J. P., USDA Technical Bulletin, No. 1075 (1953).
12. Monlatt, G., and D. N. Hyder, J. Range Management. 23(4), 170-174 (1970).
13. Shelton, A., and G. Pollock, Trans. Amer. Fish. Soc.. 95(2), 183-187 (1966).
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II. A GENERAL DESCRIPTION OF THE SAGEBRUSH GROWING LANDS
OF THE WESTERN UNITED STATES
A. General
Sagebrush is native to a vast area of western North America. It
occurs from Montana and western Nebraska to British Columbia and California.
The term "sagebrush11 includes a variety of shrubby species of the genus which
grow on the mountain slopes and particularly on semiarid plains, mainly
between 1,500 ft to 10,000 ft altitude, where they are often the most con-
spicuous feature of the vegetation. More than one-half of the total acreage
of this sagebrush is located in Wyoming, Idaho, Montana, and Nevada.—' The
remaining, approximately 47 percent, is spread throughout Utah, Colorado,
New Mexico, Arizona, California, Oregon and Washington. At least 11 species
of Artemisia grow in the western United States, and cover approximately 270
million acres. By far the most important* species is the "big sagebrush"
(Artemisia tridentata). which covers about 144 million acres or 53 percent
of the sagebrush areas.
The sagebrush study region investigated in this report includes
11 western states (Washington, Idaho, Montana, Wyoming, Colorado, Utah,
Oregon, Nevada, California, Arizona and New Mexico) and encompasses the
highest, driest, and most rugged regions of the United States. No other part
of the nation has so many different and dramatically unique physical and
climatic characteristics as this region, yet, when viewed in terms of economics
and human livelihood, many of these differences merely add up to the same
conclusions, that this land has a limited potential for supporting a large
human population or large numbers of animals.
In broadest terms, the region is divided into two major parts:
the Great Plains, situated east of the Rocky Mountains, and the Rocky Mountain
and Intermountain Plateau areas located between the Great Plains in the east
and the Sierra Nevada Mountains in the west (Figure 1).
B. The Plains of Eastern Montana. Wyoming. Colorado, and New Mexico
General Characteristics; In these plains agriculture is by far
the leading and most basic industry. Except for petroleum and gas fields
and scattered coal mines, agricultural resources are the foundation upon which
this region's economy is built. However, these agricultural resources are
limited.
Because rainfall is scarce, less than 20 in., farmers must grow
such drought-resistant crops as wheat, barley, and sorghum. Moreover, rain-
fall is highly variable, and the farmer must be prepared to face repeated
failure or part-failure in order to reap the benefits of better years.
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Figure 1 - The General Physiographic Provinces Located in the Study Region
(After Lobeck, 1932 Rev.)
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A large percentage of the farmland is not plowed, but instead is
allowed to remain in pasture or grazing land. The result is that there is
a much larger supply of forage feed which stimulates a great cattle and sheep
ranching industry than of feeds for fattening.
Because of lower rainfall, rougher topography, and short growing
season, the grazing land and croplands yield much less production per acre
than do farms in the Corn Belt. As a result, to yield a respectable liveli-
hood, farms must be very large in size.
Strenuous efforts have been made, and are still continuing to
be made, to bring water to these dry lands. Irrigated tracts are found along
the river valleys, along the margins of the mountains, and even at spots
where water can be lifted to the surface by pumps.
Physiography: More specifically, the Plains Region is an elevated
plateau that slopes gradually upward to the west. In most parts, the surface
is almost monotonously flat and treeless, but there is much broken and rough
land too. The principal rivers—the Canadian, Cimmaron, Arkansas, Platte,
Yellowstone, and Missouri River and their tributaries--have eroded the lands
paralleling their course to such an extent that much of it is very rolling
and broken. Isolated mountains, high hills, and mesas in eastern Montana,
Wyoming, Colorado and New Mexico add to the quantity of the land that does
not follow the characteristic tableland patterns.
Mineral Resources: Mineral resources are very limited in this
region, with fuels being the most important. Coal is mined in Colorado,
Wyoming and Montana, but the volume of production is small in comparison with
output in other U.S. regions. Petroleum and gas resources are also secondary
in comparison to those fields in central Texas, Oklahoma and the Gulf Coast.
Deposits of lignite, low-grade coal, and some uranium, are found in the
region, but they are minor compared to the mineral resources of the Rocky
Mountains.
Soils and Climate: The soils are moderately fertile. As a general
principle, moisture, not soil, is the limiting factor in crop production in
the region. Except for the rougher lands mentioned above, and sections
where the soil is sandy, the land could be tilled and the soil rendered highly
productive if there were sufficient moisture.
Moisture-laden winds precipitate their moisture on the western
slopes of the Rocky Mountains. When they cross the Great Divide, they become
warm and dry and furnish very little rainfall to the region. The average
rainfall, in the range of 12 to 16 in/year, is uncertain and variable, and it
is not uncommon for some areas to receive one-half or twice its annual rain-
fall.
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Another major agricultural problem is soil erosion. Where the
soil is floury and light, it blows easily in the high winds, which are
common. Damage can also result from water erosion in the unusually wet years
or torrential rains that occasionally occur.
Animal Ecology: Among the larger and most important animals in
this area are the pronghorn antelope. The coyote is a marauder on sheep and
game. Prairie dogs, rabbits, :gp,phers, snakes and lizards thrive because they
require but modest quantities of food and water, and because they avoid
hazardous conditions by remaining'muchfof the tiine 'underground. Grasshoppers
and locusts in dry years are plentiful.
The Wyoming Big Horn Basin: Characteristic of this region is the
Big Horn Basin in Wyoming. Because it is adjacent to the Rocky Mountains,
much of the land is hilly, broken, and rough, and much of the soil is stony
or has a clay composition. Since the basin is almost completely surrounded
by mountains, there is only a scanty rainfall. There is scarcely enough
rain to make the rangeland worth grazing in many years, and far too little
for dry-farming in most parts. There are no forests, only a few mines, and
a modest scattering of oil fields. Nevertheless, the population of the Big
Horn Basin is prosperous and lives at a level of comfort that surpasses that
of the plains located to the east.
The technological secret of this success has been irrigation.
Streams descending from the mountains have been tapped, and long strips of
irrigated land extend out into the flatlands. Large farms and raches are
based on the principle of modest returns from vast tracts of land, averaged
out over a period of years.
Outside the strips that have been transformed by irrigation, some
of the most adverse agricultural conditions in the entire region are found.
C. Rocky Mountains and Intermountain Basins
Introduction: The majority of the sagebrush study region is comprised
of mountains and intermountain basins. Characteristically this region is
composed of rugged mountains that are too high, rocky, barren, and steep for
settlement, and vast deserts too hot and dry to support more than a token
amount of plant life. As a result of these conditions, this region has a
small population.
Interspersed throughout this generally unfavorable setting are
plateaus, valleys and river bottoms that have enough rainfall and sufficiently
good soil to produce drought-resistant cereal and other crops, or which can
be irrigated to produce a great variety of cash crops and livestock feed.
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In many sections the soil and other conditions for agriculture are ideal,
except for a deficiency of moisture. Huge irrigation and reclamation projects
have converted several such places into highly productive agricultural garden
spots, including the Snake River Plains of southern Idaho, the Great Salt
Lake in Utah, the Gila River and Salt River of Arizona and the Columbia
Basin in Oregon and Washington.
In addition to scattered rich agricultural areas, large deposits
of minerals exist. A major share of the nation's supply of copper, lead,
silver, gold, zinc, tungsten, and other minerals is mined here at widely
scattered points.
Because of more limited rainfall, the forests of this region are not
so dense and quick-growing as in the Pacific Northwest. Even the semibarren
desert wastes, if not grazed too heavily, are able to support livestock.
Major Physical Characteristics: When viewed in economic terms,
this vast area has four major physical regions, described in the following
paragraphs.
The Rocky Mountain Ranges: This area is a tangled mass of
peaks and ranges extending from Montana, Idaho, Wyoming, Colorado to
New Mexico. High ranges with deep valleys between them are characteristic
of the region. At medium altitudes, on more gentle slopes, forests grow,
and several scattered wider valleys can be farmed.
Western Desert, Semidesert and Mountains: This area comprises
the Great Basin, Colorado Plateau and Columbia Plateau territory west of the
Rocky Mountains. Scattered mountain ranges are interspersed with broad
prairie-like and nearly level stretches of desert or semidesert land, or
eroded plateaus that also are very scantily vegetated. All of Nevada,
southern, western and eastern Utah, northern Arizona and southeastern Oregon
and eastern California fall into this region.
The Snake River and Wasatch Front: This area is an oasis
wedged in between the Rockies and the desert. It is a man-made region; water
from mountain streams has been diverted to irrigate the desert and to support
growing commerical and industrial cities.
The Trans Pecos and Southern New Mexico; This area is a
southward extension of the Rocky Mountains. Here the ranges are not so
high, and are more scattered with broader valleys between. Because of less
rainfall, even on the upper slopes, this is semiarid county where the lower
slopes and valleys are covered only with brush and grass.
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Mineral and Water Resources; Mineral deposits of a very great
variety may be found at many different locations in the region. Copper
deposits in Montana, Utah, New Mexico and Arizona are most important; uranium
finds on the Colorado Plateau and in the Wyoming Basin somewhat less so.
Silver, lead and zinc are also found.
Moisture falling on the mountain slopes is a valuable resource for
generating electrical power and for irrigating the desert lands. Limited
urban development and economic growth have resulted in large part from the
damming of the mountain stream and rivers for these purposes. The economy
of much of the region rests on the ability to control and exploit water
resources.
The region is drained primarily by the Snake and Colorado Rivers
and their tributaries, and by streams that have no outlet. Instead of
draining moisture to points outside, these streams merely develop temporarily
after a rain and flow across the desert plateaus to low basin-like depressions
where the water is absorbed or is evaporated into the dry hot temperature.
Shortly after a storm, the stream and the lake into which it empties have
both dried up. After being repeated for many centuries, this process has
caused large quantities of mud and silt to be washed from the mountains into
the flats, and (together with wind erosion) is responsible for the level
terrain between most of the ranges, particularly in the Great Basin, and for
an accumulation of saline and alkaline chemicals in the soil, which destroy
plant life.
Agriculture: The majority of the agricultural enterprises are
characterized by migratory grazing of large herds of sheep and cattle. The
amount of forage available per acre is so small that herds must be moved to
prevent overgrazing and to take advantage of seasonal growth. The animals
may be driven to upper mountain pastures in the summer and wintered in the
valleys. Two of the major problems faced by ranchers are water for their
cattle and growing sufficient feed for the winter months when the range is
either covered with snow or provides inadequate grazing. Wild hay, sorghum,
barley and irrigated forage crops, are grown to relieve this problem.
Irrigated farming, another major agricultural enterprise, is
important in growing cash crops of sugar beets, potatoes, vegetables and
fruits. Where soil conditions are favorable and water can be diverted from
streams, obtained from artesian wells, or pumped from drilled wells, this
type of agriculture is found. In some places these developments are the
result of very large reclamation projects, and have involved a complete
transformation of the desert. In other instances they are little more than
exploitation of a small stream to irrigate a narrow strip of valley soil,
or pumping water to irrigate an isolated tract. Although a small percentage
of the land area is irrigated cropland, roughly one-third of all farm income
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is derived from the cash sale of crops grown on irrigated land. Dry-land
fanning, dairy and poultry farming are definitely secondary types of farming
in the region.
Climate and Weather; The great physical varieties found in this
region affect the climate in the region. While certain generalizations are
possible, relief exerts the main control upon temperature and precipitation,
and overall descriptions of climate become impossible.
The eastward flowing winds precipitate a liberal amount of moisture
upon most of the western slopes of the Rockies and Sierra Nevada Range,
and even upon the upper slopes of the lower ranges of mountains lying between
them. Hence, forests grow on the mountain slopes, and a very active and
large lumbering and wood products industry is located here. However, all
the lower-lying areas—the valleys, the ihtermountain basins, and the lower
plateaus—receive very little rainfall. Because of silty or sandy soil
most of the moisture that does fall on them quickly evaporates and the land
is largely treeless.
The northwestern parts of the region are under the influence of
Pacific Coast air, and have a winter-spring rainfall maximum, while the
southeastern part has a summer maximum and receives much of its rain from
violent thunderstorms. Everywhere local conditions of rain and rain shadow
are produced by local relief. The main rain-bearing winds west of the
Continental Divide blow from the Pacific and bring 80-100 in. of precipitation,
including heavy falls of snow to the mountains along the coast. Immediately
east of these mountains occurs a change of dramatic suddenness: the rain
shadow falls across the adjoining plateaus and basins, and the dense forests
of the mountain slopes are separated by only a narrow transition belt from
desert-scrub areas where annual precipitation averages 8 to 10 in. Eastward
again the surface rises, and the rainfall gradually increases toward the
Rockies.
Vegetation; Climate in turn affects vegetation, which tends to
vary with both the amount of rainfall and the time and duration of the
wetter season. A regular sequence of vegetation zones can be distinguished,
both horizontally and vertically; that is, a sequence of zonal changes
generally holds good, both at low elevations and high, and between the heart
of the desert and the better watered lands surrounding it. The vertical
changes move, in general terms, from scrub through grass, woodland and
forest. At one end are the lowest-driest areas, desert-shrub vegetation
covers the floor of much of the Great Basin. Those parts of the area that
are beds of former lakes form salt deserts, on which saltgrass and sage are
found. From this vegetational nadir, an increase in rainfall produces a
sagebrush-grass combination.
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In the southwestern states there is sufficient late summer rain
to produce semidesert grasslands, valuable for yearlong grazing. Elsewhere
in the intermountain region, however, lack of rain restricts growth of
grasses, and the value of range for grazing purposes varies inversely with
the amount of sagebrush.
Animal Ecology: The animal ecology follows closely the dominant
climate and natural vegetation variations in the region. Since the dominant
natural vegetation is grassland and steppe desert, it follows that the
fauna are largely herbivorous. In New Mexico the pronghorn antelope ranges
into the subtropical grassland; farther west are the Arizona white-tailed
and mule deer. Several important carnivores—the coyote, desert fox and
puma—live by preying upon them and upon smaller animals.
The grasses of the steppe supply an abundance of seeds, the shrubs
and occasional areas of dry forest furnish nestling places, and the mild
winter offers a refuge from more rigorous climates. As a result, these
lands contain a plentiful bird life: ctacks, geese, turkeys, guinea fowl,
pheasants, and others.
Smaller subtropical steppe animals include rabbits, marsupial
rats, lizards, and snakes. Insect life is at times abundant despite the
general aridity. The drier margins of the steppe are the natural breeding
grounds of locusts and grasshoppers.
D. Current and Potential Sagebrush Areas
Figure 2 indicates current and potential sagebrush areas in the
United States. Much of these areas are characterized by thin soils,
restricted moisture, and other extreme environmental conditions. However,
large acreages of productive agricultural land in the 11 states also have
deteriorated as a result of overgrazing and indiscriminate plowing. The
result has been the growth of sagebrush (see Table I) and cheatgrass on
much of the land, replacing valuable perennial grasses; the potentially
productive aspen has been taken over by timber and brush burns, and many
semidesert brush and grass ranges. However, improved farming practices
and strict grazing management are restoring large parcels of this land
where the more productive kinds of grass exist; where there is good topsoil;
and where sagebrush and mesquite, which compete for available moisture with
more valuable forage plants, can be economicaly eliminated.
11
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Wyoming
F-— Nevada
Utah
Colorado
California
Arizona
New Mexico
,*\ Sagebrush Steppe (Artemisia)
Great Basin Sagebrush (Artemisia),
Wheatgrass-Needlegrass Shrubsteppe (Agropyron-Stipa-Artemisia)
Figure 2 - Potential Natural Vegetation (After Kuchler, 1966)
(Areas of Artemisia Dominance)
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TABLE I
CHARACTERISTICS OF SAGEBRUSH (ARTEMISIA) WHERE IT
IS THE DOMINANT POTENTIALNATURAL VEGETATION
Great Basin Sagebrush (Artemisia)
Physiognomy: Fairly dense to open vegetation of low to medium tall
shrubs.
Dominants: Big sagebrush (Artemisia tridentata)
Other Components: Agropyron smithii (northern part), Artemisia nova.
Artiplex confertifolia. and species of Astragalus,
Chrysothamnus, Coleogyne (southern part), Ephedra,
Eriogonum, Lupinus. Phacelia. Tetradymia
Occurrence: Great Basin, eastward to Colorado, southward to
Arizona and Mew Mexico
/
Sagebrush Steppe (Artemisia-Agropyron)
Physiognomy: Dense to open grassland with dense to open shrub synusia
Dominants: Bluebunch wheatgrass (Agropyron spicaturn), Big sagebrush
(Artemisia tridentata)
Other Components: Artemisia arbuscula (western part), A. nova (eastern
part), Balsamorrhiza sagittata. Festuca idahoensis,
Lithospermum ruderale, Lupinus sericeus, Orvzopsis
hymenoides. Phlox spp., Poa nevadensis. P. secunda.
Purshia tridentata. Sitanion spp.
Occurrence: Pacific Northwest and eastward to Rocky Mountains
Wheatgrass-Needlegrass Shrubsteppe (Agropvron-Stipa-Artetnisia)
Physiognomy: Open grasslands, sometimes fairly dense, with scattered
dwarf shrubs
Dominants: Western wheatgrass (Agropyron smithii). Big sagebrush
(Artemisia tridentata). Plains bluegrass (Poa arida),
Needle-and-thread grass (Stipa comata)
Other Components: Agropyron spleaturn, Artemisia cana, A. frigida. Artiplex
canescens. A^ confertiofolia. Carex filifolia. Eurotia
lanata. Koeleria cristata. Sarcobatus vermiculatus
Occurrence: Montana, Wyoming
Source: American Geographical Society, Manual to Accompany the Map "Potential Natural Vegetation
of the Conterminous United States. A. W. Kuchler, 1964, Special Publication No. 36.
13
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Acreage of Sagebrush. Location and Species: There seem to be
differences of opinion as to the acreage of sagebrush in the 11 western
states.
The most common estimate of 90 to 96 million acres no doubt comes
from the publication by McArdle et al. '(1936),— / but more recent surveys,
and publication by Beetle (1960),i/ state that McArdle's estimate is
approximately 50 million acres too small for big sagebrush (A. tridentata).
Instead of 90 to 96 million acres as originally estimated, we could adjust
this figure upward to 144 million acres.
Although there are vast acreages of sagebrush in the 11 western
states, commercial pesticide applicators, ranchers, advocates of the sage-
brush control program as well as those adverse to the .program., realize that
a large number of species exist. Some species are specific-site indicators
of poor, shallow soils with limited moisture-holding capacities. These areas
should -not be ^controlled because results will not lead to increased forage
production and costs may be excessive.
The following table (Table II), extracted from Beetle's (1960)
bulletin, gives square miles of the respective sagebrush types in the
western states.
14
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TABLE II
SQUARE MILES OF SAGEBRUSH IN THE WESTERN UNITED STATES
A. Square Miles of Sagebrush in the 11 Western States Listed Individually
by States and by Species (Note: for acreage, multiply by 640)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Wyoming
Idaho
Montana
Nevada
Oregon
Utah
Colorado
California
Washington
Arizona
New Mexico
58,201
58,021
54,211
53,032
42,021
41,132
30,203
28,221
23,011
17,112
17,110
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
A.
A_^
A.
A.
A.
A,
A'.
A.
A.
A.
tridentata
cana
nova
arbusoula
bigelovii
tripartita
rigida
longiloba
rothrookii
pygamea
argilosa
226,374
53,221
43,301
39,112
34,010
13,002
8,010
5,120
103
21
1
Total square miles - 422,275
B. Square Miles of Sagebrush Types by States (gjquare miles in parentheses)
1. A^ argilosa: Colorado (1)
2. A. arbuscula subsp. arbuscula: Oregon (10,000), Idaho, California
and Nevada (8,000), Montana and Wyoming (2,000), Washington
(1,000), and Utah (10)
3. A^ arguscula subsp.thermopola; Wyoming (100), Idaho and Utah (1)
4. A. bigelovii; Arizona and New Mexico (12,000), Utah (8,000),
Colorado and Nevada (1,000), and California (10)
5- A. cana subsp. cana: Montana (20,000), Wyoming (6,000), and
Colorado (100)
6. A. cana subsp. bolanderi; California (6,000), Oregon (4,000), and
Nevada (10).
7. A. cana subsp. viscidula; Wyoming (5,000), Colorado (4,000), Utah
(3,000), Nevada (2,000), Montana (100), and New Mexico (10)
15
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8. Aj, longiloba: Wyoming (2,000), Colorado, Idaho and Nevada (1,000),
Utah (100), and Montana and Oregon (10)
9. A. nova; Nevada (18,000), Utah (10,000), Idaho (6,000), Colorado
and Wyoming (4,000), Montana (1,000), Arizona, California and
New Mexico (100), and Oregon (1)
10. A. pygmaea; Nevada and Utah (10), and Arizona (1)
11. A. rigida; Oregon and Washington (4,000), and Idaho (10)
12. A. rothrookii; California (100), Colorado (2), and Wyoming (1)
13. A. tridentata subsp. tridentata; Idaho (25,000), Oregon (22,000),
Nevada (20,000), Utah (13,000), Washington (11,000), California
(10,000), Colorado (8,000), Arizona and New Mexico (5,000),
Wyoming (1,000), and Montana (100)
14. A. tridentata subsp. tridentata f. parishii: Arizona, California,
Oregon, and Washington (10)
15. A. tridentata subsp. vaseyana: Wyoming (35,000), Montana (30,000),
Colorado (12,000), Idaho (10,000), Utah (7,000), California and
Washington (4,000), Nevada (3,000), and Oregon (1,000)
16. A._ tridentata subsp. vaseyana £_._ spiciformis; Wyoming and Colorado
(100), Idaho and Utah (10), and Montana, Washington, California
and Nevada (1)
17. A. tripartita subsp. tripartita; Idaho (5,000), Washington (3,000),
Montana, Idaho and Wyoming (1,000), Utah and Nevada (1)
18. A^ tripartita subsp. rupicola; Wyoming (2,000)
C. Square Miles of Sagebrush in States by Types (square miles in parentheses)
1. Arizona: A. bigelovii (12,000), A^ tridentata subsp. tridentata
(5,000), A._ nova (100), A^ tridentata subsp. tridentata f. parishii
(10), A. cana subsp. viscidula (1), A. pygamea (1)
2. California: A. tridentata subsp. tridentata (10,000), A. arbuscula
subsp. arbuscula (8,000), A. cana subsp. bolanderi (6,000),
A. tridentata subsp. vaseyana (4,000), A. rothrookii and A._ nova
(100), A^ bigelovii and A_^ tridentata subsp. tridentata f_^ parishii
(10), and A. tridentata subsp. vaseyana f. spiciformis (1)
16
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3. Colorado: A._ tridentata subsp. vaseyana (12,000) A_._ tridentata
subsp. tridentata (8,000), A._ nova and A._ cana subsp. viscidula
(4,000), A^ bigelovii and A._ longiloba (1,000), A^ cana and A_._
tridentata subsp. vaseyana f^ spiciformis (100), and A^ argilosa
(1)
4. Idaho: A. tridentata subsp. tridentata (25,000), A. tridentata
subsp. vaseyana (10,000), A. arbuscula subsp. arbuscula (8,000),
A. nova (6,000), A. tripartite subsp. tripartite (5,000), A. cana
subsp. viscidula (3,000), A. longiloba (1,000), A. rigida and
A. tridentata subsp. vaseyana f^ spiciformis (10), A_^ arbuscula
subsp. thermo pola (1)
5. Montana: A. tridentata subsp. vaseyana (30,000), A. cana subsp.
cana (20,000), A. arbuscula subsp. arbuscula (2,000), A. nova and
A._ tripartita subsp. tripartite (1,000), A_._ tridentata subsp.
tridentata and A_._ cana subsp. viscidula (100), A_._ longiloba (10),
and A. tridentata subsp. vaseyana f. spiciformis (1)
6. Nevada: A. tridentata subsp. tridentata (20,000), A. nova (18,000),
A. arbuscula subsp. arbuscula (8,000), A. tridentata subsp. vaseyana
(3,000), A^ cana subsp. viscidula (2,000), A. bigelovii and
A. longiloba (1,000), A_._ cana subsp. bolanderi. A^ pygmaea.
A._ tridentata subsp. tridentata f. parishii (10), and A. tripartita
subsp. tripartita and A. tridentata subsp. vaseyana £_._ spiciformis
(1)
7. New Mexico: A. bigelovii (12,000), A. tridentata subsp. tridentata
(5,000), A. nova (100), A. cana subsp. viscidula (10)
8. Oregon: A. tridentata subsp. tridentata (22,000), A. arbuscula
subsp. arbuscula (10,000), A. rigida (4,000), A^ cana subsp.
tripartita (1,000), A^ longiloba and A^ tridentata subsp. tridentata
f. parishii (10), and A. nova (1)
\
9. Utah: A. tridentata subsp. tridentata (13,000), A. nova (10,000),
A^ bigelovii (8,000), A. tridentata subsp. vaseyana (7,000),
A._ cana subsp. viscidula (3,000), A._ longiloba (100), A^ tridentata
subsp. tridentata J_._ spiciformis, A^ pygmaea. and A. arbuscula
subsp. arbuscula (10), A^ tripartita subsp. tripartita and A^
arbuscula subsp. thermopola (1)
10. Washington: A. tridentata subsp. tridentata (11,000), A. rigida.
A^ tridentata subsp. vasevana (4,000), A._ tripartita subsp.
tripartita (3,000), A^ arbuscula subsp. arbuscula (1,000),
A^ tridentata subsp. tridentata £._ parishii '(10), and A_^ tridentata
subsp. vaseyana f. spiciformis (1)
17
-------
11. Wyoming: A. tridentata subsp. vaseyana (35,000), A. cana subsp.
cana (6,000), A. cana subsp. viscidula (5,000), A. nova (4,000),
A. tripartita subsp. rupicola. A. longiloba and A. arbuscula
(2,000), A_^ tridentata subsp. tridentata and A., tripartita
subsp. tripartita (1,000), and.A. tridentata subsp. vaseyana f.
splciformis and A._ arbuscula subsp. thermopola (100)
18
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REFERENCES
1. Beetle, A. A., A Study of Sagebrush (the section of tridentatae of
Artemisia), Wyoming Experiment Station Bulletin 368, p. 83 (1960)
2. McArdle, R. F., et al., "The White Man's Toll," Western Range, U.S.
Senate Doctrine 199, pp. 81-116 (1936).
General
Bogue, Donald J., and Calvin L. Beale, Economic Areas of the United
States. The Free Press of Glencoe, Inc. (1961).
Feneman, Nevin, Physiography of the Western United States. McGraw-Hill
Book Company.
Highsmith, Richard M., Jr., Atlas of the Pacific Northwest. Oregon
State University Press (1968).
Hunt, Charles B., Physiography of the United States. W. H. Freeman
and Company (1967).
Kuchler, A. W., Manual to Accompany Map, "Potential Natural Vegetation
in the Conterminous United States" (1964).
LaRousse Encyclopedia of World Geography. Odyssey Press, New York (1965).
Lechleitnes, R., Wild Mammals of Colorado (1969).
McKenny, Margaret, Wildlife of the Pacific Northwest (1954).
Patterson, J. H., North America. A Geography of Canada and United
States, Oxford Press, 3rd Edition (1965).
Smith, J. Russell, and M. Ogden Phillips, North America. Its People
and The Resources. Development, and Prospects of The Continent As the
Home of Man, Harcourt, Brace and Company, New York (1942).
White, C. Langdon, and George T. Renner, Human Geography. An Ecological
Study of Society. Appleton-Century-Crofts, Inc., New York (1948).
19
-------
Yocum, Charles, Wildlife and Plants of the Southern Rocky Mountains (1969)
Western Vegetation
Castetter, Edward F., The Vegetation of New Mexico, Albuquerque, New
Mexico, University of New Mexico, Third Annual Research Lecture (1956).
Daubenmire, Rexford F., "Vegetational Zonation in the Rocky Mountains,"
Botanical Review, Vol. 9, pp. 325-393 (1942).
Darrow, Robert A., Arizona's Range Resources and Their Utilization I:
Cochise County, Tucson, Arizona, University of Arizona, Agricultural
Experiment Station, Technical Bulletin No. 103 (1946).
Fautin, Reed W., "Biotic Communities of. the Northern Desert Shrub Biome
of Western Utah," Ecological Monographs. Vol. 16, pp. 251-310 (1946).
Gardner, J. L., "Vegetation of the Creosote Bush Area of the Rio Grande
Valley in New Mexico," Ecological Monographs. Vol. 21, pp. 379-403
(1951).
Heerwagen, Arnold, Mixed Prairie in New Mexico. In: J. E. Weaver and
F. W. Albertson: Grasslands of the Great Plains, Lincoln, Nebraska,
Johnson Publishing Company, pp. 284-300 (1956).
Humphrey, Robert R., Arizona Range Resources II; Yavapai County. Tucson
Arizona, University of Arizona, Agricultural Experiment Station,
Bulletin No. 229 (1950).
Humphrey, Robert R., Forage Production on Arizona Ranges III; Mohave
County, Tucson, Arizona, University of Arizona, Agricultural Experiment
Station, Bulletin No. 244 (1953).
Humphrey, Robert R., Forage Production on Arizona Ranges IV; Coconino.
Navalo and Apache Counties, Tucson, Arizona, University of Arizona,
Agricultural Experiment Station, Bulletin No. 266 (1955).
Humphrey, Robert R., The Desert Grassland, Tucson, Arizona, University
of Arizona, Agricultural Experiment Station, Bulletin No. 299 (1958).
/
Humphrey, Robert R., Forage Production on Arizona Ranees V; Pima. Final
and Santa Cruz Counties. Tucson, Arizona, University of Arizona,
Agricultural Experiment Station, Bulletin No. 302 (1960).
20
-------
Hurd, Richard M., "Grassland Vegetation in the Bighorn Mountains, Wyoming,"
Ecology, Vol. 42, pp. 459-467 (1961).
Johnson, W. M., Vegetation of High Altitude Ranees in Wyoming as Related
to Use By Game and Sheep. Laramie, Wyoming, University of Wyoming,
Agricultural Experiment Station, Bulletin No. 387 (1962).
Lindsey, Alton A. , "Vegetation and Habitats in a Southwestern Volcanic
Area," Ecological Monographs. Vol. 21, pp. 227-253 (1951).
Livingston, Burton E., and Forrest Shreve, The Distribution of Vegetation
in the U.S. asRelated to Climatic Conditions. Carnegie Institution
of Washington, Publication No. 284 (1921).
Marks, John B., "Vegetation and Soil Relations in the Lower Colorado
Desert," Ecology. Vol. 31, pp. 176-193 (1950).
Nichol, A. A., The Natural Vegetation of Arizona. Tucson, Arizona,
University of Arizona Agricultural Experiment Station, Technical
Bulletin No. 127 (1952).
Parish, S. B., "Vegetation of the Mohave and Colorado Deserts of Southern
California," Ecology. Vol. 11, pp. 481-499 (1930).
Ramalay, Francis, "Sandhill Vegetation in Northeastern Colorado,"
Ecological Monographs. Vol. 9, pp. 1-51 (1939).
Shreve, Forrest, "The Desert Vegetation of North America," Botanical
Review. Vol. 8, pp. 195-246 (1942).
Shreve, Forrest, The Vegetation of the Sonoran Desert. Carnegie
Institution of Washington, Publication No. 591 (1951).
Strickler, Gerald S., Vegetation and Soil Condition Changes on the
Subalpine Grassland in Eastern Oregon. Portland, Oregon, Pacific
Northwest Forest & Range Experiment Station, Research Paper No. 40
(1961).
Whitfield, C. J., and E. L. Beutner, "Natural Vegetation in the Desert
Plains Grassland," Ecology. Vol. 19, pp. 26-37 (1938).
Wright, J. C., and Elnora A. Wright, "Grassland Types of South-Central
Montana," Ecology, Vol. 29, pp. 449-460 (1948).
21
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III. THE HISTORY OF HERBICIDE USE IN THE STUDY AREA
Prior to L940, relatively few synthetic organic pesticides were
available. Only 14 herbicides were sold in the United States then; eight
times that number were sold in 1963.—'
In previous years, ranchers attempted to control sagebrush mainly
by burning.—' In many instances that method of treatment was of little
value, and the sagebrush returned, often thicker than before. Roto beating
and other control measures also were tried, but generally these proved; to
be slow and expensive.
As early as 1946, big sagebrush was shown to be susceptible to
treatment with the sodium salt of 2,4-D.-3-/ Other studies in the 1950fs
confirmed the feasibility of using 2,4-D for the control of sagebrush.Ar5/
Following those initial studies, treatment of sagebrush with herbicides
was initiated in several areas. For example, in 1952 the University of
Wyoming, with the cooperation of the Big Horn National Forest officials
and the Big Horn National Forest Permittees Association, carried out one
of the first significant aerial sprayings of sagebrush with chemicals.£/
The results of those trials demonstrated that it was possible to treat sage-
brush with herbicide at a reasonable cost with a 200 to 400 percent increase
in grass production.
In 1954, approximately 1,000 acres of sagebrush were sprayed in
Sublett County, Wyoming, under the auspices of the Agricultural Conservation
Program of the Agricultural Stabilization and Conservation Service (ASCS).lj./
During the next year an additional 1,100 acres were sprayed in Sublette
County and 890 acres were sprayed in Washakie County. Thereafter, the
number of acres sprayed steadily increased each year. Table III summarizes
the extent of spraying for sagebrush control in Wyoming between 1952 and
1970. Nearly 1,300,000 acres of sagebrush have been sprayed in Wyoming by
all government agencies and individuals through 1970. Of that total acreage,
about 800,000 acres were sprayed by landowners under ASCS sponsorship,
and about 200,000 additional acres were treated by ranchers without ASCS
support. Through 1967, approximately 300,000 acres were chemically treated
by various other public agencies. Data concerning the number of acres
treated for 1968, 1969, and 1970 are incomplete at the present time. However,
if we assume that about 50,000 acres of sagebrush were treated each of the
three years by public agencies, an estimated total of 1,449,607 acres would
have been treated between 1952-1970 in Wyoming.
A typical sagebrush area on the Red Desert of Wyoming is shown
in Figure 3. Average production for the area is only 100 Ib/acre of air-dry
grass. Figure 4 shows the same area after spraying with 2,4-D. Following
herbicide treatment, grass production averaged over 300 Ib/acre.
22
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TABLE III
ESTIMATED TOTAL ACREAGE OF SAGEBRUSH SPRAYED
WITH CHEMICALS IN WYOMING. 1952-1970
Chemical Control of Sagebrush By:
Landowners
Year
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
Totals
Under ASCS
1,000
1,990
10,083
3,795
19,533
24,912
16,656
25,246
35,374
38,621
59,712
82,602
83,005
115,923
96,601
96,573
92,036
803,662
Not Under ASCS
1,050
420
570
3,417
5,105
7,597
7,283
9,437
14,204
22,656
15,379
18,288
17,398
16,995
17,077
14,399
14,427
13.964
199,666
Agencies
33
690
3,473
1,725
8,186
5,475
21,623
16,351
18,303
12,860
19,868
21,997
25,498
41,742
58,205
40,250
296,279-/
Total
1,083
1,110
5,043
3,715
21,686
14,375
48,753
48,546
44,396
52,310
77,898
75,997
103,498
141,742
158,205
173,250
111,000
111,000
106.000
1,299,607
a/ Through 1967.
Sources: Acreage Under ASCS--Wyoming State ASCS Offices.
Acreage by Public Agencies—Wyoming State Bureau of Land Management
and Individual U.S. Forest Service Supervisor's Offices.
1952-62 Data—Kearl. W. G., "A Survey of Big Sagebrush Control in
Wyoming, 1952-1964," Wyo. Exp. Sta., M.C. 217 (Nov. 1965).
1963-67 Data—Kearl, W. G., Unpublished Data.
23
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**P!>^^'- '•^>"
-------
In Arizona, the records of the Bureau of Land Management (BLM)
show that about 30,827 acres of sagebrush have been treated since 1954.U
Only about 10,577 acres were treated with herbicide, i.e., aerial application
of 2,4-D. The remainder was treated by dragging a heavy anchor chain or
railing, and by twice-over disc plowing. About 357,000 acres in Arizona
are classified as sagebrush type. Most of the pinyon-juniper type has an
understory of sagebrush, but is not included in the total sagebrush acreage.
The major species of sagebrush in the state include big sagebrush, Artemisia
tridentata; sand sagebrush, A. filafalia; and black sagebrush, A. nova.
