Sweetpotato tolerance and Palmer amaranth control with indaziflam

Field studies were conducted in North Carolina in 2018 and 2019 to determine sweetpotato tolerance to indaziflam and its effectiveness in controlling Palmer amaranth in sweetpotato. Treatments included indaziflam pre-transplant; 7 d after transplanting (DATr) or 14 DATr at 29, 44, 58, or 73 g ai ha–1; and checks (weedy and weed-free). Indaziflam applied postemergence caused transient foliar injury to sweetpotato. Indaziflam pretransplant caused less injury to sweetpotato than other application timings regardless of rate. Palmer amaranth control was greatest when indaziflam was applied pretransplant or 7 DATr. In a weed-free environment, sweetpotato marketable yield decreased as indaziflam application was delayed. No differences in storage root length to width ratio were observed. Nomenclature: indaziflam; Palmer amaranth; Amaranthus palmeri S. Watson; sweetpotato; Ipomoea batatas (L.) Lam.