Evaluation of Different Weed Management Practices and Crop Geometry on Weed Control Efficiency and Yield of Direct (Dry) Seeded Rice (Oryza sativa L.)

A field experiment was conducted during Kharif season of 2017 in D2 block at Norman E. Borlaug Crop Research Centre of G. B. Pant University of Agriculture and Technology, Pantnagar intending to find out the efficacy of different pre and post -emergence herbicides for controlling the weeds and also their effect on direct (dry) seeded rice in three planting geometries. The maximum weed control efficiency 96.59, 72.81, and 82.32 percent was obtained at a row spacing of 25 cm with the pre- and post- emergence application of pendimethalin 1kg /ha fb penoxsulam 22.5 g/ha at 40, 60 and 80 DAS. Row spacing of 25 cm recorded the highest grain yield (4.2 t/ha) which was comparable to 20 cm row spacing and significantly superior to 30 cm row spacing. Application of pendimethalin 1 kg/ha fb penoxsulam 22.5 g/ha recorded highest grain yield (4.4 t/ha) after weed free. Highest B:C ratio (2.0) was obtained with 25cm spacing along with the pre-emergence application of pendimethalin (1.0 kg/ha) fb post-emergence penoxsulam (22.5g/ha) which was followed by the row spacing of 20cm along with the post-emergence application of cyhalofop-butyl + penoxsulam (Readymix) 150g/ha (1.7).