Big sagebrush comprises about 90 percent of the total.
The chemical control of sagebrush in Montana (BLM land) started
in 1958.—' For about 10 years, the chemical control of sagebrush was the
major tool emphasized in some areas for watershed site improvement and
protection.
Although rest-rotation systems are currently being employed, in
some instances sagebrush spraying is still an important tool. Spraying is
carried out particularly in areas where it is not practical to wait for
comparatively slow results produced by livestock management.
The chemical used in Montana has been 2,4-D with a variety of
carriers, including water, diesel oil and invert emulsion. Application
rates and pounds of chemical applied per acre have varied according to the
carrier used. The following table shows the rates and pounds per acre:
Pounds/Acre Application
Carrier 2.4-D Rate/Acre
No. 2 Diesel Oil 2 3 gallons
Water 2 5 gallons
Invert Emulsion 1.75 3 gallons
Although BLM personnel in Montana have tried a variety of appli-
cation and chemical rates, the best results have been obtained with the
3 gal. oil mix. That formulation has been used on a majority of projects,
and aircraft were used to apply the herbicide. Table IV shows a breakdown
of acres sprayed by calender year.
The first chemical control projects in Oregon were carried out
about 1956, utilizing information and results provided largely by the
Department of Agriculture Research Station, Squaw Butte, Oregon.-' Table V
gives the number of acres of BLM acreage sprayed per fiscal year.
25
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TABLE IV
ACRES OF SAGEBRUSH LANDS SPRAYED WITH 2.4-D
IN MONTANA
Acres
Year Sprayed
1958 1,200
1959 1,957
1960 1,195
1963 6,664
1964 12,343
1965 6,798
1966 11,262
1967 17,361
1968 18,124
1969 8,334
1970 8,501
1971 6,063
Total 95,450
TABLE V
CHEMICAL SAGEBRUSH CONTROL IN OREGON
Brush Control
Fiscal Year (Acres)
Prior to 6/30/63 185,000
1964 46,200
1965 43,800
1966 65,100
1967 40,100
1968 62,600
1969 56,300
1970 37,300
1971 3,500
Total 539,900
26
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In New Mexico, the Bureau of Land Management reported that there
have been three chemical sagebrush control projects.—' All were aerial
applications as follows:
1. 1964 - 320 acres - 2 Ib of 2,4-D/acre in 5 gal. of water
per acre—considered a failure.
2. 1970 520 acres - 2 Ib of 2,4-D/acre in 5 gal. of water
per acre--80 percent kill.
3. 1971 - 560 acres - 2 Ib of 2,4-D/acre in 5 gal. of water
per acre—kill not counted to date (October, 1971).
Information about total acreages of sagebrush treated on all
lands within the state is incomplete.
Artzll/ surveyed range management specialists in Idaho, Nevada,
Oregon and Utah, and determined that the following areas of sagebrush
have been treated chemically to date (1971):
Sagebrush Acres Treated
Area (2.4-D)
Idaho - Nonfederal 550,000
Nevada 150,000
Oregon 760,000
Utah 240,000
Forest Service Nevada,
Southern Idaho, Utah 300,000
Bureau of Land Mgt. - Idaho,
Nevada, Oregon, Utah 1,250,000
Total 2,950,000 Acres
Range specialists in the listed areas estimate that the treated
land represents less than 4 percent of the total acreage of sagebrush
(approximately 80,000,000 acresX— The Forest Service lands in Oregon,
which were not included in the estimate of total sagebrush area, might add
another 100,000 to 200,000 acres.
The estimated number of acres of sagebrush that have been treated
by nonchemical methods are shown in Table VI.
27
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TABLE VI
ACRES OF SAGEBRUSH TREATED BY NONCHEMICAL MEANS
(PRIMARILY PLOWED AND DRILLED) IN FOUR WESTERN STATES
States
Acres
Idaho - Nonfederal (very
rough est,)
Nevada- Nonfederal
Oregon- Nonfederal
Utah - Nonfederal
Forest Service - Utah, Nevada
and Southern Idaho
Bureau of Land Mgt. - Idaho,
Nevada, Oregon, and Utah
500,000
150,000
110,000
120,000
150,000
2,500,000
3,480,000
The number of acres of sagebrush treated chemically, and by
annual plowing and seeding are shown in Table VII.
TABLE VII
ACRES OF SAGEBRUSH TREATED WITH 2.4-D AND TREATED
BY PLOWING AND SEEDING IN FOUR WESTERN STATES
Acres Currently Treated
Annually
States
Idaho - Nonfederal
Nevada - Nonfederal
Oregon - Nonfederal
Utah - Nonfederal
Forest Service - Nevada,
Southern Oregon, and Utah
Bureau of Land Mgt. - Nevada,
Idaho, Oregon, and Utah
Chemically
(2.4-D)
60,000
10,000
105,000
19,000
30,000
49,000
273,000
Plowed &
..Seeded
11,000
12,000
11,000
8,500
10,000
113,000
165,000
Further insight concerning chemical sagebrush control is available
from data furnished by the Agricultural Stabilization and Conservation
Service (ASCS) on acres treated to control range shrubs under cost-sharing
programs (ASCS Practice B-3). The number of acreas treated by chemical
sagebrush control in Idaho, Nevada, Oregon, and Utah are as follows:
28
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Average Annual Acreage
State
Idaho
Nevada
Oregon
Utah
Remaining Acres
1957-61
22,000
7,000
20,000
11,000
60,000
Suitable
1963-66
43,000
12,000
37,000
27,000
119,000
for Treatment:
1968-70
53,000
13,000
114,000
16,000
196,000
Table VIII shoi
of the remaining sagebrush acreages believed to be suitable for treatment
by the use of current technology.—'
TABLE VIII '
ESTIMATED SAGEBRUSH ACREAGES SUITABLE
FOR FURTHER TREATMENT
Area
Idaho - Nonfederal
Nevada - Nonfederal
Oregon - Nonfederal
Utah - Nonfederal
Forest Service - Utah,
Nevada, and Southern Idaho
Bureau of Land Mgt. - Utah,
Nevada, Oregon and Idaho^'
By Chemicals
(2.4-D)
1,400,000
2,000,000
5,500,000
1,830,000
438,500
12,500,000
23,668,000
By Other
Methods
350,000
1,000,000
1,100,000
623,000
281,500
25,000,000
28,354,500
a/ Based on recent estimates tlhat about 10 percent of the range improvement
job is complete.
These data suggest that roughly another one-fourth to one-third
of the total sagebrush acreage, i.e., approximately 23.7 million of 80
million acres, in the four western states shown above could eventually be
treated with 2,4-D to further reduce sagebrush density.
29
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Typical of parts of these untreated regions is the big sagebrush
infestation common to range areas at the higher elevations (i.e., 8,000 ft)
receiving 20 in. annual precipitation. This is shown in Figure 5. Figure 6,
on the other hand, is a photograph of the same area after spraying with
2 Ib/acre of 2,4-D butyl ester. Air-dry forage production increased to
over 1,800 Ib/acre within 2 years following treatment.
30
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:3plPt£j
^&ta&i$
•x.•«!'... \vmtst v *» J
Figure 5 - Typical Big Sagebrush Infestation Common to Range Areas
Receiving 20 In. Precipitation per Year at 8,000 Ft Elevation.
Air-dry grass production is limited to approximately 500 Ib/acre,
Figure 6 - The Same Area as Above that was Sprayed with 2 Lb/Acre
2,4-D Butyl Ester at a Total Cost of $3.00/Acre. Air-dry forage
production increased to over 1,800 Ib/acre within 2 years after
application.
31
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REFERENCES
1. Ennis, W. B., Jr., "Selective Toxicity for Herbicides," Weed Res. 4,
93-104 (1964). ~"
2. Hyatt, A. W., "Sagebrush Control—Costs, Results, and Benefits," Paper
presented at the 18th Annual Meeting, American Society of Range
Management, Las Vegas, Nevada, February 9-12, 1965.
3. Hyder, D. W., "Controlling Big Sagebrush With Growth Regulation," J_..
Rge. Management. 6(2), 109-116 (1953).
4. Cornelius, D. R., and C. A. Graham, "Selective Herbicides for Improving
California Forest Ranges." J. Rge. Met.. 4J2), 95-100 (1951).
5. Kes singer, N. A., Jr., A. C. Hull, Jr., and W. T. Vaughn, Chemical Control
of Big Sagebrush for Central Wyoming. Rocky Mountain Forest and Range
Exp. Sta. Paper No. 9 (1952).
6. Kearl, W. C., "A Survey of Big Sagebrush Control in Wyoming." 1952-1964,
Mimeo Circular No. 217, Division of Agricultural Economics, University
of Wyoming, Laramie, November 1965.
7. Letter, Virgil L. Hart, Acting Chief, Division of Resources, Bureau of
Land Management, Phoenix, Arizona, October 8, 1971.
8. Letter, Harold C. Lynd, Acting State Director, Bureau of Land Management
Billings, Montana, November 3, 1971.
9. Letter, Howard R. DeLavo, Acting Chief, Division of Resources, Bureau
of Land Management, Portland, Oregon, October 20, 1971.
10. Letter, Keith E. Norris, Chief, Division of Resources, Bureau of Land
Management, Santa Fe, New Mexico, October 8, 1971.
11. Personal Communication, John L. Artz, Extension Range Specialist,
University of Nevada, Reno, Nevada, October 11, 1971.
12. U.S. Tariff Commission, United States Production and Sales of Pesticides
and Related Products, September 1971.
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IV. INVENTORY AND CURRENT HERBICIDE USE
Based on the number of acres of sagebrush reportedly treated by
spraying in 1970, both on government and private lands, slightly less than
400,000 acres were treated. This represents about 0.3 percent of the total
big sagebrush acreage. Current estimates of the total acres of sagebrush
treated with 2,4-D in the major states within the study area are shown in
Table IX.
The usual application rate of 2,4-D for sagebrush control in
1970 was 2 Ib of herbicide per acre for a total of approximately 800,000 Ib.
The U.S. Tariff Commission reported that the total sales of 2,4-D in this
country amounted to 43,917,000 Ib in 1970.1/ Therefore, it appears that
less than 2 percent of the 2,4-D sold was used for sagebrush control.
The only herbicide used for sagebrush control to any significant
extent is 2,4-D. Actually, 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) is
also an effective chemical control agent, but its cost, like that of another
useful phenoxy herbicide, Silvex, is the determining factor in the lack of
their use. In 1970, 2,4-D cost $0.30/lb as compared to $0.74/lb for 2,4,5-T,
and $1.05/lb for Silvex.!/
TABLE IX
ESTIMATED TOTAL NUMBER OF ACRES OF SAGEBRUSH
TREATED WITH 2,4-D IN THE STUDY AREA DURING 1970
Area Treated Number of Acres
Idaho, Nevada, Oregon, Utah^ 273,000
WyomingW 106,000
Montana^/ 8,501
Arizona, New Mexico^/ 1.000
Total 388,501
a/ Artz, J. L., Extension Range Specialist, University of Nevada (1971).
b/ Alley, H. P., Professor of Weed Control, University of Wyoming (1971).
£/ Lynd, H. C., Acting State Director, Bureau of Land Management, Billings,
Montana (1971).
d!/ Hart, V. L., Acting Chief, Division of Resources, Bureau of Land Manage-
mane, Phoenix, Arizona (1971).
33
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REFERENCES
1. U.S. Tariff Commission, United States Production and Sales of
Pesticides and Related Products, September 1971.
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V. APPLICATION TECHNIQUES AND HERBICIDE FORMULATIONS
USED TO CONTROL SAGEBRUSH
A. 2.4-D Formulations
Virtually all commercial spraying of sagebrush is now conducted
with one of the formulations of 2,4-D. The most common formulation em-
ployed is the butyl or isopropyl ester of 2,4-D with some use of a low
volatile ester near susceptible plants, or when spraying under critical
growing conditions.!/ The salts of 2,4-D (amine) are not highly effective
on sagebrush and are used only when 30-50 percent control is desired. This
practice is common where game animal forage considerations are of major
importance.
The selection of 2,4-D as the chemical of choice for treating
sagebrush evolved over a period of years of testing, and as a result of
experimentation with a variety of herbicides. Not only has 2,4-D proven
to be effective against sagebrush, but the material is safe when properly
used and its cost is reasonable.—'
As early as 1946 a limited study conducted in Oregon!/ showed
big sagebrush to be susceptible to the sodium salt of 2,4-D. Cornelius and
Graham!/ stated that big sagebrush was highly susceptible or hypersensitive
to 2,4-D, and showed that a satisfactory kill was obtained by applying 1 Ib
of the butyl ester of 2,4-D per acre in late June. The higher rates of ap-
plication gave higher kills, but not enough to warrant the greater expense.
One pound per acre applied 30 June gave 85 percent control, and 5 Ib/acre
applied 30 June gave 100 percent control.
Kissinger, Hull and Vaughn,^/ reporting on experiments conducted
at the Beaver Rim area near Lander, Wyoming, found that the isopropyl and
amyl esters of 2,4,5-T gave consistently highest kills for a given amount
of chemical. For example, 1 Ib acid equivalent of 2,4,5-T usually gave
somewhat higher kills than 2 l,b acid equivalent of 2,4-D, while both 2,4,5-T
and mixtures of 2,4,5-T and 2,4-D were more effective than 2,4-D alone.
The isopropyl ester formulations killed more big sagebrush than the propyl-
ene, glycolbutylether or the butoxyethanol esters. Maleic hydrazide and
the dinitro weed killers had little effect on big sagebrush in these experi-
ments. These studies revealed that 75 percent and higher kills of big sage-
brush could be obtained with as little as 1 Ib of 2,4,5-T ester per acre
or 2 Ib of the 2,4-D ester per acre.
Hull and Vaughn5-/ stated that the type and amount of chemical
which killed two-thirds or more of the brush plants varied with the carrier
and season. The butyl ester formulation of 2,4-D gave better results than
35
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did mixtures of 2,4-D and 2,4,5-T, or the contact sprays. They also found
that the higher the concentration of the chemical the better the kill.
One pound per acre of the 2,4-D killed, on an average, 63 percent of the
sagebrush plants; 1-1/2 Ib averaged a 64 percent kill; and 3 lb averaged
an 80 percent kill.
Hyder£/ working in Oregon stated that the butyl ester of 2,4-D
gave the best results for the money, even though the growth regulator,
2,4,5-T, killed more brush. One and one-half pounds per acre of butyl
ester gave 70-80 percent kill. Colorado workersZ/ showed that volatile
esters of 2,4-D gave more economical control of big sagebrush than the low
volatile esters. The herbicide, 2,4,5-T, made a poorer showing as an eco-
nomical means of control, was less effective than 2,4-D, and more costly.
Their tests demonstrated that the best all-around buy in chemicals for con-
trol of big sagebrush was the volatile ester of 2,4-D, such as butyl or iso-
propyl. A 1:1 mix of the isopropyl esters of 2,4-D and 2,4,5-T in an oil
emulsion caused an average mortality of 90 percent when applied on May 2,
16, and 24.^/ On the other hand, 2,4-D butyl ester in oil emulsion killed
86 percent, 2,4-D butyl ester in water killed 84 percent, and 2,4-D sodium
salt in an oil emulsion killed 35 percent. The difference between 84 per-
cent and the 90 percent is probably not a significant difference, and
therefore the two compounds may be considered to have been equal in effec-
tiveness.
Kissinger and Hurd£' related that, based on sagebrush plants
killed per dollar of treatment cost, 1 lb acid equivalent of 2,4,5-T iso-
propyl and amyl esters, mixed with diesel oil to a total volume of 3 gal/acre,
was the most efficient treatment tested. Other promising treatments in-
cluded 1 lb of 2,4,5-T low volatile propylene glycolbutyletherester per acre
and 2 Ib/acre of either isopropyl or low volatile esters.
Bohmont,2' observing the effects of chemicals 75 days after
treatment, noted that the low volatile (pentyl) ester of 2,4-D at 2 lb acid
per acre caused the most observable toxicity to sagebrush. While 2,4,5-T
treatments suppressed seedhead development, the plants partially recovered
and seedheads formed during the growing season. With 2,4-D treatment, seed-
heads were prevented from forming. BohmontlP.' also stated that 1 lb acid
per acre of the volatile ester gave 75 percent control 1 year after treat-
ment, and was equal to 1 lb acid/acre of the low volatile ester of 2,4-D.
The 2-lb ester treatment was equal to the 2-lb low volatile ester with an
average control of 34 percent. Highest control resulting from a single
treatment was 3 lb of 2,4-D ester, which killed 96 percent of the sage-
brush. The pentyl ester of 2,4,5-T at 1 Ib/acre was least effective, giv-
ing only 60 percent control.
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Bohmont further stated that 2,4-D compounds (both low volatile
and volatile) produced the greatest control per dollar invested. For the
western region as a whole, 2,4-D ester formulations were recommended for
the most economical control. One year's application of the 2,4-D acid
at 2 Ib/acre could be expected to kill 70-90 percent of the sagebrush, with
a second year application of 2 Ib 2,4-D acid per acre giving complete kill.
On the basis of extensive work conducted by Alley!!/ on the
effectiveness of herbicides for sagebrush control, the following conclu-
sions were reached;
(1) While 2,4-D and 2,4,5-1 may be used for the control of
big sagebrush, 2,4,5-T is neither as effective nor as economical as 2,4-D.
(2) There was no difference in the final sagebrush control
resulting from the 2 Ib acid per acre treatment of either the volatile or
low volatile esters of 2,4-D where growing conditions were not critical.
(3) One application of chemical is economical if 75 percent
or more of the brush is killed. Two applications would insure a maximum
control, but the cost would be greater.
Early reports on the chemical control of sagebrush varied in
their estimates of the effectiveness of the various 2,4-D and 2,4,5-T
formulations. None of the western experiment stations, nor the government
agencies engaged in the chemical control of sagebrush, recommend 2,4,5-T
or the amine formulations of 2,4-D for use in effective control of big
sagebrush. All stations in the western United States now recommend either
the butyl or isopropyl ester for control purposes. The Wyoming Agricul-
tural Experiment Station does, however, suggest that the low volatile ester
of 2,4-D be used in situations of poor moisture and poor growing conditions.
Research work and observations of spraying operations have indicated that
as high as 20 percent additional control can be obtained with the low vol-
atile ester as compared to the conventional esters under critical growing
conditions.
B. Carriers Used
Kissinger, Hull and Vaughn4-/ reported that the highest average
sagebrush kills were obtained when diesel oil was used as a carrier in
chemical treatment. Kissinger and Hurd§/ also reported that diesel oil
has generally been a better carrier for all chemicals than water. On the
other hand, the USDA Annual Report!!/ reported that average kill had been
higher when using water than when using oil, except in the ease of 2,4-D
isopropyl ester. Bohnumt^/ stated that there is no apparent difference in
the use of carriers in applying the chemical; water «r oil is recommended.
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However, Hull and Vaughnl/ relate that there was a tendency for oil as a
carrier to be more effective than water over longer periods. AlleyjJ./
states that water or oil can be used as a carrier in applying the chemical.
Because of the lower volumes of carrier utilized in aerial application and
the better coverage and penetration, oil is more popular and more exten-
sively used than water. Two gallons total volume of diesel oil and chemi-
cal per acre have given satisfactory coverage and control, whereas more
water is required to do the same job.
The grade of oil used should be no lower than No. 2 Grade diesel
oil. Use of low grade oil has caused rapid burning of sagebrush foliage,
poor translocation of the chemical, and poor control.
Although oil and water are the most common carriers for 2,4-D in
spraying operations in recent years, there has been tremendous interest in
the use of the invert emulsions, especially by the Department of Interior's
Bureau of Land Management. There are probably several reasons why this
one organization has used the invert emulsions, even though early research
and research conducted by Alley in Wyoming in 1Oftftl4/ shows that the use
of inverts produces large droplets that are not as effective, and do not
give adequate coverage, resulting in poor control of big sagebrush.
In the early 1960's, the Bureau of Land Management changed from
the use of oil to the use of water as a carrier for the chemicals. Although
no specific reasons were given for the change, indications were that the
Bureau believed there was a possibility of getting more chemical into the
mountain streams by the use of oil than water. However, Alley has pointed
out that oil is a very good penetrant of plants (i.e., sagebrush), and that
it is almost impossible to wash off.JA/ On the other hand, water will form
droplets on a leaf, and rainfall immediately after application can remove
herbicide from the leaves and increase the possibility of contaminating
underground water or streams within the area.
The Bureau of Land Management has conducted studies with invert
materials. In 1966, over 30,000 acres of big sagebrush were sprayed in
the desert areas of Wyoming using a bifluid invert system developed by the
Stull Chemical Company, As a result of those trials, the Bureau of Land
Management is now working on methods to reduce the size of the invert drop-
lets; satisfactory control cannot be obtained on big sagebrush without com-
plete coverage, and this cannot be accomplished with droplets in the neigh-
borhood of 50-100 microns. (The bifluid invert droplets originally; were
about 500 microns.)il'
The drift of herbicides, which can damage desirable susceptible
crops, is a function of wind and droplet size. Generally, the smaller the
droplets the greater the drift. However, it is essential to have a large
38
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number of droplets to obtain satisfactory control of wood species like
big sagebrush. In 1 gal. of spray per acre, there are only nine 500-micron
size droplets per square inch, as compared to 1,164 droplets of 100
microns.11 / These data indicate the need for small droplets to obtain
coverage necessary for the control of sagebrush. In the opinion of most
weed-control experts, the most effective and efficient way of obtaining
satisfactory control of big sagebrush is the use of oil as a carrier.M/
Invert emulsions appear to have their place, but apparently until the
liquid is broken up into about 100 microns in size, sagebrush will not be
effectively controlled. With this degree of pulverization, inverts will
drift as readily as droplets of oil.
C. Time of Application
Date of spraying or stage of plant growth was found to be one
of the most important factors for the success of spraying. Hull and
Vaughtui/ concluded that when twigs were 1/2 in. long and had approximately
one-half of their season's growth, the sagebrush plants were more sensitive
than when the twig growth was near completion and the flower stalks had
commenced to elongate. Averaging all treatments in which early and late
applications might be directly compared, there was an average kill of 66
percent for early spraying and 47 percent kill for late spraying. Treat-
ments made just prior to or during the early bloom stage of native blue-
grass gave the highest sagebrush kill.2.' Past work indicates that the
maximum susceptibility occurs during the period of most active growth in
spring or early summer.
Cornelius and Graham!/ reported that sagebrush in northern
California was more susceptible to 2,4-D when about 7 in. or half of the
twig growth had been obtained. However, in certain areas twig growth is
often less. Extreme variations in annual twig growth have been noted be-
tween different sites, between plants, and between years, according to
Bohmont.l/ He relates that the activity of 2,4-D and 2,4,5-T is adversely
affected by factors which impede normal plant growth. The optimum time to
treat a given plant to obtain maximum control is at the most active growth
stage, coupled with the lowest ebb of stored food reserves. Data collected
throughout the region indicate that big sagebrush should be sprayed when a
native blue grass (Poa secunda complex) is in full bloom; the common phloxes
are in the early seed formation stage of growth; and Idaho fescue (Festuca
idahoensis) is starting to head, this being the most active growth stage.
The sagebrush twigs should have rapid elongation at the time the chemicals
are applied for maximum effect.
39
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The Colorado workers indicate that the best time for spraying
in the Great Divide area, with its 7,000-ft altitude, is from the last
week of May until June 15. For each additional 1,000 ft in elevation,
spraying should be delayed 7 to 10 days, and for each 1,000 ft lower ele-
vation, spraying should be 7 to 10 days earlier.
Hull and Vaughn!./ state that sagebrush reacted much the same
regardless of age class. There was a tendency for small plants to be
either completely dead or completely alive, but the percentage of plants
killed was similar for both young and old. Sagebrush plants did not trans-
locate spray materials rapidly. Portions which were missed in spraying
remained alive and vigorous, in spite of the fact that other portions of
the plant were completely killed. Conclusions drawn from the observations
made on the Big Horn experimental plots indicate that the young sagebrush
have a tendency to be more tolerant to the selective herbicides than older
sagebrush, and that parts of sagebrush clumps completely covered by the
chemical spray remained alive.
D. Method of Application
Most spraying of sagebrush in the West is accomplished with the
use of fixed-wing aircraft, the majority of which are new-generation air-
craft built after 1959 specifically for agricultural aviation application.
In some areas, helicopters are used, and it is generally agreed that they
get a better penetration and work better in tight areas. The main limita-
tion is the ability to follow the helicopter to the job site with support
equipment. Most operators have put in landing strips so that they can con-
tinue to use fixed-wing aircraft.
These aircraft are equipped with standard spray assemblies cal-
ibrated to deliver the proper amount of material per acre. Usually, 2,4-D
is distributed in 2 to 3 gal. of No, 2 diesel oil per acre. Because of the
nature of the sagebrush plant, diesel fuel provides better penetration and
better coverage (than water, e.g.), and usually 2 gal. of oil are equiv-
alent to using 5 gal. of water per acre. In general, most applications
attempt to hold droplet size to 50-100 microns.
Many factors can be used to determine when to apply chemicals.
However, experienced operators place more emphasis on the general appear-
ance of the sagebrush, the soil moisture, and temperature. Soil moisture
is a limiting factcr.
Cook—' notes that success in sagebrush control has been sporadic
on dry foothill sites. Some ranchers have been disappointed by the results,
even though they followed recommended practices very carefully. These fail-
ures probably come from spraying according to the calendar rather than from
40
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close observation of the growing conditions of the plants. To get good
results, the sagebrush plants must be in a state of rapid growth.
In Utah--where soil moisture was about 12.5 percent in the upper
foot of soil, maximum daytime temperatures were at least 70°, and the tem-
perature at night did not go below 40--control of big sagebrush was good.
During extended cold periods the sagebrush plant is inactive; hence, chem-
icals applied during this period are poorly translocated, and low sagebrush
kill results. The clay loam soil in this experimental site area felt moist
to the touch. Plants get their moisture more easily from silt loam soil or
sandy loam soil than from clay loam soil. Moisture at 10.5 percent in a
silt loam soil and 5.5 percent in sandy loam is just as available to plants
as 12.5 percent in clay loam soil.
41
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REFERENCES
1. Personnel communications, F. Farrel HIgbee, Executive Director, Aerial
Applicators Association, Washington, D.C., October 1971.
2. Hyder, D. W., "Controlling Big Sagebrush with Growth Regulators,"
J. Rge. Met., £(2), 109-116 (1953).
3. Cornelius, D. R., and C. A. Graham, "Selective Herbicides for Improv-
ing California Forest Ranges," J. Rge. Mgt., 4(2), 95-100 (1951).
4. Kissinger, N. A., Jr., A. C. Hull, Jr., and W. T. Vaughn, "Chemical
Control of Big Sagebrush in Central Wyoming," Rocky Mtn. Forest &
Range Exp. Sta. Paper No. 9 (1952),
5. Hull, A. C., and W. T. Vaughn, "Controlling Sagebrush with 2,4-D and
Other Chemicals," J. Rge. Met.. 4(3), 159-164(1951).
6. Hyder, D. W., "Spray to Control Big Sagebrush," Oregon State College
Sta. Bull. No. 538 (1954).
7. Anonymous, "New Life for Ranges," Farm & Home Research, Colorado Agr.
Exp. Sta., 5(2), 3-4 (1954).
8. Kissinger, N.A., Jr., and R. N. Hurd, "Control of Big Sagebrush with
Chemicals and Grow More Grass," Rocky Mtn. Forest Range & Exp. Sta.
Paper No. 11 (1953).
9. Bohmont, D. W., "Chemical Control of Big Sagebrush," Wyoming Agr.
Exp. Sta. Mimeo Circ. No. 26 (1953).
10. Anonymous, "Chemical Control of Big Sagebrush," Wyoming Agr. Exp.
Sta. Mimeo. Circ. No. 39 (1954).
11. Alley, H. P., "The Chemical Control of Big Sagebrush and Its Effect
Upon Production and Utilization of Associated Native Grass Species,"
M.S. Thesis, University of Wyoming, Laramie, Wyoming.
12. USDA Annual Report, Rocky Mtn. Forest & Range Exp. Sta., 20-22 (1951).
13. Alley, H. P., "Big Sagebrush Control," Agr. Exp. Sta., University of
Wyoming, Laramie, Bull. 354R (1965).
14. Personal communication, Dr. H. P. Alley, Professor, Weed Control
Sci., University of Wyoming, Laramie, September 1971.
15. Cook, W. C., "Timing Vital if Sagebrush Getting 2,4-D," Range
Improvement Notes, £(3), 9-10 (1963).
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VI. ABIOTIC FACTORS IN SAGEBRUSH CONTROL
A. Soil Erosion
According to Pechanec et a1.,!/ the erosion hazard usually is not
increased by spraying sagebrush. Erosion normally is checked by dead
standing brush, undisturbed litter cover, and undisturbed soil and grasses.
Furthermore, plant cover generally is increased following spraying, thereby
reducing the possibility of erosion.
Burning as a method of sagebrush control presents the greatest
hazard of erosion.!/ Debris and litter are largely consumed by fire, and
the soil is seriously exposed to wind and water erosion. Burning is not
recommended on steep slopes or on soils that blow or wash readily.
Because the ground cover is improved as a consequence of sage-
brush removal, runoff, and sheet and gully erosion are greatly reduced.
B. Effects on Watershed Areas. Moisture Retention and Snow-Holding
Capacities
Upon initiation of commercial sagebrush control programs in the
early 1950's, concern was expressed that watersheds (sagebrush lands at
the 7,200- to 8,200-ft elevations) might be affected to such an extent that
the snow accumulation patterns, moisture reception and depletion, soil
erosion, sedimentation, etc., might cause considerable damage to the water-
shed areas.
Soil-moisture retention and snow-holding capacities, as affected
by the chemical control of big sagebrush (Artemisia tridentata Nutt.), were
initiated by the Wyoming Agricultural Experiment Station in 1958. Although
similar studies have been reported since that time, this study was probably
the first such project directly related to chemical control of big sagebrush
and its abiotic effects.
The research was conducted by Sonder and Alley—' in the Big Horn
Mountains of north central Wyoming and in the Red Desert of south central
Wyoming. In the Big Horn Mountain area elevations reach 8,200 ft and there
is an average annual precipitation of 20 in. The original spray trials
were applied in 1952 and 1953, the amount of sagebrush control varying from
0 to 100 percent as a result of the various chemical treatments.
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The Red Desert area has an elevation of 7,000 ft and an average
annual precipitation of 10 in., most of which falls as snow. The plots in
this area were treated with butyl ester and the propylene glycol-butyl-ether
ester formulations of 2,4-D in June of 1957.
In the Big Horn Experimental trials, three areas with 100 percent
control of sagebrush and three untreated areas were selected at random for
conducting soil-moisture studies. Four sites were selected at random on
the 80-100 percent control and the uncontrolled areas on the Red Desert
experimental area. At each of the station locations, in both of the areas,
random soil samples of uniform soil type were collected from the surface
inch and from depths of 6-7, 12-13, and 18-19 in. The samples were placed
in closed metal containers, taken to the laboratory, weighed, oven-dried
at 150°C for 24 hr, and the percentage of moisture in the soil was deter-
mined.
A second method for determining the relative moisture of the
soil was the use of Bouyoucos moisture-absorption blocks. These plaster-
of-paris blocks were placed in the soil in July of 1958 at the Bald Ridge
study site, and August 1958 in the Red Desert site, at depths of 6, 12,
and 18 in., the depths being replicated five times at each of these stations.
Snow surveys were conducted in the Red Desert and Big Horn areas
in 1958 and were continued until April 1959. Snow depth and soil moisture
measurements were taken along a mapped course across each of the treated
and untreated strips. Ten measurements and samples were taken from the
treated and untreated areas.
1. Results From the Red Desert Soil-Moisture Studies; Soil-
moisture studies made 1 year after initial chemical treatment indicated
that areas of 80-100 percent sagebrush control retain more soil moisture
than do the untreated areas. The chemically treated areas retained a sig-
nificantly higher percentage of moisture at the 6-7, 12-13 and 18-19 in.
soil depths than did noncontrolled areas. The largest difference in mois-
ture occurred at the depth of 18-19 in. The average difference in total
moisture between the controlled and uncontrolled sagebrush areas, regard-
less of depth, was 1.7 percent, which is significant at the 1 percent level
of probability.
Data show that at the 18-19 in. soil depth there was a differ-
ence of 3 percent soil moisture between the controlled and uncontrolled
sagebrush areas during the summer of 1958; therefore, the controlled! area
actually contained 63.8 percent more soil moisture than the uncontrolled
areas. The greatest moisture difference was observed at the sampling date
in July, with an average difference of 3.1 percent at the 6-7 in. depth,
2-4 percent at the 12-13 in. depth, and 4.3 percent at the 18-19 in. level,
with a controlled area containing the highest percentage of soil moisture.
44
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The chemically controlled sagebrush plots exhibited a sharp
drop in soil moisture from 20 July to 21 August with a slight increase in
moisture content from 21 August to 28 September; however, the live sage-
brush areas exhibited a steady decline in moisture percentage from July
through September.
In June and July 1959, 2 years after treatment, a significantly
higher percentage of soil moisture was found at the 12-13 in. and the 18-19
in. depth in the controlled areas than that of the uncontrolled sagebrush
area. The controlled area contained 26.6 percent (a difference of 2.4 per-
centage points) more soil moisture at the 12-13 in. depth and 34.7 percent
(a difference of 3.2 percentage points) more water at the 18-19 in. depth
than the uncontrolled sagebrush areas on 8 June, with no appreciable
difference noted at any depth in July.
2. Big Horn Soil-Moisture Studies;' Moisture-retention studies
on the Big Horn experimental area 6 years after the initial chemical treat-
ment for control of big sagebrush indicated that a smaller difference in
soil moisture existed between the 100 percent chemical controlled and the
uncontrolled areas. However, when the factors of dates and depths were
disregarded, analysis showed no significant difference between the con-
trolled and uncontrolled areas, even though the 100 percent controlled
sagebrush area on the Big Horn site contained 18.2 percent more soil mois-
ture than the untreated area.
Since it requires approximately 3 years for the native grass
species to obtain maximum ground cover and production after spraying, it
is assumed that the increased grass cover is utilizing moisture released
by the dead sagebrush. One should not expect large differences in soil
moisture after this lapse of time. Either sagebrush (live) or grass util-
izes the available moisture,
3. Big Horn Snow Study; Snow surveys made in April 1958 and
May 1959 on the chemically controlled big sagebrush plots in the Big Horn
Mountains, an area where veryilittle drifting of snow occurs, indicated
that areas of 100 percent control retained snow later in the spring than
areas of no control. On 10-April 1958, there was an average snow depth
of 23.7 in., containing 6.9 in. of water on the 100 percent chemically con-
trolled areas and only 7.7 in, of snow containing only 2.5 in. of water on
the 0 percent controlled areas.
On the uncontrolled areas the ground was frozen and covered with
an ice sheet approximately 2 in. in thickness, but on the chemically con-
trolled areas these conditions were absent, and the surface of soil was
found to be quite mellow. The soil surface immediately around live sage-
brush plants was completely bare.. This condition may be caused by the
45
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greater canopy of live sagebrush providing more evaporative areas as well
as the "black body" radiator effect. The chemically controlled areas were
observed to have a very even depth of snow with complete absence of bare
areas. The snow measurements made on 2 Hay 1959, showed that the con-
trolled areas had an average of 9.8 in. of snow, containing 3.4 in. of
water, compared with the live sagebrush area which held 8.3 in. of snow
containing 2.1 in. of water. One of the uncontrolled plots was completely
void of snow, but a 100 percent control plot next to it was still partially
covered with snow. Figure 7 is a photograph showing uniform snow cover in
a sprayed area, and the absence of snow around sagebrush in an untreated
area. Conclusions of the study were:
a. Eighty to 100 percent sagebrush control areas in the Red
Desert experimental area, retained a significantly higher percentage of
soil moisture 1 year after chemical control than uncontrolled areas.
b. Six years after chemical control, 100 percent controlled
areas in the Big Horn Mountains contained a significantly higher percentage
of soil moisture in late July than the uncontrolled areas.
c. Sagebrush control had no effect upon the snow-holding capacity
in the Red Desert in south central Wyoming, where drifting of snow usually
occurs.
d. Controlled sagebrush areas in the Big Horn Mountain region
retained snow longer in the spring of the year than did uncontrolled areas.
e. The various width strips, in regions where drifting usually
occurs, did not have a measurable effect upon the snow-holding capacity.
q /
As stated in a report by Hutchinson,—' the eradication of sage-
brush on western grazing lands to increase forage from more palatable under-
story vegetation may also affect water yields from these lands. Many of
these grazing lands lie at elevations where the large portion of the annual
precipitation occurs as snow. This snow is often redeposited in the lee
topographic and vegetative barriers by wind. Where sagebrush is the domi-
nant overstory plant in these vegetative areas, its eradication could affect
snow accumulation and change the hydrology of these high elevation grazing
lands.
