Effect of weed-management practices on system of rice (Oryza sativa) intensification under southern dry zone of Karnataka

A field experiment was conducted during the rainy season (kharif) of 2014 and 2015 at Zonal Agricultural Research Station, V.C. Farm, Mandya, Karnataka, to know the effect of weed-management practices on system of rice intensification (SRI) method of rice (Oryza sativa L.) cultivation under southern dry zone of Karnataka. The experiment consisted of 8 treatments, replicated thrice in a randomized complete block design. Among the various treatments, weed-free check recorded significantly higher grain yield (6.04 t/ha) and it was found at par with herbicide treatment, viz. pre-emergence application of bensulfuron-methyl 0.6% + pretilachlor 6% GR (Londax Power) @ 10 kg/ha fb post-emergence application of bispyribac sodium (Nominee Gold) @ 25 g/ha at 20 days after sowing (DAS) (5.53 t/ha). Among the weed the management practices, pre-emergence application of bensulfuron-methyl 0.6% + pretilachlor 6% GR (Londax Power) @ 10 kg/ha fb post-emergence application of bispyribac sodium (Nominee Gold) @ 25 g/ha at 20 days after sowing (DAS) found effective in control of all types of weeds and registered higher net monetary returns (53,270/ha) and benefit: cost ratio (2.80). Uncontrolled weed growth caused 49.5% reduction in grain yield.