Efficacy of pre-emergence herbicides for control of complex weed flora in transplanted rice

A field experiment was conducted at Chiplima, Sambalpur, Odisha during the rainy season of 2014 and 2015 to study the effect of sand-mix application of pre-emergence herbicides on weed population yield and economics of transplanted rice (Oryza sativa L.). Application of chlorimuron + metsulfuron 4 g/ha, bensulfuron 60 g/ha and pyrazosulfuron 16 g/ha alone was selectively effictive on broad-leaf weeds while pretilachlor 500 g/ha was effective on grasses. Pre-emergence application of pyrazosulfuron with pretilachlor (16 + 500 g/ha) was more effective in minimizing the density (10/m2), biomass (4.8 g/m2) of weeds and enhancing the weed control efficiency (89.3%), grain yield (6.14 t/ha), net returns (` 53.2 x 103/ha) and benefit: cost ratio (1.37) than pretilachlor alone.