The plots which served as the basis of the snow accumulation and
disappearance studies conducted by Hutchinsoni' were only 1/10 of an acre,
compared to the 5- to 7.5-acre plots of Bonder and Alley's studies .I/
Although the Hutchinson report does not show the extreme differences re-
ported in the Sonder and Alley study, it does state that the metamorphism
and subsequent melt of snow began earlier and proceeded at grater rates in
46
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Figure 7 - The Area in the Background is a Sprayed Area With a
Uniform Cover of Snow. The area in the foreground is an
unsprayed area showing the absence of snow around the live
sagebrush clumps.
47
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and adjacent to sagebrush crowns, a fact reflected in greater water loss
from the nonsprayed sagebrush plots during the first month of melt. Little
melt occurred in the snow pack over the grassed area (sprayed) during this
time, and a gain in water content was measured.
Sonder and Alleyi/ reported that a 2-in. layer of ice covered
the soil in the nonsprayed sagebrush areas, evidently a result of inter-
ception and alternate melting and freezing of the snow melt. Hutchinson
reports just the opposite;^/ he observed ice sheets only on the grass-
covered plots, and since less snow accumulates on grass cover, conversion
of sagebrush areas to grass may understandably have profound effects on
the hydrology of these high elevation grazing lands. Conclusions of the
Hutchinson study were as follows:
a. In areas where induced snow accumulation by topographic
configuration is negligible, significantly more snow accumulates in sage-
brush-covered areas than in comparable grass-covered areas because of the
efficiency of sagebrush crowns in inducing deposition of drifting snow.
b. Continuous layers of ice observed during the considerable
portion of the snow-melt period over soil and within the snow pack on the
grass-covered areas may change the hydrology of the high-elevation grazing
lands when sagebrush is eradicated.
c. The hydrologic importance of the characteristic melt pattern
in sagebrush should be further investigated. The trapping of snow and
dispersion after spring snowfalls may be important in terms of water
yield.
Even though there are some differences in the findings of these
two reports, it is only logical to assume that there is more snow accumu-
lated in areas where the sagebrush has been killed than in uncontrolled
areas. Sagebrush stands with a 50-60 percent canopy cover intercept large
quantities of snow during the winter season. A black-body radiator effect
of the live sagebrush clumps causes melting of the snowfall, which in turn
reduces the snow cover; much of it is evaporated back into the dry winter
air. Robertson^/ writes that even though sagebrush spreads and disperses
a large amount of rain and snow, the competition for soil moisture is be-
lieved to be more important.
The amount of evaporation lost is relative to the quantity of
precipitation intercepted; it varies with the kind of vegetation and the
type and size of storm. Measurements show that interception losses are
usually between 5 and 15 percent of the annual rainfall and are fairly
constant, under the same vegetative conditions, at various locations.
48
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Ackermanm et al.— also stated that sagebrush intercepts and holds snow,
increasing the total surface area of the snow. Snow is released from the
vegetation by wind or melting. There is often abundant evidence of both.
The melting of snow from shrubbery vegetation just before freezing weather
may result in the formation of a layer of ice on top of the soil. Forslingi/
states that a layer of ice on the surface of the soil will increase the run-
off from the area.
Although the above three reports may be controversial in their
results, observations of the sagebrush-covered watersheds and personal
consultation with ranchers, who have sprayed watersheds, clearly show that
more snow with a higher percentage of moisture accumulates on sagebrush-
sprayed areas. In addition, more of the melt goes into the ground and comes
out as underground water flow rather than as runoff in the spring. This
phenomenon has been noted by ranch operators where watersheds have been
sprayed. They report use of springs throughout the growing season. Before
the sagebrush was sprayed, the springs dried up early in the year.
Mr. Wes Hyatt, a rancher at Hyattville, Wyoming, and an ardent
supporter of chemical control of big sagebrush, stated (personal communica-
tion) that "the benefits of moisture conservation on sprayed watersheds may
be of greater value than the increased forage production." Before Mr. Hyatt
sprayed his watershed, he needed two jeeps, each with a 500-gal. water tank,
and two drivers to haul water to his sheep and cattle; since the watershed
has been sprayed, a spring has supplied water the entire season. This and
other reports of more continuous spring flow clearly show that the water
is going into the soil, coming out as clear cool water supplying better
trout streams and causing less soil erosion, and reducing the turbidity
created by excessive runoff from spring snow melt.
C. Comments on Soil Moisture Retention and Snow-Holding Capacity as
Affected by the Chemical Control of Big Sagebrush
Water has long been a key resource in the development of the
arid West. The earliest surveys on record searching the potential values
of the western United States emphasize the great expanse of arid land in
the limited but lush green valleys wherever water occurred. John Wesley
Powell's report to the Fifty-First Congress placed on record the importance
of watersheds to the maintenance of the great rivers of the U.S. With the
ever-increasing population pressure and change in demands for water, there
is a growing need to re-evaluate the factors which influence the flow of
water in the western United States.
49
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Many conflicting theories have been expounded pertaining to the
importance of the sagebrush plant as a means of conserving soil, holding
snow and intercepting rainfall. Robertson!/ writes that even though sage-
brush spreads and disperses a large amount of rain and snow, the competi-
tion for soil moisture is believed to be most important. He further sug-
gests that the normal removal of sagebrush cannot be recommended because of
its known benefits in restricting erosion by wind and water and the loss of
snow. Renner and Lowe,— in surveying the effect of woody species on micro-
climate, indicate that once a species is established on normal grasslands,
it has the effect of increasing the aridity of the area because it provides
but little protection against runoff and makes it almost impossible for
grasses to become naturally established.
AlleyE' points out that the sagebrush plant affords limited pro-
tection to soil erosion. In dense areas of sagebrush which have a canopy
cover of 60 percent, there is only 3 percent basal density. In other
words, sagebrush plants do not afford protection on the soil surface. The
basal area is quite small. When the sagebrush plant is killed, native
grass species increase in basal ground cover, affording better soil pro-
tection than in uncontrolled areas.
Ackermanm and associates,—' in surveying where our water comes
from, indicate that interception losses are usually between 5 and 15 per-
cent of the annual rainfall regardless of the various organic covers. They
further suggest that changing the vegetation to reduce the total volume of
the brushy canopy would reduce water loss. Studies by Alley and BohmontiP-'
in Wyoming show that sagebrush treated by chemical management practices has
a definite beneficial effect on snow retention. Increases in stored mois-
ture of 300 percent were obtained in areas on which the sagebrush had been
chemically controlled, compared to adjacent lands on which the sagebrush
was untreated. Hyder and Sneva—' concluded that sprayed areas improved
moisture relationships by better retention of precipitation, but that the
moisture depletion was faster on the chemical-treated areas.
Jones,1=.' in working with the transpiration rate of Artemisia
species, found that an acre of sagebrush on the Red Desert transpired
93,660 gal. of water over a 4-month period, which is equal to 3.44 in. of
precipitation. The area receives approximately 8 in. of precipitation
annually. In another study, Sheets!!' showed that the maximum evapotrans-
piration of the untreated plots was 0.10 in/day as compared to 0.06 in/day
for the treated sagebrush plots.
Annual precipitation for the Fecos River Basin in New Mexico is
approximately 14 in. annually. Only 3-1/2 percent of the total precipita-
tion is drained down the Pecos. More than half of the precipitation is
evaporated, and the remainder, taken up through the roots of woody plant
species, is transpired through the leaves. Far more water is lost through
transpiration than by runoff.il/
50
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Many of the woody species are not good retardants of soil
erosion. Often people do not understand that these species only afford
2-3 percent basal density, whereas grass canopy cover may be as high as
50-60 percent. Native grass species or introduced grass species afford
much better protection to soil erosion and percolation of moisture received
into the soil.
Chemical sagebrush control has been accepted as a range improve-
ment technique, and many thousands of acres of sagebrush-infested land
have been and are being sprayed annually. U.S. Forest Service, Bureau of
Land Management, Natural Resources Board, Soil Conservation Service, and
many others became concerned with the effect of the control of sagebrush
upon the snow-holding and moisture-retention capacity of watershed areas
which were being sprayed.
D. General Comments
Most of the sagebrush lands in the West are potentially produc-
tive. The increasing land values, shortage of additional rangelands,
economic requirements for more efficient production, along with the in-
creasing need for more livestock production, more livestock products and
game populations to meet the ever-increasing human population, clearly
indicate the need for more production on sagebrush-infested land. The
eradication program must be accepted as a range-improvement technique.
Of equal importance may be the manipulation of densely infested
watersheds to increase the longevity of water flow from these areas. Water
has become one of the most hotly contested items throughout the western
drainage area. Any practice which would aid in the increase of water to
meet the irrigation or consumptive uses of the expanding population is of
utmost importance. Although data may be limited, there is every indication
that the manipulation of undesirable vegetation on our vast drainage areas
holds great promise for increasing the water flow from these areas.
51
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REFERENCES
1. Pechanec, J. F., Sagebrush Control on Rangelands, Handbook No. 277,
U.S. Department of Agriculture, February 1965.
2. Sender, Leslie W., and Harold P. Alley, "Soil Moisture Retention and
Snow-Holding Capacity as Affected by the Chemical Control of Big
Sagebrush (Artemisia tridentata Nutt.)." Weeds. 9(1), 27-35 (1960).
3. Hutchinson, Boyd A., "Snow Accumulation and Disappearance Influenced
by Big Sagebrush," U.S. Forest Service Res. Note RM 46, U.S. Forest
Service (1965).
4. Robertson, J. H., "Season Root Development of Sagebrush (Artemisia
tridentata Nutt.) in Relation to Range Seeding," ficol., 24,
125-126 (1947).
5. Ackermanm, W. C., E. A. Coleman, a"nd H. 0. Ogrosky, "Where We Get
Water," Water, USDA Yearbook of Ag., pp. 41-52 (1955).
6. Forsling, C. L., "Snow Melt," Climate and Man., USDA Yearbook of Ag.,
pp. 557-560 (1941).
7. Robertson, J. H., "Seasonal Root Development of Sagebrush (Artemisia
tridentata Nutt.) in Relation to Range Reseeding," Ecol., 24,
125-126 (1947).
8. Renner, F. G., and L. B. Lowe, "Management of Water on Western Range-
lands," Water. USDA Yearbook of Ag., pp. 415-423 (1955).
9. Alley, H. P., "Big Sagebrush Control," Wyo. Agr. Exp. Sta. Bull.
354R (1965).
10. Alley, H. P., and D. W. Bohmont, "Big Sagebrush Control," Wyo. Agr.
Exp. Sta. Bull. 354R (1958).
11. Hyder, D. N., and T. A. Sneva, "Herbage Response to Sagebrush Spray-
ing," Ecol.., 9J1), 34-38 (1956).
12. Jones, W. G., "Development of a Method for Determining Transpiration
Rate of Artemisia Species," M. S. Thesis, University of Wyoming
(1962).
13. Sheets, W. B., "The Effect of Chemical Control of Big Sagebrush on the
Water Budget and Vertical Energy Balance," Ph.D. Thesis, University
of Wyoming, Laramie (1968).
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VII. EFFECTS OF HERBICIDE USE ON THE BIOTIC FACTORS (FLORA AND FAUNA)
Many conservationists, wildlife biologists, other scientists,
and laymen have expressed concern about the possible effects of sagebrush-
control programs on the plant and animal life within treatment areas.
In some instances such concern has been well justified, and in other
situations objections have been based largely on emotional considerations
rather than factual data. Game and fish are--as we know—resources close
to the people.I/ In the following sections, the effects of 2,4-D herbi-
cide (as used to control sagebrush) on the flora and fauna of the range-
lands will be discussed.
A. Direct Effects of 2,4-D on Animals
When properly applied at recommended rates and techniques,
2,4-D is not considered poisonous to man, domestic animals, fish or
game.2/ A review of the literature on the toxicity and hazards of 2,4-D
is given in Section IX of this report (pp. 109 to 121).
B. The Effect of 2.4-D on Microorganisms
The effects of 2,4-D on microorganisms have been investigated
by several workers. After studying 10 species of bacteria and fungi,
Lewis and Hammer concluded that 2,4-D applied at normal rates would not
seriously affect soil microorganisms.2.' It was suggested that impurities
in the herbicide preparation might have some effect on the microorganisms
studied.
The United States Department of Agriculture reported that 2,4-D
did not accumulate in the soil, and had no adverse effects on soil micro-
organisms ,2/ Conversely, Thornton reported finding 2,4-D residual in the
soil,— and 2,4-D residues also were found in the soil and killed seedlings
6-9 months after application when the chemical was used as a pre-emergence
treatment to kill weeds.L/ The persistence of 2,4-D in soil is dependent
upon physical factors like temperature, rainfall, and soil type as well as
microflora present.4^67 Therefore under certain conditions, it could
have a more pronounced effect on soil microorganisms than at other times.
A number of organisms in the soil can degrade 2,4-D. They in-
clude Mycoplana sp., Rhizobjum melilote. Corynebacterium sp., Arthrobacter
globiforme. Achromobacter sp., Flavobacterium aquatile, and Nocardia
coeliaca.Z/ The more rapid degradation of 2,4-D observed with repeated
treatments is probably because of increased populations of these organisms.
53
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In one study, the persistence of 2,4-D in moist soil was deter-
mined by adding 2,4-D to soil in glass jars and placing the jars horizon-
tally at the depths the soil samples were obtained, namely, at the 6, 16,
and 36-in. soil depths. Bioassay showed that the 2,4-D was degraded during
the first 5 months at all soil depths.£/ Bounds and Colmerl/ incubated
a streptomycete (apparently S, viridochromages) with 2,4-D for 7 days.
Bioassay of the extract by the cucumber root growth test showed a 42 per-
cent reduction in activity. Glucose-grown cells oxidized 2,4-D after a
short lag period.
A soluble enzyme preparation from Arthrobacter grown on 2,4-D
metabolized ring-labeled 2,4-D to succinic acid.10,1I/ The enzymes cata-
lyzed the conversion of 3,5-dichlorocatechol to 2,4-dichloromuconic acid,
which was converted to chloromaleylacetic acid, which in turn was converted
to succinic acid. They propose this as the pathway of 2,4-D degradation
by microorganisms.
While some microorganisms can metabolize 2,4-D, other micro-
organisms appear to be inhibited by 2,4-D. Audus-LZ' reported that three
fungi, Gloeosporium olivarum. G. kaki, and Schjzophyllum commune» if
grown in nutrient media containing 2,4-D or 2,4,5-T, produced an anti-
biotic metabolite which was active against a range of other fungi at con-
centra tiDns of 20-200 ppm. This result has not been demonstrated in soil.
Arvik, et al.,12_/ reported that a 1:4 commercial mixture of pic lor am and
2,4-D caused no change in composition of algal flora over an 18-month
period when applied to soil at a rate of 1.12 to 4.48 kg/ha of 2,4-D.
The growth of Cylindrospermum licheniforme was inhibited by 50 ppm of
picloram, but not by a picloram-2,4-D mixture at 250 ppm. 2,4-D alone
at concentrations below 400 ppm produced no inhibitory affects on C.
licheniforme nor on Chlorella vulgaris (Beyer) or Chlorococcum sp. A
herbicide concentration of 250 ppm in the top acre 6 in. of soil would
be about 500 Ib/acre.
Cullimorell/ reported that with the bacteria, Aerobacter aerogenes
and Escherichia coli 2,4-D affected the endogenous oxidative activity,
which caused a delayed lethal effect. The delayed bactericidal effect of
2,4-D might be affected by cell division and cross wall formation. In the
absence of cell division, the cell synthesized protoplasm, but eventually
dies.i4-/
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C. The Response of Sagebrush and Other Shrubs to Treatment With 2.4-D
Spraying of sagebrush with 2,4-D by recommended procedures
usually results in a kill of sagebrush ranging from 73 to 92 percent,
but kills as low as 33 percent or as high as 100 percent may be obtained.
Some of the variability in kill is due to the effect 2,4-D has on vari-
ous species of sagebrush. For example, a better kill of silver sagebrush
(A. cana) has been obtained by spraying at a date later than that con-
sidered optimum for killing big sagebrush.!§/ Of course, the majority
of sagebrush control is concerned almost entirely with big sagebrush
(A. tridentata).
Environmental conditions also influence the amount of kill. As
the soil moisture decreases, sagebrush becomes less susceptible to 2,4-D,
particularly when the moisture is lost from the top 12 in. of soil.iZjJL?.'
It has also been observed that the kill of sagebrush was decreased when
the moisture content in the upper 2 ft of soil was less than 12 percent,
or when maximum and minimum temperatures were below 70°and 40°F, respec-
tively at the time of application.I2/
Generally, a satisfactory kill can be expected if environmental
conditions are favorable for rapid sagebrush growth.20/
In addition the age of sagebrush influences the mortality rate
obtained with 2,4-D treatment. Higher mortality rates were obtained with
sagebrush seedlings than in plants 4 years old.ll/ Young, mature sagebrush
was reported to be more resistant to 2,4-D than old, mature plants.2_0/
Small sagebrush plants tend either to be killed or to survive
rather than be partially killed. However, the percentage killed was
similar for both young and old plants .H/ Hull et al., indicated that
sagebrush plants reacted similarly to 2,4-D regardless of age.11.' They
based their theory on the fact that since treatment is generally directed
toward killing the mature plants which are considered the most resistant
group then young plants also should be killed. One explanation might be
that seedlings were protected from exposure to herbicide by larger plants.247
Untreated seedlings could then dominate the area because of reduced com-
petition from older plants. In one study, the number of seedlings on
sprayed areas increased as kill of sagebrush increased up to 40-60 percent,
and the number of seedlings decreased if higher kills were obtained.2_5/
Other workers reported fewer young sagebrush plants on areas where there
was an initial kill of 75 percent or more, and they estimated that the
ranges would remain relatively free of sagebrush seedlings for 4 years.^JJ/
Johnson concluded that where high kill rates were obtained, re-establish-
ment of sagebrush would be slow.2-!' It was determined that the average
maximum dispersal of sagebrush seedlings from parent plants was 42 ft,
with 90 percent within 30 ft.27/
55
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Partial killing of individual plants is an important factor in
appraising the effectiveness of sagebrush spraying. Cook believed that
if less than 80 percent of the foliage of a sagebrush plant was killed,
the plant would probably regain its original size in a few years;!2/ when
less than 20 percent of the foliage remained, the plant likely would die
in a few years. Therefore, plants with more than 20 percent of their
foliage remaining can provide a nucleus for repopulation.
The re-establishment of sagebrush is largely dependent upon the
supply of viable seed and the competition from other vegetation.?_2/ Com-
petition is related to the density and vigor of associated grasses in the
area. For example a thin stand of grass with little litter is more favor-
able for sagebrush establishment than a vigorous stand of grass with a
large amount of litter.!£/
The postspraying density and vigor of grasses are influenced by
their prespraying density and vigor, growing conditions, and grazing
management.
Some workers believe that, finally, the repopulation by sagebrush
is dependent upon the climax characteristics of the area. If sagebrush is
climax vegetation for a treated area, then it will become re-established.
Similarly, if grass is climax, the elimination be over spraying will limit
sagebrush density.30-32,197
The effects of 2,4-D on other shrubs can be another important
factor in evaluating the total effect. Of particular significance is the
effect of the herbicide on rabbitbrush which is associated with sage grouse
habitat. A greater dosage of 2,4-D is required to kill rabbitbrush than
sagebrush.JJL/ Further, rabbitbrush is more sensitive to 2,4-D later in
the year than is sage, and it may never reach a susceptible stage in dry
yparg.17.18/ Rabbitbrush is more difficult to control than sagebrush be-
cause it resprouts, is prolific, and efficiently disperses seed.23.27.347
Therefore, rabbitbrush quickly invades deteriorated ranges.33.7 If rabbit-
brush is present, it should be expected to increase substantially after
sagebrush has been killed in the area.
A limited number of investigations have been made to determine
the effects of 2,4-D on other shrubby plants when the chemical was applied
for sagebrush control. Generally, only cursory observations have been
reported in the literature.297 it was observed that horsebrush (Tetradymia
convescens) was sometimes damaged by 2,4-D, but usually it was either un-
affected or grew back the following yoart22.23/ Some investigators have
reported that it appears that Tetradymia is benefited by spraying.34.357
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There is evidence that bitterbrush (Purskia sp.) also benefited
from spraying.35/ Conversely, Hyder and Sueva found that bitterbrush
(Purshia tridentata) less than 12-in. tall was killed consistently, and
that plants over 12-in. tall were not severely damaged if spraying occurred
at the time of leaf origin.!£/ Survival of bitterbrush was dependent upon
a sufficient growing season prior to spraying with 2,4-D.
Serviceberry (Amelonchier alnifolia) was found to be severely
damaged by spraying with 2,4-D.
D. Response of Forbs to 2.4-D in Sagebrush Treatment Areas
Only a small number of studies have been made with the sole
objective of evaluating the effects of 2,4-D on forbs growing on sagebrush
ranges.±Z.' Observations of the effects on grass as a part of primary
studies on sagebrush and grasses have been reported.
Generally, spraying of sagebrush with 2,4-D reduced forbs in
the treatment area.35,37-39/
Blaisdell and Mueggler reported that of 38 forb species studied,
damage was nil to 15, light to 10, moderate to 3, and heavy to 10,3A' In
other studies on a grassland type, forbs decreased markedly on sites
sprayed at an unusually heavy rate of 5.3 Ib (acid equivalent) per acre.38/
On the other hand, Alley and Bohmont found decreases in some species were
countered by increases in other species resulting in little change in forb
density.M!/ It also was reported that spraying restricted the growth erf
weeds during the year of application, but no species were completely elim-
inated, and weed growth was greater on sprayed sites than on unsprayed
areas.!£/
It was noted also that weed density increased in a year of
abnormally high precipitation.
A summary of the observations of the effects of 2,4-D on forbs
is given in Table X (modified from data by Carr).29/
Different workers conducted studies under various conditions
and no standard methods or descriptions of degree of kill were followed.
Therefore, Carr attempted to separate those species most likely to be
damaged from those least likely to be damaged by 2,4-D applied according
to usual recommendations for sagebrush control.2£/
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TABLE X
EFFECTS ON VARIOUS FORBS OF 2,4-D APPLIED FOR SAGEBRUSH CONTROL
Effect
Beneficial to
slight
damage
Moderate to
severe
damage
Moderate to
severe
damage
Species
Achillea sp.
Arenaria sp.
Cerastium
arvense
Eriogonum
arcuatum
Gallum boreale
Penstemon
radicosus
Polygonum
bistortoides
Senecio
integerrimus
Taraxacum
officinale
Agoseris glauca
Agoseris sp.
Antennaria
parvifolia
Antennaria rosea
Arnica fulgens
Astragalus
stenophylus
Aster foliaceus
Castilleja lutea
Chrysopsis
villosa
Erigeron
caespitosum
Erigeron sp.
Eriogonum sub-
alpinum
Frasera speciosa
Lupinus sp.
L. caudatus
Authorities
Hurd, Bohmont
Kurd, Bohmont
Hurd, Alley and
Bohmont
Gierisch
Hurd
Blaisdell and
Mueggler
Hurd
Blaisdell,
Mueggler, and
Gierisch
Bohmont, Alley and
Bohmont
Hurd
Bohmont
Gierisch
Hurd
Hurd, Bohmont
Blaisdell and
Mueggler
Hurd
Hurd
Gierish
Wilbert
Mueggler and
Blaisdell
Hurd
Hurd
Mueggler, Blaisdell,
Bohmont
Blaisdell, Mueggler
References
42,38
42,38
42,41
39
42
35
42
35
39
38,41
42
38
38
42
42,38
35
42
49
39
43
35
42
42
38
35
58
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Effect
TA.BLE X (Concluded)
Species Authorities
L. leucophvlus
Hertensia
oblongifolia
Myosotis
alpestris
Qrthocarpus
leteus
Exytropis sp.
Petradoria
pumila
Phlox sp.
PX hoodii
P. multiflora
Potentilla
glaucophvlla
£._ hippiana
Zygadenus
paniculatus
Blaisdell and
Mueggler
Blaisdell and
Mueggler
Kurd
Gierisch
Bohmont
Laycock
Bohmont, Hull, et al«
Hull and Vaughn
Wi.lbert
Hurd
Hurd
Gierisch
Hyder and Sneva
References
35
35
42
39
38
24
22
43
42
42
39
18
Species most often reported as moderately to severely damaged
were phlox (Phlox SP.) and lupine (Lupinus sp.^.22.41/ However, one
worker concluded that Phlox multiflora was intermediately affected by
2,4-D, and others noted that damaged Lupinus grew again the following
year.23/ Gierisch found that umbrella plant (Eriogonum sp.) and golden
aster (Chrysopsis villosa) produced numerous seedlings the year follow-
ing herbicide spraying.38/
Mueggler and Blaisdell observed severe damage to fleabone
(Erigeron sp.) and they indicated that forbs in general might have been
damaged more if a better kill of sagebrush had been obtained. 15/ It was
reported that Erigeron caespitosutn was severely damaged by an unspecified
chemical.£2/ Hurd considered aster (Aster foleaceus), Eriogonum subalpinum.
forget-me-not (Myosotis alpesties) and Phlox multiflora to be intermediate
between susceptible and resistant.41/
59
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Some of the variation observed in the response of forbs to 2,4-D
probably was due to the kill criteria used. Oiersch believed that changes
in the frequency of occurrence did not necessarily indicate comparable
changes in basal area or forage production.2§/ For example, it was reported
that pussytoes (Antennaria sp.-) on sprayed sites decreased markedly in
basal area, but only slightly in frequency.
In summary, 2,4-D at recommended application rates for sagebrush
control is toxic to most broadleafed plants. Susceptibility of any species
is related to growing conditions, and to the developmental stage of the
plants at the time of herbicide application. Annuals are most susceptible
when they are young, and perennials are most susceptible from early-bud
to early bloom stage.f£J
E. Response of Grasses to 2,4-D
Concentrations of 2,4-D recommended for treating sagebrush should
not damage grasses.44_/ in fact, grasses appear to be stimulated by 2,4-D.H.'
This response may be primarily a result of the effects of 2,4-D on associated
shrubs and forbs. Often grass production has increased after spraying. In
these cases, sagebrush was sufficiently reduced, and grasses were present
prior to treatment.29/ Increased production was a result of increased
vigor and spread of original plants rather than the introduction of new
plants from seed. 1^23^36.7
When sagebrush competition is eliminated, increased water avail-
ability usually results in increased grass production. It has been sug-
gested, however, that increased grass production may follow less competition
for nitrogen.2£/ It also was demonstrated that extracts prepared from sage-
brush leaves depressed germination and vigor of several species of grasses
including smooth brome (Bromus inermis). squirrel-tail (Sitanion hystrix)
and slender wheatgrass (Agropyrow trachycaulunO .45,46/
Some variation in species response have been noted, and these re-
sponse differences perhaps were because of adaptive variations of the
original vegetation. For example, one species might decrease in one area
following sagebrush control, and it might increase in another even after
herbicide treatment.2^'
Increased grass production is often associated with specific
species. Needlegrasses often are increased;16.36.377 blue grasses were
found to increase significantly (presumably Poa jjj.);37/ other workers
found Sandberg bluegrass (P_. nevadensis) to increase ;16J42_/ p_. secunda
was observed to increase only slightly in one study area.21L/ Other grasses
that have been found to increase following sagebrush treatment are grama
60
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(Bouleloua gracilis). bluebrush, wheatgrass (Agrogyron spicatum). thick-
spike wheatgrass (A. dasystachum).42/ wheatgrasses (Agropyron sp.) and
fescues (Festuca sp,).3_7/ Sitanion hystrix.16/ and June grass (Koeleria
c_ristuta) .36.' It also was observed that Sitanion hystrix responded best
under wet conditions and Koeleria crestata under arid conditions.367
Some grasses have decreased after sagebrush control, e.g.,
Sitanion hystrix.42./ Idaho fescue (Festuca idahoenis)39./ and plains reed-
grass (Calamagrostls') .42/
Establishment of grasses has varied considerably from one loca-
tion to another, depending to a large extent on the vigor of the original
grasses and the amount of killed sagebrush. In one study, the production
of grasses was increased from 220 Ib/acre (air dry) on untreated sites
to 460 lb after a 60 percent sagebrush kill, to 540 Ib with an 80 percent
kill, and to 590 lb with a 95 percent kill.47/ (jorneluis and Graham re-
*r
ported that grasses produced over four times more dry weight on sprayed
areas than on unsprayed sites.i£/ Where a fair understory of grasses existed,
grass production increased two- to threefold after a 60-90 percent kill of
sagebrush. Figure 8 shows understory of grass and forbs in unsprayed
sagebrush area. Figure 9 shows the same area 3 years after spraying with
increased grass production.
Grasses respond quickly after sagebrush competition is eliminated.
However, two to three growing seasons usually are required before maximum
production is reached.35.' Hull et al., concluded that 2 years were needed
to obtain a two- to threefold increase in grass production,^/and the results
of another investigation indicated that grass production was greater two
to three growing seasons after spraying.I!/ However, Hyder and Sueva
stated that grass production was greatest in the year of treatment, and
decreased after that time.36/
The maintenance of increased grass production is dependent upon
the climax vegetation of the area, and on the grazing practices. When
grass is climax vegetation, the developed stands likely will become well-
established. Once a vigorous growth of grass is established, the re-
establishment of sagebrush will be retarded as well as other species,
provided that the grass is not damaged by overgrazing, drought, or other
factors .12/
61
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Figure 8 - Understory of Grass and Forbs in Unsprayed Big Sagebrush.
Grasses are present but are held back in growth by
competition with live sagebrush clumps.
Figure 9 - The Same Area as in the Top Photo 3 Years After Spraying
to Kill Big Sagebrush. The increased ground cover
stabilizes the soil and increases moisture penetration.
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F. Effects of Sagebrush Control on Certain Game Species
The major species of game animals within the sagebrush areas of
the rangelands are the pronghorn antelope, mule deer, elk, whitetail deer,
moose, bighorn sheep, rabbits, chucker partridge, and sage grouse. Of
these species, sage grouse and pronghorn antelope are most closely asso-
ciated with sagebrush. However, there are other relationships between
wildlife and sagebrush of a less spectacular nature.^§/ It is well known
that species other than antelope and sage grouse utilize sagebrush as food.
Certain species also depend upon various forbs for food during some seasons.
Some of these forbs are reduced in abundance when they occur with sagebrush
within an area treated with 2.4-D.4JI/ Such a reduction could conceivably
have an effect on some species of wildlife. A discussion of the effects
of sagebrush control on certain species of wildlife follows.
1. Pronghprn Antelope:
a. Historical background: The exact number of antelope
that roamed the continent prior to the entry of white man is unknown, but
it has been estimated that there were 30 to 40 million or more.^2/ It has
been speculated that antelope exceeded the number of bison (Bison bison)
during the pre-Columbia period. The number of antelope began to decrease
during the early nineteenth century, and by the latter part of the century,
the population was declining at an alarming rate. Only about 13,000 ante-
lope remained in the entire United States by the second decade of the
twentieth century, the lowest population level ever recorded.50_/ Table XI
shows the estimated number of antelope over a 10-year period. In 1924,
Nelson reported slightly over 26,600 antelope in the United States, and
the population steadily increased to about 365,000 in 1964.51/ The 1964
population represented an increase of more than 1,000 percent over the
original census in 1924.
TABLE XI
ESTIMATED ANTELOPE POPULATION INCREASES AT 10-YEAR INTERVALS
Year
1924
1934
1944
1954
1964
FROM 1924
Population
Estimate5-/
26,600
131,500k/
246,000
360,000
365,200
TO
1964 IN THE UNITED STATESk/
Source of Data
Nelson, 1925k/
U.S
U.S
U.S
Ref
. Bureau Sport Fisheries and Wildlife,
. Bureau Sport Fisheries and Wildlife,
. Bureau Sport Fisheries and Wildlife,
. 2
1939
1946
1956
a_/ All figures rounded to closest hundred.
k/ No data available for 1934, consequently, figures for the closest
known year (1937) were substituted.
63
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Table XII shows a comparison of estimated antelope population
in 1924^2^ with 1964 by state.
TABLE XII '
A COMPARISON OF ESTIMATED PRONGHORN ANTELOPE NUMBERS IN
1924 (NELSON 1925:3) WITH 1964 FOR THE UNITED STATES52/
Difference Between 1924 and 1964
State 1924^; 1964 No. of Animals Percent Increase
1. Arizona 650 10,000 9,350 1,438
2. California 1,060 2,690 1,630 153
3. Colorado 1,230 15,250 14,020 1,140
4. Hawaii — 130 130
5. Idaho 1,480 4,700 3,220 217
6. Kansas 10 140 130 1,300
7. Montana 3,030 95,000 91,970 3,035
8. Nebraska 190 9,000 8,810 4,637
9. Nevada 4,250 4,500 250 6
10. New Mexico 1,680 22,500 20,820 1,239
11. North Dakota 220 14,240 14,020 6,373
12. Oklahoma 20 180 160 800
13. Oregon 2,040 8,950 6,910 339
14. South Dakota 680 27,410 26,730 3,931
15. Texas 2,410 9,380 6,970 289
16. Utah 670 970 300 45
17. Washington -- 120 120
18. Wyoming 6.980 140,000 133.020
Total 26,600 365,160 338,560
a/ Original published figures rounded to closest tenth.
The decline in antelope herds from 35,000,000 to less than
20,000 in 75 years was directly related to the movement of the white man
across the North American continent.51/ The antelope herds were quickly
reduced by relentless year-round shooting of. animals for food and pleasure.
Man also occupied their preferred habitats, and did not allow the antelope
to regain their former abundance.
64
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During the period 1924-1964 the antelope population was re-
established by carrying out several sound conservation and game-management
practices. Those measures included: (1) controlled hunting, (2) return
of historical range to antelope habitat, and (3) accelerated wildlife
management programs.H/ The most significant factor in bringing about
an increase in antelope population was the control of man's hunting
activities.J>2/
b. Habitat: The natural home of the pronghorn antelope
was the treeless, grassy and often desert plains of the continent east of
the Rocky Mountains. They were abundant on the short-grass plains. In
the Great Basin, they inhabited the semidesert bunch-grass and low-sage-
brush ranges. In the southwest, antelope occupied the salt desert shrub
type, but sometimes wintered among the pinyon-juniper forests. They also
frequented the open, grassy, ponderosa pine forests of the mountains, par-
ticularly in the park-like openings.27 Historically, antelope were found
in all the western states except Washington, and as far east as Minnesota
and Iowa. Their range also extended from Canada to the Gulf Coast. The
eastward extent of the antelope's range has retracted to about the 101st
meridian.
In Wyoming, where antelope are most abundant, they inhabit
a great diversity of vegetation types, but a combination of sagebrush,
rabbitbrush and forbs is found on a large portion of their range. On the
Red Desert, the aspect is big sagebrush, 6 to 12 in. high. In the Great
Basin, several low-growing sagebrush species comprise the vegetation type
frequented by antelope. Antelope normally avoid dense stands of tall
sagebrush where visibility and mobility are restricted. In New Mexico,
antelope range from the short grass and desert shrub up to the mountain
grasslands, pinyon-juniper and into the edge of the ponderosa pine—Douglas
fir type.53/ in central Montana, the big sagebrush-grassland type on the
rolling plains receives the greatest use by antelope, winter and summer.54_'
In Texas and Oklahoma, antelope showed definite preference for open grass-
lands, but travel wooded hillsides and in canyons when necessary.55_/
c. Life history; Prior to the breeding season, bucks gather
small harems of up to six or eight doe. Antelope commonly breed as
yearlings. As winter approaches, antelope gradually gather into large
bands and begin their migratory movements. In the spring, range doe
isolate themselves a week or two before the fawns are born in May or June.
Twin births commonly occur. Young are able to run with the does in 10
days to 2 weeks, and remain dependent about 2 months. Fawns weigh about
7 Ib at birth, while adults weigh 90 to 115 Ib. Antelope have a life span
of 9 or 10 years.
