Influence of Soil Moisture on Absorption, Translocation, and Metabolism of Florpyrauxifen-benzyl

Abstract

AbstractFlorpyrauxifen-benzyl is a new active ingredient that represents an additional tool in rice (Oryza sativaL.) weed control by providing an alternative mechanism of action. Studies were conducted to evaluate soil moisture influences on florpyrauxifen-benzyl absorption, translocation, and metabolism in three problematic weeds. In the absorption/translocation study, barnyardgrass [Echinochloa crus-galli(L.) P. Beauv.], hemp sesbania [Sesbania herbacea(Mill.) McVaugh], and yellow nutsedge (Cyperus esculentusL.) were treated with [14C]florpyrauxifen-benzyl under two soil moisture regimes (7.5% and 60% field capacity). Greater absorption occurred under moist conditions (60% soil moisture content). More translocation of the herbicide to the area above the treated leaf occurred under moist versus dry soil across all weed species.Sesbania herbaceatranslocated 25% of the absorbed herbicide above the treated leaf, a result greater than that of the other two weed species at 60% soil moisture. However, no differences in translocation occurred among the weed species at the 7.5% soil moisture regime. In the metabolism study, 95% of the herbicide recovered was in its acid form under the high soil moisture regime forS. herbacea, a species that shows extreme sensitivity to even low doses of this herbicide, and soil moisture influenced the amount of acid form found in all species. While these data provide a limited view into the physiological processes being affected, they do suggest that forE. crus-galli,S. herbacea, andC. esculentus, soil moisture content in the field will likely play a significant role in absorption, translocation, and metabolism of florpyrauxifen-benzyl.