Effects of Common Peanut Herbicide Residues on Cover Crop Establishment

In 2016/2017 S-metolachlor, pyroxasulfone, and acetochlor resulted in the largest stand reductions for rye, wheat and vetch at 50 OAP. In 2017/2018 more stand losses were observed at 150 OAP than 50 OAP. Diclosulam caused more stand reductions affecting all cover crops except for oats over both years. Trifloxysulfuron, diruon, and prometryn did not affect the establishment of any grass cover crop stands either year. Oats showed the most tolerance with no treatments significantly reducing stands or plant heights for either year. The type of cover crop planted should be based on the residual herbicides applied to row crops the previous season as well as the biomass goal and nutrient needs of the field. Although initial injury and stunting may occur, biomass of those cover crops may not be affected by herbicide residues evaluated in this study. Overall, cover crop stand establishment varied over the years but not locations similar to previous studies done in corn and soybean rotation. Residual herbicide dissipations varied year to year possibly due to weather such as rainfall, ambient and soil temperatures, etc. but this needs to be evaluated further in future studies. This experiment is completed and was presented at American Peanut Research and Education Societies' annual meeting in 2018 and Weed Science Society of America's annual meeting in 2019. The presentation was nominated for the Bailey Award from American Peanut Research and Education Societies. The data will also be published in a peer reviewed journal, Peanut Science, hopefully by the end of 2019.