U.S. Department of Agriculture Agricultural Research Service
.. ; t "'"
~': ::..,, ,,li
Western rangelands are getting a
helping hand from ARS researchers at the
Forage and Range Research Laboratory
in Logan, Utah. There, scientists are
collecting and improving-through
selective breeding-hardy native plants
to protect, beautify, and boost the
productivity of rangeland ecosystems
throughout the West. These wildlands
provide forage for livestock and wildlife,
water for cities and industries, and wide-
open spaces perfect for hiking, camping,
fishing, hunting, and other outdoor
This issue of Agricultural Research
describes three native plant varieties that
the Logan scientists helped develop.
Timp Utah sweetvetch, Rimrock Indian
ricegrass, and Sand Hollow squirreltail
each have passed the Logan lab's
Earlier investigations at Logan have
produced other new options for seeding
western sites. The team, for instance, has
combined the best traits of two native
grasses-thickspike wheatgrass and
bluebunch wheatgrass-into a unique
hybrid line called SL-1. This vigorously
growing plant provides nutritious forage
Too, Logan tests of plants called
globemallows have yielded two species
well-suited for planting on mine spoils
or along roadsides. Scarlet globemallow
and Munroe globemallow are drought-
and heat-tolerant, as well as winter-hardy.
And their brilliantly colored flowers
make these globemallows a pleasing
addition to small seed packets sold for
home gardens or to the big bags of
wildflower seed mix for more extensive
Today's ARS studies of other promis-
ing native species may also open the door
to wider use of native plants. A bluebunch
wheatgrass now in the final stages of
testing, for example, is the result of cross-
breeding parent plants from 25 different
sites throughout 6 western states and
The genetic diversity of this "mul-
tiple-origin polycross" exceeds that of
any bluebunch wheatgrass sold com-
mercially in the United States today. The
broad-based lineage of this new poly-
cross should significantly enhance its
ability to survive and flourish throughout
the species' native range.
Other experiments deal with an in-
triguing race of Great Basin wildrye that
produces attractive bluish foliage. With
further development, this drought-
tolerant plant might be sold at nurseries
for low-maintenance gardens.
Many of the experiments with native
plants are meant to provide nutritious
forage for cattle, sheep, deer, elk, buffalo,
and other livestock and wildlife. But one
innovative project at Logan has the
opposite intent. Studies of a plant called
robust needlegrass are designed to take
advantage of the fact that animals find
the plant unpalatable if the seed is
infected with a natural fungus called
Further tests may reveal whether
planting Neotyphodium-infected robust
needlegrass along roadsides could dis-
courage animals from grazing too close
to roadways. That could help prevent the
collisions that can injure or kill the ani-
Though the Logan lab has probably
collaborated in the release of more plant
species native to American rangelands
than any other ARS team, the Utah
scientists work with introduced plants as
well. Some of these plants are descen-
dants of parent plants collected-as
seed-many decades ago by USDA plant
The lineage of other varieties extends
to plant seed graciously provided by
collaborators working at research
institutes around the globe. Still other
introduced plants result from the Logan
scientists' own international expeditions
to collect plants. These arduous ventures
have taken them to some of the most
remote places on Earth.
Why is there a need to collect,
selectively breed, and release introduced
plants? In some circumstances, intro-
duced plants can do a better and faster
job than most native species of bringing
certain American rangeland sites back to
health. When used properly, the intro-
duced plants do not threaten to outcom-
pete native vegetation.
The Logan work is part of a national
ARS effort to protect and enhance the
health and biodiversity of America's 1.2
billion acres of rangeland. This research
goal is a priority not only with the Utah
team, but also with ARS research units
at more than two dozen other locations
throughout the United States.
The long-term productivity of
American rangelands depends on
choosing the best plant for each eco-
system. Our research helps ensure that
the individuals responsible for managing
and protecting America's rangelands
always have the best possible array of
plant species for that job.
Allen R. Dedrick
Associate Deputy Administrator
Natural Resources and Sustainable
Agricultural Research/April 2000
Vol. 48, No. 4
lhr;lliritl Rt i ,[i' ( iS published monthlN b\
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Agricultural Research Service
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Hardy Natives at Home on the U.S. Range 4
A New Wood Adhesive 8
Spinosad Battles Crop Pests 10
Ozone Puts New Wrinkle in CO2 Yield Projection 13
Mapping the Way to Disease-Free Chickens 14
Ugly Duckling Corn Repels Borers 17
Elevating Grain Storage Practices 18
Fending Off Siberian Moths 20
Amazing Graze 21
New Trefoils Give Breeders More Options 22
Lab Diets for Two Pest Insects 22
Science Update 23
Cover: At the ARS Forage and Range Research Laboratory in Logan, Utah,
researchers strive to improve native and non-native plant species for use on western
rangelands. Here, geneticist Tom Jones searches for bluebunch wheatgrass to increase
genetic diversity in a breeding program. Photo by Jack Dykinga. (K8663-1)
In the next issue!
(* NEW PARTNERSHIP BETWEEN BRAZIL AND ARS-Scientists with
ARS are working closely with Brazilian scientists on many projects that
will benefit agriculture in both the United States and Brazil.
(, SEARCHING FOR NEW POLLINATORS-Honey bees still do most of
the crop pollination performed by insects, but lesser known pollinators
may play an increased role in the future.
( TIPPING NATURE'S CHECKS AND BALANCES-ARS Researchers
in Frederick, Maryland, are evaluating disease pathogens for their ability
to weaken a weed population's ecological grip over native competitors.
Agricultural Research/April 2000
HARDY NATIVES AT HOME
ON THE U.S. RANGE
JACK DYKINGA (K8662-1)
You have four legs, a
four-part stomach, and
you're ready for a
snack. What's to eat?
If you're lucky, you
may soon be munch-
ing on Timp Utah
native plant having a
Timp, along with
ricegrass and Sand
are native plants read-
ied for growers by
scientists at the ARS
Forage and Range
in Logan, Utah, and
A Seed heads of various native
grasses (left to right): western
wheatgrass, Snake River wheatgrass,
Indian ricegrass, Great Basin wildrye,
squirreltail, and green needlegrass.
1 Geneticists Steven Larson and
Kevin Jensen observe inherited traits
in hybrids resulting from crosses
between Great Basin wildrye and
V Geneticist Tom Jones examines
Utah sweetvetch flowering at North
Ogden Pass in the Wasatch
JACK DYKINGA (K8657-2)
Agricultural Research/April 2000
Hardy and well-adapted, these plants
help hold soil in place and revegetate
lands denuded by wildfire or disturbed
by mining. What's more, they help stop
the takeover of native ecosystems by in-
vasive weeds like cheatgrass.
"Our lab is the only Agricultural
Research Service unit that breeds native
plants for western ranges," says N. Jerry
Chatterton, the head of the Logan labora-
tory. "Although we have also produced
non-native grasses for planting in the
West, we help develop natives, as well,
because in some instances native species
are the best plants for the job at hand."
A Taste-Tempting Legume
Timp Utah sweetvetch, Hedysarum
boreale, belongs to the legume family,
so it is a relative of peas and beans. Timp
is best suited for its native intermountain
region of Utah, Colora-
do, Wyoming, and Ida-
ho, and-within that
areas with 12 to 18
inches of annual
Its abundant, at-
tractive flowers pro-
duce long, flattened
seedpods that, when
still green and soft, can
be eaten by animals. It pro-
vides early spring forage not only
for cattle and sheep, but for wild rumi-
nants as well, including deer, bison, elk,
"This plant is so popular with ani-
mals," says ARS plant physiologist
Douglas A. Johnson at Logan, "that, after
planting, it needs to be protected from
grazing for about a year to give it a
chance to get established."
Scientists selected Timp from among
other promising candidates because of its
vigor, adaptability, and seed production.
The ARS researchers worked with
colleagues from USDA's Natural Re-
sources Conservation Service (NRCS)
Plant Materials Center at Meeker,
Colorado; USDA's Forest Service; the
State of Utah; and Colorado and Utah
Johnson and colleague Timothy M.J.
Ford-at that time a graduate student-
scrutinized Timp and other candidate
sweetvetches during 3 years of green-
house and outdoor tests. They monitored
about 40 key traits, including how much
leaf and root tissue the plants produced.
They also compared the plants' ability
to fix nitrogen; that is, to capture the
gaseous form of this nutrient from the
atmosphere and turn it into fertilizer.
