Determining pest and pesticide interactions as a means to optimize soybean yield

Soybean cyst nematode (SCN), Heterodera glycines Ichinohe, and soybean aphid (SBA), Aphis glycines Matsumura, are significant pests of soybean and can cause substantial yield losses. Farmers can now use native, host-plant resistance to manage SCN and SBA. Pesticidal seed treatments also can complement host-plant resistance to SCN and SBA. Seed treatments can include nematode protectants to lessen root injury by SCN, and insecticides to suppress SBA and other pests. For our 2013 field study, we studied combinations of host-plant resistance for SBA, SCN with different seed treatments and foliar insecticides. The field study was replicated at two different locations in Iowa. Our goal was to determine how these integrated pest management approaches affected soybean yields and pest abundance. We hypothesize that the soybean varieties with host-plant resistance for both SBA and SCN and receiving a seed treatment would have greater yield than susceptible varieties and soybeans without the seed treatments. Results from the first season of the field study will be presented.