New Additions Funding Opportunities Projects Affiliated Centers Integrated Pest Management Research Publications

Reduced-risk and organically acceptable seedcorn maggot control on inland Pacific Northwest vegetable crops

Grant Recipient:

Washington State University Irrigated Agriculture Research and Extension Center
24106 N. Bunn Rd. Prosser, WA 99350

Dr. Douglas Walsh, IPM Coordinator
Fax: 509-786-9287

Project Period:

February 21, 2009 April 30, 2010

Principal Investigator:

Dr. Douglas Walsh


WSU Walsh Proposal.doc (67.5 KB)
R10 2009-04 IPR1.pdf (145.22 KB)

Seedcorn maggot infestations can reduce germination and stand establishment of inland Pacific Northwest carrots, onions, beans, peas, corn, and other crops. These crops have traditionally been treated post-seeding and pre-emergence with organophosphates, carbamates, or pyrethroids, with varying degrees of effectiveness. For the past several years seed treatments of cloronicotinyl insecticides including imidacloprid, thiamethoxam, and clothianidin have provided effective control of maggots on several of these crops, but there are no effective treatments available for maggot control for organic vegetable producers or growers producing vegetables under 3rd party certification programs that prohibit the use of organophosphates, pyrethroids, carbamates, or chloronicotinyls.

Preliminary studies conducted in 2008 demonstrated the potential for increased stand establishment of several vegetable crops seed-treated with spinosad. Indeed, stand establishment in our trials was significantly greater (p

Project goals and objectives
Short term: At least 500 acres of carrots, onions, beans and sweet corn will employ seed treatment with Spinosad against seedcorn maggot in Spring 2010

Overall long-term measures include the following for each subject crop.
Carrots: Replace the 8,000 lbs of diazinon used annually for maggot control on carrot fields with 440 lbs of spinosad applied as a seed treatment.
Onions: Replace the 14,000 lbs of chlorpyrifos used annually for maggot control on onion fields with 2,100 lbs of spinosad applied as a seed treatment.
Sweet Corn: Adoption of the use of spinosad seed treatment as a control for seedcorn maggot by the growers of processing sweet corn in Washington State.
Peas: Get 25% of pea producers to use spinosad as a seed treatment for maggot control.
Beans: Get some producers to switch to spinosad seed treatment versus chloronicotinyl seed treatments.

American Farmland Trust