Bio-efficacy of Acetachlor in Transplanted Rice (Oryza sativa L.)

Field experiments were conducted during the kharif seasons of 2000 and 2001 to study the bio-efficacy of acetachlor in transplanted rice (Oryza sativa L.). Application of lower dose (100 g ha⁻¹) of acetachlor at three days after transplanting (DAT) appreciably lowered the weed population, weed biomass and increased the weed control efficiency than higher doses of acetachlor (125, 150 and 300 g ha⁻¹), and was comparable to two hand weedings (25 and 40 DAT). The former treatment fetched a maximum net monetary return (Rs. 12470 ha⁻¹) and benefit: cost ratio (2.2). All the herbicidal treatments gave significantly higher grain yield over weedy treatment.