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d. Migration; The daily range of antelope is about 3 square
miles, but antelope drift from one range to another without seasonal rhythm.ls/
Antelope movements are affected more by storms, forage supplies and avail-
ability of water than fixed migration pattern or seasonal movement. Ante-
lope do not thrive when restricted, and transplanting sites should have at
least 1 square mile of range for each animal. 5_7/ However, in central
Montana, most antelope leave the outlying range areas with the first severe
snow storms and winter in rough "breaks." These antelope move from 10 to
23 miles seasonally .!§/ At the first heavy snow, antelope of the upper
Jackson Hole, Wyoming, migrate 150 miles southward to the Red Desert, but
when climate and food supply permit they remain as permanent residents in
Jackson Hole. IE/
e. Habitat factors ;
Cover; Cover is not a factor for adults except
during periods of severe storms, when in some areas, antelope move into
breaks and coulees or even woodlands. 1Z/ Antelope typically frequent
open, rolling plains. Grasslands, low growing brush-grassland and similar
semiarid vegetation types permitting good visibility are commonly preferred.
Terrain covered by high, dense sagebrush usually is avoided.il/ The aspect
of typical antelope range on Wyoming's Red Desert is big sagebrush, 6 to
12 in. high, while in southeastern Wyoming little sagebrush is present.
In the Great Basin, low shrubs 9 to 18 in. high provide the most satis-
factory kidding ground. ^P./ When frightened, antelope follow somewhat
well-defined paths which usually course along the natural contours, or
draws that are sufficiently open to permit unrestricted movement.
(2) Food: Requirements include quantity and quality
considerations. Forage studies on the Red Desert in Wyoming indicate
antelope consumed an average of 1.8-1.9 Ib of oven dried forage daily .^l/
Feeding trials with penned animals averaged 1.5 Ib/animal day over an
18-day period. ^l/
Antelope prefer plants having the highest protein
levels in all seasons. In a Saskatchewan study, grass was dominant in
the diet in April, forbs in May and June, deciduous browse in August to
October and sagebrush (Artemisia cana) and creeping juniper from November
to March. Pronghorns were concentrated in the sagebrush- juniper areas in
winter. M.' In the Hart Mountain study in Oregon, sagebrush was 'the dominant
food from September through March. Forbs and bitterbrush made up most of
the diet in spring and summer, while green grass was taken readily when
available during late fall and early spring. Low sagebrush (Artemisia
arbuscula) was the preferred species of sagebrush. !£/ In Montana, the
winter diet, by plant utilization, consisted of 93 percent shrubs, 6 per-
cent forbs, and a minor amount of grass. Big sagebrush provided 45 percent
66
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of the food in winter. Poor body condition of antelope was probably re-
lated to the quality of sagebrush in the diet.£L/ A report from Oregon in-
dicates that antelope preferred low sagebrush or nonsagebrush vegetational
types and generally they avoided big sagebrush.££/ In a 6-day study in
Utah, where antelope were given free choice of 16 browse species in an en-
closure, big sagebrush made up about 55 percent of the plants consumed,
followed by black sagebrush (A. nova) and juniper which made about 20 per-
cent each. Calculated protein and total digestible nutrient content in-
dicated the nutritional value of the feed was above the maintenance level
requirements for livestock.£!/ Food preferences at other times of the year
were not indicated.
In a 2-year study of vegetation use by antelope and
sheep in the Red Desert of Wyoming, forage consumption by antelope, as
detected by range analysis methods, was primarily of Douglas rabbitbrush,
followed by consumption of big sagebrush.&!/ .,The annual forage production
during the 2 years was 147 and 267 Ib/acre for big sagebrush, and 89 Ib/acre
each year for rabbitbrush. The yearly consumption of these species was 13.2
and 9.6 Ib/acre of sagebrush and 20.1 and 26.2 Ib/acre of rabbitbrush. These
two species made up 93 and 97 percent of the total forage consumed in the 2
years. The fall and winter use of sagebrush slightly exceeded the use of
rabbitbrush 1 year when heavy snows covered most of the forbs and much of
the rabbitbrush. In the second year the use of rabbitbrush was twice as
great as for sagebrush, although there was three times as much sagebrush
available. Allowable use on shrub species is generally set at 50 percent
of yearly production. On this basis, about 60 percent of rabbitbrush was
utilized in the year of heaviest use and 10 percent of the sagebrush pro-
duction was utilized. Severson and May, 1967,^?.' report that in a year-long
diet study of antelope, as determined by stomach analysis, on Wyoming's Red
Desert, big sagebrush comprised from a low of 39.8 percent of the forage con-
sumption in the fall of 1965 to a high of 90.4 percent in the winter of 1964.
The same thesis presents data on antelope forage consumption as detected by
range analysis methods during the same periods of time as for the stomach
analysis study. The range analysis study, reported in pounds of forage consumed
per acre, showed a low of 10.8 percent of sagebrush consumed in the summer
of 1964 to a high of 50.8 percent in the fall and winter of 1964.
f. Effect of 2.4-D spraying: During an extensive livestock
range rehabilitation program carried out in Oregon by the Bureau of Land
Management, Reeher of the Oregon State Game Commission reported the results
of a 6-year evaluation study.M/ He concluded that the antelope do not use
extensive stands of big sagebrush. Investigations also were made to determine
if antelope production was different on native ranges as compared to rehabil-
itated areas. Data obtained by aerial census taken in August 1966, 1967,
1968, and 1969, showed that sage range rehabilitation did not increase the
rate of kid production above that on native ranged/ Table XIII shows the
results of the aerial counts.
67
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21
75
30
21
73
47
36
39
13
17
59
14
20
73
28
36
172
88
14
73
29
29
192
80
TABLE XIII
ANTELOPE PRODUCTION COUNTS ON TREATED
AND NATIVE RANGE. AUGUST 1966-1969
1966 1967 1968 1969
Treated Native Treated Native Treated Native Treated Native
Bucks
Does
Kids
Kids/
100 does 40 64 33 24 40 51 40 42
Other major conclusions made based on the 6-year study were:
(1) Killing of big sagebrush and other woody species by
spraying does not make an area attractive to antelope.
(2) Seeding with wheatgrass into sprayed areas does not
make the area attractive to antelope.
(3) On spring and summer antelope range, the amount of use
on a seeding will be greatest the first few years, then will drop to a
lower level.
(4) A plowed and seeded area will receive more antelope use
than a sprayed or a sprayed and seeded area.
Results of a survey of ranchers in Wyoming reported that
there was no decrease in range use by antelope following spraying of sage-
brush.—' In fact, there were numerous accounts of increased use by ante-
lope in spring and summer, and some reports of increased use by antelope
in fall and winter.
2. Mule Deer: The deer of North America are classified as the
mule deer and the white-tailed deer. In each classification there are
many subspecies which are somewhat limited in range. Mule deer are the
prominent species in the study area.
a. Habitat: The mule deer extends from central South
Dakota to the Pacific Ocean and from Mexico to central Canada. Apparently,
only a lack of feed restricts the location of the deer.697
68
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b. Life history; The breeding season for the mule deer is
quite variable, depending on location. In Canada, it starts in late October
and lasts about 3 weeks. Toward the south, the season starts later and
lasts longer. In New Mexico, mating occurs from November to January. The
gestation period for mule deer is about 210 days. Fawn drop may occur from
early June in northern areas to mid-August in Arizona. Antler drop on the
bucks is about 2 months after initiation of the breeding season. As fawn-
ing time approaches, the doe separates from the family groups in which they
commonly appear, and seeks a place of concealment on the margins of meadows
or open glades. Twins are common in mule deer. Fawns weigh about 8 Ib at
birth and may grow to 475 Ib or more, although 200-250 Ib is the more common
size of a mature buck.
c. Forage and food habits of mule deer; Mule deer consume
a great variety of plant species. The palatability of the different species
varies with the plant association. A plant may be more highly favored in
one association than in another, and seasonally. In spring, grasses make
up a high percent of the diet, but drops off in summer as forbs and the
new growth of shrubs are consumed in larger amounts. In fall, there is
generally an increase in shrubby vegetation and a drop in forbs. Grasses
may also increase if autumn rains bring out new growth. In winter herbaceous
vegetation may be covered with snow and deciduous shrubs have no leaves, so
only the taller browse plants are available. The more important shrubs and
trees used in winter include bitterbrush, mountain-mahogany, sagebrush,
serviceberry, junipers, cherries, ceanothus, oaks, aspen and cliffrose.
Deer do well in the prairie and short grass plains region
where shrubs and hardwoods are a component of the grassland.
Winter range is the limiting factor of deer populations over
much of their habitat .ZP_/
Sagebrush has long been considered an important component of
the winter feed for mule deer. Smith!!/ attempted to determine the value
of sagebrush as a winter food since the chemical analysis of big sagebrush
showed it to be half as high in digestible protein and twice as high in
digestible fats and carbohydrates as green alfalfa. The digestible nutrient
content is well above the minimum for domestic ruminants. Of four doe and
two bucks fed a choice of big sagebrush (Artemesia tridentata) and black
sagebrush (A. nova), one doe refused to eat, one died, two doe ate so
little they were removed from the test and put on more desirable feed, and
the two bucks lost 6-1/2 and 9 Ib in a 21-day and 31-day period, respec-
tively, while consuming 2.1 to 2.8 Ib of sagebrush daily. Black sage was
preferred over big sagebrush.
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In another feeding test with captive deer, Smith et al.,2i/
gave deer a choice of 15 species of browse. Sagebrush was grazed for the
shortest time of all species in 1 year and ranked 12th in amount consumed.
In a second test, sagebrush ranked fifth in time grazed and sixth in amount
consumed out of six browse species.
In a third test, Smith!!/ fed mule deer on diets of sage-
brush, juniper, oak and combinations of the three species during three
winters. Doe were weighed weekly as a guide for judging the duration of
the test. The shortest mean duration was recorded with sagebrush. The
greatest average weight loss was observed in deer on sagebrush only. The
average daily consumption was as follows:
Sagebrush 0.43 Ib
Juniper 0.78
Oak 2.25
Sagebrush plus juniper 1.23
Sagebrush plus oak 2.20
Juniper plus oak 1.44
Juniper, oak and sagebrush 2.73
Sagebrush is highly nutritious, but low in palatability for deer. The
data on the above tests suggest that deer have a limit on their consump-
tion of sagebrush which is little affected by other forage available.
Smith and Julanderli/ studied the similarity of diet in
sheep and deer. In spring and summer both animals ate large quantities
of the same species. Deer wintered on the sheep autumn range, and the
sheep were moved to new range. Sagebrush made up 64 percent of the deer's
diet as compared to 3 percent for sheep. Bitterbrush, oak, and mountain
mahogany were over utilized on the deer winter range.
In Montana, WilkinsZ^/ collected rumen samples to determine
the diet of deer. In the summer, summer forbs made up about 75 percent of
the samples and browse about 20 percent. Bitterbrush and huckleberry were
the most important browse species. In the fall months, browse made up
about 75 percent of the diet with bitterbrush and snowberry the most
important of nine species. Sagebrush first occurred in the samples in
mid-October. In winter, browse was again the dominant type food with big
sagebrush ranking first and making up 25 percent of the diet. The amount
of bitterbrush dropped off sharply. The decline in bitterbrush use and
increase in sagebrush might be attributed to the decreased availability of
bitterbrush. When the use of bitterbrush declined, the plants appeared
to be over utilized.
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The apparent preference by deer for browse species other
than sagebrush is possibly a result of the effect of the essential oils
of sagebrush on the rumen microbial activity. These oils inhibit the
action of gram-positive and gram-negative bacteria and also the growth of
deer rumen microorganisms.!£/ In artificial rumen studies, the rate of
cellulose digestion was decreased by the addition of 0.002 ml of oil and
inhibited by 0.04 ml. The addition of 0.1 ml of oils to deer rumen con-
tents decreased the rate of gas production and the volatile fatty acid
concentration. The appetite and rumen movement of a fistulated steer
ceased completely after three 7 Ib/day portions of sagebrush were added.
Olfaction is the primary sense used by deer in selecting
food. Certain volatile substance in plants which contribute to their
aroma inhibit the growth of rumen bacteria. Deer tolerate small amounts
of unpalatable plants. Good correlation has been found between unpalata-
bility and the inhibitory effect of essential oils.ZZ/ PowellZl/ found
that the volatile oil content in big sagebrush leaves varied greatly on
different sites, ranging from 3.5 percent of air dry weight in short plants
to 6.0 percent in tall plants on favorable sites. Oil content was highly
correlated with sagebrush size and the amount of magnesium and phosphorus
in the A horizon. He suggests that tall big sagebrush plants on favorable
growth sites should be replaced with more palatable species.
Plutnmer, et al.,~' suggests treatment of areas covered with
dense brush to improve big game range. A good balance of browse and her-
baceous plants is desirable. Even with ample browse, an area may not have
enough grass and forbs to provide succulent forage in the critical periods
of late winter and early spring.
Bitterbrush digestibility appears to be less in November
and December (the period of greatest use) than in March. Big sagebrush
was extremely unpalatable. Bitterbrush appeared to be extremely palatable
and would maintain deer for several weeks with only a slight loss of weight.
When the decrease in bitterbrush was noted, the use was excessive.£P-'
Studies in Montana have indicated that mule deer use a high
amount of forbs in summer, including the following investigations: Lovaas;!!/
Little Belt Mountain; Southj§2/ Scudder Creek Area, Beaverhead County;
Mackie;32/ Missouri River Breaks and Morris and Schwartz;§3/ and National
Bison Range. All the studies reported the utilization of one or more species
of Artemisia and Mackieil/ reported Artemisia tridentata as the most impor-
tant taxon in the diet of mule deer for both winter and spring.
71
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Figure 10 shows the average contents found in the stomachs
of 101 mule deer. The studies were carried out in Colorado during the
winter period, 1964-65, by Keiss.§!/ Grass accounted for about 28 percent
of the stomach contents, and sagebrush (Artemisia) approximately 8 percent.
The results of the study indicated that grass was the major winter food
of the mule deer, and that sagebrush also was important as a food item.
Figure 11 also supports those indications and shows the fre-
quency of occurrence of various materials in 101 mule deer stomachs. Twig
fragments were found about 73 percent of the time, grass 74 percent, deer
hair 65 percent, and sagebrush approximately 52 percent.M/
d. Effect of 2.4-D spraying; Studies made by Anderson in
Colorado demonstrated that mule deer used oak-dominated habitats signifi-
cantly more than three sagebrush-and coniferous-dominated habitats both
before and following spraying with 2,4-D.85/ Conversely, cattle were ob-
served to utilize the sprayed areas more than the oak- and conifer-dominated
areas both prior to and after herbicide treatment.
Reeher conducted a study over a 6-year period in which he
estimated the land use by deer in areas before and after 2,4-D spraying.86/
Spraying was carried out in May 1965 at the Horse Flat area in southeastern
Oregon. From 1965 through 1967 the deer use of the treated land was greater
than of the control site. In 1968, the use of the control area was slightly
more than the sprayed area.
3. Whitetail Deer; The whitetail deer, one of the two species
of deer found in North America, is within the study area. However, the
mule deer is the most prominent species in the sagebrush areas.
a. Habitat; Generally, the whitetail deer is found pri-
marily east of the Rocky Mountains. However, there are several subspecies
of whitetail deer in the northern and southern states of the western United
States.527
D. Forage and food habits of the whitetail deer; The food
habits of the whitetail deer on Missouri River bottomlands in northcentral
Montana were studied by Allen,!2/ He found that rumen collected from 10
deer in summer contained about 54 percent forbs. Studies of feeding sites
showed a 95 percent utilization of forbs (percent of all plant usage).
Major native forbs used included hemp dogbone (Apoeynum cannabinum), kochia
(Kochia scoparia), and bushy knotweed (Polygonum vamosissiunQ. Browse com-
prised 81 percent of the contents of 13 fall rumen samples, and forbs made
up 17 percent.
72
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Grass
Twig Fragment
Artemisia
Populus
Leaf Fragment
Salix
Prunus
Unknown Fragment
Juniperus
Bark Fragment
Amelanchier
Pseudotsuga
Deer Hair
Chrysothamnus
Solsola
Pinus
Ribes
Gravel
Picea
Opuntia
Holodiscus
Symphoricarpos
Rhus
Physalis
Unknowns
No Contents
10
PERCENT
15
20
25
«^—
> Less than 0.1 %
Figure 10 - Average Contents Found in Each of 101 Mule Deer Stomachs
73
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10 20
30
PERCENT
40 50 60
70 80 90 100
Twig Fragment
Grass
Deer Hair
Artemisia
Populus
Leaf Fragment
Salix
Primus
Unknown Fragment
Bark Fragment
Juniperus
Chrysothamnus
Salsola
Ribes
Amelanchier
Pseudotsuga
Alnus
Gravel
Picea
Opuntia
Pinus
Holodiscus
Symphoricarpos
Rhus
Rose
Physalis
Unknowns and
Miscellaneous (Avg.)
Figure 11 - Frequency of Occurrence in 101 Mule Deer Stomachs
74
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Examination of rumens during the winter revealed that browse
was the most significant component, accounting for 65 percent of the con-
tents. Longleaf sagebrush (Antemisia longifoUa) was a significant item,
or 12 percent of the rumen. Four deer collected from "breaks" had utilized
the most sagebrush (Artemisia sp.).
Thirteen rumens examined during the spring revealed per-
centages of 43, 18, and 38, respectively for browse, forbs, and grass.
Grass apparently was a significant food item only during spring, and only
for a short period which coincided with the initial "green up."
A total of 25 winter feeding sites of whitetail deer in the
Sun River area (Montana) were studied by Schallenberger.^8/ He reported
that the percentages of use for grass and grass-like plants, forbs, and
browse were 5, 30, and 65, respectively. Fringed sagewort (Artemisia
frigida) rated seventh among the browse plants used by the deer.
c. Effect of 2.4-D spraying; The effects of 2,4-D appli-
cation for sagebrush control would be expected to be about the same for
the whitetail deer as for the mule deer (see p. 71). A drastic reduction
of certain forbs on summer ranges possibly could have the most serious
detrimental effect on the whitetail deer.
4. Sage Grouse (Centrocerus urophasianus):
a. Habitat; The original range of the sage grouse closely
conformed to the distribution of the big sagebrush, Artemisia tridentata
Nutt, and related species. The area included the semiarid plains of the
intermountain and northwestern states and the southern border of the three
southwestern Canadian provinces. It originally extended from western
Kansas, western Nebraska and the western Dakotas westward to include
northeastern Arizona, northwestern New Mexico, the northwestern section
of Colorado and practically all of Montana, Idaho, Wyoming, Nevada, and
Utah; excluding the forested mountainous regions. It extended into the
east central portion of California, the eastern halves of Oregon and
Washington and the southern border of three provinces of Canada. Within
this extensive area the sagebrush grass and salt desert shrub type ranges
furnished the habitat requirements of the sage grouse. The sagebrush
grass range varies in elevation from 2,000 to 8,000 ft, with a precipita-
tion varying from 5 to 30 in. The precipitation of the salt desert shrub
ranges vary from 5 to 10 in. yearly. Sage grouse are most commonly en-
countered near the mountains. High plateaus and intermountain valleys
provide the best conditions for the survival of sage grouse populations.§2'
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More than 50 percent of the original sage grouse habitat
has been eliminated, yet the geographical distribution of the species has
remained relatively unchanged. A reduction in sage grouse numbers has accom-
panied the change in habitat.8£/ The principal habitat areas presently
include the Great Basin, Wyoming, and eastern Montana.
b. Life history; Hale sage grouse may engage in strutting
activities in late January or early February on their daily roosting areas.
Usually in March they move to their strutting grounds. The time of maximum
appearance on the strutting grounds will vary with location and the weather
conditions. In Wyoming the peak appearance is from about April 10 to May 20.
Hens may appear on the strutting grounds in mid-March, but the peak of mating
is usually after mid-April.89/
The size of strutting ground varies from a few hundred square
feet to several acres, depending on the number of males utilizing the
grnnnde.89.90/ A strutting ground may support a few to several hundred
birds. The grounds appear to be located at random. The same strutting
grounds are used year after year. Usually the grounds are rather bare of
brush, and frequently areas cleared by bulldozers or fire are used as a
strutting area. The nesting areas are usually in the vicinity of the
strutting ground, but a hen may travel as far as 15-20 miles after mating
before nesting.2!/
Hens start laying in 7-14 days after mating, and take about
10 days to lay a clutch which may contain from a few eggs to as many as 13.
The incubation period is 21-22 days. Within a few hours after hatching,
the chicks are ready to leave the nest, and are able to fly within 2 weeks.
By 8 weeks the young birds have essentially acquired their full plummage
and look like the hen. The young chicks attain a state of independence
from the hen at about 10 to 12 weeks of age, and reach maturity at about
6 months.£2/
Sage grouse are inclined to be gregarious at all seasons
of the year and even nest in close proximity. The mature birds possess
well developed senses of orientation and homing, and have returned to
their original grounds after being planted 100 miles or more distant.££/
With the onset of fall, the sage grouse retreats to the
sagebrush grass range type. The daytime resting areas are in the taller
brush in draws and gullies and along stream beds. At night the birds
merely squat within openings or at the bases of individual bushes. During
the fall and winter a single roosting area may encompass several dozen
acres and involve several hundred birds.§2/
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Migration of sage grouse is dependent on locality. In
some areas there is little migration; in others, they require relatively
large areas to complete their annual cycle. Wintering usually occurs in
areas of low snow depths. In summer the birds move upward in elevation,
or on to meadow areas. Food plants develop along an elevational gradient
and sage grouse, especially the broods, move along the same gradient as
the vegetation at the lower elevations becomes dessicated.2£l2£/ The dis-
tance traveled in a normal cycle may exceed 50 miles. In agricultural
areas sage grouse commonly summer in the vicinity of alfalfa fields or
other crops.
c. Survival factors;
(1) Food; The juvenile sage grouse's diet consists
predominately of insects and forbs. During the first week after hatch-
ing, insects make up the greater part of the diet.!!/ Peterson!^/ reported
that insects made up 60 percent of the diet during this period, while
Patterson§2/ reported insects make up 77 percent. As the birds grew older
they consumed less insects and a progressively greater percentage of forbs.
Peterson2£/ found that insects made up about 5 percent of the diet at 12
weeks and forbs averaged 75 percent of the diet through this period. The
preferred forbs were dandelion and salsify. Sagebrush received little use
until the birds were 11 weeks old, but the amount gradually increased during
the summer thereafter. Patterson^/ reported that sagebrush made up about
45 percent of the adult bird's diet in the summer, 81 percent in the fall,
99.7 percent in winter and 86 percent in spring. The average percent sage-
brush from all stomach content analyses for a year was 77 percent.
Stomach analysis of sage grouse killed in early Septem-
ber in California showed that sagebrush made up 64 percent of the volume
in 2 years, but only 29 percent in a third year.^A/ Clover leaves and
rush leafage were important components the first 2 years, while prickly
lettuce flowers and grasshoppers made up 21 and 22 percent, respectively,
of the volume in the third year.
found that sagebrush made up 56 percent of
stomach contents of adult cocks in the summer, the remainder being pre-
dominantly forbs. Dalke, et al.,— ' reported that black sagebrush (A. nova)
vas preferred over big sagebrush (A. tridentata) as a winter feed. Barber9-^
found that penned sage grouse fed almost exclusively on small sagebrush,
i.e., plants less than 5 in. tall. An analysis of big sagebrush leaves
showed that the leaves of small plants were lower in ether extract and
essential oils than were the leaves of the taller plants .227 The tall
big sagebrush plants grew on the more favorable sites that tend to have
a higher content of magnesium and phosphorus in the A horizon. There is
uncertainty as to the importance of the content of essential oils in the
77
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since sage grouse appear to excrete these oils in the feces in quantities
roughly equal to amounts ingested.2£/
Broods occupy sites with fewer shrubs than do the
adult grouse as forbs are more abundant where the brush is less dense.
As the vegetation at the lower elevations dries up, the broods move upward
or on to meadow areas with a good water supply.2s.' The meadows often be-
come a necessity to juvenile sage grouse as a sole source of desired food
species. Hens and chicks congregate only on these portions of meadow
having some typical meadow vegetation. Bare areas or water sources with-
out desired vegetation are ignored. The meadow areas are used almost
exclusively by the hens and chicks, but in dry seasons a few males may be
observed feeding there.
The heavy and continuous use of sagebrush as a food
for sage grouse is understandable because of the harsh climate which they
inhabit.££/ Sagebrush is an evergreen shrub with a high digestible nutrient
content and is practically the only plant food available throughout the
year in parts of Wyoming regardless of snow conditions or drought.
In studies conducted in Montana, the contents of 35
crops of sage grouse were analyzed during the summer.1P_P_/ xt was found
that sagebrush (mainly big sagebrush) and dandelion (Taraxacum officiuale)
made up over two-thirds of the crop contents. Sagebrush and three genera
of forbs together composed 94.6 percent of the samples. It was observed
that leaves and flower clusters of sagebrush and dandelion comprised 79.4
percent of the crop contents.
In Wyoming, Patterson reported that only during summer
does sagebrush compose less than 80 percent of the food volume consumed
by sage grouse.52/ Volumes observed for sagebrush were 86.5, 44.9, 80.7,
and 99.7 percent for spring, summer, fall and winter, respectively.
(2) Cover; Sage grouse habitat is predominantly a
sagebrush association. Sagebrush and other associated shrubs are used as
cover for nesting, rearing broods, loafing and roosting. KlebenowlOl/
found that in mixed stands of big sagebrush (A. triventata) and three-tip
sagebrush (A. tripartita) in Idaho, sage grouse preferred the three-tip
site for nesting with 91 percent of the nests occurring there. In areas
with little shrub cover, sage grouse nest in the moderately dense portion,
but not in the very dense parts.I22/ Hens did not nest in areas of'tall,
dense sagebrush with little understory. The average density of shrubs in
nesting vicinities was 18 percent. No nests were found where shrub cover
exceeded 35 percent or where sagebrush cover was greater than 25 percent.
78
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Grouse nests are frequently placed under a sagebrush limb or between tvo
adjacent clumps of sagebrush, but rarely a nest is built on open ground
with no cover. The average height of sagebrush at nesting sites was 14 in.
in Wyoming§i/ and 17 in. in Idaho. 121/
Nesting birds and adult males tend to select areas with
a moderate amount of shrub cover, but hens with broods choose sites with
less shrub cover since the preferred forbs are usually more abundant there.
Food plants develop along an elevational gradient and broods follow the
same gradient in their summer movements. The most important variable in
the discrimination between brood and nonbrood habitat is the sagebrush
density. Broods occupy sites with fewer big sagebrush plants. The crown
cover of big sagebrush on sites where broods are found was 8-1/2 percent
as compared to 14.3 percent cover for adult birds. Few broods are found
in areas with greater than 31 percent shrub cover.
- e
In the dry part of the year, the sage grouse begin to
form large flocks in the vicinity of green meadows and water holes. Sage-
brush, willows, tall grass or uncut fields of hay serve as nesting cover
in summer.—' In the fall, sage grouse leave the higher meadows or fields
and return to the sagebrush prairies. They obtain water by daily movements
to streams, springs, or marshy meadows. They tend to choose the taller
sagebrush in draws and gullies and along stream beds for the mid-day rest-
ing stops. At night they choose areas of smaller and more open stands of
sagebrush for roosting. The sagebrush serves no function other than cover
as the birds neither roost nor rest on the branches, but merely squat on
the ground in openings or at the base of bushes.£2/
d. Effects of sagebrush control; Sagebrush is considered
a part of the climax vegetation in many areas of the West. In some areas
it has increased due to the influence of grazing until it is the dominant
vegetation of a site. In adjoining pastures, or pastures on similar sites,
the productivity of sagebrush may vary from about 10 percent to 55 percent
or more of the total production, depending on the condition of the range.122.
On pristine areas in Idaho, sagebrush made up 2 to 14 percent of the total
productivity over a 5-year period on three soil types.12^.' These data
suggest that, under conditions of no use or proper use by livestock, the
density of sagebrush in many areas should not exceed 15 percent of the
canopy cover. Over utilization by livestock has upset the delicate balance
between grasses and sagebrush in many areas, resulting in dense stands of
brush.
79
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As mentioned earlier, sage grouse make little, if any, use
of the tall, dense stands of big sagebrush with little understory.iPJ/
The variety of sites used by sage grouse for strutting grounds suggests
that improvement of the presently occupied range can provide opportunity
for greater numbers of mature males to set up strutting territories and
adjacent nesting areas .22.' New strutting areas can be created by fire or
by using mechanical means to make openings of 1/4 to 1/2 acreas in dense
stands of sagebrush. Sage grouse moved from old strutting grounds to
newly cleared patches of ground created by bulldozing or fire.
HigbylPJL/ reported on a sagebrush clearing project in
Wyoming in which approximately 12,000 acres were sprayed with 2,4-D over
a 5-year period, and 80 to 90 percent control was obtained. About 1,000
sage grouse used the treated and adjacent areas for wintering prior to
treatment. The year spraying was completed, no grouse were observed in
the area. The year after spraying stopped, birds began using the first
area sprayed and the number of birds increased yearly thereafter. Strutting
ground counts by years in the treated area, beginning the year spraying was
initiated, were: 1961-50; 1962-28; 1963-7; 1964-8; 1965-0; 1966-11; 1967-
20; 1968-16; and 1969-31.
Three untreated areas located in different directions and
about 25 miles from the treated area, showed a large variation in bird
count over these years. In 1963, the count was low at all locations, but
higher populations were observed in later years. In 1969, the total num-
ber of birds on the three untreated areas was essentially the same as in
1961.
Autenrieth-i0-^-' reported that, where 90 to 100 percent sage-
brush control was obtained on 50-ft strips with alternate strips left un-
sprayed, sprayed strips provided prime feed areas for a favored brood forb.
Grass and dandelion increased on the sprayed area. As broods moved upward
in elevation in summer, they congregated on sprayed strips to feed. The
sprayed strips were also used for roosting, while the unsprayed strips
were used for shade, loafing and escape cover. The increase in grass
cover on the sprayed areas utilized enough of the soil moisture in drier
summers that the forbs remained green longer in the brushy areas, and late
moving birds were located mostly in these areas. MartinlPJ!/ found only
4 percent of observed sage grouse on sprayed strips on which 92 percent
of the sagebrush was killed. The productivity on the sprayed areas was
80 percent grass and 20 percent forbs, while on the unsprayed area the
ratio was 60:40. Favored forage plants for sage grouse were more abundant
on unsprayed areas than on sprayed areas, and the number of grouse in the
various strips was related to vegetative composition.
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KlebenowI02/ found that nesting stopped in an area sprayed
for sagebrush control, and it had not been initiated again within 3 years,
but a new nest was found on an area 5 years after spraying. Nesting sites
were most abundant where brush cover was 17 to 18 percent. Broods were
affected less by spraying than were nesting birds. Of the potentially
good brood habitat, 34 percent were sprayed and 29 percent of the broods
were observed within that sprayed area. On the sprayed areas the stand
of sagebrush was reduced, but the amount of bitterbrush and other woody
species increased. Sagebrush was reduced by burning, but the stand re-
covered faster on burned areas than on sprayed ones and eventually resulted
in an increase in cover. The effectiveness of a spray treatment affects
the length of time before an area will recover sufficiently for nesting.
A longer time is needed where a high level of control is obtained. Spray-
ing may change the forb composition and make it more suitable for broods
even though the total forb abundance decreases.
In areas with little shrub canopy cover, sage grouse nest
in the more dense portion, but not in the very dense stands. Klebenow^P.V
suggested that controlling tall, dense sagebrush and allowing the native
forbs and grasses to recover their former productivity could only benefit
sage grouse. Something less than complete control of sagebrush would be
desirable. On ranges with less than 10 percent shrub cover and where shrubs
are low-growing, the best sites for grouse are the depressions and drain-
ages where the shrubs are taller. He recommended that these areas should
be left undisturbed. A good sage grouse habitat would be an open stand of
sagebrush with a scattering of other shrubs and an understory of perennial
grasses and forbs.
Carr and Glover,!2§/ reporting on the effects of block and
strip spraying using 50-yd strips, found that 1-1/2 years after spraying,
sagebrush control did not affect strutting grounds or activities, nor nest-
ing density or success. Nests were found on sprayed and unsprayed areas,
but in the sprayed areas they were relatively close to the unsprayed areas.
Block-sprayed areas were avoided except for strutting. Areas sprayed in
50-yd strips had no obvious affect on the distribution or movement of adult
grouse.
Reeher reported that in Oregon the sage grouse use on big
sage range was reduced by spraying or spraying and seeding.109/ Indications
were that continuous big sage areas are marginal grouse habitat, and that
the loss of habitat by spraying is small.
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5. Chukar Partridge; The chukar partridge is found throughout
most of the study area. However, the bird is not as closely associated
with sagebrush as is the sage grouse. Very limited data are available
concerning the effects of sagebrush control on the chukar.
Reeher reported that 2,4-D spray projects on good chukar habitat
did not reduce the chukar use of the areas.IPjl/ There were some indica-
tions that spraying increased the chukar use. At the initiation of the
study it was thought that killing sage cover in chukar habitat would be
detrimental to the bird population. However, that hypothesis was not
substantiated by the results obtained. Figure 12 shows the land use by
chukars in the sprayed and control areas based on pellet counts. Spray-
ing was carried out in 1963, and the land use by the birds was greater in
the treated area every year except 1965 than in the control area. The
low counts in 1965 through 1967 reflected a general decline of chukars
throughout the area where the tests were conducted. The amount of the
difference in use of the two areas in 1964, 1966, 1967, and 1968, was much
greater than the difference observed in 1963, the year the area was sprayed.
In the test area, winter cover for the chukars was juniper trees,
patches of aspen (Populus sp.), wild current (Ribes sp.). mountain mahogany
(Cercocarpos ledifolius). rose, clematis and mock orange (Philadelphia
lewisii). Some of the individual plants of those species were killed by
2,4-D spraying, but most survived.
6. Elk; Elk are present in various sections throughout the
study area. Rouse reported that elk (Cervus canadensis) consumed about
90 percent forbs in their diet during the summer in the Gravelly Mountains
in Oregon. 122.' The major forbs utilized were sticky geranium (Geranium
vise os is simum) , mule' s ear (Wyethia sp.), pussy toes (Antennovia. sp_.),
groundsel (Senecio sj».), and forget-me-not (Myosotis alpestris).
In the winter, grasses and sedges comprised 90 percent of the
contents of three rumen samples, but examination of feeding sites showed
heavy use of browse (55 percent of plant use). The heavy use of browse
was recorded over a 10-day period of severe cold and heavy snow cover.
Three-tip sage (Artemisia tripartata) was estimated to account for 49 per-
cent of the observed plant use.
Other studies have confirmed high usage of forbs in the summer
by «»ik 110-112/ By contrast, Morris and Schwartz reported that grass pre-
dominated in the diet of elk during the summer as well as during other
months of the year, on a range where grasses comprised about 79 percent
of the vegetation.113/ However, stomach samples taken in August contained
a large quantity of forbs, and June and July samples contained significant
amounts of forbs. Mackie reported that about one-half of the browse use
82
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2bU
240
200
| 160
B
O
4-
"3
a.
120
80
40
ft
274
253
-
.
—
•
S
\
\
N
N
\
\
\
\
\
\
\
\
\
\
\
23d
m^^m
ss
\
\
\
\
\
\
S
s
s
s
s
s
\
\
\
s
s
\
«
^
\
^.
^^
••••
Sprayed Control
Area Area
15C
^•M
1
38
T
\
\
100
t c
96
\
\
^
\
\
\
57
^•^
64
S
\
\
37
^^H
241
\
\
\
\
\
\
s
\
s
s
\
\
s
s
\
\
\
137
^^m
1963
1964
1965
1966
1967
1968
(Light Cattle Use)
Figure 12 - Land Use By Chukar Partridge on 2,4-D Sprayed and Control Areas
83
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by elk in winter was on big sagebrush, Artemisia tridentata. Browse use,
however, was minor as compared to grass use (only 17 percent of plant use).
7. Moose: The moose is usually a browser even in summer. How-
ever, Knowlton concluded that forbs made up 70.6 percent of 6,770 instances
of plant use recorded during the summer in the Gravelly Mountains in
Montana.UA/ Sticky geramium alone provided 64.2 percent of all instances
of use recognized. The high usage of forbs was apparently related to un-
usually high precipitation during the summer study period. Similar studies
made by Peek in the same general area, during dryer summers, showed that
the moose there had a marked preference for willow.1I5/
8. Bighorn Sheep; Bighorn sheep have been studied to determine
their feeding habits. Schallendberger examined 67 feeding sites of the
animals during winter in the Sun River Area of Montana. He found the mean
percentages for instances of plant use were 36, 21, and 43 for grass and
grass-like plants, forbs and browse, respectively. Fringed sagewort was
a frequently used browse species.
