Efficacy of crop establishment techniques and weed control measures on weed dynamics, weed control efficiency and productivity in rice (Oryza sativa)

The field experiment was conducted during kharif season 2013 and 2014 at C S Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh to assess the performance of four rice establishment techniques and four weed control measures on weed dynamics, weed control efficiency, productivity and profitability of rice. Weed dynamics were higher in direct seeded rice (DSR) as compared to transplanted rice (TPR). The highest total weed density (214-282 plants/m(2)) and total weed biomass (40.5-52.2 g/m(2)) were recorded in DSR while the lowest in TPR. The efficacy of Sesbania brown manuring was significantly higher in both DSR and TPR. Compared with the weedy plots, two hand weeding at 20 DAS/DAT and 45 DAS/DAT followed by Bispyribac sodium 25 g/ha + (Chlorimuron + metsulfuron) 4 g/ha followed by one hand weeding at 45 DAS/DAT provided significant weed control. In both seasons, weed control efficacy was better in DSR and TPR. Across the weed control measures, the mean weed control efficiency ranged from 59.8 -98.6% and 64.2-98.5% at 30 DAS and maturity stage, respectively. TPR produced the maximum rice grain yields. On an average of both years, weed control treatments produced 21 to 43% higher rice grain yield than the weedy plots.