Broadleaf weeds have always been and still remain, from the point of view of weed management, a major challenge for the technicians and farmers who work with soybean. This study aims at seeking alternative management for these species within a production system using RR soybeans. The experiment was conducted in a randomized block design in a sub-plot with four replications subdivided wherein five winter cover plots, six management chemical pre-sowing soybean subplots, and three management chemical post-emergence soybean sub-subplots were tested. None of the treatments proved to be phytotoxic to soybean plants. The sequential applications post-emergence showed a trend of reduction of plant height, which did not negatively impact the productivity of the plots. In treatments with a coverage of oats, wheat, or ryegrass, any combination of managements in pre- and post-sowing returned horseweed control values above 90%. In general, the best treatment for the control of Euphorbia as the combinations of glyphosate and glyphosate + diclosulam or sulfentrazone in pre-planting soybeans. When soybeans are planted in fallow areas, productivity is on average 8% lower than when sown in areas with coverage of oats or wheat. In general, treatments that returned the highest yields were implanted using glyphosate or glyphosate + diclosulam or sulfentrazone in pre-planting soybeans.
cover crops; weeds; Euphorbia heterophylla; Conyza bonariensis