In a study of the Sun River area of Montana, Couey concluded
that grass constituted the bulk of food on the winter for bighorn sheep.U^/
He also observed that Artemisia frigida seemed to be a preferred food, and
that it was commonly consumed in the winter.
9. Rabbits: Jack rabbits and cottontails occur throughout most
of the study area.
In one study, there were no consistent differences between the
rabbit use for areas where sagebrush was controlled, and untreated areas.122/
In one other area, there was a consistently lower rabbit use on
rehabilitated sites than on control sites. These results were attributed
to winter conditions. The test area was located on a high plateau that
is usually snow covered during part of the winter. During those periods,
rabbits would have to move out of the sprayed areas into surrounding brush
areas in search of food and cover. No such movement would be necessary
in the untreated control area.
G. Comments
From the data given in the preceding paragraphs (1-9) concerning
various species of wildlife that inhabit the sagebrush rangelands, it is
apparent that forbs and browse, including sagebrush, play a role of impor-
tance to the survival of those animals. Any program which removes or
drastically reduces those forage classes, or areas occupied by those
84
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species, possibly could be detrimental to their welfare. 48/ A drastic
reduction of certain forbs on summer ranges could adversely effect ante-
lope, sage grouse, mule deer, whitetail deer, elk, and possibily moose
under some conditions. The elimination of sagebrush on winter ranges
probably would be most detrimental to sage grouse, antelope and mule deer.
However, there are some indications that whitetail deer, elk, and bighorn
sheep also could be adversely affected.
Many different wild animals graze on sagebrush sites. Elk graze
primarily on grasses and forbs83/ and use little if any sagebrush. Control
of sagebrush in Jackson Hole, Wyoming increased the frequency of occurrence
of elk grazing on the treated site as compared to an treated. IIP/ A study
in Utah showed that the blacktailed jackrabbit grazed big sagebrush during
the winter .lii/ The grazing preference of jackrabbits was similar to
sheep, i.e., they prefer green grasses and forbs, but will go to sagebrush
and rabbitbrush during the dormant season.
A good balance of browse and herbaceous plants is desirable. '
Even with ample browse, an area may not have enough grasses and forbs to
provide succulent forage in the critical periods of late winter and early
spring.
Many areas now support vegetation that do not provide satis-
factory forage or watershed protection. Such areas include inter alia
dense stands of sagebrush supporting few perennial grasses and forbs. On
such areas, undesirable vegetation must be destroyed or greatly reduced to
allow establishment of desirable species. The method used need not com-
pletely eliminate the competing plants, but should thin enough to minimize
direct competition for moisture.
Big sagebrush is desirable on most big game and livestock ranges,
and especially on sage grouse range. However, where big sagebrush has
usurped the site and excluded understory species, the stand must be thinned
to permit establishment of grasses and forbs.
Big sagebrush is abundant in protein, but the foliage contains
considerable amounts of aromatic oils which reduce palatibility somewhat.
It is an important winter forage on foothill areas for big game and live-
stock in Utah. Its value is enhanced by its unusually rapid growth and
exceptional ability to spread naturally from seed. Since wildings and
seedlings are transplanted easily, big sagebrush can be used widely for
stabilizing gullies and eroding spots on hillsides.
Some ranges, where associated grasses and forbs have been grazed
out, have become closed stands of sagebrush. These closed stands must be
thinned, and adapted grasses and forbs seeded to provide a suitable and
balanced cover .Z2'
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Ranges with some remnants of desirable grasses will improve
rapidly after sagebrush control. Nearly a twofold increase in forage
was obtained after treating range in fair condition and fourfold increase
on poor condition range.
86
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REFERENCES
1. Dietz, R. D., R. H. Udall, and L. E. Yeager, "Chemical Composition
and Digestibility by Mule Deer of Selected Forager Species," Cache
La Poudre, Rouge, Colorado, Colorado Game & Fish: Tech. Pub. 14
(1962).
2. U. S. Department of Agriculture, "Chemical Control of Brush and Trees,"
Farmer's Bulletin. 2J.85_ (1961).
3. Lewis, R. W., and C. L. Hammer, "The Effect of 2,4-D on Some Micro-
organisms," Mich. Agr. Exp. Ata. Quart. Bull.. 29:112-114 (1946).
4. Thornton, B. J., "The Use of 2,4-D and 2,4,5-T in Controlling Herbaceous
and Woody Plant Growth," Colo. Agr. Exp. Sta. Misc. Ser. Paper, 470
(1950).
5. Crafts, A. S., and W. W. Robbins, "Weed Control," 3rd Edition McGraw-
Hill Book Company, Inc., New York (1962).
6. Ogle, R. E., and G. F. Warren, "Fate and Activity of Herbicides in
Soils," Weeds . 3j 257-273 (1954).
7. Andus, L. J., "Herbicides Behavior in the Soil," II Interactions
With Soil Microorganisms, In: The Physiology and Biochemistry of
Herbicides, Edition by L. J. Anuds, pp. 163-206 (1964).
8. Lavy, T. L., F. W. Roeth, and C. R. Fenster, "Detoxification of
Atrazine and 2,4-D in Two Soil Profiles in the Field," Abstracts
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87
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52. Buechner, H. K., "Regulation of Numbers of Pronghorn Antelope in
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Mountains Wildlife Refuge," Trans, of the North American Wildlife
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Wildlife Management Institute, Washing-ton, D. C., 238 pp. (1948).
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Colorado Game and Fish Dept., 110 pp. (1959).
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Use in Central Montana With Special Reference to Alfalfa," Montana
Fish and Game Tech. Bull. No. 2, 39 pp. (1958).
59. Seton, E. T., "Lives of Game Animals," The Literary Guild of America.
Inc.. 3, p. 421 (1929).
60. Einerson, A. S., 1948 (Previous reference).
61. Severson, K., M. May, and W. Hepworth, "Food Preferences Carrying
Capacities, and Forage Competition Between Antelope and Sheep in
Wyoming's Red Desert," Sci, Mono.. 10, Agri. Expt. Sta., University
of Wyoming, 51 pp. (1968).
62. Severson, K. E., and M. May, "Food Preferences of Antelope and Domestic
Sheep in Wyoming's Red Desert," J. Range Manage.. 20_, 21-25 (1967).
63. Dirschl, H. J., "Food Habits of the Pronghorn in Saskatchewan,"
J. Wildlife Manage.. 2£, 81-93 (1963).
64. Mason, E., "Food Habits and Measurements of Hart Mountain Antelope,"
J. Wildlife Manage.. 16, 387-389 (1952).
65. Bayless, S. R., "Food Habits, Range Use and Home Range of Antelope
in Montana," J. Wildlife Manage.. 33, 538-551 (1969).
91
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66. Stanton, F. W., "Effects of Sagebrush Spraying on Game Animals in
Oregon," J. Wildlife Manage., 16th Annual Meeting, Amer. Soc. of
Range Manage. 61-62 (1963).
67. Smith, D. D., D. M. Beale, and D. D. Doell, "Browse Preference of
Pronghorn Antelope in Southwestern Utah," Trans. 13th North American
Wildlife Confer.. 3£, 130-141 (1965).
68. Reeher, J. A., "The Effect of Large Scale Livestock Range Rehabilita-
tion on Game Species," Final Report, Project No. W60K01-5 (September
1, 1963 - June 30, 1969), Oregon State Game Commission, July 1, 1969),
69. Taylor, W. P., The Deer of North America. The Wildlife Management
Institute, Washington, D. C. (1956).
70. Hill, R. R., "Forage, Food Habits, and Range Management of the Mule
Deer," In Deer of North America, pp. 393-415 (1956).
71. Smith, A. D., "Sagebrush as a Winter Feed for Deer," J. of Wildlife
Manage.. 14.O), 285-289 (1950).
72. Smith, A. D., and R. L. Hubbard, "Preference Ratings for Winter Deer
Forages from Northern Utah Ranges Based on Browsing Time and Forage
Consumed," J. Range Manage.,7. 262-265 (1954).
73. Smith, A. D., "Adequacy of Some Important Browse Species in Over-
wintering of Mule Deer," J. Range Manage.. 12_, 8-13 (1959).
74. Smith, J. G., and 0. Julander, "Deer and Sheep Competition in Utah,"
J. Wildlife Manage.. 1£, 101-112 (1953).
75. Wilkins, B. T., "Range Used, Food Habits and Agricultural Relation-
ships of the Mule Deer, Bridge Mountains, Montana," J. Wildlife
Manage.. 2J., 159-169 (1957).
76. Nagy, J. G., H. W. Steinhoff, and G. M. Ward, "Effects of Essential
Oils of Sagebrush on Deer Rumem Microbial Activity," J. Wildlife
Manage.. 2£, 785-790 (1964).
77. Longhurst, W. M., H. K. Oh, M. B. Jones, and R. E. Kepner, "A Basis
for the Palatability of Deer Forage Plants," 33rd North American
Wildlife Confer., pp. 181-192 (1968).
i
78. Powell, J., "Site Factor Relationships With Volatile Oils in Big
Sagebrush," J. Range Manage.. 23, 42-46 (1970).
92
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79. Plummer, A. P., D. R. Christensen, and S. B. Monsen, "Restoring Big
Game Range in Utah," Publication No. 6803 Utah Division of Fish
and Game, 183 pp. (1968).
80. Bissell, H. D., B. Harris, H. Strong, and F. James, "The Digestibility
of Certain Natural and Artificial Foods Eaten by Deer in California,"
California Fish and Game. 41, 57-78 (1955).
81. Lovaus, A. L., "Mule Deer Food Habits and Range Use," Little Belt
Mountain, Montana, J. Wildlife Manage.. 22, 275-283 (1958).
82. South, P. R., "Ford Habits and Range Use of the Mule Deer in the
Scudder Creek Area, Beaverhead County, Montana," Unpub. Master's
Thesis, Montana State College, Bozeman (1957).
r
83. Morris, M. S., and J. E. Schwartz, "Mule Deer and Elk Food Habits on
the National Bison Range," J. Wildlife Manage.. 21, 189-193 (1957).
84. Keiss, R. E., "Notes on Deer and Elk Nutrition Winter 1964-65,"
Colorado Game and Fish and Parks, Ft. Collins, Colorado (1966).
85. Anderson, A. E., "2,4-D, Sagebrush, and Mule Deer-Cattle Use of Upper
Winter Range," Special Report No. 21, Colorado Division of Game,
Fish and Parks, July 1969.
86. Reeher, J. A., "The Effect of Large Scale Livestock Range Rehabilita-
tion on Game Species," Final Report, Project No. W60K01-5 (September
1, 1963 - June 30, 1969) Oregon State Game Commission, July 1, 1969).
87. Allen, E. 0.,"Food and Range Use Habits of Whitetail Deer on Missouri
River Bottomlands in Northcentral Montana," Unpub. Master's Thesis,
Montana State University, Bozeman (1965).
88. Schallenberger, A. D., "Food Habits, Range Use and Interspecific
Relationships of Bighorn Sheep in the Sun River Area, Westcentral
Montana," Unpub. Master's Thesis, State University, Bozeman (1966).
89. Patterson, R. L., "The Sage Grouse in Wyoming," Wyoming Game and Fish
Commission," Sage Books, Inc., Denver, 341 pp. (1952).
90. Dalke, P. D., D. B. Pyrah, D. C. Stanton, J. E. Crawford, and E. F.
Schlatterer, "Ecology, Productivity and Management of Sage Grouse
in Idaho," J. Wildlife Range Manage.. 27, 811-814 (1963).
91. May, T. A., and B. E. Poley, "Spring and Summer Movements of Female
Sage Grouse in North Park, Colorado," 6th Biennial Western States
Sage Grouse Workshop, pp. 173-177 (1969).
93
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92. Klebenow, D. A., "The Nesting and Brood Habit of Sage Grouse/'
Dissertation Abst. B29 1890-B (1968).
93. DaIke, P. D., D. B. Pyrah, D. C. Stanton, J. E. Crawford, and E. E.
Schlatterer, "Ecology, Reproduction and Management of Sage Grouse
in Idaho," J. Wildlife Manage.. 2£, 811-814 (1963).
94. Savage, D. E., "The Relationship of Sage Grouse to Upland Meadows in
Nevada," 6th Biennial Western States Sage Grouse Workshop, pp. 134-
141 (1969).
95. Klebenow, D. A., and G. M. Gray, "Food Habits of Juvenile Sage Grouse,"
J. Wildlife Ranee Manage.. 21(2), 80-83 (1968}.
96. Peterson, J. G., "The Food Habits and Summer Distribution of Juvenile
Sage Grouse in Central Montana," J. Wildlife Range Manage.. 34(1),
147-155 (1970).
97. Leach, H. R., and A. L. Hensley, "The Sage Grouse in California With
Special Reference to Food Habits," California Fish and Game. 40(4),
385-396 (1954).
98. Barber, T. A., "Nutrition and Dietary Preference of Penned Sage
Grouse," 6th Biennial Western States Sage Grouse Workshop, pp. 180-
188 (1969).
99. Powell, J., "Site Factor Relationships With Volatile Oils in Big
Sagebrush," J. Wildlife Range Manage.. 23J1), 42-46 (1970).
100. Martin, N. A., "Effects of Chemical Control of Sagebrush on the
Occurrence of Sage Grouse in Southwestern Montana." Unpub. Master's
Thesis, Montana State College, Bozeman (1965).
101. Klebenow, D. A., "Sage Grouse Nesting and Brood Habitat in Idaho,"
J. Wildlife Range Manage.. 33J3), 649-662 (1969).
102. Klebenow, D. A., "Sage Grouse Vs. Sagebrush Control in Idaho," J._
Wildlife Range Manage., 23(6), 396-400 (1970).
103. Cooper, H. W.., "Amounts of Big Sagebrush in Plant Communities Near
Tensleep, Wyoming, as Affected by Grazing Treatment," Ecology. 34,
186-189 (1953).
104. Passey, H. B., V. K. Hugie, and E. W. Williams, "Herbage Production
and Composition Fluctuations of Natural Plant Communities as Related
to Climate and Soil Toxonamic Units," Forage Plant Physiology and
Soil-Range Relationships, ASA Spec. Public.No. 5, 206 (1964).
94
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105. Higby, H. L., "A Summary of the longs Creek Sagebrush Control Project,"
6th Biennial Western States Sage Grouse Workshop, pp. 164-168 (1969).
106. Autenrieth, R. E., "Impact of Strip Spray on Vegetation and Sage
Grouse Use on Summer Habitat " 6th Biennial Western States Sage
Grouse Workshop, pp. 147-157 (1969).
107. Martin, N. S., "Sagebrush Control Related to Habitat and Sage Grouse
Occurrence," J. Wildlife Range Manage.. 34J2), 313-320 (1970).
108. Carr, H. D., and F. A. Glover, "Effects of Sagebrush Control on Sage
Grouse," 35th North American Wildlife Conference, pp. 205-215 (1970).
109. Reeher, J. A., "The Effect of Large Scale Livestock Range Rehabilita-
tion on Game Species," Final Report,, Project No. W60K01-5 (September
1, 1963 - June 30, 1969), Oregon State Game Commission, July 1, 1969).
110. Mackie, R. J., "Range Ecology and Relations of Mule Deer, Elk, and
Cattle in the Missouri River Breaks, Montana," Unpub. Ph.D. Thesis,
Montana State College, Bozeman (1969).
111. Stevens, D. R., "Range Relationships of Elk and Livestock in the Crow
Creek Drainage, Elkhorn Mountains, Montana," Unpub. Master's Thesis,
Montana State College, Bozeman (1965).
112. Kersih, J. B., "Range Use Relationship to Logging, and Food Habits
of the Elk in the Little Belt Mountains, Montana, Unpub. Master's
Thesis, Montana State College, Bozeman (1962).
113. Morris, M. A., and J. E. Schwartz, "Mule Deer and Elk Food Habits on
the National Bison Range," J. Wildlife Range Manage.. 21, 189-193
(1957).
114. Knowlton, F. F., "Food[ Habits, Movements, and Populations of Moose
in the Gravelly Mountains, Montana." J. Wildlife Range Manage.. 24_,
162-170 (1960).
115. Peek, J. M., "Reproduction of Moose in Southwestern Montana," Unpub.
Master's Thesis, Montana State College, Bozeman (1961).
116. Couey, F. M., "Rocky Mountain Bighorn Sheep of Montana," Federal Aid
in Wildlife Rest. Proj. 1-R, Bull. 2, Montana Fish and Game
Commission (1950).
117. Hedrick, D. W., D. N. Hyder, F. A. Sneva, and C. E. Poulten, "Ecological
Response of Sagebrush Grass Range in Central Oregon to Mechanical and
Chemical Removal of Artemisia," Ecology, 4£, 432-439 (1966).
95
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VIII. HERBICIDES IN AQUATIC ENVIRONMENTS
A. Sources of Herbicides
Environmental contamination has been classified under two general
categories: intentional (direct) application and unintentional (indirect)
contamination.!/ Utilizing this basic concept, Ware and RoanI/ developed a
classification specifically for aquatic environments. In their classifica-
tion many of the sources that originally were classified as "unintentional"
were changed to "intentional." This classification was justified because
pesticides are in fact knowingly added to the aquatic environment. The
classification is shown in Table XIV.
TABLE XIV2-/
SOURCES OF PESTICIDES IN THE AQUATIC ENVIRONMENT
A. Intentional introduction
1. Control of objectional flora
2. Industrial wastes
a. Pesticide manufacturers and femulators
b. Food industry
3. Disposal of unused materials
4. On-site field cleaning of application,
mixing and auxiliary equipment
5. Disposal of commodities with excessive residues
6. Decontamination procedures
B. Unintentional introduction
1. Drift from pesticide applications to control
objectional flora.
2. Secondary relocation from target area via
natural wind and water erosion.
3. Irrigation soil water from target areas.
4. Accidents involving water-borne cargo.
5. Application accidents involving missed targets
or improper chemicals.
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This classification is applicable, in part, to 2,4-D herbicide
used to control sagebrush within the study area. Some of the sources
listed would be more applicable than others because of arid conditions,
lack of major industrial operations, relatively low population density,
and various other factors characteristic of the area.
B. Entry Into Aquatic Environments
The principal avenues of 2,4-D entry into an aqueous system are:
(1) runoff from treated soil, (2) inadvertent application over a body of
water while treating terrestrial plants, (3) use for the control of aquatic
weeds, and (4) accidental contamination.
1. Runoff from treated soil: Barnett et al.^-' measured the
2,4-D losses from bare soil runoff on a 5-7 percent slope. Thirty-five
percent of an iso-octyl ester formulation of 2,4-D was lost off a 35-ft
plot in 1/2 hr, and as the rate of 2,4-D application doubled, the amount
of runoff more than doubled. The maximum concentration from a 4.4 Ib/acre
application was 4.2 ppm. The concentration in runoff tended to decrease
with time. The amount of 2,4-D lost in runoff did not increase with in-
crease in slope length from 35-75 ft, a fact which suggests that water from
upslope was percolating into the soil downslope. Ester formulations were
more subject to removal in runoff than were amine salts. The average loss
of 2,4-D in runoff was 13 percent for esters and 4 percent for amines in a
1-year frequency storm.
To determine the amount of 2,4-D that would enter the water
environment during a typical application, Aldhous^' measured the 2,4-D in
drainage furrows across a slope that was sprayed at -the rate of 4 Ib/acre.
The site was marshy and there was no runoff from the soil surface, only
drainage from the high water table. The concentration of 2,4-D detected
in the water (minimum detectable concentrations of 0.005 ppm) the day before
spraying and 1, 2, 4, 7 and 28 days later was 0, 1.5, 1.6, 2.0, 1.6 and 0
ppm, respectively. The concentrations observed were probably as high as
can be expected without runoff from rainstorms.
The concentration of 2,4-D in irrigation water was measured by
sampling at stations 1/4, 1-1/4, 2-1/2, 5, 7-1/2 and 10 miles below the
point of actual field application. Where high concentrations of 2,4-D
occurred at the first two stations, there was a dissipation with distance
from the starting point. When low levels of 2,4-D occurred at the first
two stations, the average concentration at successive stations was rela-
tively constant with only a slight dissipation. The maximum concentration
of 2,4-D at any sampling station in 11 and 18 canals was below 50 ppb; in
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six canals it was between 50 and 100 ppb; in the other two it was 138 and
213 ppb. The 213-ppb concentration occurred below an overlapping application
of 3 Ib/acre of 2,4-D. In most canals the concentration of 2,4-D declined
with distance. There was not a measurable amount of 2,4-D in the water ar-
riving at the stations after the dye marker, which was applied immediately
after the herbicide treatment, had passed.sL' Rates of 2,4-D application
varied from 1.4 to 2.5 Ib/acre.
2. Inadvertent application over water while treating terrestrial
weeds; In one study!/ 2,4-D was applied at a rate of 1.9 to 3 Ib/acre for
weed control along the banks of a canal. Maximum concentrations of 25-61
ppb of 2,4-D were detected in the water after application, and negligible
concentrations of the herbicide were found after the water traveled a
distance of 20-25 miles.
It was concluded that the low concentration of herbicides ob-
served in the irrigation water likely would not be hazardous to crops or
animals. Further, levels of 2,4-D were reduced to traces or nondetectable
quantities within 30-60 min.
3. Application for the control of aquatic weeds; The selective
herbicIda1 properties of 2,4-D were discovered in 1944, and research on
its use for aquatic-weed control was initiated in 1947 by several govern-
ment agencies.2.' The herbicide, 2,4-D, has been reported to be the most
commonly used chemical for the effective control of rooted submersed,
rooted, immersed, floating, and marginal weeds in ponds, lakes, irrigation
ditches, and canals.Z' When used for aquatic plant control, 2,4-D is ap-
plied as the water-soluble sodium, potassium, ammonium, or amine salts, or
as short chain alkyl esters such as methyl, propyl, butyl, or vityl, or as
heavy nonvolatile esters. The esters are usually applied as granules, ab-
sorbed onto clays, or formulated in emulsifiable liquid concentrates in
different oils and organic solvents. Application rates range from 20-100 Ib
of 2,4-D acid equivalent per acre of water.2J
Averitt reported that the concentration of 2,4-D in the water
from a 4 Ib/acre application for water hyacinth control was 739, 802, 446
and 74 ppb daily for the first 4 days after application.£/ The concen-
tration declined gradually to no detectable 2,4-D after 102 days. A second
test showed a maximum concentration of 600 ppb in 3 days, 80 ppb the 4th
day, and then a gradual decline.
In tests in which 2,4-D was applied at 1-10 Ib/acre on water
hyacinths growing in water from 1-7 ft deep and at various times of the
year, the concentration of 2,4-D in the water varied with the rate applied,
water temperature, water depth, and the time lapse after treatment. The
maximum concentration of 2,4-D applied at 4 Ib/acre in 1-ft depth pools
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was 831 ppb. At the 4 Ib/acre rate, the concentration of 2,4-D was reduced
by 58 ppb for each 2-ft increase in water depth, 115 ppb for each 10-degree
increase in temperature about 60°F, and 53 ppb for each 7-day interval
after application. With a water temperature of 61°, 2,4-D concentration
declined very little in 28 days. When the water temperature was 75° or
above, the 2,4-D concentration after 28 days was generally 10 percent or
less of the maximum concentration,.£/
Frank and ComesiP./ measured a maximum concentration of 2,4-D of
0.067 ppm 18 days after applying granular 2,4-D butoxyethanol ester to
pond water at a concentration of 1.33 ppm. Low concentrations were found
in water for 24 days and in soils for 55 days. The concentration in the
top 1 in. of soil the day after treatment was 4.96 ppm, which declined to
0.10 ppm by 56 days. The low concentration in the water could be due to
absorption by weeds. The amount of 2,4-D salt'or esters sorbed on faento-
mite, illite or kaolinite varied from 0.02 to 0.14 mg/g. Esters of 2,4-D
were hydrolyzed in lake water to the acid in 9 days, but persisted for
120 days under aerobic conditions. 2,4-D was biologically decomposed in
lake mud and disappeared completely in 35 days in a previously treated
lake, and in 65 days in untreated water. 2,4-D did not disappear from
lake mud that was treated with sodium azide.il'
12 /
Smith and Isom==' found that less than 1 ppb of 2,4-D in pond
waters treated at rates of 40-100 Ib/acre for watermilfoil control at eight
out of nine sampling stations. They concluded that 2,4-D did not produce
adverse effects on water quality. De Marco et al.H' reported 2,4-D in
river water was biologically degraded under warm-aerobic, cold-aerobic and
cold-anaerobic conditions. Under warm-aerobic conditions 2,4-D was de-
graded in 6 days; under cold-anaerobic it took 55-80 days. Low-oxygen
conditions had more effect on rate of degradation than temperature had.
CopeM/ treated ponds with the PGBE ester of 2,4-D at concentra-
tions of 0, 0.1, 0.5, 1.0, 5.0 and 11 ppm, active ingredient. The residues
levels in the water dissipated rapidly. The 5-ppm and 10-ppm concentrations
persisted for 2 and 3 weeks, respectively. In the 10-ppm pond, the aquatic
weeds were controlled by 80-100 percent. 2,4-D in the vegetation was almost
completely dissipated in 3 months. 2,4-D was detectable in bottom sediments
for 44 and 94 days, respectively, at the 5- and 10-ppm rates.
4. Accidental contamination; Application accidents involving
missed targets could account for the unintentional introduction of herbicide
into the water environment. Aerial spraying is the most common method of
herbicide application, and once the material is released into the atmosphere,
the exact behavior of the aerosol cannot always be predicted or controlled
precisely. Herbicide aerosols occasionally drift from the target area outo
waterways like streams, rivers, ponds, lakes, and irrigation ditches.
99
-------
In the study areas, it is general practice to dispose of empty
herbicide containers by crushing them and then burying the flattened con-
tainers in a landfill.JJL/ The containers are usually drained of any re-
maining liquid; however, a residue of the herbicide undoubtedly remains on
the inside surfaces. It is possible that some 2,4-D eventually could find
its way into a water system. Rain or snow could carry the chemical into a
stream, reservoir, or other body of water; it appears, however, that such
disposal practices do not constitute major sources of water pollution.
Unquestionably better disposal techniques could be developed and imple-
mented.
C. Impact of 2,4-D Pollution on the Water Environment
It appears that 2,4-D is relatively nontoxic in an aquatic en-
vironment. In the direct application of 2,4-D at 2 Ib/acre across running
streams in Alaska, Sears and MeehanM' reported no mortality to fish. The
concentration of 2,4-D in water and fish samples was below levels considered
toxic. The application of 2,4-D to pond« at a rate of 100 ppm had no ap-
parent effect on the hardiness or reproductive ability of say mesquito
larvae.1Z/ There was little uptake by fish from applications of 40-100
Ib/acre of 2,4-D butoxyethanol ester granules, but there was uptake by
mussels. No adverse effects were observed upon aquatic fauna by high ap-
plication rates of 2,4-D. MacekM' reported no apparent effect on scud
(Gammarus fasciatus) in a 96-hr TLtjg test with concentrations of 2,4-D
amine up to 100 mg/liter. Ware and RoanI2' reported a decrease in C(>2 fix-
ation by phytoplankton during a 4-hr exposure to some ester formulations
of 2,4-D at 1 ppm, but not by the acid or amine formulation used. Oysters
and clams held in the center of a plot treated with 2,4-D at 30 Ib/acre for
watermilfoil control had a residue of 3.5 to 3.7 ppm.IP-' Bluecrab and fish
had residues of 0.3 and less than 0.8 ppm, respectively. The chromotropic
acid color test, which gives a characteristic color to any substance that
breaks down into formaldehyde, was used to determine 2,4-D.
Cope!!/ reported that bluegill exposed to the propyleneglycol-
butylether (PGBE) ester of 2,4-D developed pathological symptoms within a
few days. Glycogen was removed from the liver, and glycoproteins were
deposited in the circulatory system, causing stasis in some vessels. This
pathology lasted more than 3 months. No residues of 2,4-D were found in
whole-body residue studies of bluegill exposed to 2,4-D PGBE ester for 30
days at a concentration of 10 ppm.22/ The time of bluegill spawning was
delayed 2 weeks in ponds treated with 5 and 10 ppm of 2,4-D PGBE. Repro-
duction apparently proceeded normally and resulted in an average hatch of
fry. High-treatment groups of bluegill ended the experiment with small
numbers of larger fish, whereas the low 2,4-D treatment groups had more
fish of small size. Increased fish size was probably due to the greater
100
-------
amounts of available food. The data available on the effects of herbicides
on the reproduction of fish do not appear to prove that quantity or quality
of eggs, hatching of eggs, or quality of offspring are seriously affected
by exposure of adults to weed killers ,23/
Rodgers and Eller found no pathological intoxication in rain-
bow trout, bluegill or channel catfish by exposure to C14- labeled 2,4-D
butoxyethanol ester in contact baths at concentrations of 0.3 and 1.0 mg/
liter. The fisn did not absorb any detectable amount of 2,4-D or metabo-
lites after an initial absorption period of 3-4 hr. The residues in in-
dividual organs reached a maximum in 2-3 hr, and rapidly diminished there-
after, except in the gall bladder. The residues were associated almost
exclusively with the bile. The maximum concentration of radioactive mate-
rial in the bile of trout, catfish and bluegill was 105, 268 and 311 lig/g
of organ, respectively, in the bath containing, 1.0 mg/liter, and 26, 659
and 29 Ug/g in the 0.3 mg/liter bath. Rodgers and Stalling?5./ reported
water was more important than feed as a source of fish contamination with
2,4-D. Bluegill in water containing 2 mg/liter of C1^- labeled 2,4-D had
body residues of radioactive materials of 0.20 Ug/g, while fish fed a diet
containing 2 mg/kg of labeled 2,4-D retained whole body radioactive residues
of 0.005 Hg/g. The principal location of radioactive material after 4 weeks'
exposure to C^- labeled 2,4-D in water was in the bile with a concentration
of 55 lig/g.
Grant and Mehrle^Jl' injected male goldfish with spermiation
gonadotrophin after a 6- to 8-day exposure to 2,4-D at 700, 300, 150, 70
and 0 ug/liter. The spermiation response occurred in all treatment groups,
but the magnitude of response was proportionately less as the concentration
increased above 70 ug/liter, the no-effect level. A treatment of 2-4 Ib/acre
of 2,4-D in 1-ft depth water may interfere directly with spawning in goldfish
and could be more detrimental to less hardy species.
CopelZ/ treated ponds containing bluegill with 0, 0.1, 0.5, 1.0,
5.0 and 10 ppm of 2,4-D PGBE. Fish mortality at the three highest rates
was 19, 0.30 and 0.16 percent, respectively. There was no mortality below
1.0 ppm, 2,4-D residues were detectable in the fish only at the 5- and
10- ppm concentrations. The higher the 2,4-D concentration, the greater the
fish growth. Fish in 10 ppm of 2,4-D attained twice the length and three
times the weight of the control. Intermediate rates gave intermediate in-
creases in fish growth. There was no difference in number of offspring.
The increase in growth was probably due to an increase in food made avail-
able by control of aquatic plants or by a decrease in fish population in
the pond. The single exposure of 2,4-D at 10 ppm, while resulting in severe
pathological changes, was followed by eventual complete recovery.
Additional data on 2,4-D residues and toxicities in aquatic
species are shown in Table XV.
101
-------
TABLE XV
2.4-D RESIDUES AND TCKICITIES FOR AQUATIC SPECIES
A. 2.4-D Residues (u^/g^'in Fish Tissue
Tissue Bluegill Channel Catfish Largemouth Bass
Blood 68 29 6
Brain 97 27 5
Eggs 76 — 6
Storage fat -- -- 3
Striated muscle 40 6 1
Lateral-line muscle 30 13 3
Posterior kidney 88 35 4
B. Acute Toxicity of 2.4-D to Aquatic Species (dimethylamine salt)lP-/
Species Weight Temp. 24 hr 96 hr
Bluegill 1 g 17»C 154,000-262,000 125,000-177,000
Fathead minnow 1 g 17°C 389,000 335,000
Coho salmon 1 g 17°C 154,000 125,000
Channel catfish 1 g 17°C 154,000 125,000
Largemouth bass 1 g 17°C 154,000 125,000
C. Toxicity of 2.4-D PGBE toAguatic Speciesil/
Species 48-hr EC^n Values (ppb)
Rainbow trout 1100
Bluegill 900
Stonefly nymphs (Pteronarchys californicus) 1800
Water flea (Daphnia pulex) 3200
Water flea (Simocephalus serrulatus) 4900
102
-------
D. Degradation of 2.4-D in an Aouatic Environment
The biodegradation of 2,4-D apparently is a function of the size
and nature of the microbial population of the aquatic environment.2£/
About 68 percent of the 2,4-D concentration is used in the respiration
process, whereas 32 percent is incorporated into the microbial cells as a
reserve energy source. Results of studies indicate that the biodegrada-
tion of the herbicide follows zero-order kinetics. The rate of biodegra-
dation is dependent on several factors. One is the time necessary for the
enzyme system to become acclimated to the chemical, and the second is the
effect of age of the acclimated microorganisms on the rate. As the rate
decreases, the acclimation period increases until it reaches a stabiliza-
tion point. Therefore, new additions of 2,4-D degrade faster than pre-
vious ones, provided the stabilization point has not been reached. The
natural condition of the aquatic environment also is a factor. As an
illustration, 65 days were required to detoxify' 2,4-D in bottom mud of a
lake, and in contrast only 12 to 14 days were needed for degradation in
soil. The conditions in water may not be as conducive to the biodegrada-
tion of herbicides as those in soil.At/ The metabolism of 2,4-D was much
slower in water than in a terrestrial environment.
DeMarco et al.^r.' showed that a period of 12-14 days was needed
for the acclimation of aquatic microorganisms to biodegrade 2,4-D. After
the initial lag period, the rate of biodegradation of 2,4-D increases to
a maximum value dependent on a given concentration of microorganisms.
When the ratio of microorganism concentration to 2,4-D concentration was
held constant, constant oxidation rates were observed, suggesting that the
enzyme systems were saturated with substrate. Therefore, substrate con-
centrations were not a limiting factor, a fact further substantiating the
appropriateness of the zero-order kinetic model.
The biodegradation of 2,4-D appears to follow the stoichiometry
illustrated by the following equation.!!/
OCH2COOH
Cl
2H20 + 2 HC1
To recapitulate, these variables must be considered in studying
the biodegradation kinetics of 2,4-D: (1) microorganism concentration,
(2) substrate concentration, and (3) the ratio of microorganism concentra-
tion to substrate concentration.2!/ These three variables affect the rate
at which 2,4-D is converted to carbon dioxide, water, and hydrochloric
acid.
103
-------
E. 2,4-D Content of Water in WesternStates
In October 1966, the U.S. Geological Survey began a program of
monitoring pesticides in the streams of the western United States.!!'
The program has continued to date. One of the herbicides included in
the surveillance program was 2,4-D.
Table XVI shows the results of 2,4-D analysis of water samples
from 13 sampling stations located within or near the study area. From
October 1966 through June 1971, a total of 383 samples were analyzed for
2,4-D content, and only with 68 of the samples was it possible to detect
any of the herbicide (about 17.8%). The concentration of 2,4-D ranged
from 0.00 to a high of 0.99 ug/liter. The amounts of 2,4-D reported are
far below the 100 ug/liter concentration permissible in public water sup-
plies.!^/ There were no positive samples from November 1970 through
June 1971.
104
-------
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t*C CONTENT OF SELECTED STREAMS IN THE WESTERN UNITED STATES IMIcromm/Unr I
-------
REFERENCES
1. Wertlake, N. E., and F. A. Gunther, "Organic Pesticides in the
Environment," Adv. Chem. Series, 60, 110 (1966).
2. Ware, G. W., and C. C. Roan in Residue Reviews. 33, 15-45 Springer-
Verlac, New York, Hiedelberg, Berlin (1970).
3. Barnett, A. P., E. W. Hauser, W. W. White and J. H. Holladay, "Loss
of 2,4-D in Washoff from Cultivated Fallow Land," Weeds. 15,
133-138 (1967). ~~
4. Aldhous, J. R. , "2,4-D Residues in Water Following Aerial Spraying
in a Scottish Forest," Weed Research. 7. 239-241 (1967).
^^""^•^~^"^^^^^~ **J
5. Bartley, T. R., and A. R. Hattrup, "2,4-D Contamination and Persistence
in Irrigation Water," Proceedings. Western Soc. of WeedScience,
23, 10-33 (1970).
6. Frank, P. A., R. J. Dement and R. D. Comes, "Herbicides in Irrigation
Water Following Canal-Bank Treatment for Weed Control," Weed Sci..
18(6), 687-692, November 1970.