Restoring With Rimrock
Animals looking for another snack
might try Rimrock Indian ricegrass, or
menoides. A peren-
nial bunchgrass, In-
dian ricegrass ranges
from the western
Great Plains west to
the Cascades and the
Sierra Nevada, ac-
cording to Logan plant
geneticist Thomas A.
"Rimrock," he says,
"is ideal for restoring
damaged native ecosys-
tems on sandy soils."
Jones tested it with co-researchers from
the NRCS Plant Materials Center at
Bridger, Montana, and the agricultural
experiment stations of Montana and
Ricegrass gets its name from its stalks.
When in bloom, they vaguely resemble
those of a rice plant. "Some Native
Americans who lived in the Great Basin,"
says Jones, "used ricegrass seed for food.
They ground it into flour for making a
Agricultural Research/April 2000
JACK DYKINGA (K8659-1)
JACK DYKINGA (K8660-1)
Rimrock's seeds also make an excel-
lent food for game birds like mourning
dove and valley quail or for songbirds
such as green-tailed towhee. What's
more, it retains mature seed longer than
many other Indian ricegrasses-even in
high winds and heavy rains.
"Discovering that trait in Rimrock,"
says Jones, "was our most important con-
tribution to this collaborative research."
Indian ricegrasses that retain seed long-
er are desirable because their seed has a
better chance of staying on the plant un-
til harvest instead of dropping to the
"Better seed retention," Jones says,
"should help make mechanical harvest-
ing easier and less expensive. That lowers
the cost of producing seed and opens the
door to wider use of Indian ricegrass in
A Grass Called Squirreltail
Sand Hollow squirreltail-named for
its showy, plumelike heads-grows up
to 20 inches tall. A perennial, squirreltail
is known to botanists as Elymus
Sand Hollow is the first squirreltail
released for commercial production.
Says Jones, "It withstands wildfires and
Jones and colleagues selected Sand
Hollow from among squirreltails collect-
ed at sites in more than a half-dozen
states, including California, Colorado,
Montana, Nevada, Utah, Washington,
and Wyoming. The scientists put the
plants through 3 years of outdoor evalu-
ation in Utah.
One of Sand Hollow's primary in-
tended uses is to restore rangelands
currently overwhelmed by highly ag-
gressive, non-native plants such as
cheatgrass or medusahead wildrye. The
native plant, Jones says, is best suited
for sandy soils throughout the Snake
River region of southern Idaho, as well
as in parts of Oregon, Nevada, and Utah.
Its attractive golden plumes produce
more seeds than the other squirreltails
Agricultural Research/April 2000
4 Far left photo, geneticist Tom Jones
and plant physiologist Doug Johnson
(right) observe seed head maturity in a
cultivated plot of squirreltail.
4 In an ARS test plot (on a
University research farm) Utah State
University research assistant Mayme
Seng pollinates Snake River
- In a cultivated field of bluebunch
wheatgrass, geneticists Kay Asay (left)
and Tom Jones discuss seed yields.
tested by Jones, ARS colleague Douglas
A. Johnson, and scientists with Utah
State University and with NRCS' Plant
Materials Center at Aberdeen, Idaho.
"Native plants," says Jones, "are of-
ten erratic in seed yield-that is, the
pounds per acre of seed that they pro-
duce. For that reason, Sand Hollow's
prolific seed production is among its
most valuable traits."
Sand Hollow squirreltail may soon
have a role in restoring burned-out sites
at the unique Snake River Birds of Prey
National Conservation Area located
about 35 miles south of Boise, Idaho.
This 81-mile stretch of winding canyon
and broad plain is home to what is
thought to be the country's greatest con-
centration of nesting birds of prey-ea-
gles, falcons, hawks, ospreys, and owls.
"Sand Hollow," says Jones, "could
help restore habitat used by small ani-
mals like Townsend's ground squirrels,
a favorite of prairie falcons, or by the
black-tailed jackrabbits that are essen-
tial to the survival of golden eagles."
The area's destructive cycle of wild-
fires is blamed largely on cheatgrass, an
alien annual plant that dries out in sum-
mer, providing an ideal fuel each year
for wildfires. "In the past 20 years,"
Jones says, "more than 60 percent of the
conservation area's grass and shrub ec-
osystem has been hit by wildfire."
If selected to displace the trouble-
some cheatgrass, Sand Hollow squirrel-
tail may help boost the survival of the
Snake River Canyon's magnificent
raptors.-By Marcia Wood, ARS.
This research is part of Rangeland,
Pasture, and Forages, an ARS National
Program (#205) described on the World
Wide Web at http://www.nps.ars.usda.
N. Jerry Chatterton, Douglas A.
Johnson, and Thomas A. Jones are with
the USDA-ARS Forage and Range Re-
search Laboratory, 690 N. 1100 E.,
Logan, UT 84322-6300; phone (435)
797-3066, fax (435) 797-3075, e-mail
Agricultural Research/April 2000
ay RS (
goal is to fi
t arch-based fit
d to make alternatives to plas-
mulch films now us to curb
rth in high-value agrr ral.crops.
The scientists made biodegradable films from a slurry of
starch and dissolved polyvinyl alcohol, which they processed
through a machine called an extruder. Noting the hot film was
quite sticky while coming out of the extruder, the researchers
considered the chemistry. "We reckoned the material could be
made into an excellent adhesive to bind layers of veneer," Imam
said. "What we needed to do was make the material more flow-
able so it could be easily brushed onto wood."
Breathe With Ease
Imam and his colleagues weren't just thinking of farmers
who would like to see increased demand for commodities such
as corn. People working in wood industries and consumers
might also benefit.
The researchers developed a process to make a flowable,
strong, and moisture-resistant adhesive from a combination of
cornstarch, polyvinyl alcohol, latex, and citric acid. The main
safety benefit: The process required no volatile formaldehydes
or phenols found in conventional wood adhesives. That could
be a major selling point for wood products companies-indoor
air quality that poses less health risk to workers.
Residents of new and recently furnished homes and offices
might also breathe a sigh of relief knowing the products sur-
rounding them contain fewer toxic chemicals. Pressed wood
starch adhesive neing applied to a rellets or sticKy extruded ma
products, especially those made with urea formaldehyde res-
ins and having edges not fully covered by a water-repellent
finish, may emit unacceptably high levels of toxic compounds
into humid indoor environments that are poorly ventilated.
A fire retardant could be added to composite wood products
made with starch adhesive. This could be useful for kitchen
counter tops where many destructive fires begin. But should
the new-style wood composites burn anyway, they would not
produce fumes as toxic as those from products containing form-
aldehyde and phenols.
Because of environmental interests, several U.S. companies
as well as the United Nations Industrial Development Organi-
zation and the International Center for Science and High
Technology, Trieste, Italy, have expressed interest in the new
How expensive is it to make this safer glue? Given present
prices for ingredients, the cost of making it may be 25 to 30
cents per kilogram more than the cost to make conventional
adhesives, according to Lijun Mao, a senior scientist for Planet
Polymer Technologies, Inc., San Diego, California.
Owens Coming has been evaluating Imam's adhesive under
a materials transfer agreement. "We're conducting further
research because the starch adhesive provided excellent
bonding strength," said chemist Liang Cheng, a senior scientist
who is involved in the company's project to possibly modify
current phenolic binder systems.
In his research, Imam and his coworkers used partially
melted starch. To a slurry of the starch and dissolved polyvinyl
alcohol powder they added the chemical hexamethoxy-
methylmelamine which, with the help of the catalyst citric
acid, firmly bound the starch to the alcohol. Then they added
latex to the mix before brushing it on wood. Hot plates pressed
the adhesive-covered veneer layers together for 15 minutes.
The latex helped increase the strength of the adhesive bond-
ing and also provided resistance to weakening by moisture.
Research still in progress will show whether adding wax to
the formulation will further improve water resistance.
Considerable improvement in mois-
ture resistance might be needed to help
the plywood stand up in outdoor settings,
Imam says. But for conditions harsher
than most indoor settings, his birch ve-
neer plywoods measured up to commer-
cial ones. In these tests, he first stored
the plywood samples at normal or high
..humidities for a month or soaked them
'. in water for 2 hours. Then he measured
the force needed to pull the layers apart.
In 98 percent of samples from each of
trial. the storage environments, the adhesive
proved stronger than the wood.
