P-139 - Evaluating the Effect of Cereal Rye Variety and Herbicide Choice on Seedling Disease and Yield of Corn

Cover crops (CC) are widely used to improve soil health, reduce erosion, and enhance nutrient cycling within cropping systems. Cereal rye (CR) (Secale cereale) is the most planted CC in the Midwest due to its winter hardiness and ability to suppress weeds. However, reductions in corn (Zea mays) yield after using CR CC have been reported, thus farmers are hesitant to implement this practice. Reduced yield has been attributed to various factors, including CR variety and seedling disease. Prior to planting corn, CCs are usually terminated with glyphosate, which may result in greater seedling disease since root pathogen populations increase following glyphosate applications. The main objective of this study was to evaluate the effect of CR variety and herbicide on seedling disease, growth, and yield of corn. A field trial was established in which corn was planted following four cultivars of CR CC (Serafino, Elbon, Aroostook, and Rymin) and a control (no CR CC). CR was terminated using either glyphosate or paraquat.  Seedling root rot severity, number of barren plants, and yield of corn were evaluated. An interaction between variety and herbicide on root rot severity was detected (P=0.023). Radicle rot was more severe in plots where glyphosate was applied compared to paraquat (P=0.00014). Yield of corn was greatest in the control plots (P< 0.05), and no differences in yield were observed among CR varieties for both herbicides. Results from these studies will provide information for improved cover crop management practices, specifically variety and herbicide choices.