Weed Control in Water- and Dry-seeded Rice,Oryza sativa

Abstract

Herbicides were applied as single, sequential, or tank mixture treatments at different growth stages and rates and were compared with standard treatments for control of barnyardgrass, bearded sprangletop, elipta, spreading dayflower, and aquatic weeds in water- or dry-seeded rice. In water-seeded rice, thiobencarb granules applied alone or sequentially selectively controlled bearded sprangletop and aquatic weeds in the 1- to 4-leaf stages better than standards of propanil alone or mixed with bentazon. Fenoxaprop plus bentazon selectively controlled 1- to 4-leaf bearded sprangletop but failed to control 1- to 4-leaf aquatic weeds. In dry-seeded rice, treatments of fenoxaprop applied to tillering rice after earlier applications of preemergence thiobencarb or postemergence applications of propanil selectively controlled barnyardgrass, bearded sprangletop, eclipta, or spreading dayflower better than standards of propanil alone or mixed with thiobencarb. Fenoxaprop alone or in tank mixtures with other herbicides applied early postemergence either injured rice or failed to control weeds. Esprocarb applied preemergence controlled weeds but injured rice while early postemergence treatments of propanil plus esprocarb performed better than standard herbicide treatments.