Effect of new generation herbicides on mixed weed flora and yield of direct seeded rice (Oryza sativa L.)

A field experiment was conducted during the “Navarai” season of 2019 and 2020 at Experimental Farm of the Department of Agronomy, Annamalai University, Annamalai Nagar, to find out the effect of new generation herbicides on direct seeded rice (Oryza sativa L.). The herbicide used were pre-emergence application of pyrazosulfuron-ethyl 10% WP at 200 g ha-1, pre-emergence application of metsulfuran-methyl 10% + chlorimuron-methyl 10% WP at 20g ha-1, pre-emergence application of pretilachlor 50% EC at 1250 ml ha-1, Early post-emergence application of pretilachlor 6% + pyrazosulfuran-ethyl 0.15% G at 615g ha-1, Early post-emergence application of bispyribac-sodium at 300 ml ha-1. The experimental result revealed that the new generation herbicide has a significant influence on weed flora and yield attributes and yield of direct seeding rice. The result indicated that application of Bispyribac-sodium 10% SC at 300 ml ha-1 at 15 DAS + one Hand weeding at 30 DAS recorded the lowest weed population, weed dry matter production and higher weed control index (WCI) and yield. Then twice hand weeding at 15, and 30 DAS was next in order. The lowest weed control index and yield were recorded with un-weeded control.