Growth and yield of aerobic rice as influenced by integrated weed management practices

A field experiment was conducted during kharif 2009 at Zonal Agricultural Research Station, V C. Farm, Mandya, Karnataka. The experiment consisted of 12 treatments laid out in randomized complete block design with three replications consisting of four pre-emergence herbicides integrated with one intercultivation at 40 days after sowing, hand weeding twice at 20 and 40 days after sowing, intercultivation thrice at 20, 40 and 60 days after sowing compared with weed free and unweeded check. The predominant weed flora observed in the experimental field were Echinochloa colonum, Digitaria marginata, Ageratum conyzoides, Spilanthus acmella, Commelina benghalensis, Celosia argentia, Cyperus iria and Cyperus rotundus. The results revealed that pre-emergence application of bensulfuron methyl+pretilachlor (6.6 GR) @ 0.06+0.60 kg/ha+one intercultivation at 40 days after sowing recorded significantly higher grain and straw yield (4425 and 5020 kg/ha, respectively), lower weed population and their dry weight (17.0 g and 2.32 g 0.25/m², respectively). Further the net returns and B: C ratio were also high with the pre-emergence application of bensulfuron methyl + pretilachlor (6.6 GR) @ 0.06 + 0.60 kg/ha+one intercultivation at 40 days after sowing.