Areawide IPM Project a Success for Northwest Orchards

WAPATO, Wash., Oct. 4--Nearly one-third of Washington State's apple and pear orchards now rely on nonchemical pest management tools, thanks to a 5-year USDA-sponsored research program targeting codling moths and other pests, Agricultural Research Service administrator Floyd P. Horn announced today.

"Young codling moths are the infamous 'worms in the apple,'" said Horn. "But growers and scientists together have shown that integrated pest management can rein them in and use about two-thirds less insecticide. Now, as was intended at the program's start, scientists are ready to turn the mechanics of the program over to growers."

"Some apple and pear growers using the IPM approach have not sprayed for moths or for any other orchard pest in two years," he noted.

The Codling Moth Areawide Suppression Program was set up by USDA's Agricultural Research Service in 1994. It relies on ARS- and university-developed technology for confusing the moths with sex attractants, or pheromones, so they cannot find a mate. This tactic is supplemented with intensive monitoring and limited pesticide spraying.

"Without control, codling moths could destroy 80 percent of the northwest apple crop and half the pear crop," said Horn. More than half the nation's commercial apples come from Washington.

Normally, growers sprayed up to six times per year for codling moth, and four to six more times for leafrollers, aphids and other secondary pests. This meant using about 2 million pounds of insecticides annually at a cost of $60 to $150 per acre. Overall, pesticide use has been reduced by at least 70 percent.

"We started the 5-year program with 5 sites and 68 participants encompassing 3,000 acres," said Carrol Calkins, research leader at the ARS Yakima Agricultural Research Laboratory in Wapato, Wash. "Since then, 17 more sites were established for one year to get other growers started. Mating disruption is now used on at least 60,000 acres in Washington and another 8,000 acres of orchards in California, Colorado and Oregon."

Calkins coordinates the cooperative project, which includes researchers at Washington State University in Pullman, Oregon State University in Corvallis and the University of California in Berkeley.

More growers are expected to join in, now that key pesticides like methyl parathion (Penncap-M) and azinphos-methyl (Guthion) are being eliminated or greatly restricted next year by the Food Quality Protection Act.

"Initially," Calkins said, "the IPM mating disruption strategy cost more than using pesticides. But now, with widespread participation and new dispensers, IPM costs less. It works better, too."

Studies by Calkins and ARS colleagues at Wapato showed that using commercial insecticides can still leave one or two percent of the apples damaged by insects. With IPM, that drops to less than one percent, in some cases as low as one apple in 10,000, he said.

"This program proves that IPM can give growers a viable option to strictly chemical pest control--if they get together and make it happen over a large area," said Horn.

Other ARS-funded IPM programs are underway to control corn rootworms, the rangeland weed leafy spurge and insects in grain storage bins.

Scientific contact: Carrol O. Calkins, ARS Yakima Agricultural Research Laboratory, 5230 Konnowac Pass Road, Wapato, WA 98951; phone (509) 454-6550, fax (509) 454-5646, calkins@yarl.gov.