Rice (Oryza sativa) Weed Control with Soil Applications of Quinclorac

Abstract

Field studies were conducted from 1988 to 1990 on a Sharkey clay to evaluate residual weed control in rice with quinclorac applied PPI, PRE to dry soil, and PRE to moist soil. Quinclorac applied at 0.4 or 0.6 kg ai ha−1PPI or PRE to dry or moist soil controlled more than 80% of barnyardgrass, pitted morningglory, and hemp sesbania without rice injury. Quinclorac applied at 0.3 kg ha−1controlled these three weed species substantially but inconsistently. No rice injury was observed from any quinclorac treatment. Except for one of three years when irrigation was delayed for 7 d after PRE application to dry soil, application timing did not consistently affect weed control or rice yield.