When using glyphosate plus dicamba, 2,4-D, halauxifen or pyraflufen/2,4-D for glyphosate-resistant horseweed (<i>Erigeron canadensis</i>) control in soybean, which third mix partner is better, saflufenacil or metribuzin?

Abstract Glyphosate-resistant (GR) horseweed interference in soybean can reduce yield up to 93%. Glyphosate plus dicamba, 2,4-D ester, halauxifen-methyl or pyraflufen-ethyl/2,4-D applied preplant (PP) provide variable GR control soybean. The objective of this study was determine if the addition saflufenacil metribuzin glyphosate halauxifen-methyl, will improve level and consistency control. Four trials were conducted over 2020 2021 field seasons fields with populations. controlled 96%, 77%, 71%, 52%, respectively, at 8 wk after application (WAA). When added dicamba not improved WAA. by 27% 25%, pyraflufen-ethyl/2,4-D, 47% 37%, when compared each herbicide alone. Synergism observed Though all treatments including resulted highest most consistent