Field Crops IPM

Alfalfa Seed "Alternatives to Burning" Research
An interdisciplinary team of WSU and USDA-ARS research scientists representing entomology, plant pathology, and weed science sought and received funding from the Washington State Department of Ecology in May of 2005 to conduct research on the economy and pest management implications of various potential alternatives to burning alfalfa seed stubble. The results of these studies are presented in the following reports:

Carrot Research at WSU Prosser
Seed treatments against seed corn maggot were conducted in 2002. As a result of this work, low-toxicity imidacloprid was subsequently registered as a seed treatment, resulting in a decrease of diazinon use by some 4,000 lb annually on the part of Washington State carrot growers. Click on link below.

• 2002 Presentation: Seed Corn Maggot Control (pdf)

Onion Research at WSU Prosser
In onion, the Western flower thrips was found to be more abundant than onion thrips. Thrips were more abundant within onion fields compared with weedy field borders. Insecticide efficacy trials in 2002 showed that no insecticide tested was successful in suppressing thrips for more than two weeks. Click on link below.

• 2002 Presentation: Thrips and Storage Losses (pdf)

Mint Research at WSU Prosser
Good control was documented for many of the insecticides tested against spotted cutworm in mint. Similarly, many acaricides successfully suppressed two-spotted spider mite in mint efficacy trials, but also suppressed predatory mites. The miticide abamectin, and the insecticides acephate and chlorpyriphos, proved significantly lethal to both species of predators in leaf-disk bioassays. Repellency and repulsiveness behaviors in two-spotted spider mite were examined for pesticides utilized in mint.

Two generations of spotted cutworm were observed in mint. It is the second generation that overwinters and causes damage in mint the following spring.

A mint grower survey was conducted across Washington in 2003. Growers were polled on pest management practices and results were compared to a 1995 Washington mint survey. The results, indicating changes in pests, pesticide usage, and pest management practices, were published in two (short version and long version) WSU Extension Bulletins which are linked below.

• 2003 Report: Economic and Biorational Screening of Candidate Insecticides and Acaricides on Mint (pdf)
• 2003 Presentation, Pacific Branch ESA: Cutworm Control on Washington Mint (pdf)
• Mint Grower Survey Results (Short Version) (pdf)
• Mint Grower Survey Results (Long Version) (pdf)