More research is needed to determine
the commercial potential of the new
adhesive. Accordingly, ARS is seeking cooperators to speed
the technology for defined uses. A cooperative research and
development agreement (CRADA), for example, might entail
temporary use of a company's scaled-up research equipment
in a recently renovated NCAUR pilot plant.-By Ben Hardin,
This research is part of New Uses, Quality, and Market-
ability of Plant and Animal Products, an ARS National Pro-
gram (#306) described on the World Wide Web at http://
www. nps. ars. usda.gov/programs/cppvs.htm.
Syed H. Imam is at the USDA-ARS National Center for
Agricultural Utilization Research, 1815 N. University St.,
Peoria, IL 61604; phone (309) 681-6335, fax (309) 681-6689,
e-mail firstname.lastname@example.org. *
Agricultural Research/April 2000
Technician Bob Gibbons (left) and
entomologist Roger Vargas apply protein
bait droplets to coffee leaves to evaluate
their attractiveness to Mediterranean
fruit fly and its natural enemies.
In coffee fields, medflies lay their eggs in
ripening, cherrylike fruits that house the
new, environmentally friend-
ly insecticide called spinosad
may soon become a widely
accepted alternative to the
malathion sprays used today for fighting
insect pests such as the Mediterranean
Medfly can attack more than 200 dif-
ferent kinds of fruits and vegetables and
ranks as one of the world's worst insect
pests. In California, medfly battles have
cost taxpayers nearly $500 million dur-
ing the past 25 years. A 1997 attack on
medfly in Florida's Tampa Bay region
lasted 9 months and cost $25 million.
Spinosad gets its name from the
microbe that produces it, a soil-dwelling
bacterium called Saccharopolyspora
spinosa. When applied at recommended
rates, spinosad poses less risk than most
insecticides to mammals, birds, fish, and
beneficial insects. That's why Agri-
cultural Research Service scientists in
Hilo, Hawaii, and Weslaco, Texas, are
exploring its potential.
Spinosad is already approved for use
on more than 100 crops, including ap-
ples, almonds, citrus, eggplant, tomatoes,
and cotton (see "Spinosad Tests on Cot-
ton Pests-Bollworms and Budworms,"
In coffee fields in Hawaii, ARS sci-
entists compared spinosad to malathion
and to phloxine B, a red dye widely used
in cosmetics, pharmaceuticals, and other
products. Phloxine B is also a promising
alternative to malathion insecticide. The
scientists looked not only at each chem-
ical's effectiveness in zapping medflies,
but also at its effects on one of the most
Agricultural Research/April 2000
important natural enemies of medfly in
Hawaii-a tiny wasp known as Fopius
The female wasp lays her eggs inside
the developing medfly egg. A young
wasp grows inside the medfly, eventu-
ally killing it. F arisanus wasps are
harmless to humans.
Steven L. Peck, formerly with ARS
and now with Brigham Young Univer-
sity, along with entomologist Roger I.
Vargas and biologist Grant T. McQuate
of the ARS U.S. Pacific Basin Agri-
cultural Research Center in Hilo, Hawaii,
led the experiments. They worked with
entomologists John W. Armstrong at
Hilo, C. Glen Jackson of ARS at Phoe-
nix, and John D. Stark of Washington
State University, Puyallup.
The scientists selected coffee fields
for the test site because medflies love
coffee berries. The insects don't harm the
crop, though they do lay their eggs in
the ripening, cherrylike fruit that houses
the coffee beans.
Each chemical was combined with a
bait to entice the medflies to eat.
"Malathion was more effective than ei-
ther of the two alternatives in control-
ling the medflies," reports Peck. "But
both spinosad and phloxine B gave im-
pressive levels of control. Our results
suggest spinosad and phloxine B may
need to be applied more frequently than
malathion, but the total amount of ac-
tive ingredient put into the environment
using spinosad or phloxine B would be
Combining Controls for Added Punch
Colleague Vargas' scrutiny of the
beneficial wasp showed that the little
reddish-brown-and-black insect "had
high susceptibility to malathion and low
susceptibility to both spinosad and
phloxine B." He says the findings also
suggest the wasp "might be an ideal
candidate for use-in conjunction with
spinosad or phloxine B-in an experi-
mental areawide program for suppressing
medfly and several of its pestiferous
relatives in Hawaii."
Sexually sterile medflies could be add-
ed to the arsenal. "Spinosad could be used
first, to knock down most of the medfly
population. Then, sterile medflies could
be released perhaps a week or so later,"
When sexually sterile males mate with
wild females, no fertile offspring result-
meaning the population should crash.
"The combination of using spinosad plus
the sterile-insect technique," adds Peck,
"has the potential to suppress medfly
populations to even lower levels than
The Hawaii tests required trapping
flies for 10 weeks, applying sprays for 8
of those 10 weeks, and harvesting more
than 150,000 berries from some 25,000
coffee plants. This was one of the most
extensive field studies ever conducted on
the effect of these chemicals on medfly
and the F arisanus wasp.
Taste Tests for Best Bait
Unlike malathion, which can kill in-
sects that come in contact with it,
spinosad kills mainly by ingestion. Im-
proving the baits needed to entice hungry
medflies to eat spinosad is the intent of a
new cooperative research and develop-
ment agreement between an ARS lab in
Weslaco, Texas, and the manufacturer of
spinosad products, Dow AgroSciences
LLC, of Indianapolis, Indiana.
The research on spinosad fits right into
the mission of Weslaco's Crop Quality
and Fruit Insects Research Unit, led by
Robert L. Mangan. Located near Mexi-
co, where citrus is grown for international
trade, Mangan's team researches new,
environmentally safe ways to keep the
fruit free of insect pests.
Biologist Grant McQuate examines the
sticky insert of a trap baited with a
synthetic food bait. The traps in this coffee
crop are used to catch medflies to assess the
effectiveness of spinosad.
In laboratory studies by entomologists
Mangan and Daniel S. Moreno, most
Mexican fruit flies died within 72 hours
of eating their fill of a bait containing 1
part per million (ppm) spinosad. Similar
results followed in lab experiments with
sapote and Caribbean fruit flies.
"We formulated several baits so the
flies could tell us what they liked best,"
The winning delicacy: a combo that
basically consists of hydrolyzed spray-
dried protein and an assortment of inert
ingredients. Called Solbait, the ARS-
developed elixir is now registered for
emergency use with spinosad to control
or help eradicate fruit flies in Florida.
SCOTT BAUER (K8844-1)
Technician Russell Ijima uses an all-
terrain vehicle to apply a band of protein
bait spray (containing spinosad) in a
Agricultural Research/April 2000
Besides being tasty to fruit
Solbait has other desirable feature
can be applied with conventional
equipment, and it clings easily to
In the lab tests, a minuscule (
ppm concentration of spinosa
Solbait proved lethal to 50 perce
the Mexican fruit flies in 72 houi
did 0.14 ppm for medflies. Sir
concentrations were as effective
against other fruit flies. In
comparison, a malathion dosage
about three times higher (0.44
ppm) was required to kill 50
percent of the Mexican fruit flies
as well as Caribbean and West
Indian fruit flies.
Moreno and colleagues with
the Florida Department of Plant
Industry and Dow AgroSciences
conducted 6-day field tests of
spinosad in De Soto County,
Florida. The results: 80 ppm
spinosad in Solbait was as
effective as 195,000 ppm mala-
thion in the standard hydrolyzed
protein spray used to apply this
Now the scientists want to
enhance spinosad's effective-
ness-in combination with
Solbait-so even smaller quan-
tities of the insecticide could be
used.-By Marcia Wood and
Ben Hardin, ARS.
This research is part of Crop Prn
tion and Quarantine, an ARS Nati
Program (#304) described on the V
Wide Web at http://www.nps.ars.u,
To reach the scientists mention,
this article, contact Marcia W
USDA-ARS Information Staff,
Buchanan St., Albany, CA 94710; p.
(510) 559-6070, fax (510) 559-586
mail email@example.com. *
Biologist Grant NMcQuale I Ifl a
technician Russell Ijima tamine
catch from a protein bail Irap use
a coffee field.
Spinosad Tests on Cotton Pests-
Bollworms and Budworms
ARS agricultural engineer Ivan W. (Buddy) Kirk and
entomologist Jesus F Esquivel at College Station, Texas,
have years of expertise developing new tactics to fight two
of cotton's worst enemies-cotton bollworms and bud-
worms. So, Dow AgroSciences LLC, makers of spinosad,
in\ ited the scientists to test this new insecticide in some
commercial cotton in the state.
