Evaluation of Bispyribac-sodium for Weed Control in Transplanted Rice

Bispyribac-sodium was evaluated against mixed weed flora in transplanted rice at Karnal, Haryana. Major associated weeds were Echinochloa glabrescens and E. colona (L.) Link among grasses, Ammannia baccifera L. and Euphorbia sp. among broad-leaved weeds and Fimbristylis miliacea (L.) Vahl, Cyperus iria L., C. rotundus L. and C. difformis L. among sedges. Weeds allowed to grow throughout crop season caused 68 and 27% yield reduction during 2006 and 2007, respectively. Bispyribac applied at 15 or 25 DAT was found equally effective against grassy weeds, but control of broad-leaved weeds and sedges was comparatively more when applied at 15 DAT. Bispyribac 25 g/ha applied at 15 or 25 DAT was adjudged the most suitable herbicidal treatment resulting in 174–199% and 37–41% increase in the rice grain yield over weedy check during 2006 and 2007, respectively. There was no phyto-toxicity of bispyribac on rice and no residual toxicity on succeeding crop of wheat during both the years of study.