UC, USDA provide California farmers a full pest control toolbox

Even though California agriculture leads the world in economic value, pesticide manufacturers consider most of the crops grown in the state—including nuts, grapes, strawberries, tree fruit and all citrus—“minor crops.”

”Minor” status deprives many California growers of the ability to use certain chemicals to grow and store produce, but University of California and USDA researchers are letting the state’s agricultural industry know that federal dollars are available to provide them the tools they need to control unwanted insects, diseases and weeds.

For example, the federal money will help California orange growers deal with an exotic pest that recently entered the state from Mexico. Citrus leafminers crossed the border in 2000. They were found in Ventura last season and are working their way up to the San Joaquin Valley.

”Citrus leafminer damage makes the tree’s foliage look terrible,” said Beth Grafton-Cardwell, UC Riverside citrus entomology specialist. “Growers will be crushed.”

Mature citrus trees can usually take the damage without an affect on fruit number or quality, so the mature trees do not need treatment, Grafton-Cardwell said. Insecticide treatment is definitely needed to protect the foliage and maintain normal growth of citrus trees in nurseries and new field plantings. The pesticide imidacloprid (Admire) is used as a systemic in other parts of the world against citrus leafminer, and Grafton-Cardwell said it works fairly well. However, nurseries also need an insecticide they can apply to the foliage. The federal testing program should soon give citrus growers in California a green light for a foliar treatment with methoxyfenozide (Intrepid) to control the impending leafminer threat.

A drive down rural American highways illustrates the need for this federal funding of potential minor crop pesticide treatments. California travelers see a mosaic of orchards, vineyards, vegetable plots, cotton fields and many other ag operations. In the Mid-West, a single crop—wheat, corn or soybeans—might carpet the landscape to the horizon in all directions. For pesticide producers, huge acreage of a single crop means fewer expensive trials to test the safety of particular pesticide treatments. Often, it doesn’t make economic sense for a chemical company to conduct the rigorous research necessary to register a pesticide for much smaller acreage or uses. California growers end up with limited insecticides, herbicides and fungicides legally registered to control their pest problems.

The USDA set out to address the issue when it created the IR-4 project in 1963. The cryptic name belies a straightforward, solution-oriented program that fills an important need for California growers. IR-4 stands for Inter-Regional Program No. 4. IR-4 has recently begun referring to “minor” crops as “specialty” crops. A few examples of these specialty crops include tomatoes, peppers, squash, carrots, broccoli, apples and plums.

Even though many more requests for IR-4 research are received than there is money to conduct them, the program’s representatives want to spread word of its availability so farmers of all commodities know they can make a request that will be among those considered for funding.

The University of California is a research and administrative partner with IR-4. The project’s Western Regional office is at UC Davis, and pesticide trials for the program are conducted at UC sites around California. In fact, the number of IR-4 studies under way at the UC Kearney Research and Extension Center near Parlier—a total of 45 -- is the highest in the nation. Statewide, about 120 IR-4 research projects are being conducted this summer by UC.

IR-4 research is carefully monitored by the IR-4 Project staff and EPA regulators to represent real-life agricultural practices and precision in collecting research data. Researchers rely on UC farm advisors and farmers to ensure common farming practices are used on the test crops.

”I want to see a plot that looks commercial, not a garden bed,” said Stephen Flanagan, IR-4 Western regional assistant field coordinator. “The crop must be a commercial variety, from a commercial source, grown how the farmer grows the crop. This is not creative research, this is regulatory work.”

Researchers apply the pesticide using sprayers that distribute the material to mimic the application farmers would use. Once the crop is ready for harvest, samples are collected into bags and frozen within the hour. The frozen samples are shipped in a freezer truck to a laboratory in Davis where pesticide residues are analyzed.

The research procedures, chain of custody and laboratory work are documented in excruciating detail. If the residues are found to meet federal safety guidelines, the information is passed on to the pesticide’s manufacturer so its availability can be added to the pesticide label, making it legal for farmers to use the material in crop production.

Michael Parrella, UC Davis associate dean and UC administrative advisor to IR-4, believes the IR-4 project is a natural fit with UC’s agricultural and natural resources research mission.

”Delivering something useful to farmers is the key,” Parrella said. “While farmers are coping with insecticide resistance, invasive species and integrated pest management, rules and regulations are increasingly governing the use of pesticides. The IR-4 project counters that by providing pest management tools for growers.”

Requests for IR-4 research are made by filling out a brief online form, found at http://ir4.rutgers.edu . Farmers are cautioned to plan ahead. From the time the request is made to the time when that usage appears on the material’s label for legal usage, typically takes 3 to 7 years.

For more information on the IR-4 Project, contact Rebecca Sisco, Regional Field Coordinator, (530) 752-7634, [email protected]

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