Bio-efficacy of acetochlor doses and stages of application were studied in transplanted rice. Sacciolepsis interrupta. Leersia hexandra. Scirpus juncoides. Fissendocarpa linifolia and Monochoria vaginalis were the dominant weeds. Application of acetochlor at 100 g ha" at three or eight days after transplanting resulted in significant reduction in weed
density, weed dry matter accumulation and was at par with higher doses (125, 150 and 300 gha·'). The highest grain yield of rice was recorded with the application of acetochlor at 100 g ha-' applied three days after transplanting.