Fenclorim rice safening and weed control with fall‐applied acetochlor and pyroxasulfone

Applications of very long‐chained fatty acid elongase (VLCFA)‐inhibiting herbicides are currently not labeled within U.S. rice (Oryza sativa L.) production but have been used in Asian rice production to suppress weedy rice and control other annual grasses and small‐seeded broadleaves. Therefore, separate experiments were initiated in the fall of 2019 and 2020 to evaluate rice tolerance and weedy rice (O. sativa L.) control with acetochlor and pyroxasulfone in the following spring. A three‐factor experiment within a randomized complete block design was implemented with the factors being (1) herbicide choice (acetochlor or pyroxasulfone), (2) a low or high herbicide rate (2100 and 4200 g ai ha−1, and at 237 and 475 g ai ha−1 acetochlor and pyroxasulfone, respectively), and (3) without or with a fenclorim seed treatment (2.5 g ai kg−1 of seed). Throughout the experiments, rice exhibited