7. Aly, 0. M., and S. D. Faust, "Removal of 2,4-Dichlorophenoxyacetic
Acid Derivatives from Natural Waters," Journ. AWWA. 221-230,
February 1965.
8. Averitt, W. K., "A Summary of a Study of the Persistency and Residues
of Some Herbicides in Surface Waters," Abstracts, 1968 Weed Sci.
Soc. of America Meeting, p. 65 (1968).
9. Gangstad, E. 0., and W. R. Averitt, "Dissipation of 2,4-D Residues in
Ponds, Lakes, Bayous and Other Quiescent or Slowly Moving Bodies of
Water," Abstract, 1971 Meeting of Weed Sci. Soc. of America, p. Ill
(1971).
10. Frank, P. A., and R. D. Comes, "Herbicidal Residues in Pond Water and
Hydrosoil," Weeds. 15, 210-213 (1967).
11. Aly, 0. M., and S. D. Faust, "Studies on the Fate of 2,4-D and Ester
Derivatives In Natural Waters," J. Agri. Food Chem.. 12, 541-546
(1964).
12. Smith, G. E., and G. B. Isom, "Investigation of Effects of Large-
Scale Applications of 2,4-D on Aquatic Fauna and Water Quality,"
Pesticide Monitoring J.. U3>» 16-21 (1967).
107
-------
13. DeMarco, J., J. M. Symons and G. G. Robeck, "Behavior of Synthetic
Organics in Stratified Impoundments," Amer. Water Works Assoc. J.,
59, 965 (1967).
14. Cope, Oliver B., "Some Chronic Effects of 2,4-D on the Bluegill
(Leponis macrochirua)," Transactions of the American Fisheries
Society. £9, 1-12 (1970).
15. Personal communication, Mr. F. Farrel Higbee, Executive Director,
Aerical Applicators Association, Washington, D.C., August 30, 1971.
16. Sears, H. S., and W. R. Meehan, "Short Term Effects of 2,4-D on
Aquatic Organisms in the Nakwasin River Watershed Southeastern
Alaska," Selected Water Resources Abstracts. 3J4), 29 (1970).
17. Smith, G. E., and G. B. Isom, "Investigation of Effects of Large-
Scale Applications of 2,4-D Upon Aquatic Fauna and Water Quality,"
Abstracts, Weeds Sci. Soc. of America Meetings, p. 55 (1968).
18. Macek, K. J., "Acute Toxicity of Pesticides to Aquatic Invertebrates,"
Fish and Wildlife Service Resource Public. T7, 94 (1968).
19. Ware, G. W., and C. C. Roan, "Interaction of Pesticides with Aquatic
Microorganisms and Plankton," Residue Reviews. 33, 15-45 (1970).
20. Coakley, J. E., J. E. Campbell and F. F. McFerren, "Determination of
Butoxyethanol Ester of 2,4-Dichlorophenoxyacetic Acid in Shellfish
and Fish." J. Agri. and Feed Chem.. 12/3). 262-265 (1964).
21. Cope, 0. B,, "Some Responses of Fresh-Water Fish to Herbicides,"
Proc., 18th Southern Weed Conference, pp. 439-445 (1965).
22, Cope, 0, B., "Contamination of the Fresh-Water Ecosystem by Pesti-
cides," J. Applied Ecology. 3_ (suppl.), 33-44 (1966).
23. Cope, 0. B., "Some Responses of Fresh-Water Fish to Herbicides,"
Proc., 18th Southern Weed Conference, pp. 439-445 (1965).
24. Rodgers, C. A., and L. L. Eller, "Metabolism of Pesticides in Fish,"
Bureau of Sports Fisheries and Wildlife, Resource Public, 77,
100-101 (1969).
25. Rodgers, C. A., and D. Stalling, "Metabolism of Pesticides," Bureau
of Sports Fisheries and Wildlife Resource Public., 88, p. 16.
108
-------
26. Grant, B. F., and P. M. Mehrle, "Pesticide Effects on Fish Endocrine
Function," Bureau of Sports Fisheries and Wildlife Resource Public.,
88, p. 13-14 (1970).
27. Cope, 0. B., "Some Chronic Effects of 2,4-D on Bluegill (Lepomis
macrochirys)," Transactions of Amer. Fisheries Soc., 99, 1-12
(1970).
28. Schultz, D. P., "Special Report on 2,4-D Investigations," 1970 Progress
in Sports Fishery Research, Bureau of Sports Fisheries and Wildlife.
29. Heinmett, R. B., Jr., and A. D. Faust, Residue Reviews. 29, 191-207
(1969).
30. Kennedy, H. D., "Acute Toxicity of Pesticides to Fish," Prog, in
Sport Fisheries Research, pp. 3-9 (1970).
31. Schwartz, H. J., "Microbial Degradation of Pesticides in Aqueous
Solutions," J. Water Pollut. Control.. Feb., 39^, 1.701 (1967).
32. DeMarco, J. J., M. Symore and G. G. Robeck, "Behavior of Synthetic
Organics in Stratified Empoundments."
33. Manigold, D. B., and J. A. Achulze, "Pesticides in Selected Western
Streams—A Progress Report," Pesticides Monitoring Jour.. 3, 2,
124-135 (September 1969).
34. Water Quality Criteria—Report of the National Technical Advisory
Committee to the Secretary of the Interior, FWPCA (1968).
109
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IX. TOXICITY AND HAZARD OF 2.4-D TO ANIMALS AND MAM
A. Introduction
Herbicides have been employed to control undesirable vegetation
for many years. Chlorinated phenoxyacetic acid and closely related com-
pounds have proven to be some of the most effective weed and brush control
agents. The compound,2,4-D (2,4-dichlorophenoxyacetic acid), presently
used to control sagebrush on rangelands is a prototype of that group of
herbicides. Because of the long history of use of 2,4-D, considerable
data concerning the toxicity of the compound are available. In the fol-
lowing sections, the toxicity and hazard to both animals and man are
discussed.
B. Toxicity and Hazard to Animals
Among the first to conduct toxicity studies with small animals
using 2,4-D was Bucher in 1946.—' In experiments with mice, rats, rabbits,
and dogs, temporary myotonia lasting from 8-24 hr or more was observed
following a single injection of 150-250 mg/kg of the compound. Repeated
injections of smaller amounts, 50-100 mg/kg/day, for 90 days failed to
elicit either a characteristic chronic syndrone or a striking histological
picture. Normal litters were born to female mice during the course of the
treatment. Also, repeated injections of 2,4-D did not alter the rate of
growth of two transplanted mouse sarcomas.
Toxicological studies with various preparations of 2,4-D were
reported by Hill and Carlisle in 1947..£/ In acute oral studies, it was
found that the 0)50 for mice to be 375 mg/kg; for rats, 666 mg/kg; for
rabbits, 800 mg/kg; and for guinea pigs, 1,000 mg/kg. A dose of 21.4 mg/kg
was administered to a monkey without serious after-effects. A dose of 428
mg/kg caused nausea, vomiting, lethargy, muscle incoordination, and head
drop. All species tested reacted similarly, and there was no significant
difference in potency between crude and purified preparation, or between
the sodium or ammonium salts. Death resulting from large doses apparently
was because of ventricular fibrillation. If death was delayed, myotonia,
stiffness of extremities, ataxia, paralysis, and coma were observed.
In subacute studies, it was observed that severe intoxication
occurred in dogs after six daily intravenous injections of 25 g/kg of 2,4-D.
Rats were fed a diet containing 1,000 parts per million (ppm) of 2,4-D for
a month without harmful effects, and guinea pigs tolerated 10 doses of 100
mg/kg during a 12-day trial. In addition, the inhalation of the sodium
salt of the herbicide failed to cause systemic effects in guinea pigs.
110
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There was some evidence of chronic intoxication in rats. They exhibited
visceral congestion and edematous kidneys with degenerative changes in the
tubules. Dogs showed hepatic damage with central degeneration and con-
gestion.
In 1948, the results of studies carried out on chicks with
alkanolamine salt of 2,4-D were reported by Bjorn and Northern.I/ They
found the acute oral lethal range to be 380 to 765 rag/kg. When repeated
doses (12) were given over a 28-day period, 28 mg/kg/dose was without
effect, while 280 mg/kg/dose resulted in a depression of growth. The work-
ers concluded that there was little likelihood of any toxic effects on
chickens from 2,4-D used under the prevailing conditions. They pointed
out that at a spraying rate of 1 Ib of 2,4-D per acre (a normal application
rate), a chicken weighing 1 kg would have to consume all the 2,4-D applied
on 72 sq ft within a day or two to obtain a lethal dose.
The results of acute and chronic oral toxicity studies on 2,4-D
and 2,4,5-T herbicides were reported by Drill and Hiratzka in 1953.^
Acute oral LDjg values of about 100 mg/kg were obtained for both compounds.
At that dose concentration, 2,4-D produced definite myotonia accompanied
by anorexia and weight loss in dogs. No adverse effects were observed when
2,4-D was fed five times a week for 90 days at dosage levels of 2, 5 and
10 mg/kg. Doses of 20 mg/kg of 2,4-D caused serious effects, and three or
four dogs died. Dogs receiving the high doses of 2,4-D exhibited stiffness
of the hind legs, difficulty in swallowing, bleeding gums, necrotic changes
in the buceal mucosa, and mild liver and kidney changes. There was a sig-
nificant decrease in lencocyte counts observed terminally in three or four
animals. These workers also pastured sheep and cows on forage sprayed with
more than recommended amounts of 2,4-D and no adverse effects were observed.
In another experiment, a lactating cow was fed 5.5 g of 2,4-D daily for
106 days without ill effects. A demonstrable quantity of 2,4-D was not
found in milk from the cow, nor could the herbicide be found in the serum
of a calf fed the milk. However, a concentration of 8.4 ppm of 2,4-D was
present in the cow's serum, although none was found in the liver, kidney,
or fatty tissues.
In 1950, the results of studies with 2,4-D and domestic livestock
were reported by Grigsby and Farwell.l/ Alfalfa was sprayed with three dif-
ferent preparations of 2,4-D and horses, dairy and beef cattle, sheep, swine,
and chickens were immediately pastured in the freshly treated area. The
investigators concluded from the results of the study that none of the 2,4-D
preparations had any serious physiological effects upon the livestock in-
volved. They also stated that, since the application rates were two to four
times greater than recommended dosage, it seemed that the use of the mate-
rials for pasture weed control was a reasonably safe procedure.
Ill
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The acute oral toxicity of 2,4-D compounds was summarized by
Rowe and Hymas.i/ Table XVII is a tabulation of their data.
As shown in Table XVII, the acute oral LD5Q values for 2,4-D
and its derivatives commonly used in herbicide formulations fall in the
range of 300-1,000 mg/kg for rats, mice, guinea pigs, and rabbits. Gen-
erally, dogs are more sensitive to 2,4-D on a weight basis, and chicks
more tolerant to the material. The toxicity to cattle apparently is
about the same as the toxicity to ordinary laboratory animals.
The acute oral LDjQ values obtained were approximately propor-
tional to the amount of active ingredient, and inert ingredients in the
herbicide formulations did not appear to contribute to the oral toxicity.
In other studies, amine and alkali salts and esters of 2,4-D
were fed to calves, pigs, rats and chickens by Erne.2/ The salts were
readily absorbed and completely distributed in the body, but 2,4-D ester
was incompletely absorbed and reached only a low level in the plasma and
tissues. The highest tissue levels of 2,4-D were found in liver, kidney,
spleen and lungs and the level in these organs sometimes exceeded the level
found in the plasma. Penetration of 2,4-D into placental tissue of pigs
was recorded, but there was little or no evidence of penetration into adi-
poise tissue or the central nervous system. Elimination of the compounds
was rapid, the plasma half-life being about 3 hr in rats, 83 in calves and
chickens, and 12 in pigs. The tissue half-life values ranged from 5-30 hr.
No retention of 2,4-D was noted in the tissue. There was no accumulation
after repeated dosing, and in pigs there was an increase in the rate of
elimination after repeated administration. In all species the main ex-
cretory route was via the kidneys.
Khanna and Fang^' traced the metabolism of C*" labelled 2,4-D in
rats dosed at rates from 1-100 ing/animal. Radioactivity was found in all
the organs studied with some accumulation as early as 1 hr after dosing.
At the 1-mg dose rate a concentration peak developed after 6-8 hr but de-
creased thereafter and was nondetectable for 24 hr. At the 80-mg dose the
peak occurs at 8 hr and persisted for 17 hr. Extracts of the tissues con-
tained mainly unchanged 2,4-D residues. No radioactivity was found in the
expired carbon dioxide. Elimination in urine and feces was dose dependent.
At the 1- to 10-mg doses, 93-96 percent of the 2,4-D was excreted unchanged
in the urine in 24 hr. At the 20- to 100-mg doses, greater amounts of 2,4-D
were found in the second 24-hr period after dosing with a linear decrease
in percent recovery with increase in dose. To determine the fate of 2,4-D
in dairy cattle, a cow was fed 5 ppm (based on a daily ratio of 50 Ib) of
2,4-D for 5 days. No residues were found in the feces or milk during the
period of treatment or 2 days thereafter, using a system which would detect
a concentration of 1 ppm of 2,4-D. The rumen content of 2,4-D in a fistulated
112
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TABLE XVII
ACUTE ORAL TOXICITY OF2.4-D COMPOUNDS
Material
2,4-D (2,4-dichlorophenoxyacetic acid)
2,4-D, alkanolamine salts
2,4-D, sodium salt
2,4-D, isopropyl eater
2,4-D, mixed butyl esters
2,4-D, mono, di-, tripropylene glycol
butyl ether esters
Species
Sex
Vehicle
LD50
(19/20 confidence
limits)
(ing/kg)
Rats
Mice
Guinea pigs
Chicks
Dogs (4)
Chicks (3)
Rats
Rats (2)
Guinea pigs
Guinea pigs (2)
Mice (2)
Rabbits (2)
Rats
Guinea pigs
Mice
Chicks
Rats
Guinea pigs
Rabbits
Mice
Chicks
Rats
M
M
M and F
M and F
F
M
M and F
M
M
M and F
F
F
F
F
M and F
F
Olive oil
Olive oil
Olive oil
Olive oil
Capsule
Water
(dosage on
acid equiv-
alent basis)
Water
Water
water
Water
Water
Water
Olive oil
Olive oil
Olive oil
Olive oil
Corn oil
Corn oil
Corn oil
Corn oil
Undiluted
Corn oil
375 (302-465)
368 (312-484)
469 (397-553)
541 (358-817)
Range
100 (25-250)
Range
— (380-765)
805 (610-1,063)
666
551 (417-727)
1,000
375
800
700 (569-861)
550 (451-671)
541 (398-736)
1,420 (1,127-1,789)
620 (320-954)
848 (604-1,1 )
424 (252-712)
Range
713 (500-1,000)
2,000 (1,350-2,950)
570 (510-640)
-------
heifer decreased from 3.5 ppm to less than 0.5 ppm in 24 hr, but the con-
centration remained constant in an artificial rumen, indicating no degrada-
tion in the rumen. The reduction in 2,4-D concentration in the rumen might
be due to dilution or absorption on the rumen walls..2/ A steer fed the above
concentration of 2,4-D eliminated over 88 percent of it in the urine,IP./
No 2,4-D was found in the urine 3 days after feeding.
Milk from dairy cows grazing a pasture sprayed with 2,4-D ester
at 2 Ib/acre contained 0.01 to 0.09 ppm 2,4-D acid during the first 2 days
after spraying and lower amounts thereafter. No ester formulation was
found. Residues from cows placed in the pasture 4 days after spraying
were below 0.01 ppm, the limit of precision of the instrument used.H/ No
bound forms of 2,4-D were found in the milk.li,/
Radioactive 2,4-D was administered to sheep in a gelatine capsule
at a rate of 4 mg/kg live weight, the calculated maximum daily dose a sheep
might eat on a treated pasture. About 15 percent of the 2,4-D was excreted
in the urine within 1-1/2 hr after treatment. By 70 hr, 95.8 percent of
the radioactivity was excreted in the urine, 1.4 percent in the feces.
Radioactivity in the blood reached a peak in 1-1/4 hr, and then decreased
rapidly to the background level. All edible tissue contained less than
0.05 ppm. It was concluded 2,4-D is excreted unchanged.12/
No ill effects were observed in cows grazed on a pasture treated
with a 2:1 mixture of 2,4-D and 2,4,5-T when applied at a rate of 2,4-D of
2, 4, or 8 Ib/acre. A cow, calf, sheep and sows with pigs were sprayed with
1/2 gal. of the spray mixture with no harmful effects. Cows were given the
2,4-D—2,4,5-T mixture in water at a rate of 2,4-D of 28 rag/5 gal. of water
and on the hay at a rate of 26 mg of 2,4-D per day for 41 days with no ill
effects. Calves did not show a preference for a weedy pasture sprayed with
2,4-D and 2,4,5-T over an unsprayed pasture.!^/
Dobsonll/ sprayed 2,4-D on grassed chicken runs daily for 14 days
at normal and 10 times normal dose rates. Egg production was affected the
second week of spraying and the following week. There was no effect on
fertility, and the progeny reared well. Some of the 2,4-D fed to hens was
excreted in their eggs.l§/ Eggs injected with 0.5, 5 and 10 mg of 2,4-D per
egg resulted in a reduction in hatching of 20-50 percent. None of the
chicks hatched were deformed.il/
Palmeri§/ gave daily oral doses of 2,4-D alkanolamine salt to
steers for 5 days a week. Signs of poisoning occurred in animals dosed at
250 mg/kg after 15 doses and after 86 doses at 100 mg/kg. No ill effects
were recorded at 50 mg/kg after 112 doses. He concluded that cattle could
ingest enough 2,4-D from a concentrated solution to produce illness or
death, but it would be unlikely that an animal would eat enough over a
114
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period of time from grazing to cause serious ill effects. Palmer and
Radeleffli/ found no ill effects in cattle from 10 doses of 2,4-D propyl-
eneglycolbutylether ester at a rate of 100 mg/kg, but three doses at 250
mg/kg was toxic. Sheep suffered an 11 percent weight loss during the
administration of 481 daily doses of 2,4-D amine at a rate of 100 mg/kg;
the ester formula at this dosage rate produced no ill effects. A 250- or
500-mg/kg dosage repeated daily was toxic to sheep. Lisk et al.?P./ fed
a steer 113.5 mg of 2,4-D in a diet containing 5 ppm of 2,4-D; 100.6 g
were excreted in the urine; no 2,4-D was found in the urine 3 days after
feeding.
The maximum safe dose of 2,4-D for monkeys is 214 mg/kg.— /
In short-term trials Bjorklund and Erne??/ found that calves and
pigs showed definite but reversible symptoms of poisoning after single
doses of 2,4-D of 200 and 100 mg/kg, respectively. Rats did not show any
sign of distress after a single dose of 100 mg/kg. Fowl tolerated daily
doses of 300 mg/kg in their feed for several weeks without visible effects.
Palmer and Radeleffli/ found a gain in growth rate of chicks given 50 mg/kg
of 2,4-D ester for 10 days but the growth rate was reduced at the 100 mg/kg
or higher rates.
Erne??.' fed five young pigs 500 ppm of 2,4-D for up to 12 months.
Although toxic effects were noted and growth rate was affected, none of the
pigs died. When 2,4-D was fed to a sow throughout gestation and for 6 weeks
thereafter, 10 of her 15 piglets died within 24 hr after birth and the
mother was subsequently slaughtered because of abnormalities that developed
in her spine. Dosing of pregnant rats with 1,000 ppm of 2,4-D in their
drinking water for over 10 months and dosing of their off-spring for up to
2 years did not produce unequivocal signs of toxicity but did lead to re-
tarded growth and increased mortality. Continued administration of 500 ppm
of 2,4-D in feed or 1,000 ppm in the drinking water of fowl led to reduced
egg production and kidney abnormalities. It was concluded that the chronic
toxicity of 2,4-D to their test animals was moderate.
Deer harvested in a forest area treated with 2,4,5-T and 2,4-D
accumulated very small amounts in the organs and tissues examined; the
highest concentration was 54 ppb in the thyroid. Intestinal concentra-
tions up to 127 ppb in the feces provide abundant evidence of exposure to
2,4-D, but the low levels in most body tissue is evidence of breakdown
within the animal or passage through the digestive system.!!/ Jftile deer
given 80 or 240 mg/kg of 2,4-D daily for 30 days showed slight symptoms
of toxicity, but there was no loss of weight.??.'
115
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Residues of 2,4-D, applied to sagebrush at 2 Ib/acre, were found
in sage grouse muscle and brain tissue according to Carr and Glover. £!/
Samples of tissue contained 0.3 to 2.7 ppm, and the composite brain sample
had 6.0 ppm. However, the method of analysis showed a concentration of
2,4-D of 3.6 ppm in sagebrush samples collected 2-1/2 miles from any sprayed
areas, so possibly something besides 2,4-D was being measured. They con-
cluded it was unlikely that sage grouse would be harmed seriously by 2,4-D
from sagebrush treatments.
Zielinski et al.— ' measured the disappearance rates of 2,4-D
in mice using gas chromatography. The half-turnover rate (t-1/2) value
was 4.12 hr. The butyl ester of 2,4-D disappeared from mice bodies faster
than the acid. The data suggest 2,4-D is excreted unaltered. Courtney?-?-'
injected 2,4-D at a dosage of 100 rag /kg in female rats. In whole blood,
2,4-D occurred only in the blood serum with a peak of 73 mg/ml in 2 hr.
Giving rats pretreatment injections with 2,4-D, phenolbarbital, DDT, lindane,
DMSO or chlordane increased the rate of metabolism of 2,4-D by rat liver
homogenates .
Pocket gophers fed 2,4-D at a rate of 200 mg/kg live weight
showed no deleterious signs. However, the gopher population decreased
87 percent in Colorado^./ and 93 percent in Idaho£2/ on areas sprayed with
2,4-D. The 2,4-D treatments reduced the stand of freshly-rooted forms
utilized by pocket gophers for feed.
Herbicides affect insects directly, or indirectly, by killing
the plants on which the insects feed. It has been reported that 2,4-D is
toxic to bees as a result of drinking contaminated water trapped on treated
plants. Possibly 2,4-D might have some effect on nectar which made it
toxic to bees. Radioactive 2,4-D can be translocated to the nectar of some
plants and may be detectable there for 2 or 3 days after treatment .12'
Palmer- Jones!!/ found no effect on bees that had been directly
dusted with 2,4-D or had crawled through a 2,4-D dust in order to enter the
hive. 2,4-D has been classed as a stomach/contact poison of low toxicity
to bees .. johansen=!' reported that 2,4-D and related compounds were not
toxic to bees, except when formulated as the alkanolamine salt or the iso-
propyl ester. Other workers reported total mortality of bees within 4 days
of feeding 20 mg.^Jt' Morton fed bees 2,4-D at 100 ppm in 60 percent sucrose
and found a reduction in reproduction.!!' He feels the "no effect" level
in this type exposure is about 50 ppm. There was no evidence of bees bring-
ing 2,4-D back to the colony from sprayed plants. When only 2,4-D^contami-
nated water was available to bees, broad reproduction was eliminated, but
was restored when good water was made available. Some bees were drowned
in 2,4-D-treated water, but this was caused by the wetting action of the
surfactant used with 2,4-D. The surfactant was not toxic per se.
116
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C. Toxlcity and Hazard of 2.4-D to Man
Despite the extensive use of 2,4-D for weed and brush control,
poisoning by the material is not common in man. It is generally accepted
that auxin-type herbicides, when correctly handled or used for weed con-
trol,!' do not present a direct toxicity harard to man.
The principal routes of entry to man are either orally or by
inhalation. There appears to be little hazard of transport through the
skin, although individual allergies can develop. Eyes may be directly,
but usually temporarily, affected.
In 1945, Kraus reported that he had taken 0.5 g of 2,4-D per
day for 21 days with no demonstrable ill effects.3_6/ in 1951, Assouly
experimentally consumed 500 mg of 2,4-D daily for 3 weeks with no apparent
detrimental effects.^!'
In 1959, Goldstein et al. reported three cases of peripheral
neuropathy following exposure to an ester of 2,4-D.M/ Monarca and DeVito,
in 1961, described neurological symptoms, i.e., atoxia and reflex disorders,
following the inhalation of a large amount of 2,4-D vapor. Symptoms per-
sisted for 3 months, leaving no reported residual.li/ In 1962, Todd de-
scribed a patient with a peripheral neuritis lasting almost 2 years and
attributed the condition to exposure to the same material. Berkley and
Magee in 1965 reported a fifth case of neuropathy in a farmer after expo-
sure to the dimethylamine salt of 2,4-D. All these cases involved skin ex-
posure to the herbicide.
There appears to be only one documented fatal case of 2,4-D
poisoning by the oral route.£?./ A 23-year old man committed suicide in
1965 by apparently drinking 125 ml of a 50 percent solution of 2,4-D di-
methylamine salt. The weight of 2,4-D in the body was about 10 percent
of the total weight of active material ingested (equivalent to 80 rag/kg).
The principal damage appeared to be to nerve tissue and the central nervous
system.
Recently, Berwick reported a case where a man accidentally in-
gested a commercial preparation of 2,4-D herbicide.*!/ The patient was a
49-year old white farmer. While operating his tractor in the hot sun, he
became thirsty and swallowed a mouthful of concentrated weed killer (Knox-
weed), believing that it was iced tea. Although the exact quantity is un-
known, it was estimated that he ingested approximately 30 ml. It was cal-
culated that the farmer consumed about 110 tug/kg of 2,4-D. He exhibited
fibrillary twitching and paralysis of intercostal muscles, and there was
evidence of generalized sketetal muscle damage as indicated by marked ele-
vation of serum glutamic oxaloacetic transaminase, serum glutamic pyruvic
transaminase, lactic dehydrogenase, aldolase, and creatine phosphokinase
117
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levels. Hemoglobinuria as well as myoglobinuria (previously unreported in
this condition) was observed. The patient recovered, and 36 months later
he did not show any signs or symptoms of peripheral neuropathy.
Since the amount of 2,4-D found in food crops has been insig-
nificant, it would seem that there is little hazard to man from those
sources. Williams was unable to detect any residues in a number of total-
diet samples down to the limits of sensitivity (0.01) of his analytical
techniques.42/ Duggan calculated chemical residues in total-diet samples
collected on 46 days in 25 American cities over a 699-day period.^!/ xhe
samples represented a food and drink supply sufficient for 644 days. It
was found that 2,4-D averaged about 0.003 rag/day, and that the compound
was found in oils and fats (0.001 mg) and in sugars and sugar products
(0.002 mg in 1965-66 and 0.004 mg in 1964-65).
D. TeratogenicEffects
During 1965-1968, Bionetics Research Laboratories carried out
teratogenic studies with 2,4-D as well as other pesticides.44/ Using
mice as test animals, a statistically significant increase in abnormal
fetuses within litters was observed when 2,4-D isoctyl ester, 2,4-D butyl
ester, and 2,4-D isopropyl ester was administered. The isopropyl ester of
2,4-D was statistically significant at the 0.01 level for one or more tests,
while the isoctyl ester of 2,4-D was statistically in those factors only at
the 0.05 level. An increase only in the proportion of abnormal litters of
mice born during 1965 was observed following treatment with 2,4-D methyl
ester; the statistical significance of the incidence was weak.—'
Collins and Williams investigated the terotogenic effects of
2,4-D from three different manufacturers on hamsters. The Incidence of
fetal anomalies resulting from the administration of the three materials
was quite low, and the incidence that occurred most frequently was the
same anomaly that was observed in the control animals. Fused ribs were seen
in nine of 11 reported anomalies among 132 live fetuses from dams fed 2,4-D.
The three anomalies in the control group of 942 live fetuses were fused ribs.
The lowest dose causing these effects, i.e., 60 mg/kg, would be approximately
600 ppm in the diet. The maximum human dietary exposure to 2,4-D from per-
mitted tolerance is 0.3 ppm.
118
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26. Zielinski, W. L., Jr., and L. Fishbein, "Gas Chromatographic Measure-
ments of Disappearance Rates of 2,4-D and 2,4,5-T Acids and 2,4-D
Ester in Mice," Jour. Aeri. Food Chem.. 15J5), 841 (1967).
27. Courtney, D. K., "2,4,5-T: Excretion Pattern, Serum Levels, Placental
Transport, and Metabolism," In Pesticides Symposia, W. B. Deichman
(Ed.), Halos and Associates, Incorporated, Miami, p. 277 (1970).
t
28. Keith, J, 0., R. M. Hansen, and A. L. Ward, "Effect of 2,4-D on
Abundance and Foods of Pocket Gophers," J. Wildlife Mgmt., 32(2),
137 (1959). ~~
29. Hull, A. C., "Effect of Spraying with 2,4-D upon Abundance of Pocket
Gophers in Franklin Basin, Idaho," J. Range Mgmt.. 24(3), 230 (1971).
30. Way, J. M., "Toxicity and Hazard to Man, Domestic Animals, and Wildlife
from Some Commonly Used Herbicides," Residue Review, 26, 37-62 (1969).
31. Palmer-Jones, T., "Effect on Honeybees of 2,4-D," New Zealand J. Agr.
Research, 7, 339 (1960).
32. Glynne Jones, G. D., and J. U. Connell, "Studies of the Toxicity to
Worker Honeybees (Apis mellifera L.) of Certain Chemicals Used in
Plant Protection," Ann. Applied Biol.. 41, 271 (1954).
33. Johansen, C., "Bee Poisoning, a Hazard of Applying Agricultural
Chemicals," Wash. State Coll. Agr. Expt. Sta. Circ. No. 356 (1959).
34. Way, J. M., "Toxicity and Hazard to Man, Domestic Animals, and Wild-
life from Some Commonly Used Herbicides," Residue Review. 26, 37-62,
(1969).
35. Morton, H. L., Personal communication (1971).
36. Way, J. M., "Toxicity and Hazards to Man, Domestic Animals, and Wild-
life from Some Commonly Used Auxin, Herbicides, Residue Review. 26,
37-62 (1962).
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37. Assonby, M, "Desherbants Selectifs et Substances de Croissance.
Apercu. Technique. Effect Falbologique Sur L'Homme Au Cours de
la Fabrication de L'Ester du 2,4-D," Arch. Mai. Prof.. 12, 26-30
(1951).
38. Goldstein, N. P., P. H. Jones, and J. R. Brown, "Peripheral Neuropathy
After Exposure to an Ester of Dichlorophenoxyacetic Acid," JAMA.
171, 1306-1309 (1959).
39. Monarca, G., and G. De Vito, "Acute Poisoning Through 2,4-Dichloro-
phenoxyacetic Acid." Folia Med.. 44, 480-485 (1961).
40, Nielsen, K., B. Kaempe, and J. Jensen-Holm, "Fatal Poisoning in Man
by 2,4-Dichlorophenoxyacetic Acid (2,4-D): Determination of the
Agent in Forensic Materials," Acta Pharmaeol.. 22_. 224-234 (1965).
41. Berwick, Philip, "2,4-Dichlorophenoxyacetic Acid Poisoning in Man,"
5 AMA. 214J6), 1114-1117, November 9, 1970.
42. Williams, A., "Pesticide Residues in Total Diet Samples," Jour. Office
Agri. Chem.. 47_, 815 (1964).
43. Duggan, R. E., and J. R. Weatherwax, "Dietary Uptake of Pesticide
Chemicals," Science. 157(3792), 1006-1010 (1967).
44. Moak, E. M., Report of the Secretary's Commission on Pesticides and
Their Relationship to Environmental Health, Department of Health,
Education, and Welfare, Government Printing Office, Washington, D.C.,
p. 666 (1969).
45. Collins, T. F. H., and C. H. Williams, "Teratogenic Studies with 2,4,
5-T, and 2,4-D in the Hamster," Bull, of Env. Cont. and Tax. 6(6)
(1971).
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X. ALTERNATE METHODS OF SAGEBRUSH CONTROL
(OTHER THAN WITH HERBICIDES)
A. Introduction
Spraying with herbicides is presently the most widely used method
of sagebrush control. However, other methods including both mechanical and
nonmechanical techniques, have been employed. Generally, the equipment that
is used was designed for other purposes. Examples of such equipment are the
one-way disc (Wheatland type), the plow and off-set disc, the anchor chain or
roadnipper, and brush cutter and beater (built for other types of brush).
A few implements were designed especially for sagebrush control like the
sagebrush rail, the pipe harrow, and brushland plow.
Of the many methods developed to kill sagebrush, no one technique
is universally the best because the brush grows under widely varied condi-
tions. The suitability of control measures varies with density, height, and
age of the sagebrush stand; associated shrub species; amount of grass under-
story; topography; amount of rock on the area; type of soil and its suscep-
tibility to erosion; facilities available for doing the work; size of the
area to be treated; personal preference; and other related factors.—
B- Selection of a Method of Sagebrush Control
Pechance et al.,i' recommended that the following eight points be
considered in selecting a method of sagebrush control:
1. Employ a Method That Kills Most of the Sagebrush: A method
that provides an extensive kill of sagebrush is highly desirable. A
treatment that leaves fewer than three sagebrush plants per 100 square feet
is considered successful, because the reestablishment of sagebrush then is
very slow, and the seed sources have been greatly reduced.
2. Employ a Method That Also^ Kills Associated Undesirable Species;
It is very desirable to eliminate other unwanted species of vegetation asso-
ciated with sagebrush. After sagebrush has been eliminated from the area,
other undesirable plants may then become established. Plants like rabbit-
brush or horsebrush may increase following sagebrush elimination, and pre-
vent improvement of the rangeland. Annuals like cheatgrass and halogeton
also can populate a treated area, and interfere with the growth of seeded
grasses.
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Other species of plant may become prevalent In a treated area that
has some usefulness as range forage, depending on the kinds of livestock or
game using the range. Plants like broad-leaved herbs, perennial grasses,
bitterbrush, and fourwing saltbrush, are usually considered as desirable vege-
tation.
3. Employ a Method That Does Little Damage to Perennial Grass
Remnants and Other Desirable Plants, if_Artificial, See_djjig_ iajnot Necessary,
but if Seeding is Planned. Use a Method That Kills Most of the Vegetation;
In many range areas, enough grass is present that revegetation will occur
following removal of sagebrush. If the remants of grass are destroyed by the
treatment, seeding will be necessary and the cost of the treatment is nearly
doubled. Seeding is sometimes uncertain, and stands of desirable grasses
should be preserved if possible.
All vegetation should be killed if seeding is planned to improve
forage quality. Seeding to supplement the desirable species in a treated
area often has not been successful. Therefore, it usually is better to kill
all plants and to prepare a good seedbed. New grass becomes established more
easily, and competition from native vegetation is eliminated.
4. Employ a Method That Leaves the Land Suitable for Seeding,
Where Seeding is Necessary; Sometimes the method of sagebrush removal leaves
a barrier of dead woody material that makes the use of grain drills difficult.
Additional operations often are necessary to remove the barrier before seeding
can be carried out.
5. Use a Method That is Widely^ Applicable; Employ a treatment
that kills the most sagebrush of different ages and various sizes, and that
is effective on terrain varying in slope and stoniness. Such a method is
more useful than a method applicable to restricted conditions.
6. Use a Method That Utilizes Readily Available Equipment Adapted
to Other Uses; The acquisition of equipment designed specifically for sage-
brush control generally is not practical. Only if a very large amount of
control is carried out will the cost of such specialized equipment be justified.
Sometines it is feasible for a group of ranchers to purchase expensive items
for use on a cooperative basis. The use of equipment that can be used for
other purposes, and the contracting for sagebrush control by commercial op-
erators, are the most common practices.
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7• Use a Method That Will Not Increase Erosion Hazards; Some
methods remove so much of the vegetation from an area that wind and water
erosion become serious factors. In terrain where soils are light and sub-
ject to drifting, or on slopes, methods should be selected that will leave
litter and plant material as a protective cover on the soil surface. Methods
that help fill gullies and break down existing erosion patterns are desirable.
8. Choose a Method That is Economical but Also Satisfies Any of
the Other Seven Points That May Apply to the Area to be Treated; An effec-
tive method that is reasonable in cost should be used. However, consideration
also should be given to other factors as well. Methods should be employed
that do not encourage erosion, and that produce the maximum range improve-
ment, although these methods may not necessarily be the lowest in cost.
C. Methods
The most widely used non-chemical methods for control of sagebrush
on rangelands include burning, plowing or disking, chaining, cutting and
harrowing.i/ These methods are discussed in the following section.
1. Planned Burning; Burning has been used as a technique for
sagebrush control for many years. The technique is inexpensive and widely
adaptable; however, it must be used skillfully to insure range improvement.