"Cotton bollworms and budworms have
developed resistance to many standard com-
mercial insecticides," says Kirk, who is with the
Areawide Pest Management Research Unit in
College Station. "These insects infest over 75
percent of the U.S. cotton crop."
Kirk and Esquivel conducted the experiment
on a 200-acre commercial field of conventionally
bred cotton in Burleson County, Texas. Some
plots were sprayed with spinosad; others received
standard pesticides. The researchers evaluated
spray rates of 2 and 5 gallons per acre and droplet
sizes of 200 and 400 microns.
Spinosad was more effective when aerially
applied with the smaller (200-micron) droplet
size and the higher (5-gallon) spray rate. Com-
monly used spray rates for standard insecticides
average only 2 to 3 gallons.
However, cotton treated with spinosad "had
fewer damaging bollworm and budworm larvae
ad than plots treated with the other pesticides,"
the Esquivel says. "Larvae found on cotton treated
ed in with standard insecticides were more mature,
suggesting that spinosad prevented small larvae
from becoming larger and more damaging. Our
findings also suggest that some larvae were probably
resistant to the standard insecticides."
Too, the experiment helped establish that spinosad is
nontoxic to most beneficial insects. "More lady beetles
and pirate bugs were found on cotton treated with spinosad
than with the standard insecticides," says Esquivel.
The study was conducted through a trust fund cooper-
ative agreement between ARS and Dow AgroSciences.-
By Linda McGraw, ARS.
Ivan W (Buddy) Kirk and Jesus Esquivel are at the
USDA-ARS Areawide Pest Management Research Unit,
2771 F&B Road, College Station, TX 77845; phone (409)
260-9584, fax (409) 260-9386, e-mail firstname.lastname@example.org.
Agricultural Research/April 2000
. i i.-. i Ill- 1 n 1. I
Ozone Puts New Wrinkle in CO2 Yield Projection
Concentrations of carbon dioxide in our air are on
the rise. During this century, CO, levels are ex-
pected to double what they were in preindustrial
Rising CO, stimulates growth and increases
yield in a variety of food and fiber crops. But will yields surge
enough to feed the world's population of 9 billion expected by
To find out, scientists have developed computer models for
each of the major crops-mainly grains. "We use models to
project the effects of both rising CO2 and projected climate
changes on world food supply," says Cynthia Rosenzweig. She
heads the project at NASA's Goddard Institute for Space Stud-
ies at Columbia University in New York City.
New ARS research suggests that the models may often over-
estimate how much CO2 enrichment will stimulate growth. The
scientists are proposing that another gas be included in the
models: the air pollutant ozone. This oxidizing agent damages
plant tissue and decreases crop yield.
"But studies to measure the positive effects of CO2 and the
negative effects of ground-level ozone on crop yield have tra-
ditionally looked at each gas separately," says plant physiologist
Joseph E. Miller. He is the head of ARS' Air Quality-Plant
Growth and Development Unit in Raleigh, North Carolina.
Miller and colleagues Allen S. Heagle, Edwin L. Fiscus, and
Fitzgerald L. Booker have been combining the two gases in
various concentrations on several crops throughout the grow-
ing season. The results suggest that much of the CO2 yield boost
reported by other researchers may not be true increases but
rather a case of CO2 preventing losses caused by ozone-at
least in ozone-sensitive crops.
"When ozone stress is low, increasing CO, concentration
does not always stimulate plant growth a lot, says Heagle. Ex-
tra CO2 by itself will cause some growth stimulation because
the plants have more "food" for photosynthesis.
So far, the researchers have seen this interaction in field tests
of soybeans, winter wheat, rice, and cotton and in greenhouse
tests of snap bean and white clover-a forage crop. Each crop
or variety responds to a greater or lesser degree, depending on
its sensitivity to each gas, but the trend is always the same.
Soybeans are quite sensitive to ozone, as is cotton, Miller
notes. And some varieties of wheat and rice also suffer damage
and yield loss under high ozone.
Other researchers have reported a similar interaction between
CO2 and water stress. Some crops don't respond as much to
high CO, when they get ample water throughout the growing
season, says Heagle.
He explains that extra CO2 partially closes the leaf pores, or
stomates, through which plants exchange gases. This reduces
the ozone that gets in and the water vapor that gets out. "So if
plants are under ozone or water stress, you'll get a greater
response to CO2 enrichment. The more ozone stress, the more
damage prevention and the greater the apparent growth
"It doesn't seem to matter what ozone damage we measure-
photosynthesis, foliar injury, or yield-all are prevented by
CO,," says Heagle. "The greater the ozone stress, the greater
the amount of CO2 that will be needed to prevent it, and it's not
necessarily a linear relationship."
Why do some experiments show greater response to elevated
CO, than others? "It may be due to unrecognized differences
in water or ozone stress among different studies," says Miller.
The Raleigh findings have CO, researcher Bruce A. Kimball
scratching his head. Kimball, who heads ARS' Environmental
and Plant Dynamics Research Unit in Phoenix, Arizona, says
that many of the studies reporting yield increases from CO2
enrichment were probably performed at low ozone levels.
"I think the CO2 stimulation [the Raleigh researchers] are
getting in low ozone is generally lower than what is reported
in the literature," says Kimball.
Steven J. Britz, who heads the Climate Stress Laboratory in
Beltsville, Maryland, adds, "The Raleigh experiments are a
good example that the field of CO2 response is still very much
in development." By Judy McBride, ARS.
This research is part of Global Change, an ARS National
Program (#204) described on the World Wide Web at http:/
www. nps. ars. usda. gov/programs/nrsas.htm.
Joseph E. Miller and Allen S. Heagle are in the USDA-ARS
Air Quality-Plant Growth and Development Research Unit,
3908 Inwood Rd., Raleigh, NC 27603; phone (919) 515-3312,
fax (919) 515-3593, e-mail email@example.com
SCOTT BAUER (K7443-17)
plantt physiologist Joe Miller (leit) and plant patnologist Alen
Heagle discuss an experiment on the effects of elevated carbon
dioxide and ozone on soybeans.
Agricultural Research/April 2000
the Way to
dustry is afrai
it may start
ease, as ever
T he newest version of a chicken
genome map gives Hans H.
Cheng hope for developing a
chicken resistant to Marek's dis-
ease, a viral disease that causes
tumors in the birds.
S "The poultry industry is afraid it may
start losing the vaccine race against Marek's
disease, as ever more virulent strains appear
and cause unbearable losses," says Cheng,
a geneticist with USDA's Agricultural
Research Service. "That's why using a
genome map as a guide or road map to
breeding chickens resistant to Marek's
disease is a priority."
A r arm manager Kaj KulKarm (lert) ana genetcist nans uneng
examine a day-old chick for disease resistance and susceptibility.
Each chick is tagged with a wing band for identification.
V Research associate Hsiao-Ching Liu prepares a sample of
chicken RNA. The samples are then run on DNA microarrays to
screen thousands of genes simultaneously. This new technology is
especially promising and should lead to the rapid identification of
agriculturally important genes.
Before the first vaccine was developed in the late 1960s by
scientists at the ARS Avian Disease and Oncology Laboratory
in East Lansing, Michigan, the disease caused losses of $300
million a year. Those losses came from a combination of deaths,
fewer eggs, and condemnation of carcasses at poultry slaughter
plants. Even with the vaccine, losses can still run as high as
$100 million a year.
The vaccine has to be updated periodically, in a race to keep
ahead of ever more virulent strains. Cheng is counting on the
genome map to help win the race.
"Chickens bred to resist Marek's would be the first genera-
tion bred with modern molecular techniques," Cheng says.
"The genome map will also help us build a superchicken, by
helping us find the best combination of genes and proteins for
resistance to many diseases as well as for productivity," Cheng
Agricultural Research/April 2000
says. Although their focus is on Marek's first and then other
diseases, Cheng and his colleagues are also searching for genes
that will promote better and more efficient growth.
The latest map can be viewed on the WWW at http://
poultry.mph.msu.edu/resources/conmap/conmap.htm. It is
actually a composite of three maps, including one jointly
constructed by the Avian Disease and Oncology Laboratory and
its neighbor, Michigan State University in East Lansing. The
other two maps come from the Compton Institute for Animal
Health in England and the Wageningen Agricultural University
in the Netherlands. The new map is the product of the
International Chicken Genome Mapping Project begun in 1994.
