POSSIBLE APPROACHES FOR ECOLOGICAL WEED MANAGEMENT IN DIRECT-SEEDED RICE IN A CHANGING WORLD

Labour and water scarcity are the major drivers for shifting the method of rice establishment from traditional transplanting to direct-seeding in many nations of Asia, where about 90% of world’s rice is produced and consumed. The risk of crop yield loss due to competition from weeds by all direct-seeding methods is higher than for transplanted rice. Changes in rice establishment method as well as water, tillage and weed management practices in direct-seeded rice (DSR) lead to shifts in weed communities and evolution of adoptive traits of individual weed species which present a further challenge for effective management of weeds in DSR based cropping systems. Recently, weedy rice is posing a serious challenge to DSR farming community. Effective and economic weed management is key for sustainable rice production to meet increasing food demand in changing world. The objective of this research was to summarise available ecological weed management options for managing weeds in direct-seeded rice for making direct-seeded rice more productive, profitable and sustainable in a changing world, and to identify areas where additional research is needed to bridge the gap. Ecological management of weeds in direct-seeded rice stresses on shifting the crop-weed balance in favour of rice by adapting in an integrated manner all available cultural, physical and biological weed management strategies and judiciously using herbicides as last resort rather than as only resort.