Horseweed (Conyza canadensis (L.) Cronq.) is prevalent in Kentucky and can be difficult to control. Research has shown multiple weed control methods to be more sustainable than relying on chemical control alone, so the use of multiple methods for horseweed management was examined in this study. The main objective was to determine best practice(s) to reduce horseweed prior to soybean [Glycine max (L.) Merr.]. Treatments included: fall-planted cover crop [CC; cereal rye (Secale cereale L.) or none], fall-applied herbicide (saflufenacil or none), and spring-applied herbicides (dicamba, 2,4-D ester, or none). We hypothesized horseweed densities would be reduced the most where all factors were combined. Saflufenacil suppressed horseweed densities from application through March, when densities increased due to a lack of competition from other winter weeds. Spring herbicides decreased horseweed densities until soybeans reached V1 in 2017, but in 2018 lost efficacy after CC termination. CC alone resulted in the longest horseweed suppression. The combination of spring herbicides and CC usually reduced horseweed densities to near zero between the CC termination and soybean planting. However, some low densities seen soon after soybean planting could be problematic. Further research must be conducted to determine the best integrated horseweed management system until soybean canopy closure.

Research was conducted in 2014 to evaluate the efficacy of harvest-aid systems and the performance of harvest aids applied at various timings in Mid-South soybean production. Evaluations included yield, desiccation, green stems and pods, and seed quality. Saflufenacil did not perform as well as the producer standard 14 DAT at the Starkville, MS location with desiccation levels of 78 and 98%, respectively. However, similar performance was observed 14 DAT at the Brooksville, MS location. When applied at R6.5, paraquat based treatments improved desiccation and reduced green stem 7 DAT compared to other treatments. No yield differences were observed between harvest aid treatments. However, yield differences were observed between the R6.0 and R6.5 timings. These data suggest saflufenacil is an effective harvest aid option, but may require up to 14 days for optimum desiccation. In addition, yield is not impacted by harvest aid product, but rather the timing of the application.