"This is the first such international effort," Cheng says,
although individual countries such as the United States have
worked on mapping chicken genes since 1936. "Chickens were
the first farm animal to have their genes mapped. But, in the
beginning, mapping was based on visible physical charac-
teristics such as feather color, rather than today's biotechnology
that allows DNA and RNA analysis."
Cheng, one of the
PEGGY GREB (K8763-1) co-coordinators of the
East Lansing map pro-
ject, along with Jerry
biologist at Michigan
State, says the DNA
samples used in mak-
ing these maps come
from the East Lansing
lab and the Compton
The East Lansing
lab sends these DNA samples around the world; they were taken
from the blood of 52 chicks that were specially bred in 1990.
The Compton Institute likewise sends vials of DNA samples
around the world that are taken from a similar "reference family"
of chicks. The samples were collected years ago and only from
those individual chicks.
"So," Cheng says, "the DNA samples are in limited supply.
But modern molecular techniques have greatly reduced the
amount of DNA needed for mapping, so there no longer seems
to be a danger of running out of samples."
All three maps used for the latest composite are genetic maps.
The Compton Institute published the first such map. Dodgson
is a few years away from a more detailed genome map. It is
Cheng says that
genome is like
called a physical map because the mapping a city
breakpoints used to map genes neighborhood.
are produced by a physical cutting
of DNA fragments from chromo- "First you need
somes. This contrasts with the street
genetic map in which the break-
points occur naturally, as a result signs as
of sexual reproduction. A phys-
ical map fine-tunes a genetic map, markers, then
giving a higher resolution-like you go looking
a more detailed street map.
Cheng says that mapping a ge- for individual
nome is like mapping a city houses or
neighborhood. "First you need to
use street signs as markers, then genes."
you go looking for individual
houses or genes," he says.
"We have about 2,000 genetic markers to help us locate
genes," says Cheng. "For chickens, somewhere between 2,000
and 4,000 genetic markers is a reasonable goal to begin to con-
struct a genome map and locate genes. The problem is that
about half of these markers have limited utility because they
can only map an individual chicken's genome and that of its
progeny. Unlike the rest of our markers, these markers don't
always mark the same gene in the same spot for all other chick-
ens," he says.
When Dodgson's physical map is ready, it or a composite
version will be integrated with the composite genetic map. Over-
lapping the maps helps build a better genome map.
"Every time one researcher finds another marker, another
street sign is found for the maps," Cheng says. Different maps
are lined up to provide guides for where to go next to complete
the map. A physical map may be deficient in markers so we
can use a genetic map to find those markers and vice versa."
All Creatures, Great and Small, Share Some Identical Genes
The maps also benefit from being overlaid with those of the
human genome and other animal species.
"It's surprising how well the human and avian genomes line
up," Cheng says. The human genome and chicken genome
projects complement each other. By lining up the two maps,
human immunologists and avian health researchers can help
locate genes for traits that improve disease resistance in both
"The amazing thing about evolution is that it leaves many
species-from yeast to mammals-sharing some of the same
large chunks of DNA," Cheng says. "The same mapping
Agricultural Research/April 2000
techniques work in all species-plants and animals-with
nuances caused by differences in biology and reproduction,
Since tumors are so common in chickens, the first cancer-
causing genes were isolated from chicken tumor tissue. A gene
that causes cancer in chickens will have similarities to a gene
that causes cancer in humans. The East Lansing avian lab
contributed greatly to the work on human cancer in the 1970s.
The Ultimate Science
Collaboration among geneticists-sharing and comparing
of genetic maps-is typical of how scientists often work to-
gether to discover something, Cheng says. And collaboration
is particularly needed in genome mapping.
"In that sense, genome mapping is the ultimate science.
We're all forced to collaborate, and we benefit from others'
work," he says.
"The final step, after the maps are made and all the genes
are sequenced, is to identify genes that influence the trait you're
looking for-in this case resistance to Marek's disease," says
As a practical matter, Cheng and his colleagues in effect
work on all these steps somewhat simultaneously. They are
drawing the map at the same time as they are driving city streets
and looking for house addresses.
"We take the maps we have and use them to sequence and
identify genes with resistance to Marek's," he says. He recently
began a new DNA technique called microarray to find these
genes. "It should pare years off the search," he says.
The microarray technique allows a search for a great number
of genes at one time, rather than for gene markers, Cheng says.
PEGGY GREB (K8766-1)
PEGGY GREB (K8764-1)
"RNA is put on two
The genetic material
on one slide might be
from a disease-resis-
tant chicken, with the
other slide containing
RNA from a sus-
ceptible one," he ex-
"A quick check of
such samples, en
masse shows differing
responses in RNA
levels between the
two. The differences
show which genes
may be responsible
for the trait. We hope
this new technology,
combined with gene
mapping, will enable
the rapid identifica-
tion of genes for dis-
ease resistance," he
As another aid to
Cheng and his col-
leagues have also re-
Lbpk.go r amp E
LIILw.i "I. 1 I 'g Linkae group E40
Chicks atop a picture of a genetic map of
a chicken. The chicken genome has 39
pairs of chromosomes, whereas the
human genome contains 23 pairs.
cently developed 19 inbred lines of chickens that have disease-
resistance traits linked to one or a few genes, rather than to a
complex of numerous genes. This makes identifying genes for
disease resistance easier, and facilitates creating chickens that
either are or are not disease resistant-nothing in between that
would hamper the search, he says.
"This unique genetic resource will work for other traits as
well, giving us the opportunity to quickly isolate the responsi-
ble genes," Cheng adds.-By Don Comis, ARS.
This research is part of Animal Genomes, Germplasm, Re-
production, and Development, anARS National Program (#101)
described on the World Wide Web at http://www.nps.ars.usda.gov/
Hans H. Cheng is with the USDA-ARS Avian Disease and
Oncology Laboratory, 3606 East Mount Hope Rd., East Lansing,
MI 48823-5338; phone (517) 337-6828, fax (517) 337-6776, e-
mail firstname.lastname@example.org. *
Technician Laurie Molitor (left) and research associate Christiane
Hansen analyze chicken genetic markers using DNA sequencers.
These semiautomatic machines increase the number of samples that
can be processed per day and minimize human errors.
Agricultural Research/April 2000
--- 201, ~.
Mllkug. g-.op E31 CZ5
Ugly Duckling Corn Repels Borers
An ugly duckling of the corn
family could hold secrets to
save corn from its worst en-
emy-the European corn
"B-96 is scrawny. Its
stalks are weak and its roots are
undeveloped. Its small ears have round
kernels that resemble popcorn," says
ARS entomologist Bradley F. Binder.
But B-96, a corn strain originating from
Argentina, possesses chemicals that
other corn lines covet-and that female
European corn borers find less accept-
able for egg laying.
Working at the ARS Corn Insects and
Crop Genetics Research Unit in Ames,
Iowa, Binder focuses on discovering new
alternatives-other than applying chem-
ical or microbial insecticides to protect
corn from corn borers.
"The struggle against the European
corn borer has been tough for farmers-
especially those who grow crops with
little or no chemical pesticides," he says.
Yearly, the European corn borer
causes losses of $350 million to the
nation's corn crop. Without preventive
treatments, losses can exceed $1 billion.
Besides chemical controls, the 26
only other practical alternative
available today is Bt corn-corn
genetically modified to contain
larvae-killing chemicals pro-
duced by the bacterium Bacillus
thuringiensis, or Bt.
Binder believes that he can
combine the traits of Bt corn
and B-96 corn to provide a
one-two punch against the
borer. The resistance to egg
laying from B-96 corn and
the larval control from Bt
corn should keep the bor-
er under control.
Binder discovered the
unknown trait of the B-
96 strain-an inbred
corn line-in laboratory tests
of corn strains preserved at rhe Amues
Plant Introduction Station.
Female corn borer moths have a
sophisticated array of sensors to help find
suitable sites for depositing eggs. When
a female lands on a corn leaf, she fans
her antennae to get a whiff of the plant's
aroma. At the same time, her feet scratch
the leaf's surface. This scratching
releases plant chemicals that are thought
to give insects more information about
their chosen site.