The range to be burned must be carefully selected, the time of burning is
important, and precautions must be taken to control the fire or range detior-
ation may result. Pechance et al.listed several advantages and limitations
of planned burning for sagebrush control .-=•'
a. The kill of sagebrush; Proper burning technique results
in a complete kill of plants of different ages and sizes, of big and low
sagebrush, and black sagebrush. Most threetip sagebrush is killed, but a
small percentage of the bushes may sprout from the base. Silver sagebrush
sprouts readily from the stem base and roots, and the kill is generally low.
b. Kill of associated undesirable vegetation; Rabbitbrush,
horsebrush, snowberry, and other associated sprouting shrubs usually are not
killed by burning. Late summer burning has been somewhat effective in con-
trolling rubber rabbitbrush, and earlier midsummer burning has resulted in
a much reduced stand of cheatgrass the following spring; burning in the late
summer or early fall is less effective.
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c. Effect on desirable forage plants; Burning results in
little damage to most useful forage plants, and the vigor of principal per-
ennial grasses the following year is not likely to be reduced more than 30-
40 percent. Conversely, Idaho fescue and bitterbrush (at some locations)
have been severely damaged by burning.
d. Ease of seeding after burning; Following burning, seeding
is easily carried out except on rough and rocky sites or slopes over 30 per-
cent. When land is too rocky or steep, seed can be covered by anchor chains
or a heavy pipe harrow fairly successfully. Adequate seed cover is not pro-
vided by sagebrush ashes alone.
e. Adaptability to terrain and soil; Burning can be employed
with a variety of soils under different conditions of steepness of slope and
irregularity of terrain. However, it must be possible to construct a wide
and safe fireline.
f. Effect on erosion hazard; Because debris and litter are
mostly consumed by fire, the soil is seriously exposed to erosion. Generally,
burning should not be used on steep slopes or on soils that easily blow or
wash.
g. Cost of control; For tracts of 1,000 acres or more, cost
of sagebrush control by planned burning is $1.00 to $4.00/ acre, on the basis
of 1962 wages and equipment rental rates.—' This sum includes up to $200.00
a year for constructing firelines, the direct cost of burning the area, and
the cost of leasing additional range for 1 or 2 years to permit protection of
the burned area.
h. General Adaptability of Planned burning for sagebrush
control: Mueggler and Blaisdelll/ report that burning was the only treat-
ment that injured any grasses. The Carex filifolia - Festuca idahoesis
group was most severely reduced by burning. Other grasses, though set
back temporarily, soon recovered. Grasses as a group were greatly favored
by the other treatments in the study. Although burning brought about the
greatest increase in total forbs, Antennaria microphylla and Penstemon
radicosus were injured. Astragolus. Eriogonum. and Lupinus species were
most benefited. Fechance, Stewart, and Blaisdelll/ state that (1) burning
should not be done where the principal use of the area is a watershed,
timber production, or important values other than grazing; (2) not where
soils are highly susceptible to wind and water erosion; (3) not where
important grasses, weeds, and browse are seriously damaged by fire; (4) not
where more than half of the understory is cheatgrass brome, unless the area
can be protected from accidental fires; and (5) not where there is an
abundance of such sprouting shrubs as horsebrush and rabbitbrush.
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Blaisdell=/ in his summary and conclusions stated that fire
has been widely used in sagebrush eradication, and that unrestricted burning
followed by overgrazing has often resulted in serious range depletion. Sev-
eral studies have indicated that planned burning can be a valuable tool in
the improvement of sagebrush grass ranges. In his ecological study, he found
that all grasses were injured by burning, but thickspike wheatgrass, plains
reedgrass, and bluebunch wheatgrass recovered rapidly and made substantial
increases within 3 years as compared to the same species on unburned control
areas. Other grasses were slower to recover.
As with the grasses, forbs were injured to some degree by
burning, but most of the rhizomatous species recovered rapidly and within
3 years were producing more herbage on burned than on unburned range. Yield
of suffrutescent species was greatly reduced initially, but none of the
perennial forbs were permanently damaged, and many apparently benefited from
the reduced competition as shown by significantly higher forb herbage on the
burns.
Shrubs were apparently more damaged by burning than grass
or forbs, but rubberbrush and horsebrush sprouted profusely and quickly re-
gained or surpassed original size. Substantial numbers of bitterbrush plants
also sprouted, and these were quickly able to gain a position of dominance.
Sagebrush, which must start entirely from seed, was greatly handicapped.
The amount of forage, which is affected by both availability
and palatability of the herbage, was markedly greater on the burned than on
the unburned ranges. The estimated grazing capacity of the burned range was
40 percent greater than that on the unburned.
Organic matter, nitrogen, and moisture equivalent were signi-
ficantly reduced in the top half inch of soil on the heavily burned areas,
but these reductions were only temporary. Accelerated wind erosion was marked
on the heavily burned areas that was effectively arrested within 2 years.
From the results of Blaisdell's ecological study, the
following conclusions were drawn with respect to planned burning of sage-
brush grass range.
1. Such burning is ultimately beneficial to shrubs with a
strong sprouting habit and to hirzomatous grasses and forbs, but non-sprouting
shrubs, suffrutescent forbs, and some of the finer bunchgrasses are severely
injured. Other species are only slightly affected.
2. Because of this variation in response, composition of the
stands should be carefully considered when planning a sagebrush burning op-
eration. A large number of undesirable sprouting shrubs or of desirable fine
bunchgrass or forbs may preclude improvement by burning.
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3. Although total yield of grasses and forbs is greatly
increased within 2 or 3 years after burning in comparison with production
on unburned ranges, much of this early increase may be short-lived.
4. Increased availability of herbage and ease in handling
livestock are often the main benefits from planned burning.
5. Some soil properties are highly altered by burns of heavy
intensity, but such changes are only temporary.
6. The best results are apparently produced by light burns,
but the advantages of a low intensity fire must be sacrificed in order to
secure a satisfactory coverage.
7. Normally sagebrush reestablishment following planned
burning is a gradual process, but sometimes sagebrush seedings become estab-
lished the following year on the burned areas regardless of the amount of
grass present before burning or management after burning.
8. The goal of sagebrush burning should be consistent with
the climax cover that can be obtained.
In summary: after considering the information presented in
the studies conducted with the use of fire for the control of sagebrush, one
would conclude that burning is one of the cheapest methods available to re-
move sagebrush on densely infested sagebrush lands. However, there are some
serious disadvantages to burning—the necessity for deferred grazing to en-
able the grass species that are injured to recover and invade the burned
areas; proper management of livestock on the areas; the potential of the
escape of the fire to areas not intended to be burned; and the potential
of wind and water erosion.
2. Plowing or Discing; Despite the improvement in herbicides,
plowing and discing continue to be the most valuable methods of sagebrush
clearing where seeding is to be done, especially by drilling. Plowing or
discing, correctly done, will kill 70-90 percent of all except silver sage-
brush. The bigger the sagebrush and the softer the ground, the better the
kill. Associated sprouting species, such as rabbitbrush, are not killed un-
less the discs cut much deeper than the customary 3-4 in. When this is
necessary, the cost of the control is doubled. Cheatgrass and other(undesir-
able annuals generally are effectively thinned if the work is done in the
spring after seed germination but well before ripening; control will be
ineffective if work is done after seed starts to ripen. Nearly all perennial
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plants except those that spread by rootstocks or sprout from roots are killed
by plowing or discing at a depth adequate for effective control of sagebrush.
These methods should be limited, therefore, to ranges that are to be seeded.
The average cost for plowing or discing under ordinary conditions based on
1962 wages and rates for equipment rental, range from $4.00 to $7.00/acrei^
3. .Anchor Chaining; Anchor chaining, a common method of controlling
juniper and pinyon in the West, has proved to be a rapid, low cost method for
reducing competition of big sagebrush. It provides only partial control, but
costs less than other methods. It is especially useful where a mere thinning
of the brush stands is desired and for removal of juniper and pinyon trees as
well.
Chains weighing from 25 to 90 Ib/link have been used. Chains with
links heavier than 70 Ib eliminate more sagebrush than lighter chains. Twice
over is usually desirable. A second chaining not only removes additional
brush, but also facilitates seeding operations by covering seed broadcast
between the 2 chainings or by breaking down the brush to any subsequent drill-
ing.
4. Cutting. Beating, or Shredding; In recent years the cutter,
beater, or shredder type of implement has been widely used in sagebrush con-
trol. These machines cut and shred the woody and herbaceous-type growth.
They leave a coarse litter layer on the soil surface.
Cutting is effective in tall old stands of big sagebrush; kills of
90 percent or more of old sagebrush are often obtained. Young plants of big
sagebrush are usually missed or little damaged by cutters and flails. Con-
trol of threetip, low, and black sagebrush is only partially satisfactory
because of their low, spreading branches and the tendency of threetip sagebmsh
to sprout from the base.
Grasses and broadleafed herbs growing beneath the sagebrush are not
damaged. Bitterbrush is badly damaged, but in some localities it is stimulated
into bigger sprouting from the root crown.
Cutters should not ordinarily be used on soils where rocks protrude
more than 3 inches above the soil surface. Maintenance and repair costs are
high if the blades or flails come in frequent contact with rocks. Moreover,
cutters must be operated carefully where the soil surface is uneven or is
cut up by small gullies.
The woody plant material left as a protective mulch on the soil
surface should decrease the erosion hazard. Thus, cutting is a good method
of sagebrush control where the probability of wind and water erosion is
fairly high snd watershed values must be guarded.
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5. Harrowing; Self-clearing pipe or log harrows, sometimes called
Dixie drags, have occasionally been used for sagebrush control, but are most
useful for covering grass seed on burned rangelands that are too rocky or
rough for use of other type of implements. They have been used to cover seed
on woody alpine areas and to control rather open spans of old, brittle sage-
brush on uneven ground, especially on ranges with numerous rock outcrops.
Only 30-70 percent of old, brittle sagebrush and a much lower per-
centage of younger plants are killed.
About 10-20 percent of the bunchgrasses will be uprooted by the
pipe harrow. Damage to bitterbrush is low unless it is tall and brittle.
Few plants are killed.
Harrowing usually decreases erosion. Litter and debris from up-
rooted and broken sagebrush left on the loosened ground surface and deposited
in gullies, along with the standing brush protects the soil better than
standing brush on untreated areas.
Harrowing and plowing, on sites to which they are adapted, should
cover about the same number of acres/hour at similar costs. Computed at
1962 rates, the cost would be $4.00 to $7.00/acre, or about the same as for
plowing.
6. Other Methods; Many other methods have been tried in clearing
sagebrush for farming or range improvement. They include rooting or dragging,
root cutters, mowing, ripping, rolling brush cutter, road graders or bull-
dozers, and flooding. Any one of these methods may be useful for sagebrush
control, especially if equipment is readily available. All these methods,
the limitations and potentials are discussed in Pechance et al., Bulletin No.
277. Kearl and Brannon—'studied the economics of rotobeating, railing, disc
plowing, scraping with patrol or grading and moldboard plowing. They pre-
sented the cost/acre for brush removal alone as $2.43 for the disc plow method,
$4.76 for rotobeating, $6.07 for railing, $6.61 for patrol or grader, and
$13.61 for moldboard plowing. Additional costs for seeding brought total
costs for brush removal and seeding to $6.15 for disc-plow method, $8.94 for
rotary beater method, $9.91 for the patrol or grader method, and $18.45 for
moldboard plow method. Patrol or scraping, disc plowing, moldboard plowing
noble blading and flail scrape plowing all gave fair to excellent results in
controlling big sagebrush. Scrapping with a patrol all gave results varying
from fair to excellent in controlling silver sagebrush, rabbitbrush and
pricklypear cactus. The other methods, which gave good to excellent results
on big sagebrush, gave only poor results on other brush species.
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Railing and rotary beating attempt to break off or uproot brush.
They produce poor to fair results when compared with other mechanical methods
or with chemical control. Railing in several instances actually increased
the number of other brush species observed.
Herbage production was consistent with control affecting this data
in that methods which were effective in controlling sagebrush and which were
then followed by reseeding also produced good increases in herbage. Railing
and rotary beating also increased herbage production, but the increases were
not as large as they were for methods where seeding was feasible, and was
used.
An economic evaluation of this practice was made by projecting the
useful life of the method upon conditions obseryed on the improvement sites
and results reported in literature at setting costs that the average level
determined. Forage values of $5.56/AUM are required to cover variable costs,
and $7.48/AUM is required to cover total cost from using the railing method.
Forage values of $3.79/AUM and $5.74/AUM are required to cover the variable
costs or variable-fixed costs for the patrol or grader method without re-
seeding.
These are exorbitant values/AUM, and it is doubtful that either
railing or the patrol method without reseeding is a feasible method of brush
control.
Using the rotary beater method would require a value of about
$1.49 per additional AUM to recover variable costs and $2.68 per additional
AUM to recover variable-fixed costs. Other methods, the patrol or disc plow
followed by seeding, or chemical control, would require values per AUM of
less than $1.00 up to slightly less than $2.00, depending upon the method
chosed and the extent of ASCS participation.
The railing and patrol or grader method without reseeding would
not produce enough returns to recover investment costs at any interest rate.
The rotary beater method would return about 20 percent on variable costs and
4 1/2 percent on total cost. By contrast, chemical eradication with ASC
assistance would return about 26.5 percent on total costs over the life of
the improvement practice if ASC assistance were received. This method would
yield about 10.5 percent on total cost without ASC assistance. The patrol
and disc plow methods with seeding would return about 17 and 20 percent on
variable costs and 14 and 18 percent on total cost.
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Chemical control is Che ideal method where terrain and topography
prohibit use of the patrol or disc plow followed by reseeding. Chemicals
can also be applied rapidly to large acreages. Hence, it is also an ideal
method to be used where very large acreages of brush are available for treat-
ment.
The relatively high costs of mechanical methods, including costs
for fencing and range deferment to establish a grass stand, can be prohibitive
on large acreages, even where physical conditions are suited to mechanical
methods. Total capital requirement for mechanical methods with reseeding
and the requirement for deferment of large acreages introduce serious manage-
ment and financial problems. Chemical control can be used without encountering
these types of problems.
Mechanical methods, even the patrol or the disc plow method, followed
by reseeding, are desirable (1) where preexisting fences control grazing
adequately and permit establishment of grasses, without large additional
costs for fencing; (2) where topographic, soil and moisture conditions per-
mit good establishment of grass stands; (3) where smaller areas of sagebrush
are available for the control work and (4) where the operator desires maxi-
mum returns per acre rather than the maximum rate of return on capital in-
ves tment.
Finally, Kearl states that mechanical methods with reseeding can
be recommended even on relatively large tracts if (1) the ranch operator
has sufficient capital to accomplish all that is desired, (2) has sufficient
land so he can defer relatively large tracts without incurring serious manage-
ment or financial problems. Application of a range improvement practice to
large tracts and costs of application to large tracts may vary considerably
because of fencing requirements.
Kearl and Brannon also sampled several of the sites where the sage-
brush had been controlled by the various mechanical methods and report for the
herbage production on the various mechanical sites as grading with no reseeding
a 152 percent increase in herbage production; rotary beater—no seeding, 133
percent increase; patrol with no seeding—77 percent increase; a patrol with
seeding—241 percent increase; disc plow-seeding—369 percent; a moldboard
plow and seeding—958 percent; flail-scrape-plow with seeding—226 percent
increase; noble blade, no seeding—504 percent increase in herbage production.
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REFERENCES
1. Pechance, J. F., A. P. Plummer, J. H. Robertson, and A. C. Hull, Jr.,
"Sagebrush Control on Rangelands," USDA Handbook No. 277 (1965).
2. Mueggler, W. F., and J. P. Blaisdell, "Affects on Associated Species of
Burning, Rotobeating, Spraying and Railing Sagebrush," J. Range Manage..
2(2), 61-66. (1958).
3. Pechance, J. F., G. Stewart, and J. P. Blaisdell, "Sagebrush Burning -
Good and Bad," USDA Farmers Bull. No. 1948. (1954).
4. Blaisdell, J. P., "Ecological Effects of Planned Burning of Sagebrush-
Grass Range on the Upper Snake River Plains," USDA Tech. Bull. No.
1075. (1953).
5. Kearl, W. G., and M. Brannon, "Economics of Mechanical Control of Sage-
brush in Wyoming," Agr. Exp. Sta. Scl. Mono. No. 5. (1967).
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XI. APPLICABLE LAWS AND REGULATIONS GOVERNING PESTICIDE USE
Federal and state laws and regulations concerning the use and
sale of pesticides within the study area are discussed in this section of
the report. Litigation relating to the use of herbicides, effects of
herbicide laws on the environment, and changes in laws recommended for
adequate environment protection also are included.
The material in this part of the report was prepared by Dr. Norman
G. P. Krausz, Professor of Agricultural Law, University of Illinois, Urbana,
Illinois.
A. Federal Laws and Regulations Relating to the Sale and Use of Herbicides
on Rangeland Sagebrush
Federal laws relating to pesticides are of two kinds. One is
direct such as the Pesticides Registration Law!/ and the Pood Law!/ that
requires pesticide tolerances for residues on foods. The other kind is
less directly applicable and includes the recent rash of laws for the
control of air and water pollution and setting policy for an environmental
quality program.
Pesticide Laws. Federal pesticide laws apply only to commodities
shipped in interstate commerce. However, the interstate commerce clause
has been broadly defined and few transactions escape federal jurisdiction.
Also, state regulations are patterned after federal law and often prescribe
the same tolerances.
A Federal Insecticide Act was passed in 1910 covering the market-
ing of insecticides and fungicides. It was designed mainly to protect the
farmer from substandard and fraudulent products. In 1947, the Federal
Insecticide, Fungicide and Rodenticide Act superseded the older act and
extended coverage to herbicides and rodenticides. This law requires pesti-
cide products to be registered with the EPA. Application for registration
must be accompanied by the manufacturer's statement of composition (chemical
analysis), the names of the pest or crops on which the product is to be
used, and the specific conditions under which it is to be used. Registra-
tion may be granted if the substance does not constitute a public health
hazard or cause (serious) injury to the environment.
y Federal Insecticide, Fungicide and Rodenticide Act, USCA 7-135.
21 Food, Drug and Cosmetic Act, USCA 21-346.
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In 1959, an amendment to the 1947 Act extended coverage to nemato-
cides, plant regulators, defoliants and desiccants. Another amendment in
1964 eliminated the controversial "registration under protest" provision
of the 1947 Act, and authorized the Secretary of Agriculture to require
pesticide labels to bear the federal registration number (some states also
have this requirement now). Regulations were revised in 1964 to require
"signal words" (danger, caution, warning, etc.) and "Keep Out of the Reach
of Children" to appear on the front panel of all poisonous pesticides.
The Food, Drug and Cosmetic Act (1938) provided that tolerances
be established for pesticide residues in foods where these materials were
necessary for the production of a food supply. The Killer Amendment (Public
Law 518) passed in 1954 provides that any raw agricultural commodity be
condemned as adulterated if it contains any pesticide in excessive amounts
and whose safety has not been formally cleared. ' It also gives the Secretary
of Health, Education and Welfare the power to establish such residue toler-
ances .
The two basic federal statutes, the Insecticide, Fungicide and
Rodenticide Act and the Miller Amendment to the Food, Drug and Cosmetic
Act,supplement each other and are interrelated by law and practical opera-
tion.
Registrations of pesticides may be cancelled at the end of 5-year
periods but renewals can be granted on request. If there is an imminent
hazard to the public, an economic poison registration can be suspended
immediately and may be seized if such action is deemed necessary. Cancel-
lation may follow if the requirements of the law or regulations have not
been followed.
Persons adversely affected may, within 30 days, request a public
hearing. A final order of the Agency may be appealed to the U.S. courts.
Violations of the law or the regulations of EPA are a misdemeanor
with fines ranging to $500 for the first offense and to $1,000, plus pos-
sible imprisonment up to 3 years, for subsequent offenses.
Both law and detailed regulations exist for the application of
herbicides to federal lands. A Noxious Plant Control Lawi/ also allows
states to enter federal lands to destroy weeds if the plan is approved by
the federal agency in charge. States may be reimbursed for their costs if
federal funds are available for this purpose.
I/ P.L. 90-583 (1968), 82 Stat. 1146.
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The Bureau of Land Management, Department of Interior, is guided
by Interior Memo 71-228 in applying herbicides to sagebrush. This Memo
was issued 22 June 1971, and is replete with provisions to assure that the
environment will not be damaged.
For example:
1. "The Department will use all means to reduce pollution
resulting from pesticide use.
2. "No pesticide will be used when...water will be degraded,
or hazards exist that will unnecessarily threaten fish, wildlife, their
food chain, or other components of the natural environment.
3. "Examine all alternatives and consider impact each will have
on the ecosystem and the total environment."
The Interior Department states that a working group on pesticides,
comprised of representatives from different agencies (about 30) serves as
a coordinating mechanism for the use of pesticides in the federal govern-
ment. The group reports to the Council on Environmental Quality and makes
recommendations to all federal agencies using pesticides.
The Bureau of Land Management, State Director for Montana, replied
by letter that "In Montana, we have an agreement with the Fish and Game
Department. They are notified well in advance of treatment projects (two or
more years) and make recommendations relative to protection of big game
and upland bird habitat. Normally, we have already blocked out known areas
of winter use and areas adjacent to water. We have always tried to leave
50-to 100-ft buffer strips along streams--not only for habitat protection
but to prevent stream contamination.
"We will also, this coming year prepare environmental analyses
on sagebrush control jobs, as required of the National Environmental Policy
Act.
"Because of increasing questions regarding the entire sagebrush
control field and its impact, particularly upon habitat, plus our economic
considerations, we have been decreasing our program in Montana over the
last few years. In 1972, we will probably treat less than 3,000 acres of
public land in the state.
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"Answering your last question regarding our recognition of state
laws and regulations is difficult. To our knowledge, federal restraints,
through secretarial order and internal direction, as well as through the
NEPA are far more restrictive than are Montana laws and regulations. Our
working agreement allowing State Fish and Game Department review and recom-
mendation is based upon their particular knowledge and expertise relating
to wildlife habitat which sagebrush control might affect."
Environmental Quality Laws. One can no longer use pesticides
without being concerned with the possibility of pollution. Pesticides
become pollutants when they or their degradation products remain in the
environment after desired purpose has been accomplished. Increased public
concern over the long-range effects of pesticide residues in humans and
animals has caused an increasing amount of state and federal legislation
in this area.
Federal laws in the area of pollution have focused mainly on
interstate and navigable waters. Basic legislation applicable is the
Federal Water Pollution Control Act!/ which gave the Secretary of the
Interior the power to bring abatement action against those guilty of pol-
luting interstate waters. The Water Quality Act of 1965?/ provides that
states must have minimum pollution standards for interstate waters. The
Water Quality Improvement Act of 19703/ continues to encourage states to
act by providing grants-in-aid for improvements and funds for a research
program. The primary rights and responsibilities of the states are to be
protected and aided, but when they fail to act, EPA has the authority to
enforce water quality standards.
An old law, passed by the Congress in 1899 and referred to as
the Refuse Act,—' has been used to prosecute individual polluters. It con-
tains the famous (or infamous) squealer clause allowing one-half of the
fine to be paid to the person furnishing information leading to the con-
viction.
Other federal laws provide for federal aid to projects in abate-
ment of pollution. The Water Resources Planning Act!' encourages develop-
ment and conservation of water resources with particular emphasis on co-
operation between the various levels of government. The Rural Area Water
Facilities Acti/ provides federal money for use in solving water and waste
disposals in rural areas. For the purposes of this act, a rural area, as
defined, does not include any area in which there are cities or towns of
more than 5,500 population.
II 33 USC 466.
2_/ P.L. 89-234.
3/ P.L. 91-224.
4/ USC 33-412.
£/ P.L. 89-80.
6/ P.L. 89-240.
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Closely related to the water pollution laws are the National
Environmental Quality Laws.!' The policy is to prevent or eliminate
damage to the environment and establish federal administrative offices
for control, financial and technical assistance to the states and local
governments, and requires the cooperation of all federal agencies.
A Council on Environmental Quality is established to advise the
Congress and the President on the condition of the environment and make
recommendations for improvements. An Office of Environmental Quality is
established to staff the council and assist federal agencies in appraising
their programs and establishing standards.
One special law on agriculture should be mentioned that relates
to land conservation and pollution.£/ The Secretary of Agriculture may
enter into long-term soil conservation contracts with farmers and ranchers
for the prevention of soil erosion and for water conservation, with special
authority in the Great Plains area. Measures include the objective of con-
trolling agricultural pollution from erosion. A special appropriation is
made for cost sharing for conservation practices in specified Great Plains
states.
B. State Laws and Regulations on the Sale and Use of Herbicideson
Rangeland Sagebrush
It becomes readily apparent that many state pesticide laws are
of recent vintage, usually dated within the last few years. Exceptions
are noxious weed laws and some of the "Economic Poisons Acts" that were
patterned after federal law requiring registration of pesticides. In
years past if registration was granted by USDA, usually little trouble
was encountered from the states. Recent amendments to some of the state
laws have tightened registration requirements considerably, particularly
when highly toxic pesticides are involved or when there may be serious
damage to the environment.
The following contains a summary of the various pesticide and
related laws in the states under study.
I/ National Environmental Policy Act, USCA 42-4321 (1969); Executive
Order No. 11507 (4 February 1970); Environmental Quality Improve-
ment Act, USCA 42-4371 (1970).
2/ USCA 16-590p.
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Colorado.l/ An early weed control law in Colorado placed author-
ity in the County Board. The Board can employ a Weed Superintendent and
supply him with equipment, materials and money for the control of noxious,
injurious and poisonous weeds that cause damage or loss to land or live-
stock. A special weed tax levy can be imposed to replenish county funds
used for weed extermination.
In 1965, a Pesticides Act was passed requiring registration.
Jurisdiction was placed in the Department of Agriculture as has been the
common practice in most other states. Authority is broad when compared
to similar laws in other states--"The Department may restrict or limit
the manufacture, delivery, distribution, sale or use of pesticides that
are highly toxic to man...and may issue stop sale, use or removal orders...
and institute criminal proceedings."
The 1965 law has been refined further by a new law, effective
1 January 1972. A class of "restricted use pesticides" is established
which the Department determines may create an undue hazard to persons,
animals, wildlife or land. The list is to be adopted after hearings are
held and regulations on this class may be issued to control time and con-
ditions of sale, distribution, and may require use by permit only. An
advisory committee of 13 persons is to be appointed by the State Agricul-
tural Commission to provide assistance in formulating regulations. USDA
regulations can be adopted in the interest of uniformity. As in the old
law, the Department of Agriculture may issue a stop sale, use or removal
order if there is reasonable cause to believe there is a violation. If
criminal action is contemplated, the facts are referred to the district
attorney. The new law also requires an annual license for pesticide
dealers with no qualifications specified.
Another law, also common to many other states in the nation,
enables pest control districts to be established by petition to the County
Board. Infested areas may be sprayed and a reluctant minority charged
their share of the expense.
In 1966, Water Pollution and Air Pollution Control laws were
passed, both to be administered by the Public Health Department. However,
a Water Pollution Commission was given final authority in water pollution
prevention and control administration. Remedies are through the injunctive
process and damages for loss of fish. In 1968, the Commission was given
more continuity by appointing the Executive Director of the Department of
Natural Resources as permanent chairman.
I/ Colorado Statutes—Article 5, S. 6-1-4; S. 6-9-2; Article 12, S. 66-28-1.
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A law on the use of agricultural chemicals was passed in 1967,
and amended in 1970. Commercial applicators must be licensed and carry
liability insurance up to $50,000 or show sufficient financial responsi-
bility. Some of the usual prohibitions are present in the law. For
example, it is unlawful to:
1. Apply pesticides carelessly.
2. Create a hazard from storage or use to humans, animals
or fish.
3. Dispose of empty containers so as to create a hazard.
The Commissioner of Agriculture has authority to prescribe the
materials to be used and the method of usage, which is unique in many of
these kinds of laws.
Idaho.—/ The application of pesticides has been regulated in Idaho
back to 1953, but the scope of the law has been broadened by amendments in
1961 and 1967. The present law requires licensing of commercial pesticide
applicators and they are subject to regulations by the Commissioner of Agri-
culture in the interest of public health. Further, the Commissioner can de-
fine areas or zones for specific restrictions on the use of herbicides, such
as 2,4-D, when he determines they would injure animals or crops. He may, in
fact, prohibit the use of these types of chemicals in such areas.
The old Economic Poisons Law (1963) is now addressed as the
Pesticides Law. Amendments have been frequent and it now is a compre-
hensive law covering registration of pesticides, labeling, adulteration,
enforcement and licensing of dealers. Registration of pesticides and
licensing of dealers is yearly, but the fee of $10 is minimum. The range
for most states is from $10 to $25 for each registration.
Authority to investigate the composition, uses and effects of
pesticides seems quite adequate and a possible fine up to $1,000 and
imprisonment up to 1 year may be sufficient to obtain compliance. How-
ever, enforcement is delegated to county prosecuting attorneys and it
appears they may act at their option.
A new law in Idaho (1970) addresses itself to the eradication
of weeds. Primary responsibility is placed on the property owner but the
law outlines a procedure for having the Commissioner of Agriculture, assume
control in certain cases. The law makes no mention of pesticides or their
regulation in destroying weeds. Presumably the Pesticides Law and regu-
lations would then apply.
I/ Idaho Statutes, Title 22, Ch. 24, ss. 22-2208-2230; Ch.,24, ss. 22-2441-
2462; Ch. 34, ss. 3401-3412; Ch. 42, s. 10; Ch. 120, s. 1; Ch. 240, s. 1.
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Montana.!/ Montana has an updated Weed Control Law. It still
is oriented toward named noxious weeds such as Canada thistle, but the
law allows the county commissioners to define any weed as noxious.
A 1969 amendment requires a weed control district for each county
which is to be administered by three supervisors. They can institute con-
trol measures and send the bill for expenses incurred to the land owner.
A weed fund produced from a general or special tax levy allows a positive
program. The funds can be used to pay part of the land owner's cost of
weed control.
Montana took two long strides in favor of the environment in
1971. First, the Water Pollution Law was severely amended by placing
administration in the Department of Public Health with a Director of Water
Pollution Control, by broadening the definition, of pollution to include
almost any kind of contamination, and by adding to the Pollution Advisory
Council a livestock feeder, a labor representative, a supervisor of a soil
and water district, and representatives from water recreational enterprises.
The second action relates to a completely new Pesticides Act
effective 1 January 1972. It is the most complete law surveyed out of
the six states studied for this project. Because this seems to be the
"ultimate" in current legislative drafting, a more complete summary follows:
1. It is administered by Department of Agriculture.
2. Label must contain a warning or caution to prevent injury
to man or undue hazard to the environment.
3. All pesticides for sale in the state must be registered
annually. The fee is $10. The Department must review all registered
pesticides every 2 years.
4. Pesticides registered under federal law are entitled to
state registration but the state may impose restrictions on the type of
applicator and on the time and place of application.
5. The Departments of Health and Fish and Game also must pass
on each registration. Two votes are needed (including Agriculture) for
approval. If less than two departments approve, the applicant may ask
for a joint administrative hearing and then a special advisory committee
has approval power.
I/ Montana Statutes, s. 16-1701-5; s. 69-3901; H. B. 85(1971) S. B. 126
(1971).
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6. The Department has broad powers to inspect, sample and
embargo pesticides, but must obtain approval of a district court to con-
demn the pesticide.
7. Commercial applicators must be licensed by the Department—
annual fee of $10. Additional fees may be imposed by regulation for the
purpose of controlling operators. Also proof of financial responsibility
is required.
8. Dealers selling pesticides must also be licensed--fee of
$10. Both applicators and dealers must pass an examination. Sales for
home, garden, yard and lawn may be made without restriction except for
limits on quantity.
9. Farm applicators must obtain an annual special use permit.
Each applicant must take a written examination on the use and application
of restricted pesticides and justify his -use on crops, land or livestock.
But fanners need not obtain a license for nonrestricted pesti-
cides for their own property or for noncommercial operation on lands of
neighbors.
10. Licenses and permits may be revoked for a variety of reasons
including operating in a negligent manner. Decisions can be appealed.
11. All governmental agencies are subject to the Act.
12. Persons damaged by pesticide applications are to file a
report of the loss to the Department within 30 days.
13. Hearings are required before regulations are adopted except
for federal regulations under the IFR Act which may be adopted without
hearing. Licensees are entitled to notice of such hearings.
14. The state may limit application during certain times to pre-
vent damage to persons, environment, etc.
15. In an emergency, regulations may be issued for a period no
longer than 60 days.
16. Hearings are also held on complaints that the law is being
violated. Appeal is to the Commissioner of Agriculture and then to the
courts.
17. Department is required to cooperate in developing and con-
ducting educational programs on pesticides.
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18. It is unlawful to discard pesticide containers so as to
injure people or animals or wildlife or pollute any waterway.
19. Violation of the Act is a misdemeanor.
20. The Department may ask for court injunctions to stop viola-
tions .
The only comment one might make about this new law is that the
penalty and enforcement provisions may have, to be tougher some day. Using
the judicial system for conviction on misdemeanor or for an injunction
would, in some states, be painfully slow and the penalty inadequate.
Nevada.I/ Nevada recognized water pollution and chemical appli-
cation problems earlier than most states. In 1917, a general water control
law was passed making it unlawful to deposit poisonous substances (includ-
ing chemicals) in the waters of the state. The Health Department apparently
was the official water pollution agency.
The state became concerned about air pollution in 1967 and specifi-
cally named the Health Department as the control agency. Also established
at that time was a Control Advisory Council. The Council serves in a con-
sultive capacity on proposed air control regulations. It is interesting
to note that counties also have authority to adopt regulations on air con-
taminants to control air pollution.
Another early law (1929) was the one on noxious weeds. As usual,
responsibility is placed on owners and occupants to control injurious and
noxious weeds, but a state Quarantine Officer has considerable power to
direct County Boards to take action if owners or occupants fail to destroy
such weeds. An unusual provision forbids naming a weed injurious or noxious
if it is so well established in the state as to make its control or eradica-
tion impracticable.
In 1969, Weed Control Districts were authorized. A petition
signed by 60% of the owners, who own at least 50% of the assessed value,
must be presented to the Counjty Board. Once established, the Board of
Directors has substantial powers to control weeds and place liens on prop-
erty if the cost is not paid.
I/ Nevada Statutes, Sections 445.010; 445.445; 445.465; 555.130; 555.280;
586.010; Reg. 55.30-38; 86.01-18.
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Restraints on using pesticides for weed control were placed in
effect in 1955 by the Economic Poisons Law and the Custom Applicators Law.
The Economic Poisons Law is now the Pesticide Control Act with 12 important
sections added in 1971. The additions set out a class of "restricted use
pesticides" which are injurious to man, animals or crops or detrimental to
vegetation, wildlife or to the public health.
These amendments have a heavy emphasis on protecting the environ-
ment and on searching for alternatives when balancing the public benefit
of certain pesticides against damage to the environment. Determining that
benefits outweigh damages is one of the criteria listed in the law which
the Director of Agriculture must use in deciding if a pesticide should
be restricted. A restricted use generally requires a special use permit
for each application.
The administrative procedure for enforcement is similar to other
state laws of this kind—a notice of alleged violation is followed by an
opportunity for hearing followed by referring the case to the local district
attorney for prosecution if the violation is serious and uncorrected.
The Pesticide Applicators law requires annual licensing ($25)
and liability insurance ($10,000 minimum). It is the regulations of the
Department that tighten up the law considerably. Applicants are divided
into principal, agent and operator. Licenses issued are classed as general,
limited, restricted and special. Written and oral examinations are pre-
scribed. Operational directions are comprehensive. Advance notice is
required to persons that may be in the area or have livestock therein
that may be harmed by the pesticide.
This thorough set of regulations contains much to be considered
by other state Directors of Agriculture.
Oregon.V Oregon passed its Pesticide Registration Law in 1965.
It contains the usual provisions on labeling, adulteration, misbranding,
and registration. The original law contained sale and use restrictions
if the pesticide was highly toxic to man. Protection has been extended
to animals by recent amendments.""The Registration Law is administered
by the State Department of Agriculture.
The Department also administers a well drafted Pesticide Appli-
cation Law. Licensees are classed as applicators, operators and trainees.
Governmental units are exempt from licensing. A written examination is
required of applicants on pesticide characteristics, application practices
and techniques, laws, regulations and the protection of property. Short
II Oregon Statutes, Sections 634.215; 573.006; 573.380.
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courses on these subjects are encouraged in cooperation with the state
university. Financial responsibility is required. Insurance in an
amount of at least $25,000 fulfills the requirement.
