Glyphosate tolerant/ resistant weeds (GTRW) are a daunting, widespread problem in no-till systems. Our SARE work in Wisconsin demonstrates that a late terminated cereal rye cover crop can provide highly effective GTRW suppression in “green planted” no-till soybean but has the potential to reduce yield to unacceptable levels. Our objective is to determine the optimum timing of rye termination in this system to maximize GTRW suppression without affecting yield.
On-farm strip trials will be conducted at four locations in Southeast Wisconsin over a range on soil types and environments including inherent GTRW pressure to determine this optimum timing and the growing season factors which influence it, leading to recommendations to inform management decisions.
Our outreach plan focuses heavily on producer-led watershed protection groups including our Jefferson County Soil Builders (JCSB) to maximize farmer-to-farmer interaction and impact.
Our educational outcomes will include increased knowledge of system benefits, specific management recommendations, and how this system fits into both herbicide resistance management strategies and overall agricultural sustainability.
Our action outcome is increased use of rye as a cover crop, managed optimally for GTRW management with concurrent gains in other ecosystem services from increased biomass production and soil cover, leading to greater sustainability.
Project objectives from proposal:
- Determine the optimal timing of rye termination in a “plant green” system to maximize GTRW suppression without reducing soybean yield;
- Determine if rye height or soybean growth stage is a better predictor of optimal termination timing, allowing us to develop management recommendations; and
- Share results and experiences with farmers and their technical advisors including the University of Wisconsin-Extension Weed Science Program so they can leverage our results in their routine programming.