Nikhil Kumar Singh, U.P. Singh, Sitesh Jha and Amitesh Kumar Singh
Abstract
Rice (Oryza sativa L.) is an important staple crop in India, where it is mainly grown by manual transplanting of seedlings into puddled soil. Recently, however, there is a trend toward dry- direct seeded rice (DSR) because of labour and water scarcity. In DSR, weeds are the main biological constraint. Herbicides are used to manage weeds in DSR systems, but the use of herbicides alone does not provide effective and sustainable weed control. Therefore, field experiment was conducted during rainy season 2008 and 2009 to evaluate the effect of crop establishment methods and integrated weed management on weed dynamics, growth and yield of. Rice established by zero-till DSR with anchored residue had minimum density and dry weight of grasses, sedges, broadleaves and maximum weed control efficiency, yield attributes, grain yield (4562 and 4785 kg ha-1), economics and moisture use efficiency. Among weed management methods, application of pendimethalin 1000 gha-1 fb azimsulfuron 35 g ha-1 at 15-20 DAS + one hand weeding at 40 DAS proved to be the most effective in lowering the weed density and dry weight of grassy and non-grassy weeds, enhancing the weed control efficiency, yield attributes, grain yield (5451 and 5542 kgha-1), economics and moisture use efficiency during both the years of experimentation. Although, the result of this trial confirms the effect of different weed management practices on the grain yield of rice, but the findings prove the integration of different crop establishment methods and weed management practices will manage the weedsand enhance the yield of DSR.