At the Yakima Agricultural Research Laboratory in Wapato, Washington,
technician Tom Treat applies a test pesticide to a rapeseed variety being grown
for canola oil production.
IR-4 Projects Protect "Minor" Crops
Agricultural chemical producers readily test and seek U.S. Environmental
Protection Agency (EPA) approval for new pesticides for blockbuster crops like
corn and wheat.
That's because there's a potential to market a product that can be used on
from 70 to 80 million acres. The chemicals industry recoups its investment and
makes a profit.
Other, smaller crops like mint and cucumbers are generally not worth the
industry's attention. But these minor cropsdefined as those grown on
300,000 acres or lessare helped by a federal-state project known as
Interregional Research Project No. 4, or IR-4. Its charge is to conduct field
trials and collect data needed for EPA approval of so-called minor-use
"But "minor" can be misleading," says Richard T. Guest,
national director of the IR-4 program. He's stationed at the New Jersey
Agricultural Experiment Station at Rutgers University in New Brunswick.
"According to the most recent census of agriculture, 11 million acres
of minor crops are grown annually in the United States," says Guest.
"They have a combined value of $32 billion and represent 42 percent of all
crop sales. In 27 states, these minor crops exceed the value of all the other
major crops including corn, cotton, soybeans, and wheat."
"Minor use" can also mean the infrequent use of a chemical product
on high-acreage crops like corn and wheat. Last year, the IR-4 project was
responsible for 104 minor-use pesticide clearances; in 1994, there were 141.
Since its inception in 1963, IR-4 has assisted with more than 4,400
clearances on some 208 crops, from acerola (Barbados cherry) and alfalfa to yam
and youngberry. While some of these crops have odd-sounding names like canistel
(a tree fruit grown in Florida) and kenaf (a plant that is being used for
newsprint), most can be found in the fresh produce section of any supermarket.
The IR-4 Ornamentals Research Program, which was added in 1977, has resulted
in more than 3,600 additional pesticide clearances for 263 commercially grown
floral and nursery cropsfrom abelia and acacia to zebra plant and zinnia.
Field research director Sharon Benzen collects romaine lettuce from an IR-4
test plot in Salinas, California. The samples will be frozen and shipped to a
laboratory for pesticide residue analyses.
The program took on even more importance when its role was expanded in 1982
to include registration of biopesticides. This is a commitment to develop
alternatives to chemical pest controls. IR-4 interacts with the U.S. Department
of Agriculture (USDA), the U.S. Food and Drug Administration (FDA), and EPA to
determine what data will need to be collected.
As a result of this cooperation, 68 biopesticides have been approved. One of
these is granulosis virus to control codling moths that attack apples, pears,
walnuts, and plums. Another is cinnamaldehyde for the control of
Verticillium spot and dry bubble disease of mushrooms.
"The program is important to protect growers and consumers. It enables
farmers and ranchers to use pesticides judiciously against weeds, diseases, and
insects. Otherwise, some might be tempted to spray anything that works and at
incorrect rates. Because of IR-4, consumers get foods that are wholesome, safe,
and relatively inexpensive," says Paul H. Schwartz, Jr.
Schwartz coordinates the IR-4 program for USDA's Agricultural Research
Service at Beltsville, Maryland. USDA's Cooperative State Research, Education,
and Extension Service is the lead agency. Regional laboratories servicing
satellite locations are Davis, California; East Lansing, Michigan; Geneva, New
York; and Gainesville, Florida.
"As a matter of fact," says Schwartz, "we believe the program
may actually reduce overall pesticide use. Once we have all the data, we learn
the proper doses farmers should be using. If that information weren't on the
product label, they might apply more than they actually need. That would raise
their costs and put more chemicals into the environment."
Plenty of Grower Input
"One of the reasons IR-4 is so successful is that it's a real grass
roots program," says Guest. "We have workshops open to growers,
grower groups, researchers, and any interested parties. They tell us what pest
problems they have, and that's what we work on."
And, he adds, having a close working relationship with EPA streamlines
communication and produces results more quickly.
At Wapato, technicians Kathryn Morford (left foreground) and Ronah Grigg
analyze extracts of crops grown on IR-4 test plots to determine pesticide
residue levels. Eric Fendell (left background) and Kim Foster verify findings
with a mass spectrometer.
Each trial looks at how effective the chemical is, how it might affect the
crops, how much to apply, and how much, if any, of the chemical remains on
harvested crops. There are 10 ARS test sites across the country representing
These are at Wapato and Prosser, Washington; Corvallis, Oregon; Salinas,
California; Urbana, Illinois; Wooster, Ohio; Weslaco, Texas; Beltsville,
Maryland; Charleston, South Carolina; and Tifton, Georgia.
Scientists at three ARS analytical chemical residue labat Wapato,
Tifton, and Beltsvilledetermine the amount of residue remaining on
commodities after treatment, so a tolerance level can be established. The
minute amount of chemical residue allowed to remain on commodities falls within
a safety margin set at least 100-fold below a no-effect level.
Data from laboratory research and replicated field trials is incorporated by
IR-4 headquarters into petitions and submitted to EPA. The petitions are a
request that a tolerance or exemption be established for a specific product on
a specific crop. The process generally takes from 3 to 5 years, depending on
the difficulty of the study and EPA review time.
During the fiscal year that ended September 1996, $8.3 million in federal
funds supported the IR-4 program. State agricultural experiment stations
contribute additional funding. Private industry also contributes.
