Evaluation of different weed management practices on growth and yield of transplanted rice (Oryza sativa L.) in Northeastern Zone of Tamil Nadu

Weeds cause a 57 per cent yield loss in transplanted rice and an 82 per cent yield loss in direct seeded rice, resulting in a $4.20 billion monetary loss per year. Weed infestation, species richness, density, dry matter accumulation and duration of association significantly affects rice grain production. Therefore, a field experiment was conducted in farmer’s field in Thiruvennainallur village, Villupuram District, Tamil Nadu, India during Navarai season of 2021, in order to evaluate the different weed management practices on growth and yield of rice under transplanted conditions. The experiment was laid out in a randomized block design, having fourteen treatment and replicated thrice. Treatment consists of hand weeding, butachlor, pretilachlor, pyrazosulfuron ethyl, bispyribac sodium, fenoxaprop-p-ethyl, Triafamone + ethoxy sulfuron, metsulfuron methyl + chlorimuron ethyl and penoxsulam + cyhalofop butyl were used as herbicides. Among the different herbicides tried out, pre emergence application of pyrazosulfuron ethyl 10% WP @ 0.15 g/ha fb post emergence application of bispyribac sodium 10% SC @ 0.25 l/ha recorded least weed density (15.55, 29.56 m-2), weed biomass (8.25, 16.02 g/m2) with weed index (2.18 %) and highest weed control index (89.22%, 85.18%), plant height (97.21 cm), dry matter production (12735 kg/ha), number of productive tillers/m2 (349.23), grain yield (6416 kg/ha) and straw yield (7839 kg/ha). Sequential application of pre-emergence followed by post emergence enhance the reduction of weed leads to higher productivity of transplanted rice.