Effect of Weed Management Practices on Weed Dynamics Yield and Monetary Returns of Rice (Oryza sativa L.)

Abstract

Rice (Oryza sativa L.) is a monocot plant belongs to genus Oryza under tribe Oryzae in grass family Poaceae. Rice is very rich in genetic diversity, with thousands of varieties grown throughout the world. Rice is major staple crop of the world to diet of 2.7 billion people and its contain, 7-8% protein, 3% fat and 3% fiber. Until recently, rice was considered only a starch food and a source of carbohydrates and some amount of protein. In India, rice occupies an area of 43.79 mha with production and productivity of 112.91 mt and 2.58 tonnes ha-1 respectively. The investigation entitled “Effect of weed management practices on weed dynamics, yield and monetary returns of rice” was carried out at the Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P. during kharif season of 2019. The experiment was conducted in R.B.D with three replications comprising ten treatments of weed management i.e Weedy check, weed free, One hand weeding at 40 DAT+ Bispyribac-Na (25 g a.i/ha) at 15 DAT, Penoxsulam (22 g a.i/ha) at 20 DAT, One hand weeding at 15 DAT+ Penoxsulam (22 g a.i/ha) at 30 DAT, One hand weeding at 20 DAT+ Penoxsulam (22 g a.i/ha) at 35 DAT, One hand weeding at 25 DAT+ Penoxsulam (22 g a.i/ha) at 40 DAT, Pretilachlor (750 g a.i/ha) at 3 DAT + Penoxsulam (22 g a.i/ha) at 20 DAT, Pretilachlor (750 g a.i/ha) at 3 DAT+ Penoxsulam (22 g a.i/ha) at 25 DAT and Pretilachlor (750 g a.i/ha) at 3 DAT+ Penoxsulam (22 g a.i/ha) at 30 DAT were used for the experimentation. Different observations were recorded during the crop growth period. The results indicated that the application of Pretilachlor (750 g a.i/ha) at 3 DAT + Penoxsulam (22 g a.i/ha) at 20 DAT significantly reduced the weed population and dry weight over weedy check. The highest plant height, number of tillers (m-2), dry matter accumulation, leaf area index, higher protein content, 1000-grain weight, weed control efficiency, nutrient content and grain yield (38.80 q ha-1), were recorded with the application of Pretilachlor (750 g a.i/ha) at 3 DAT + Penoxsulam (22 g a.i/ha) at 20 DAT, which established its superiority over rest of the herbicidal treatments. The total nitrogen, phosphorus and potassium uptake by rice crop was also highest (77.06, 18.45 and 75.01 kg ha-1), with the application of Pretilachlor (750 g a.i/ha) at 3 DAT + Penoxsulam (22 g a.i/ha) at 20 DAT and 42.45 and 22.50 per cent increase in grains and straw yield as compared to weedy check in rice crop. The application of Pretilachlor (750 g a.i/ha) at 3 DAT + Penoxsulam (22 g a.i/ha) at 20 DAT resulted in to higher gross return, net return and B: C ratio. Thus the application of Pretilachlor (750 g a.i/ha) at 3 DAT + Penoxsulam (22 g a.i/ha) at 20 DAT found better for sustainability of rice crop yield.