Abstract: Field experiments were conducted in 1996 and 1997 to evaluate barnyardgrass (Echinochloa crus-galli) control, rice (Oryza sativa) yield, and grain quality with cyhalofop-butyl applied early postemergence (EPOST) or late postemergence (LPOST) in drained or flooded plots at rates of 0.15 to 0.4 kg ai/ha and standard treatments of molinate or propanil. Control with cyhalofop-butyl at 0.15 and 0.2 kg/ha applied in drained plots was greater compared to propanil and generally increased when treatments were applied EPOST to plots reflooded 2 d after treatment. Barnyardgrass control with cyhalofop-butyl at 0.15 and 0.2 kg/ha applied in flooded plots was similar to or better than the control obtained with molinate. Rice yields generally reflected differences in barnyardgrass control and were greatest with cyhalofop-butyl applied EPOST in drained plots. The 0.4 kg/ha rate of cyhalofop-butyl resulted in rice foliar injury and significant reductions in grain yield. Grain qualitative characteristics (total milling yield, grain vitreosity, grain length, and grain length to width ratio) were better with cyhalofop-butyl applied EPOST in drained plots compared with propanil or molinate.
Nomenclature: Cyhalofop-butyl; molinate; propanil; barnyardgrass, Echinochloa crus-galli (L.) Beauv. #3 ECHCG; rice, Oryza sativa L. ‘Ispaniki A’.
Additional index words: Weed management, ECHCG.
Abbreviations: DAT, days after treatment; DBH, days before harvest; EPOST, early postemergence; LPOST, late postemergence; POST, postemergence.