Puffer technology breathes life into codling moth control in walnuts
Hal Crain has opened up the gate of his 200-acre walnut orchard to scientists to test the efficacy of a mating disruption practice as a way to reduce the number of insecticide sprays he uses to control codling moth. Crain is concerned that codling moth sprays lead to more expensive miticide sprays. With the increased cost of diesel to run a sprayer, less spraying will save him money.
Crain Orchards in the Sacramento Valley represent 8,000 acres of walnuts. If the use of "puffers," or pressurized aerosol cans that dispense pheromones, can reduce insecticide sprays, using the technique on all the acreage could make a big impact. Sex attractants called pheromones are chemicals that female moths give off to attract males for mating. The attractants confuse males so that they can not find the real females, thereby reducing the codling moth population.
UC IPM Advisor Carolyn Pickel said, "Regulation of the primary pesticides used to contain codling moth will increase in California because they are harmful to air and water quality. Puffers could potentially reduce the use of insecticides to control codling moth by 75 percent, depending on codling moth pressure.
"Puffers are the first effective and economic mating disruption program we've found that is commercially viable in walnuts since the trees are so big," said Pickel. "We're using the Cooperative Extension IPM Demonstration Grants Program to expand the project to Tehama County."
Through UC Berkeley entomologist Steve Welter’s research, funded by the UC IPM Program, and long-term demonstration in Butte and San Joaquin counties, mating disruption has been shown to successfully control codling moth in walnuts.
Other studies are being conducted to test mating disruption with puffers in San Joaquin, Glenn, Butte and Fresno counties. Chlorpyrifos, a harmful chemical, has been found in the surface water near the San Joaquin testing site. Farm Advisor Joe Grant, UCCE, San Joaquin County, is working with nearby growers to expand the area-wide demonstration to help decrease the likelihood of finding chlorpyrifos by watershed monitoring.
Researchers will monitor the treated areas with traps using at least two different types of lures and examine dropped nuts, as well as nuts in the canopy for codling moth damage.
"There are about 5,000 acres of walnuts where owners are using CM Puffers this season," said Steve Wulfert, technical sales manager for Suterra LLC, which makes the product. "They're deployed in all major walnut growing regions in California, from Tehama County in the north to Tulare County in the south."
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