"Unlike susceptible corn, B-96 has a
chemical defense," he says. After work-
ing with this inbred for 5 years, Binder
believes one of the chemicals is
HMBOA, which belongs to a family of
20 chemicals. He has isolated and
synthesized this compound and de-
veloped a laboratory bioassay to test its
Another chemical in this family,
DIMBOA, protects young corn plants
from feeding borer larvae. Binder found
that unlike most corn plants, B-96 plants
continue producing high levels of
DIMBOA and HMBOA as they mature.
Currently, Binder is looking at lines
related to B-96. Through field testing he
has found that corn borers lay relatively
fewer eggs on these lines than on sus-
"Apparently, female moths reject
these plants in favor of susceptible
lines," he says. He is studying the un-
derlying genetic basis for the biosyn-
thesis of these compounds in corn.
"Breeding this trait into corn could
take 10 years," Binder cautions, so he's
not taking a short-term approach.
Meanwhile, he has found another
corn line, called Illinois A (ILLA), that
"may offer even better resistance to egg
laying," he says. "But characterizing the
chemical basis for ILLA resistance will
require several more years of research."
-By Hank Becker, ARS.
This research is part of Plant, Mi-
crobial, and Insect Genetic Resources,
Genomics, and Genetic Improvement,
an ARS National Program (#301) de-
scribed on the World Wide Web at http:/
/www. nps. ars. usda. gov/programs/
Bradley F Binder is at the USDA-
ARS Corn Insects and Crop Genetics
Research Unit, Genetics Laboratory,
Room 110, Iowa State University,
Ames, IA 50011; phone (515) 294-6948,
fax (515) 294-2265, e-mail bfbinder@
The adult female
European corn borer
moth lays fewer eggs
on the B-96 corn strain
than on others. After
scratching and sniffing
the surface of a B-96
leaf, she generally
moves on to a more
Agricultural Research/April 2000
Elevating Grain Storage Practices
W ord-of-mouth advertis-
ing is important to
spreading good news
and good practices
among people. ARS
entomologist David W. Hagstrum hopes
that in a few years grain elevator opera-
tors will pass on information being gath-
ered now that could save the wheat
industry millions of dollars.
Stored-grain insects account for
multimillion-dollar losses annually in
this multibillion-dollar industry.
Each year, 2 billion bushels of wheat
are produced in the United States, with
most of it being stored at one time or
another in an elevator. Some is stored
before milling, but much of it is awaiting
export to other countries. In either case,
damage to stored grain by the lesser grain
borer, rice weevil, red flour beetle, and
rusty grain beetle costs the U.S. wheat
industry about $500 million annually.
"Pest management is important for all
types of grain elevators because insects
move along with grain as it makes its way
through the marketing system. Failure to
control pests at just a few elevators can
provide sources of insect infestation that
can lower the quality of much larger
quantities of grain as it's commingled in
the marketing system," says Hagstrum.
Hagstrum is based at ARS' Grain
Marketing and Production Research
Center (GMPRC) in Manhattan, Kansas.
Since July of 1998, he and other Kansas
and Oklahoma scientists have been mon-
itoring insect levels and current pest
management practices at 13 elevators in
Kansas and 15 in Oklahoma.
In the first year of this 5-year study,
the scientists gathered baseline data, tak-
ing more than 20,000 grain samples from
the 30 million bushels of wheat stored at
"This effort is unique. These aren't
laboratory studies; instead, they focus on
day-to-day management practices of
grain elevators-how these practices
affect the cost and effectiveness of insect
control and how, in turn, the economics
of moving and storing grain are affected,"
Integrated Pest Management
A collaborative effort between major
grain-handling companies, Kansas State
University, Oklahoma State University,
and ARS, this study is the largest of its
kind. Federal and state researchers are
working with elevator managers through
industry cooperators who own the net-
works of grain elevators. The purpose of
the project is to evaluate procedures that
PEGGY GREB (K8802-1)
insect populations, research technicians
sampled grain from elevators in Kansas
and Oklahoma and from trucks that
deliver it to terminals. The researchers
took three 1-gallon samples from every
1,000 bushels of wheat sampled-5 to
50 times larger than the commonly used
sampling rate. They found that most of
the wheat trucked to the elevators is
relatively free of insects.
"Insects are detected with probe traps
within a month after the grain enters the
elevators," says R.F. (Skip) Allen, who
PAUL FLINN (K8812-1)
The lesser grain borer develops and feeds
inside wheat kernels.
PEGGY GRFR IKRRO -I
Entomologists Paul Flinn (left) and David
Hagstrum discuss sampling methods to use
in the areawide integrated pest manage-
ment (IPM) program for stored grain.
might be useful in an integrated pest
management (IPM) system for wheat
Sampling is a key tool for determin-
ing the level of insect infestation in the
stored wheat. To estimate changes in
Insect-damaged kernels are caused by
internal-feeding grain insects. If more than
32 damaged kernels are found per 100
grams of wheat, the value of the grain is
manages the project in Hutchinson,
Kansas. In Watonga, Oklahoma, Allen's
counterpart is Stan Miller.
Hagstrum and his team identified
three main ways to improve integrated
pest management: (1) cooling the grain
Agricultural Research/April 2000
earlier in the season, particularly right
after it enters the bin; (2) cleaning empty
bins more thoroughly; and (3) fumigating
wheat only when insect infestations reach
unacceptable levels. All three practices
create an environment in which beneficial
insect parasites can thrive and attack the
stored-grain insect larvae.
"These aren't necessarily new ideas,"
says Hagstrum, "but now we have sub-
stantial data to show they are cost-
effective." Cooling newly harvested grain
right after it enters the bin, rather than
PEGGY GREB (K8809-1)
Biological technician Ken Friesen uses an
inclined sieve to separate insects from a
large wheat sample. The insects are
identified and counted to estimate
infestation in stored wheat.
waiting until fall when elevators typically
use fans to aerate (cool) the grain, can
reduce insect problems and the cost of
pest management. The cost of early cool-
ing is less than fumigation, currently esti-
mated at 1.57 cents per bushel for storage
in steel bins and 2.35 cents per bushel
for storage in concrete bins.
Most grain elevators have thin wire
cables to check the temperature of the
grain inside. These cables run through
the center of the bin from top to bottom.
Sensors are positioned every 6 feet along
the cable for measuring temperature.
"A conscientious elevator manager
records the temperatures, keeping watch
for any rise in temperature that might
indicate the presence of insects," says
Data loggers-small recording devic-
es attached to the aeration fans-are be-
ing used by the IPM researchers. "With
these, we can show the workers how long
the fans had been running-in some cas-
es many hours after the grain had already
cooled. Being able to automatically cut
back on fan operating time helps save
on energy costs," says Hagstrum.
These data will be welcome news for
the grain-storage industry. One-third of
the storage bins included in the project
have aeration fans to cool the grain, but
controlling devices are needed to shut
the fans off when the outside air tem-
perature is insufficient to cool the grain,
according to Hagstrum.
"There are five or six species of tiny
parasitoid wasps that range in size from
1/8 to 1/4 inch and are normally found
living in grain. They are the 'good guys'
because they don't feed on the grain but
attack the larvae of the rusty grain bee-
tle, lesser grain borer, and rice weevil,"
says Paul W. Flinn, an ARS entomolo-
gist at GMPRC.
The beneficial insects are another rea-
son for reducing the use of fumigation-
because it kills the good ones along with
the bad. These tiny wasps don't pose a
threat to grain quality because they're
completely removed during ordinary
Phosphine is the fumigant of choice
for controlling beetles that damage
stored grain. But the U.S. Environmental
Protection Agency is proposing new risk-
mitigating measures for phosphine.
"If fumigations were more effective
and done only when needed, the risk of
using phosphine could be substantially
less for grain workers," says Flinn.
In 1995, Flinn and other GMPRC sci-
entists designed a computer program,
Stored Grain Advisor, for farmers and
grain elevator operators to predict when
insect infestations will reach levels re-
quiring chemical pest control. The com-
puter program is available on the World
Wide Web at http://bru.usgmrl.ksu.edu/
flinn/sga. As part of the areawide IPM
project, the scientists are developing an
advanced version, Stored Grain Advisor
Pro, which will be available free to the
public on the GMPRC web site by the
end of the project.
The Kansas-Oklahoma areawide
project is one of several ARS programs
developed in response to USDA's 1994
Integrated Pest Management Initiative.
Recommendations based on this research
are expected to be made in 2002. That's
when word-of-mouth advertising should
reach its peak, hopes Hagstrum.
