Benzobicyclon carryover to crops in the Mississippi Delta

One experiment was conducted from 2015 to 2016 on a Calloway and Dewitt silt loam soil near Pine Tree (pH 8.3) and Stuttgart (pH 6.0), Arkansas, respectively. The objective was to evaluate the potential for a benzobicyclon application to carryover from rice and cause damage to corn, cotton, grain sorghum, soybean, and sunflower planted the subsequent year. No injury or stand reduction occurred for any crop after applications of benzobicyclon at 0.22 and 0.44 lb a.i. acre at either location. Grain sorghum had a 29% height reduction at Pine Tree at 12 d after planting (DAP); however, no differences in height occurred at Stuttgart, and by 40 DAP, all heights were similar between treated and nontreated plots at both locations. Plant height of corn, cotton, soybean, and sunflower was not reduced in treated plots. At Pine Tree, 53 and 56% reductions in corn yield resulted from benzobicyclon at 0.22 and 0.44 lb acre, respectively, whereas cotton, grain sorghum, and soybean yields were not affected by benzobicyclon residues. Yields of all crops at Stuttgart were not negatively affected by benzobicyclon application the previous year. This research shows that benzobicyclon applied to rice is unlikely to injure cotton and soybean or to have a negative impact on crop yield the in subsequent growing season.