Author(s):
Following the commercial launch of florpyrauxifen-benzyl, complaints and concerns surrounding the off-target movement of florpyrauxifen-benzyl to soybean arose. Consequently, research was initiated to evaluate an application method to alleviate damage from off-target movement and retain weed control in rice. Field and self-contained tub experiments were conducted in 2020 and 2021 to determine if coating florpyrauxifen-benzyl or mixtures containing florpyrauxifen-benzyl on urea would provide equivalent levels of weed control as spray applications. In the tub experiment, florpyrauxifen-benzyl sprayed at 30 g ae ha-1 and a mixture of florpyrauxifen-benzyl at 24 g ae ha-1 plus penoxsulam at 41 g ai ha-1 coated on urea resulted in 100% visible control, mortality, and no biomass production for yellow nutsedge, barnyardgrass, and hemp sesbania. However, for barnyardgrass, coating florpyrauxifen-benzyl on urea at 30 g ae ha-1 provided no greater than 27% visible control, 24% mortality, and 87% relative biomass at 4 and 5 WAT. In two separate rice flatsedge field experiments comparing application methods and herbicide combinations containing florpyrauxifen-benzyl, all treatments containing florpyrauxifen-benzyl provided 90% or greater control of ~10-cm rice flatsedge and 93% or greater control of ~25-cm rice flatsedge across all rating timings. In the ~10-cm rice flatsedge experiment, coating florpyrauxifen-benzyl or the mixture containing penoxsulam on urea resulted in greater visible ducksalad control than spray applications at 5 WAT. However, coated urea applications containing florpyrauxifenbenzyl were less effective than the spray and provided 50% and 76% visible California arrowhead and yellow nutsedge control, respectively. Coating either herbicide on urea resulted in 80% or less yellow nutsedge control compared to 96% or greater control following spray applications when applied to ~25-cm rice flatsedge. Coating florpyrauxifenbenzyl on urea provided comparable hemp sesbania, rice flatsedge, and ducksalad control a spray application. Adding penoxsulam to florpyrauxifen-benzyl improved barnyardgrass and yellow nutsedge control when coated on urea
