Integrated effect of population and weed management regimes on weed dynamics, performance, and productivity of basmati rice ( Oryza sativa L.)

Weeds caused serious problem on yield reduction of basmati rice worldwide. Losses caused by weeds varied from one country to another, depending on the presence of dominant weeds and the control methods practiced by farmers; therefore, suitable plant population and weed management practices should be adopted. Keeping these in mind, a field experiment was carried out during kharif seasons of 2009 and 2010 at crop Research Centre of SVPUA&T, Meerut, India comprising 4 planting geometries, viz. 20, 30, 40, and 50 hills m−2 as main plot factor, and 5 weed management practices (Butachlor @ 1.0 kg ha−1, Butachlor @ 1.0 kg ha−1 fb (followed by) one hand weeding, Butachlor @ 1.0 kg ha−1 fb Almix @ 4 g ha−1, two hand weedings and weedy check) in a split plot design with 3 replications. Experimental results revealed that plant population of 50 hills m−2 proved superior over that of 20 hills m−2 in respect of weed density, weed dry weight, number of tillers m−2, yield attributes, grain, straw, and biological yields. The maximum grain yield (29.00 and 31.00 q ha−1) and straw yield (51.30 and 52.50 q ha−1) were recorded in 50 hills m−2 followed by 40 hills m−2 during 2009 and 2010, respectively. In respect of nitrogen, phosphorus, and potassium removal, a reverse trend was observed: the highest in 20 hills m−2 followed by 30, 40, and 50 hills m−2. As far as the weed management practices are concerned, both chemical and mechanical methods of weed control were found superior over weedy check. The lowest weed density, dry weight, and highest weed control efficiency, maximum length of panicle−1, number of panicle (m2), and 1000-grain weight and grain yield of 30.40 and 32.60 q ha−1 were recorded with two hand weedings which was at par with Butachlor @ 1.0 kg ha−1 fb one hand weeding over rest of the weed management practices.