Testimonials From IR-4 Fans
"Survival," says Ann George, "is what the IR-4 program means
to the hops industry. We're still in business." And that's important, for
today's U.S. hops industry is a healthy one with an annual crop valued at $137
millionabout 28 percent of the world's production.
But back in the late 1980's, things looked pretty bleak when hops growers
lost registration on the primary miticide, herbicide, and insecticide they
needed to stay competitive in a worldwide market.
After using emergency exemptions from EPA on a year-by-year basis, we
have now obtained full registrations for a key insecticide and a
miticide, says George. She is administrator of the Washington Hop
Commission, as well as administrator of the U.S. Hop Industry Plant Protection
Committee in Yakima, Washington.
George says the pesticide industry was unwilling to gather data and petition
EPA for labels that would permit use of the products on 42,000 acres of U.S.
hopa drop in the bucket compared to the market potential of nearly 80
million acres of corn.
The IR-4 program also checks out chemicals applied to ornamentals like these
dahlias being examined by technician Tom Treat for evidence of damage.
Charles Matthews has a similar story. He's a representative with the Florida
Fruit and Vegetable Association in Orlando.
"The IR-4 Program assisted in providing data for certain uses of an
improved insecticideimidacloprid," says Matthews.
"Growers are now allowed to use a single application of this chemical
to control silverleaf whitefly on their tomatoes and melon thrips on peppers.
Some other previously registered insecticides required up to 20 sprays to knock
down insect populations.
"And," he adds, "imidacloprid is not harmful to beneficial
insects and is compatible with integrated pest management programs."
But when EPA required that its use entail a crop rotation, many growers were
reluctant to switch from growing high-value crops to less-income-producing
ones. Back came IR-4 with data supporting the safety of planting high-value
crops like cucumbers, squash, and melons after the tomatoes and peppers were
"This is an excellent example of what growers, IR-4, university
scientists, private industry, and EPA can accomplish when we work toward a
common goal," says Matthews.
In dry onions, pendimethalin was approved for weed control. It is more
effective and controls a broader spectrum of weeds than the major alternative
herbicide, and growers need apply only about one-tenth as much. While it costs
more per unit, the net result is that farmers pay only one-fifth of what they
used to pay for the alternative.
Gene Batali, who grows 250 acres of spearmint near Wapato, says, "We
need to control weeds in our mint fields. If any are harvested with the crop,
we end up extracting their oils along with that from the mint.
Now we have control over our weeds because IR-4 was the vehicle we
used to get the required herbicide registration.By Dennis Senft,
H. Schwartz, Jr., is on the USDA-ARS Pesticide Research Staff, Bldg. 10300
Baltimore Ave., Beltsville, MD 20705-2350; (301) 504-8256, fax (301) 504-5048.
NAPIAP Assesses Pesticide Impacts
A Brief IR-4 Timeline
1963Interregional Research Project No. 4 organized by directors of
state agricultural experiment stations in cooperation with U.S. Department of
1976ARS program formally established to assist IR-4 with
backlog of clearance requests.
1977IR-4 expanded to include commercially grown ornamentals,
such as floral and foliage plants, woody nursery stock, Christmas trees, and
1982Scope expanded to include research supporting registration
of biopesticides, such as microbials and biochemicals. More recently,
genetically engineered material was added to the mission.
1989IR-4 strategic plan developed to gather data for
reregistering by 1997 nearly 1,000 minor use labels mandated by amendments to
Federal Insecticide, Fungicide, and Rodenticide Act.
1995Goals identified for the next 7 years, providing for a
shift in program emphasis to increase the number of registrations for both
biological pest control agents and less potent products needed in integrated
pest management programs.
The primary mission of USDAs National Agricultural Pesticide Impact
Assessment Program is to promote informed regulatory decisions on registered
pesticides. NAPIAP was established to move information from USDA to EPAs
process of weighing risks against benefits, as described in our federal
The mission is accomplished by managing and coordinating USDA and state
efforts to develop and analyze information on pesticide use and pest control
practices. That includes assessing what happens if a pesticide is no longer
available for use on a particular crop to control insects, diseases, or weeds.
NAPIAP estimates the costs to farmers and consumers of losing pesticide uses,
while taking into account any issues related to human and animal health or the
NAPIAP and IR-4 have a common interest in the availability of adequate pest
control tools. Although the two programs are separate, their common interest
has led to cooperation. While IR-4 is charged with seeking registrationor
reregistrationfor new uses of existing chemicals on minor crops, NAPIAP
gathers and analyzes information on pesticides already approved for both minor
and major crops.
Our documents are designed to provide unbiased information in a timely
manner when questions about pest management and crop production arise,
particularly in relation to EPAs regulatory activities and
decisions, says Nancy N. Ragsdale, NAPIAP director. We need to be
prepared to react when regulatory actions are being considered, rather than
after they have become law. She says the most recent report the office
prepared was on rice; it was one in a series of assessments of pesticide use on
If we were asked specific questions on the value of a specific
herbicide to control weeds in rice fields, wed be able to pull the
information together quickly. This helps assist EPA early in the regulatory
process, says Ragsdale, whose position is funded by ARS. Other
participating agencies include USDAs Cooperative State Research,
Education, and Extension Service; Economic Research Service; and Forest
was chartered by acting Secretary of Agriculture Knebel 20 years ago, in
October 1976. It reports to the Office of the Under Secretary for Research,
Education, and Economics.
"IR-4 Projects Protect "Minor" Crops" was
published in the October
1996 issue of Agricultural Research magazine.