The Department can issue regulations classifying pesticides and
methods of application for each class, but it is not clear how far the
Director can go in forbidding the use of certain pesticides. Permits can
be required for the use of certain esters. A permit is necessary for
isopropyl ester of 2,4-D or any other ester of equal or higher volatility
regarding plant damage. Permits are issued upon concurrence of the State
Forester, the Director of Agriculture and a research specialist appointed
by the President of Oregon State University.
An unusual part of this law is a mandate for a herbicide research
program in cooperation with Oregon State University. This program was
financed, at least in part, by a fee of 1
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them themselves. The law provides for a lien to be placed upon the land
of any person who refuses to pay after the Board has done the work for
him. It also provides a maximum penalty of $100 for failure to comply
with the Act.
There is no law in Wyoming controlling the use of pesticides.
Bills were introduced in the last legislature to impose licensing but
they failed to pass.
The state did pass an Air Quality Act in 1967, to include "dust,
fumes, mist, smoke, other particulate matter, vapor, gas, or any combina-
tion of the foregoing." Herbicides probably fall within this definition
but a search of the law and cases did not product an answer.
To assist the Health Department with air pollution problems, an
Air Resources Council was established. Its responsibilities are to develop
programs to prevent air pollution, set standards, make investigations, and
generally to carry out the Air Quality Act.
C. Litigation Relating to the Use of Herbicides
The older laws, such as the Economic Poisons Acts and the Noxious
Weed Laws, have long been tested and found valid as a proper exercise of
the police power of the states, and in the best interest of the general
welfare, safety and health of the people. Newer laws, regulating the
sale and use of pesticides, apparently are being accepted as merely an
extension and tightening of previous legislation. No one seems to ques-
tion the obvious need for some regulation of dangerous chemicals. A check
of higher court decisions in the states under study brought no discovery
of recent litigation relating to laws on the sale or use of pesticides.
However, an interesting federal case on registration of pesti-
cides discussed the question of whether a nonapplicant for registration
has a right to be a party in court. The Federal Circuit Court of Appeals
for the District of Columbia decided that "organizations concerned with
environmental protection have legal standing to challenge the government's
decision to register or limit the use of a pesticide if they allege suf-
ficient injury to man and other living things to create a controversy."!./
With the present concern about the environment, this seems like a reason-
able position to take. >
V Environmental Defense Fund, Inc., vs. Hardin, C.A.D.C., 428 F2d 1093
(1970).
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The area of personal liability arising from pesticide applica-
tion has resulted in many lawsuits. The majority view of the courts
across the country is that the one applying the pesticide and also the
farmer on whose land it is being applied are liable for damages caused
if the application is done negligently. The basic theory is that a land-
owner must use his land in a reasonable manner with due regard for the
rights and interests of others. If he negligently permits a dangerous
substance to pass from his land to that of another he can be liable for
any damages which result.
Most courts require a showing of negligence before holding a
person liable for injury to adjoining owners or their property. Negligence
is defined as the failure to use reasonable care under the circumstances.
It might result from improper selection, mixing or application of chemicals.
A court could find negligence, for example, where spraying was
conducted on a windy day, where the spray was applied too close to a fence
line, where a pilot failed to cut off his spray over adjoining property,
or where sprayer heads were not adjusted properly. However, once it is
established that the damage was caused by his spraying, very little in the
way of careless conduct is necessary to sustain a finding of neeligence
against a grower.
A minority of state courts recognizes that even the most careful
applicator often can neither predict nor control the many elements that
cause dusts and sprays to drift. These states dispensed with the negligence
requirement and apply the doctrine of strict liability to crop spraying.
Strict liability means that a person who makes use of an unusually danger-
ous substance does so at his own risk. In the words of one court:
"The use by the applicator of a poison on his land which
if it escaped, would cause injury to another was done at his
own risk. He is responsible for its drifting and any pre-
cautions taken do not serve to distinguish his liability. The
only question is whether his activities were the cause of the
plaintiff's damages."
There is a question as to whether the grower can avoid liability
by hiring the work done by a custom operator. As a rule, one who hires an
independent contractor will not be liable for damages caused by the con-
tractor's negligence. There is an exception to this rule, however, where
the work to be performed is inherently dangerous.
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Most state courts hold that crop spraying, both ground and serial,
is sufficiently dangerous to impose liability upon the grower as well as
on the custom operator—even though damage was caused by the custom
operator.
Following is a brief explanation of the leading cases on liability:
1. Liability due to negligent application.
a. Failing to shut off spray in turning—Hammond Ranch
Corporation vs. Dodson, 199 Ark. 846, 136 SW2d 484 (1940).
b. Spraying while winds were blowing toward neighbor's
land--W. B. Bynum Cooperage Company vs. Coulter, 244 SW2d 955 (Ark. 1952);
Parks vs. Atwood, 118 Cal. App 2d 368, 25i P2d 653 (1953).
c. Failing to tell neighbor so that he may take precau-
tions—Brown vs. Sioux City, 242 Iowa 1196, 49 NW2d 853 (1951).
d. Spreading poison so close to neighbor's fence that his
cattle could reach it—Underhill vs. Motes, 158 Kan. 173 146 P2d 374 (1944).
e. Mistaking the land to be sprayed for that of another—
Cross vs. Harris, 230 Ore. 398, 370 P2d 703 (1962).
2. Liability with little or almost no evidence of fault on the
part of defendant:
a. Spray drifting and damaging cotton. Court held
Defendant liable because he should have known of the destructive effect
of the chemical and failed to confine it—Schultz vs. Harless, 271 SW2d 696
(Tex. Civ. App. 1954).
b. Damage to cotton located from 7-1/2 to 15 miles from
place of application discovered 16 days after application. The negligence
pleaded was that the Defendant had allowed 2,4-D to drift. Recovery was
allowed against the sprayer—Pitchford Land & Cattle Company vs. King,
346 SW2d 598 (1961).
Comment. Despite this tendency toward a sort of negligence-
strict liability-hybrid approach, only three jurisdictions have actually
declared strict liability in crop spraying situations. They are Oregon,
Loe vs. Lenhard, 227 Ore. 242, 362 P.2d 312 (1961); Oklahoma, Young vs.
Darter, 363 P.2d 829 (1961); and Louisiana, applying civil law, Gotreaux
vs. Gary, 232 La. 373, 94 So. 2d 293 (1957). In these cases, reasonable
or even extra care does not seem to exonerate the sprayer or the spraying
farmer from liability.
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Damage from aerial application usually results in liability--
a presumption of negligence seems to prevail.
Sanders vs. Beckwith, 283 P.2d 235 (Ariz. 1955)--Plaintiff's
dairy herd was injured by DDT and benzene herachloride.
Heeb vs. Prysock, 245 SW2d 577 (Ark. 1952)--Plaintiff's
cotton was damaged by 2,4-D.
Adams vs. Henning, 255 P.2d 456 (Calif. 1953)--Plaintiff's
potatoes were damaged by 2,4-D.
Faire vs. Burke, 252 SW2d 289 (Mo. 1952)—Plaintiff's cotton
was damaged by the drift resulting from Defendant spraying his corn.
Pendergrass vs. Lovelace, 262 P.2d 231 (N. Mex. 1953) —
Plaintiff's cotton was damaged by 2,4-D.
McPherson vs. Billington, 399 SW2d 186 (Tex. 1965)—Plaintiff's
hogs were killed by Defendant spraying arsenical on neighboring field to the
pen.
Stull Chemical Company vs. Boggs Farmers Supply, Inc., 404
SW2d 78 (Tex. 1966); Schronk vs. Gilliam, 380 SW2d 743 (Tex. 1964)--both
involved cotton damaged by 2,4-D or poisonous spray.
Recovery may be denied because of governmental immunity.
Harris vs. United States, 205 F.2d 765 (10th Cir. 1953) —
Government spraying its own land—immune from liability. But see recent
decision - Emelwon vs. United States, 391 F.2d 9 (5th Cir. 1968 applying
Florida law).
Another kind of legal right that landowners or occupiers have
is freedom from water pollution. The law, by court decisions, is reason-
ably well developed in this area but variations exist in different parts
of the country. A general discussion of the general principles follows:
Water Pollution as an Invasion of a property Right. Among the
rights one acquires when he takes title to land is the right to have any
body of water within or bounding that land continue to exist in a condi-
tion of purity and free from any improper contamination or pollution.
This is a property right one acquires in land, and as such it has been
successfully asserted in private actions against water polluters.
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This right to pure water is not an absolute one, however. The
courts have held that the right to pure water is subject to the right of
other owners to use the stream to a reasonable extent. Thus, not every
use of water which diminishes its quality gives rise to a cause of action.
Pollution is in no way justified by the fact that the stream
may already be contaminated or that others are similarly polluting the
same stream. These factors may, however, affect the damages recoverable.
Water Pollution as a Nuisance. The law of nuisances provides
the private individual with a remedy for water pollution on a tort theory.
Courts have defined "nuisance" to include '1 ..everything that endangers
life or health, gives offense to the senses, violates the law of decency,
or obstructs the reasonable and comfortable use of property." However,
nuisance law has divided itself into two general subareas: private nuisances
and public nuisances.
Water pollution falls easily into the category of public nuisances.
But the general rule allows only publicly brought suits against those creat-
ing or maintaining a public nuisance such as the pollution of a stream.
An exception usually made, however, is to allow an individual to bring a
private suit in such an instance, if he can show some special damage to
himself of a different kind than that suffered by the public at large.
Whenever a public nuisance is found to exist, the state has a
right to relief without the necessity of proving special damages since
by definition, damage to the public is presumed. Suits to abate such
nuisances are usually filed by the state's attorney or the Attorney General
in the name of the "people."
Damages. If wrongful pollution is found to exist and the injured
party can show actual monetary loss as a result of pollution, he can nearly
always recover actual damages. Proof must show that the damages proximately
resulted from the pollution shown, but the fact that those damages may be
difficult to ascertain will not bar recovery.
Injunction. Injunction often is the more appropriate remedy
where the pollution is of a continuing nature. A court-issued injunction
may restrain someone from doing an unlawful act or, in appropriate cases,
it may order him to perform an act in which case it would be a mandatory)
injunction.
Though historically, injunctions were available only when money
damages were an inadequate remedy, most cases have held that injunctions
are available in cases where invasions of water-use rights result in an
otherwise continuing nuisance.
150
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When an injunction is appropriate, it may be had concurrently
with damages. The two remedies are not exclusive and thus an injured
party may sue for either or both remedies.
D. Effects of Herbicide Laws on the Environment
It seems obvious that existing laws place restraints on sellers
and users of pesticides and that environmental factors are now considered
in setting standards and establishing classifications. This is not to say
the environment was completely ignored before but the emphasis was on fraud,
adulteration, and proper labeling. The onus was on people to read and use
products for appropriate purposes and according to directions.
A sudden awareness of our environmental problems brought about
a shift of some responsibility from the individual to government. For
example, federal laws and regulations require a consideration of possible
injury to the environment before a pesticide can be registered. Most of
the state laws studied allow an investigation of the composition, uses and
effects of pesticides before registering. Further, continuous surveillance
often is required and a pesticide which creates an undue hazard to man or
the environment may be removed from the market. This kind of economic
harshness is found only in the most recent laws and court action may be
required for complete condemnation of a pesticide, but the trend in this
direction is clear. The sale and marketing processes for pesticides must
now contend with people and their environment.
Just as dramatic has been the adoption by some states of registra-
tion requirements for dealers and applicators, and making all government
agencies subject to these Acts. Further, pesticides have been classified,
usually by regulations, according to their toxicity, resistance to degrada-
tion and impact on the environment. Special use permits are then required
for the application of the highly toxic and hard or persistant type of
pesticides.
Enforcement of these laws is most important and there could be
weaknesses in some of the states under study because authority and some
discretion for criminal prosecution is vested in the many county or dis-
trict attorneys. However, the state registration procedure has proven to
be reasonably effective and the number of serious violators for referral
to local units may be small.
151
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On the other side of the pesticide fence lies the restraints of
a militia of laws and regulations on water and air pollution and on environ-
mental quality. The federal government can prod states into action with
money for planning and facility improvements, technical assistance, and
quality standards. The Congressional mandate, at least by law, if not by
adequate funding, clearly requires an improvement in the condition of the
environment. The federal administrative machinery is in position for
forceful action, but the EPA still struggles from the effects of conglom-
eration.
Water and air pollution laws in the states under study are still
a bit thin although a few recent amendments have added to definitions of
contaminants and created Pollution Commissions or Councils to assist or
substitute for the Departments of Public Health. It appears that most of
these states are beginning to take water and air pollution problems more
seriously and are establishing additional offices for monitoring and
enforcement.
Considering the traditionally slow pace for obtaining change in
laws that impinge on economic and individual freedoms, the legislative and
Congressional'response to pesticide and pollution problems has been phenom-
enal. One can pick holes in existing laws and regulations, particularly
those not updated, and complain that more and stronger laws are needed;
but on the whole, the record is positive, and it appears that fresh efforts
are being made in these states to pass additional laws favoring the environ-
ment.
E. Change^ in Laws Recommended for AdequateEnvironmental Protection
In the vast open spaces of the states studied it seems almost
surprising that environmental quality could be a problem. Yet all of these
states register pesticides and license applicators; most of them have spe-
cial laws on weed control; and at least four of the six states regulate
water and/or air pollution. The more recent laws (e.g., Montana's Pesti-
cide Law) contain repeated references to the environment and its protection.
Federal laws comprehensively cover water and air pollution, but
there is a gap in pesticide use regulation. Congress is presently con-
sidering H.R. 10729 which is intended to correct this deficiency.
If the states wish to review their laws and regulations with
environmental protection as one of the primary objectives, the following
points should be considered.
152
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!• Pesticide Laws. In general, pesticide laws should contain
provisions for pesticide registration for dealer and applicator licensing
and for adequate enforcement. Preferably all these parts should be con-
tained in a single law to allow one set of definitions and classifications
and uniform enforcement.
a« Registration; Coordination with federal registration
would be highly desirable but reserving to the state the right to impose
additional restrictions to meet special needs. For example, a state may
want to prescribe that instructions contain the type of applicator or re-
strictions on the time and place of application.
Registration provides an opportunity to classify pesticides
as general and restricted, or as general, limited and restricted. Regula-
tions should spell out the details, the use restrictions on each class and
what the label and instructions must include.
A registration procedure should also allow other departments
such as Health, Fish and Game, Forestry, and Pollution Agencies, to review
the data on the pesticide submitted and advise the registering department,
or perhaps have a vote of approval or disapproval. A technical advisory
committee also could be established. The degree to which such procedures
are used will depend largely on how much reliance is placed on federal
registration and the unique requisites of the registering state.
A general authority to limit manufacture, restrict sale
and remove restricted pesticides from the market when human or animal
health or the environment are endangered, would seem desirable, but due
process must be observed through a hearing procedure and appeal to the
courts.
b. Dealer Licensing: If the marketing process is to be
limited in any way, it is essential that pesticide dealers be licensed.
This also provides an opportunity to require an examination to test the
knowledge of the dealer about the products being sold.
c. Applicator Licensing; The third critical part of a
pesticides law is to regulate the use of pesticides. All uses should be
regulated including applications by or for governmental agencies. The
exemption of farmers and ranchers for the use of pesticides on their own
lands has some rationale and can be controlled by requiring permits for
the most toxic and persistant chemicals. Also, the Agricultural Coopera-
tive Extension Service can be most helpful by educating their clients on
proper use and sponsoring short courses on campus.
153
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It is not quite so rational to allow a fanner or rancher to
spray pesticides on his neighbor's lands without a license, but most laws
now contain such an exemption. The potential damage must be assessed and
weighed against the economic cost and removal of another freedom so dear
to the agricultural sector.
It is the commercial applicator that must be examined for
competency and then licensed periodically. The law should allow regula-
tions to be imposed on materials, usage, restricted areas or zones, and
on disposal of pesticide containers. It is highly desirable that a hear-
ing procedure be required before use regulations are adopted.
Some laws classify applicants for a license such as principal,
agent, and operator, or as applicator, operator and trainee, or some varia-
tion of these. This helps in placing legal responsibility, facilitates
administrative surveillance, and requires more persons to become knowledg-
able about pesticides.
Newer laws also require anyone damaged from pesticides to
report to the State Department that administers the Pesticides Law (usually
the Department of Agriculture). From an administrative viewpoint this pro-
vision also would seem desirable.
d. Enforcement: The traditional dichotomy is a type of
civil penalty through the withholding or termination of licenses, and a
declaration that certain violations constitute a crime, usually a mis-
demeanor. As the pesticide chemical complex becomes more technical and
involves many more conflicts, it appears to be timely to shift more ini-
tial responsibility and authority to the administrative side. In addi-
tion to investigations, registration and licensing, there is adequate
legal precedent for administrative fines. While such penalties could be
appealed to the courts, most would not be appealed, thereby relieving the
court system of an increasing number of small but highly technical cases.
Usually a separate state administrative Board or Commission is
established to hear complaints of violations and impose fines. This Board
or Commission would have a special competence in pesticide use and perhaps
in pollution control. In some states, outside of those under study for
this project, pollution and environmental quality are matters of first
concern to such a Board, with pesticides being of interest only when they
allegedly pollute. It is suggested that such parameters may be too narrow.
154
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e. Comment: Departments of Agriculture administer the
Pesticide Laws in the states studied and perhaps this is where primary
responsibility and authority should rest. But some mechanism should be
employed to jointly engage the cooperation and expertise of all state
departments concerned with any aspect of pesticide sales and use. An
interdepartmental committee such as the working group on pesticides in
Washington might be used.
2. Weed Laws. The basic Weed Laws reviewed in the states
studied give authority to the County Board to declare weeds as noxious
but with very little, if any, power to take direct action against vio-
lators. One state law (Colorado) provides for the appointment of a Weed
Superintendent by the County Board and a tax levy to support his program.
In two states (Idaho and Nevada) the state may assume some control of
weeds.
Four of the states allow County Pest Control Districts, estab-
lished by petitioning the County Board, except for the Montana law which
automatically creates such districts for each county. All districts have
authority to carry out a spraying program when a landowner is delinquent
and charge him for the expense. In Montana, a county weed tax can be
imposed to pay for the spraying, including a partial reimbursement to
landowners.
It would seem that these various laws could be improved by the
following:
a. Enabling County Boards to impose a small tax levy for
weed control and to employ a Weed Control Officer.
b. Giving authority to County Boards to approve regulations
on weeds and pests, but subject to review by the state with regard to the
use and application of any pesticides.
c. Requiring that possible environmental damage be con-
sidered before approving countywide or local weed and pest control pro-
grams.
d. Possibly consolidating the Weed Laws with the Pest
Control District Laws to provide for coordination and cooperation between
the districts and the county, and also to assure compliance with state
regulations on pesticide use.
155
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3. Pollution Laws. This area of law is unraveling rapidly with
substantial structural changes for administration, making it difficult to
suggest changes. Unquestionably federal law is dominant at this time and
some catching up is due from most states.
One difficulty pervades Federal Pollution and Pesticide Laws.
Administration was transferred to the EPA from other departments. There
is no basic law written just for EPA. The consequence is adjustment,
some legal gaps (such as pesticide use control) and some lag in getting
regulations coordinated and appioved.
The splintered federal structure and recent reorganization may
or may not have had a negative influence on the laws of the states under
study. Two states have only very minimal laws on water pollution. An-
other state has a recent law only on air pollution. Three states have
newer laws on pollution, two of which establish a commission and a council
to assist with administration. In all cases, the cumbersome enforcement
procedure and low penalties may be weak links.
It would appear that these state laws could be improved as
follows:
a. Passing new laws or amending older ones to either broaden
the authority of the Departments of Health for pollution control and environ-
mental protection, or establish broad-based Natural Resource Departments
with multifunctional authority. Such authority would include pollution
control, water management and regulation, land use, and water and land
conservation. These functions have close ties and isolated planning and
separate enforcement is not the most sensible approach.
b. Buttressing the hearing and adjudicative procedure with
more administrative authority for enforcement and penalties.
c. Using a substate structure where needed for regional
and local administration.
d. Providing for central data collection and a mechanism
for establishing priorities. An elaborate system of sharing data and
techniques with all units should be an immediate goal.
The entire environmental quality system should be premised on
preventive cooperative action rather than remedial edict, reserving the
hard hand of power only when essential in the public interest. However,
authority must be there when it is needed.
156
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XII. CONCLUSIONS AND RECOMMENDATIONS
Based on our evaluation of the data obtained during this study, the
following conclusions and recommendations are made:
A. Conclusions
1. There are an estimated 270 million acres ot Western rangeland
covered by sagebrush, and much of these brush-infested areas have the potential
to be converted to productive grazing ranges for both livestock and game
species.
2. Big sagebrush (Artemisia tridentata) is the most prevalent
species of sagebrush, occupying about 144 million acres or 53 percent of the
total sagebrush areas in the western states.
3. The herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), is the
only chemical of any significance used to control sagebrush on the western
rangelands.
4. The butyl or isopropyl esters of 2, 4-D are the most commonly
used formulations to treat sagebrush; a low volatile ester is sometimes used
when spraying near susceptible, desirable plants or when applying under crit-
ical growing conditions; the salts of 2, 4-D (Amine) are not very effective
against sagebrush.
5. Diesel oil appears to be superior to water or invert emulsions
as a carrier for 2, 4-D. With oil, optimum coverage can be obtained and the
material will not wash off treated plants.
6. Sagebrush is most susceptible to herbicide treatment during the
period of most active growth in the spring or early summer.
7. Aerial spraying is the usual method of applying herbicides on
sagebrush, and most applicators attempt to deliver droplets 50 to 100 microns
in size.
8. Soil erosion hazard is not increased as a result of spraying
sagebrush, since erosion normally is checked by dead standing brush, undis-
turbed litter cover, and undisturbed soil and grasses.
157
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9. There is evidence that soil moisture Increases following the
erradication of sagebrush (80-100 percent kill).
10. Data show that the snow-holding capacity is uneffected by sage-
brush control in areas where drifting usually occurs, and that treated areas
retain snow longer than untreated areas.
11. Increased snow-holding capacity often results in more of the
melt entering the ground as underground water flow rather than as runoff in
the spring. Following sagebrush control in these areas, it is sometimes pos-
sible to use springs throughout the growing season when previously the water
dried up early in the year.
12. When properly applied at recommended concentrations, 2,4-D is
not considered poisonous to domestic animals, fish, or game.
13. There are a number of microorganisms that can degrade 2,4-D;
the herbicide does not persist in the soil, and it has no adverse effects on
soil microorganisms.
14. Generally, spraying of sagebrush with 2,4-D reduces forbs in
the treatment area. However, decreases in some forb species may be countered
by increases in other species resulting in little net change in forb density.
15. Adequate concentrations of 2,4-D for treating sagebrush should
not damage grasses, and grass production will increase after sagebrush com-
petition is eliminated and more moisture is available.
16. Forbs and browse, including sagebrush, are Important as food
for various wildlife that inhabit the rangelands. Reduced growth of certain
forbs on summer ranges could adversely affect antelope, sage grouse,'mule
deer, whitetail deer, elk, and possible moose. Removal of sagebrush on winter
ranges probably would be most detrimental to sage grouse, antelope, and mule
deer.
17. The use of 2,4-D for sagebrush control on the rangelands does
not appear to present a hazard as a water pollutant. The herbicide does not
persist in soil and the regions are very dry. Therefore, there is little
opportunity for 2,4-D to be washed into the few streams and bodies of water
in the sagebrush areas. Results of pesticide -monitoring programs show that
water samples from Western states contained concentrations of 2,4-D, when pre-
sent, considerably below the amount permissible in public water supplies.
158
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18. Although 2,4-D has been widely used for weed and brush control,
poisoning by the material is rare in man. It is generally concluded that
2,4-D does not present a direct toxicity hazard to man when correctly handled
or used for weed control.
19, Food crops have been found to contain insignificant amounts
of 2,4-D and it is unlikely that there is any hazard to man from those sources.
20. Many methods of sagebrush control other than spraying have
been employed. No one method is universally the best because sage grows under
widely varied conditions. Most of the alternate control methods utilize
equipment designed for other functions, are sometimes slow, are not as effec-
tive as spraying, often encourage soil erosion, and may be expensive.
21. From a study of the pesticide laws pertaining to the study
area, it was clear that the laws, regulations and court decisions place sub-
stantial restraints or. the production, sale and use of pesticides, and in
particular, on herbicides.
22. More legal attention is being given to environmental quality
protection, but with some variance between states.
23. There is an awareness of pollution problems as evidenced by
the laws passed that clearly mandate a better environment.
B. Re commendat ions
1. To meet the demands of an ever increasing population for more
livestock production, additional animal products, and larger numbers of game,
sagebrush control is necessary to provide additional and more productive range-
land acreage.
2. The use of 2,4-D herbicide to control sagebrush is a practical,
safe, and economical method, and it should continue to be used for range im-
provement in the Western states.
3. The laws concerning pesticides should be reviewed and a single
law developed covering registration and dealer and applicator licensing with
uniformity in definitions, hearings, enforcement, penalties, and regulations.
159
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INDEX TO THE USE AND EFFECTS OF PESTICIDES FOR
RANGELAND SAGEBRUSH CONTROL
Key Word or Phrase
Aerial application, herbicide
Agriculture
Air pollution
Air Pollution Control Law
Anchor chaining (method of sagebrush
control)
Animal ecology
Antelope, pronghorn
Aquatic species (flora and fauna)
Arizona
Artemisia arbuscula (low sagebrush)
Artemisia argilosa
Artemisia bigelovii
Artemisia cana (silver sagebrush)
Report Page Number
1, 22-27, 30, 31, 33, 35-41,
43-51, 55-62, 67, 68, 72,
75, 79-83, 96, 99, 123, 139,
147-149, 155, 157-159
1, 4-18, 96, 123-125, 128,
138, 146-149, 157-159
1-39, 143, 146, 152, 156
Colorado—139, Nevada—143,
Wyoming—146
129
7, 11
7, 11, 63-68, 85, 115, 158
98-103, See also Fish
4, 5, 8, 9, 12, 15, 16, 25,
33, 64, 69, 75, 105, 149
13, 15-18, 66, 125, 129
15, 17
15-17
13, 15-18, 55, 66, 125, 128,
130
Artemisia filafalia (sand sagebrush) 25
Artemisia frigida (fringed sagewort) 13, 75, 84
Artemisia longifolia (longleaf sagebrush) 75
-------
Key Word or Phrase
Report Page Number
Artemisia longiloba
Artemisia nova (black sagebrush)
Artemisia pygamea
Artemisia rigida
Artemisia rothrookii
Artemisia tridentata (big sagebrush)
15-18
13, 15-18, 25, 67, 69, 77,
125, 129
15-17
15-17
15, 16
13-18, 24, 30, 31, 35-41,
43, 45, 49-51, 55, 62,
65-71,,75, 77-79, 81, 84,
85, 125, 129, 130, 157
Artemisia tripartita (three-tip sagebrush) 15-18, 78, 82, 125, 129
Beating,
Big horn sheep
Big Horn Area (Basin) (Wyoming)
(mountain)
Big sagebrush
Biodegradation, 2, 4-D
Birds
Bitter brush
Black sagebrush
Browse
See Cutting (method of sage-
• brush control)
See Sheep, bighorn
7, 22, 40, 43-49
See Artemisia tridentata
97-105
11, 56, 63, 75-82, 85, 111-
114, 116, 158. See also
Grouse, sage, Partridge,
chukar
57, 66, 69-71, 81, 126, 127,
129, 130
See Artemisia nova
67, 69-75, 82, 84-86, 126,
158
-------
Key Word or Phrase
Bureau of Land Management, U.S. Department
of Interior
Burning (method of sagebrush control)
California
Carriea(s), herbicide
Cattle
Chemical control, sagebrush
Chukar partridge
Climate
Colorado
Control, rangeland sagebrush
Cost, sagebrush control
Cottontails
Council on Environmental Quality
Cover, sagebrush as
Coyotes
Report Page Number
38, 51, 136
Saiguna, 25, 33
Montana, 33, 136-137, 25, 26
Wyoming, 23
Idaho, 27-29
Oregon, 25-29
New Mexico, 27
Utah, 27-29
Nevada, 27-29
125-128
<
4, 5, 8, 12, 15, 16, 39, 75,
77, 105, 148, 149
25, 37-39
See Livestock
See 2, 4-D; 2, 4, 5-T; Silvex
See Partridge, chuckar
4, 6, 10, 41, 158
4-17, 40, 64, 65, 72-75, 105,
139, 140, 155
See Aerial application,
herbicide; Anchor chaining;
Burning; Cutting; Harrowing;
Plowing.
1, 22, 33, 35-37, 126-132
See Rabbits
138
11, 66, 76, 78-82, 84, 85,
157
1, 7, 11
-------
Key Word or Phrase.
Report Page Number
Cutting (method of sagebrush control)
Deer, mule
Deer, whitetail
Discing
Economic Poisons Acts
Elk
Environmental impact
Environmental Protection Agency
Farming
Faunal habitats
Federal Insecticide, Fungicide and
Rodenticide Set
Federal Water Pollution Control Set
Fish
Food chains
Food, Drug and Cosmetic Set
Forbs
Fowl
129
11, 63, 68-74, 85, 115, 158
11, 63, 72, 75, 85, 158
See Plowing (method of
sagebrush control)
138
Idaho, 140
Nevada, 144
Wyoming, 145
82, 84, 85, 158
iii, v., 1, 2, 43-51, 53-86,
96-105, 151-159
See also Herbicide Effects
134, 135, 137, 152, 156
See Agriculture
v., 7, 11, 65-68, 72, 75,
76, 82, 84, 85
134, 135
137
v., 53, 100-102, 136, 137,
140, 158
1, 63, 66, 67, 69-75, 77,
78, 82, 84-86
134, 135
57-60, 62, 65-67, 72, 75,
77-82, 84, 85, 126-128, 158
See Birds
-------
Key Word or Phrase
Report Page Number
Fringed sagewort
Game
Gophers
Grasses
Gravelly mountains
Great Divide
Great Plains
Grouse, sage
Harrowing (method of sagebrush control)
Hart Mountain (Oregon)
Herbicide (specific)
Herbicide carriers
Herbicide effects
Herbicide formulations
Herbicide use, current
Herbicide use, history
Horsebrush
See Artemisia frigida
See specific animal (by
name), i.e., mule deer,
antelope, etc.
7, 116
60-62, 65, 66, 68, 69,
71-77, 79-82, 84-86, 124-132,
157, 158
82', 84
6, 40
4, 5
v., 63, 75-81, 85, 116, 158
130
66
See by name:
2, 4-D
2, 4, 5-T
Silvex
See Carrier(s), herbicide
v., 1, 2, 22, 24, 27, 30,
31, 35-41, 43-51, 53-63, 67,
68, 72, 79-86, 100-105,
110-118
See also Environmental Impact
35-37
33
22-31
56, 123, 125-127
-------
Key Word or Phrase
Report Page Number
Hydrology
Idaho
Insects
Intermountain Plateau
Irrigation
Jackrabbits
Laws and regulations, state
Laws and regulations, U.S.
Litigation, use of herbicides
Livestock
Livestock rangeland
Longleaf sagebrush
Low sagebrush
Man, effects of herbicide on
Methods of .sagebrush control
Microorganisms
Miller Amendment U.S.
Mineral resources
See Soil, moisture retention
4, 5, 8-17, 27-29, 33, 64,
65, 75, 79, 105, 140, 155
7, 11, li6
4, 5, 75
6-10, 51, 96-100
See Rabbits
v., 138-146, 151-156
v., 134-138, 151-156
146-151
1, 7, 9, 11, 85, 111-115, 124,
140-144, 157, 159
See Rangeland
See Artemisia lon^ifolia
See Artemisia arbuscula
v., 53, 110, 117, 118, 143,
159
See Aerial application,
herbicide; Anchor chaining;
Burning; Cutting; Harrowing;
Plowing.
53, 54, 103
135
6, 9
Moisture retention
See soli, moisture retention
-------
Key Word or Phrase
Report Page Number
Montana
Mouse
Mule deer
National Environmental Quality Laws
Nevada
New Mexico
Noxious Plant Control Law
Oil, as herbicide carrier
Oregon
Partridge, chukar
Pecos River Basin
Pesticide(s)
Pesticides Set/Law
Pesticide (custom) Applicators Law
4-17, 25, 26, 33, 64-67,
70-72, 75, 76, 78, 84, 105,
136, 137, 141-143, 152, 155
v., 63, 84, 85, 158
See Deer, mule
136-138, 151-152
4, 5, 8-17, 27-29, 33, 64,
65, 75, 105, 143, 144, 155
t
4, 5, 6, 7, 8, 9, 12, 15, 16,
27, 33, 50, 64, 65, 69, 75,
105, 149.
US 135
See Carrier(s), herbicide
4, 5, 7-17, 25-29, 33, 35,
36, 64-68, 42, 75, 81, 82,
105, 144, 145, 148.
63, 82-83
8, 50
iii, v., 22-31, 96, 134-156,
159
See also Herbicide(s)
Colorado, 139
Idaho, 140
Montana, 141, 152
Nevada, 144
Oregon, 144
Nevada, 144
Oregon, 144
-------
Key Word or Phrase
Report Page Number
Pesticides Registration Law
Physiography
Plowing (method of sagebrush control)
Pronghorn antelope
Rabbit(s)
Rabbitbrush
Rainfall
Rangeland
Red Desert (Wyoming)
References (sections of)
Refuse Set (1899), U.S.
Rocky Mountains
Rural Area Water Facilities Set. U.S.
Sagebrush, U.S. acreage
Sage grouse
Sand sagebrush
U.S. See Federal Insecticide,
Fungicide and Roedenticide
Set.
4-8, 11-12
128-129
See Antelope, pronghorn
7, 63, 84, 85, 112
56, 65, 67, 123, 125-128, 130
4, 6-11, 43-50
v., 1, 7, 9, 11-13, 22, 24,
30, 31, 35, 51, 63-69, 72,
75-79, 82-86, 123-132, 136,
137, 139-146, 157-159
Note: As sagebrush-infested
land is potential rangeland,
the entire report is concerned
with rangeland.
22, 24, 43-45, 50, 66, 67
19-21, 32, 34, 42, 52, 87-95,
107-109, 119-122, 133
137
4-12
137
v., 1, 4-8, 11-21, 157
See Grouse, sage
See Artemisia filafalia
Sheep, bighorn
7, 9, 84, 85
-------
Key Word or Phrase
Report Page Number
Sheep (domesticated)
Shredding
Sierra Nevada Mountains
Silver sagebrush
Silvex (herbicide)
Snow-holding capacity, soil
Soil erosion
Soil laterization
Soil, moisture retention
Soil siltation
Spraying herbicides
Sun River (area) (Montana)
Teratogenic effects, 2, 4-D
Three-tip sagebrush
Toxicity, 2, 4-D
Utah
Vegetation
Washington
See Livestock
See Cutting (method of sage-
brush control)
4, 5
See Artemisia cana
33
See Soil, moisture retention
t
v., 1, 7-9, 43, 50, 51, 85,
125-130, 138, 157
1, See also Soil erosion
v., 6-11, 14, 41, 43-51,
55, 80, 158
1, 9, 10, See also Soil
erosion
See Aerial application,
herbicide
75, 84
118
See Artemisia tripartita
110-118
4, 5, 7-17, 27-29, 33, 41,
64, 65, 75, 105
See Agriculture
4, 5, 7, 8, 12, 13, 15-17,
64, 75, 105
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Key Word OIL Phrase
Report Page Number
Water, as herbicide carrier
Water pollution
Water Pollution Control Law(s)
Water Quality Set (1965), U.S.
Water Quality Improvement Set (1970), U.S.
Water Resources Planning Set, U.S.
Watershed(s)
Weather
Weed Control Law
Whitetail deer
Wildlife rangeland
Wyoming
2, 4-D (herbicide)
2, 4, 5-T (herbicide)
See Carrier(s), herbicide
v., 96-101, 104, 105, 134,
136-139, 141-143, 149, 150,
152, 156, 158
Colorado—139
'Montana—141
Nevada—143
137
137
137
1, 25, 43-51, 85, 126, 129
See Climate
Idaho—140, 155
Montana—141
Nevada—143, 155
Colorado—139, 155
(General)—155
See Deer, whitetail
See Rangeland
4, 5, 6, 7, 9, 12, 13, 15,
16, 18, 22-24, 33, 35, 37,
43-51, 64-67, 75, 78-80,
85, 145-146
v., 1, 2, 22, 24-31, 33,
35-37, 39, 40, 44, 53-63,
67, 68, 72, 75, 80-83, 97-
106, 110-118, 145, 148, 149,
157-159.
33, 35-37, 39, 54, 114, 115,
145
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