The benefits of areawide IPM are
within reach. Fewer workers will be ex-
posed to fumigants and fewer insects will
be able to develop resistance to fumi-
gants. Ultimately, these measures should
strengthen the competitiveness of U.S.
wheat in the export market.-By Linda
This research is part of New Uses,
Quality, and Marketability of Plant and
Animal Products, an ARS National Pro-
gram (#306) described on the World
Wide Web at http://www.nps.ars.usda.gov
David W Hagstrum and Paul W Flinn
are in the USDA-ARS Biological Re-
search Unit, Grain Marketing and Pro-
duction Research Center, 1515 College
Ave., Manhattan, KS 66502; phone (785)
776-2718 [Hagstrum], (785) 776-2707
[Flinn], fax (785) 776-2792, e-mail
hagstrum @ usgmrl.ksu.edu
Agricultural Research/April 2000
The moth is probably one of Russia's top three pests in economic damage
If the Siberian moth gets into the
northern United States and Canada,
the gypsy moth would pale by
comparison, says Victor C. Mastro,
director of USDA's Animal and
Plant Health Inspection Service (APHIS)
center at Otis Air National Guard Base
A major defoliator of spruce, larch,
and fir forests in its
native Siberia, "the
moth is probably one If the Si
of Russia's top three moth g
pests in economic
damage," he says. the norl
"We want to identify United
and block the routes
it could take to get and Car
into this country." gypsy n
USDA's Forest Serv- would p
ice and APHIS rank compare
the Siberian moth,
ans sibiricus, as a
moderate risk for becoming established
here-and a high risk for damaging
conifer forests, according to Iral
Ragenovich. She is a regional ento-
mologist with USDA's Forest Service in
Portland, Oregon. An infestation, she
adds, would also cause quarantines on
trade-within the country as well as from
Thanks to a pheromone monitoring
system, the Asian gypsy moth was de-
tected and eradicated before it became
established here, says Ragenovich.
The threat of the Siberian moth
prompted Ragenovich, Mastro, Agri-
cultural Research Service entomologist
Jerome A. Klun in Beltsville, Maryland,
and Russian entomologist Yuri N.
Baranchikov in Krasnoyarsk, Russia, to
collaborate on a project to keep the moth
from emigrating. Part of the funding
came from USDA's Foreign Agricultural
Service, the fourth USDA agency
involved in this collaboration.
The first line of defense against the
moth's invasion is to track the insect's
whereabouts and population sizes in its
native habitat and at possible ports of
entry and habitats in the United States.
That means using some kind of trapping
system for monitoring the pest. And
trapping requires a lure.
That's where Klun's expertise in
synthesizing insect pheromones came in.
Klun is with the Insect Chemical Ecol-
ogy Laboratory in
erian He analyzed
ino the real phero-
mone from the
ern female Siberian
rates moth but didn't
have enough ma-
da, the trial to positively
th identify it. So,
based on known
e by pheromones from
on. related species,
he assembled sev-
to find a company to synthesize the best
"With luck," says Mastro, "we'll
begin small-scale deployment of traps
next year in forests near likely sources
of introduction."-By Judy McBride,
This research is part of Crop Pro-
tection and Quarantine, an ARS Na-
tional Program (#304) described on the
World Wide Web at http://www.nps.ars.
usda. gov/programs/cppvs. htm.
Jerome A. Klun is at the USDA-ARS
Insect Chemical Ecology Laboratory,
Bldg. 007, 10300 Baltimore Ave., Belts-
ville, MD 20705-2350; phone (301)
504-9388, fax (301) 504-6580, e-mail
en different mix-
tures in time to
test them during the moth's late July
1998 mating season in Siberia.
One of those mixtures-four alcohols
and four aldehydes-was as potent as the
females themselves in enticing males
into traps laid by Baranchikov. He used
APHIS traps originally designed for the
gypsy moth. But the trap's entry was
enlarged to accommodate the bigger
Siberian moth with its nearly 3-inch
wingspan, compared to the gypsy moth's
span of about 1 inch.
Last summer, Baranchikov and
Ragenovich tested pure compounds pro-
vided by Klun and found the mixture was
still the best attractant. The next step is
Agricultural Research/April 2000
Cows grazed on pastures have five times more of a fatty acid called conjugated linoleic acid (CLA) in their milk. The incidence of cancer in
laboratory rats declines after they've consumed CLA.
allow cows to graze on pasture. That reason
involves a compound called conjugated linoleic
CLA is a fatty acid found in beef and dairy fats.
Scientific interest in CLA was stimulated about 12 years ago
when a University of Wiscon-
sin researcher discovered its
cancer-fighting properties in a
study of rats fed fried ham-
burger. CLA cannot be pro-
duced by the human body, but
it can be obtained through
foods such as whole milk, but-
ter, beef, and lamb.
"The interesting thing is that dairy cattle that graze produce
higher amounts of CLA in their milk than those which receive
conserved feed, such as grain, hay, and silage," says ARS dairy
scientist Larry Satter. This is true even when the nongrazers
eat pasture grass conserved as hay.
Satter, who is based at the Dairy Forage Research Center in
Madison, Wisconsin, conducted a study comparing the amount
of CLA in milk from cows grazing on pasture to the amount
from cows fed hay or silage. His findings: Pasture-grazed cows
had five times more CLA in their milk than those fed silage.
Do dairy producers need to graze cows to get them to pro-
duce more CLA? "Not necessarily," says Satter. Instead, he
devised a way to nudge the production of CLA by dairy cows
fed typical confinement diets. He added extracted whole soy-
bean and linseed oils to the corn-alfalfa diet. The added oils
boosted CLA content in the cows' milk to equal the levels ob-
tained from grazing.
ARS and the Wisconsin Alumni Research Foundation
(WARF) subsequently patented the method to increase CLA in
cows' milk. The patent, issued
in the spring of 1999, was based
on a study conducted by Satter
and his University of Wisconsin
"Animal fats have been criti-
cized for years, but now the po-
tential benefits of CLA in milk
and meat from ruminant animals
is being seriously studied. Milk fat is one of the richest natural
sources of CLA. If human trials show the same benefits as
studies with laboratory animals, the benefit of consuming milk
products could improve the economics of dairy producers every-
where," says Satter.-By Linda McGraw, ARS.
This research is part ofAnimal Production Systems, an ARS
National Program (#102) described on the World Wide Web at
http://www. nps. ars. usda. gov/programs/appvs. htm.
Larry Satter is at the USDA-ARS U.S. Dairy Forage Re-
search Center 1950 Linden Lane, University of Wisconsin,
Madison, WI 53706; phone (608) 264-5353, fax (608) 264-
5147, e-mail Isatter@dfrc.wisc.edu. *
Agricultural Research/April 2000
New Trefoils Give Breeders More Options Lab Diets for Two Pest Insects
Two new lines of narrowleaf and big trefoil plants from the
Agricultural Research Service should help breeders develop
improved forages for livestock and wildlife.
Trefoil species provide excellent nutrition. Unlike alfalfa,
these forages don't cause bloating. They also tolerate marginal
production conditions such as dry, saline, or flooded soils. Be-
cause trefoils are legumes, they fix nitrogen into the soil for
later use by grasses and forbs. This can reduce the need for
The ultimate goal ofARS agronomist Jeffrey J. Steiner and
geneticist Paul R. Beuselinck is to increase forage quality on
pastureland. That way, farmers won't have to purchase as much
feed to supplement the diets of their livestock that graze on
The popularity of birdsfoot trefoil, a related species, has
grown steadily over the past few decades. But growers have
only been able to obtain a few commercial varieties of big
trefoil, and those were not bred for U.S. farm conditions. No
commercial varieties of narrowleaf trefoil are available.
Both of the new releases-ARS-1207 narrowleaf trefoil and
ARS-1221 big trefoil-combine the characteristics of dozens
of different genetic populations that were collected from around
the world. These populations, known as accessions, are stored
in the ARS-managed National Plant Germplasm System.
"This seed is intended for breeders, not farmers," says
Steiner. "The germplasm enables breeders to evaluate all
available characteristics for each species without individually
testing each accession." That way, he says, breeders can use
the releases to develop varieties adapted to local conditions.
