Effect of rice leaf stage on tolerance to benzobicyclon in a drill‐seeded production system

Benzobicyclon is a new postflood-applied herbicide that was registered for use in U.S. rice (Oryza sativa L.) 2021 by Gowan Company. Therefore, research conducted to evaluate tolerance of commonly grown cultivars benzobicyclon. In 2018 and 2019, field experiments were near Stuttgart, AR the influence growth stage on benzobicyclon, pure line hybrid benzobicyclon following repeated acetolactate synthase-inhibiting herbicides. one two years, (leaf number) at application impacted 2018, two-leaf generally more injurious cultivars, ‘CL153’, ‘Diamond’, ‘PVL01’, ‘CLXL745’ than when applied four-leaf or tillering stages. second year, all except ‘Rondo’, not injured any stage. both indica cultivar Rondo elicited ≥97% crop injury, regardless timing. Findings from these suggest can vary across environments smaller-sized could be prone injury applications occur typical timing herbicide. general, will exhibit sufficient It especially recommended apply have predominant indica-type genealogical background. herbicides CL153 CLXL745 did pose increased risk rice.