Controlling Herbicide Resistant Weeds in Soybeans: 2019 Trials

NYS IPM Type: Project ReportHerbicide resistant weeds have become a major problem for New York soybean farmers. This project aimed to regain control of these weeds through a mix of chemical, physical, and electrical tactics. From our replicated field trials attempting to control waterhemp in soybeans, the programs that included herbicides from WSSA groups 4, 14, or 15 were most effective, and our only treatment that provided 100% control included all three of those groups. Row cultivation performed well between-rows but missed some in-row weeds. Soybean yields generally reflected the effectiveness of each weed control treatment, with untreated plots incurring a 56% yield loss. Unfortunately, the most effective two-pass treatments were also the most expensive. In a separate demonstration, our informal evaluation of an electric discharge system was successful, with most of the herbicide resistant horseweed (marestail) exhibiting complete necrosis two weeks after application