The narrowleaf line descends from 41 different accessions
originally collected in about a dozen countries. The big trefoil
germplasm incorporates more than 80 accessions from at least
Big trefoil grows in warmer, wetter areas than birdsfoot tre-
foil. Narrowleaf trefoil prefers drier, warmer areas that may be
Researchers and breeders can obtain small amounts of seed
from Steiner.-By Kathryn Barry Stelljes, ARS.
Jeffrey J. Steiner is in the USDA-ARS Forage Seed and Ce-
real Research Unit, 3450 S.W. Campus Way, Corvallis, OR
97331-7102; phone (541) 750-8734, fax (541) 750-8750, e-
mail steinerj @ ucs.orst.edu.
Paul R. Beuselinck is in the USDA-ARS Plant Genetics Re-
search Unit, University of Missouri, Waters Hall, Room 207,
Columbia, MO 65211; phone (573) 882-6406, fax (573) 882-
1467, e-mail email@example.com. *
The Y2K bugs at ARS' Insect Biocontrol Laboratory in
Beltsville, Maryland, aren't of the computer kind. Rather,
they're two crop-attacking insects: the Colorado potato bee-
tle and the silverleaf whitefly.
Both are the focus of separate, though related, projects of
entomologists Dale B. Gelman, Robert A. Bell (now retired),
Jing S. Hu, and Michael B. Blackburn. As part of their re-
search, these scientists are creating artificial diets to sustain
lab colonies of the insect pests so new weaponry can be more
easily tested against them.
Furthest along is work against the beetle, whose larvae cost
tomato, potato, and eggplant growers over $150 million an-
nually in losses and insecticide expenses.
The pesticide Admire is a standard defense, but experts
fear the beetle may soon develop resistance to it. That's why
the Beltsville team is looking for ways to streamline research
aimed at finding insecticide replacements-or biological al-
ternatives like parasitic Edovum puttleri wasps.
Until now, rearing lab colonies of beetles meant feeding
them on a living host, such as potato plants. But growing the
plants is expensive and time-consuming.
So Gelman's lab developed a relatively simple artificial
diet using oats, lettuce, potato leaf powder, and other ingredi-
ents. Dried into powder, lettuce replaces most of the potato
leaf material normally required. In addition to cutting costs,
"lettuce is easier to obtain because you can buy it at the gro-
cery store," Gelman says.
More importantly, it stimulates most beetles to eat the diet.
Gelman's lab has reared nine beetle generations on it so far.
After analyzing each generation's average weight, growth, egg
production, and other data, the scientists plan to publish their
Indications are "the diet will prove useful for growing bee-
tles in the lab for research purposes," says Gelman. "And you
can rear them on it year-round in a cost-effective manner."
Gelman, Hu, and Blackburn are also artificially rearing sil-
verleaf whiteflies to better understand the growth requirements
of wasps like Encarsiaformosa that parasitize the pests.
They hope that by learning to rear the whiteflies, an artifi-
cial wasp diet can be created. However, "this project is still in
its infancy," Gelman says. "Right now, we're just dissecting
the parasites out of the whiteflies and seeing how they devel-
op."-By Jan Suszkiw, ARS.
Dale B. Gelman, Michael B. Blackburn, and Jing S. Hu
are at USDA-ARS Insect Biocontrol Laboratory, Bldg. 003,
10300 Baltimore Ave., Beltsville, MD 20705-2350; phone
(301) 504-8909, fax (301) 504-8190, e-mail firstname.lastname@example.org
Agricultural Research/April 2000
The perfect mango melts in your
mouth. But many aren't perfect because
this tropical fruit is susceptible to injury
during cold storage. At temperatures be-
low 50 F, mango's skin becomes pitted
and discolored and its flesh darkens and
becomes susceptible to decay.
ARS and Mexican scientists recently
discovered that methyl jasmonate pre-
vents such chilling injury. This sweet-
smelling compound derived from the
essential oils of plants-especially
jasmine and honeysuckle-is safe and
relatively inexpensive. Fifty dollars'
worth could treat truckloads of fruit.
Studies showed how to use methyl
jasmonate to prevent chilling injury and
dramatically improve overall fruit
quality. The treatment worked on
mangoes at various stages of maturity and
didn't alter normal ripening and softening
processes or increase water loss.
The researchers also learned to
preserve fresh-cut mangoes by treating
slices with a combination of hexyl-
resorcinol, isoascorbic acid, and potas-
sium sorbate-all food-safe compounds
derived from natural products-and
storing the slices in plastic containers to
Mangoes could be an attractive
addition to the growing market for fresh-
cut produce, but browning and drying
have prevented such marketing. In 1998,
the U.S. population consumed 412
million pounds of mangoes-an increase
of 77 percent from 1993. Chien Y Wang,
USDA-ARS Horticultural Crops Quality
Laboratory, Beltsville, Maryland; phone
(301) 504-6128, e-mail email@example.com
Clearing the Air With Biodiesel
Buses and other diesel-burning vehi-
cles will run cleaner if they mix soy-
based biodiesel with their regular diesel
fuel. To test the feasibility of switching
to this fuel blend, ARS began a year-long
demonstration at the Beltsville (Mary-
land) Agricultural Research Center in
January. BARC has 65 vehicles operating
on "B20," a 20-percent biodiesel/80-
percent diesel mix.
This test is part of a federal effort to
reduce reliance on petroleum and create
new markets for U.S. crops. There is
interest in permanently switching as
many federal government vehicles as
possible nationwide to alternative diesel
fuels, using biodiesel from soybean and
other seed oils or animal fat.
Many farm machines at ARS' Beltsville
Agricultural Research Center are running
on a mixture of diesel fuel and biodiesel,
which is made from soybean oil.
One goal is to increase the federal
purchases of biobased fuel and other
products by 10 percent each year for the
next 5 years.
The demonstration may help en-
courage local governments and the
private sector to do the same-especially
in areas where air quality is an issue.
Crop-based diesel burns cleaner and
produces less soot, and vehicles don't
need modification before being switched
to the fuel.
Recent changes in the Energy Policy
Act of 1992 allow for credits for biodiesel
usage in existing vehicles, reducing the
number of alternative fuel vehicles that
must be purchased.
Future changes could also affect large
municipal vehicle fleets, such as buses
and public works vehicles. Ronald F
Korcak, Associate Director of Beltsville
Area, USDA-ARS, Beltsville, Maryland;
phone (301) 504-5193, e-mail korcakr@
Processing Alfalfa and Soybeans-
on the Spot
New products and increased markets
for alfalfa and soybeans may be on the
horizon for Midwest farmers, thanks to
innovative research by ARS and Uni-
versity of Wisconsin scientists in
Madison. Following a concept long used
by the petroleum industry-the sepa-
rating, or fractionating, of crude oil into
a variety of products of increasing val-
ue-researchers have tested the fieldside
processing of harvested crops.
Until now, wet fractionation of alfalfa
and soybeans has been performed at a
central processing facility. But that
necessitates transporting the herbage,
containing about 80 percent water, from
the field to the facility and then dehy-
drating the plant material and trans-
porting the waste liquid back to the field
as liquid fertilizer.
Last summer, under a cooperative
research and development agreement
with industry, a group of machines was
used in the first fieldside demonstration
of wet fractionation of soybean herbage.
Commercially available machines, plus
a modified hammermill-normally used
to pulverize grain by forcing it through
screens-were used to rupture the
herbage without reducing fiber size.
Demonstrating the feasibility of the
concept was the first step toward further
development of a mobile field processor.
Working like a combine, it would cut and
wet-fractionate the crop while juice was
being processed at the edge of the field.
Products such as cattle feed, chemical
feedstocks, mats for filtering pollutants
from water, enzymes derived by growing
fungi on the fiber, and building materials
can be made from the fiber portion.
Products from the juice fraction might
include food- and feed-grade protein
concentrates, carotenoids, antioxidants,
and industrially valuable enzymes.
Richard G. Koegel, USDA-ARS Dairy
Forage Research Center, Madison,
Wisconsin; phone (608) 264-5149, e-
mail rgkoegel@facstaff wisc.edu.
Agricultural Research/April 2000
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ookng for Some Geome information by ARS Researchers?
S Cattle Geomeap http:ww.marcusda.gov/genmecattecattehtml
Cate Genome Map http:// mp.msu.edu/resurces/conmapconmap.htn
-hicken Genome MaP http://o .pww.agron.missouri.edu/top.html
Maize Genome Dataashtno ne/
Swine Genome Map = "'ui,," ...