Effectiveness and Economics of Integrated Weed Management in Transplanted Rice (Oryza sativa)

In experimental field, Cyperus rotundus (L)., Cyperus iria (L), Cyperus difformis (L)., Fimbristylis miliacea (L) Vaha., Echinochloa colona (L). Link, Echinochloa crus-galli (L) P. Beauv, and Commelina benghalensis (L) were the dominant weed flora species in rice fields. Manual weeding at 20 and 40 days after transplanting (DAT), butachlor @1.5 kg a.i/ha preem followed by (fb) 2,4-D easter 0.5 kg a.i./ha Post Emergence (POE), butachlor @ 1.5 kg a.i/ha as pre-em fb azimsulfuron @25.0 g a.i/ha POE, bispyribac 12.5 g a.i/ha + azimsulfuron 12.5 g a.i/ha POE, butachlor @ 1.5 kg a.i/ha as pre-em fb ethoxysulfuron @ 15 g a.i/ha as POE proved equally effective in increasing most of the growth parameters, yield attributes, yield and economic advantage. The maximum mean grain yield of (5.91 t/ha) was recorded from the plots where two hand weeding at 20 and 40 DAT was performed and was statistically at par with the mean grain yield obtained under different weed management practices i.e butachlor @ 1.5 kg a.i/ha as pre-em fb azimsulfuron @ 25.0 g a.i/ha POE(5.51t/ha), bispyribac 12.5 g a.i/ha + azimsulfuron 12.5 g a.i/ha POE (5.56t/ha), butachlor @ 1.5 kg a.i/ha as pre-em fb ethoxysulfuron @ 15 g a.i/ha as POE (5.65 t/ha) and the grain yield obtained these were significantly superior to the grain yield obtained under rest of the weed management practices. Significantly lowest mean grain yield of (4.21 t/ha) was obtained from weedy check treatment. The highest net return Rs, 43083/ha was noted in treatment butachlor @ 1.5 kg a.i/ha as pre-em fb ethoxysulfuron @ 15 g a.i/ha as POE and maximum benefit: cost ratio of 1.92 was obtained in treatment bispyribac 12.5 g a.i/ha + azimsulfuron 12.5 g a.i/ha POE and lower value of net return Rs, 28488/ha and benefit: cost ratio of (1.29) were recorded under treatment weedy check.