Sesbania, Azolla and herbicide use for weed management and optimizing yield in direct-seeded rice

Abstract

The experiment was conducted at Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (U.P.) during Kharif seasons of 2009 and 2010 to assess the performance of direct-seeded rice as influenced by Sesbania/ Azolla with nitrogen levels and herbicide use for managing weeds and optimizing the yield of direct-seeded rice (DSR). Weed density and dry weight were consistently lower with Azolla culture than with Sesbania during initial crop growth stages, however, they were similar at 90 days after sowing (DAS). Among weed management practices, pretilachlor (with safener) at 0.3 kg /ha at 2 DAS as pre-emergence application followed by (fb) hand weeding (HW) at 45 DAS was effective in controlling weeds and increasing the grain yield of DSR, which resulted in higher net returns and benefit cost ratio than HW twice at 20 and 45 DAS. The higher yields were recorded under Sesbania and Azolla than DSR (sole) crop. Sesbania Azolla + 100% recommended dose of nitrogen with pretilachlor (with safener) 0.3 kg /ha at 2 DAS as pre-emergence application fb HW at 45 DAS recorded lower weeds density, dry weight and higher economic returns in direct-seeded rice.