2011 Evaluation of Fungicide and Insecticide Seed Treatments on Soybean in Iowa

The use of seed treatments on soybeans has increased considerably over the past few years. Seed treatments protect seed from seedling diseases, caused by Pythium, Phytophthora, Fusarium and Rhizoctonia, and also insect pests such as the bean leaf beetle. Although a seed treatment may help ensure uniform emergence and optimum stands, such benefits do not always result in greater yields. In Iowa, the benefits of a seed treatment on soybean have not been well studied. A 2011 field study, funded with check off dollars from the Iowa Soybean Association, evaluated the effect of commercially available fungicide and insecticide seed treatments on seedling disease, insect pests and soybean yield. The study was done at three locations in Iowa: ISU Northeast Research and Demonstration Farm (NERF) at Nashua, ISU Southeast Research and Demonstration Farm (SERF) near Crawfordsville, and a farmer’s field in Nevada (two planting dates). Twelve demonstration plots were also planted at the ISU Field Extension and Education Laboratory (FEEL) near Boone