EFFECT OF ESTABLISHMENT AND WEED CONTROL METHODS ON GROWTH AND YIELD OF RICE

Rice (Oryza sativa L.) is a major source of food for more than half of the world population. About 90% of the total rice is grown and consumed in Asia. In India it is grown on an area of 44.6 m ha with production about 103.6 m tonnes and average productivity of 2.96 tonns/ha. Jharkhand, a traditional rice growing state and 40 per cent area is under direct dry seeded cultivation. However, weeds under direct seeded rice compete with plants during all critical growth stages for space, sunlight, water and nutrient causing considerable 52 per cent yield loss. However, an effective weed control method may reduce losses caused by weeds and produce higher production. Keeping these facts in view, a field experiment entitled “Effect of rice establishment and weed control methods on productivity of rice under medium land condition” was conducted at agronomical farm of Birsa Agricultural University, Ranchi, Jharkhand during rainy season of 2014. The treatments comprising of two methods of establishment i.e. dry seeded and wet seeded methods in main plot and four methods of weed control in sub plot i) weedy check, ii) hand weeding at 20,30 and 40 days after sowing, iii) Pretilachlor (0.75 Kg a.i/ha) with safener fb Bispyaribac-sodium (250 ml/ha) and iv) Pretilachlor (0.75 Kg a.i/ha) with safener fb Bispyribac-sodium (250 ml/ha) fb 2,4-D (1.50 kg/ha) laid out in split plot design with three replications. The soil of experimental plot was acidic with pH 6.1, clay loam in texture, low in organic carbon (0.37%) and nitrogen (263.4 kg/ha) and medium in phosphorus (15.9 kg/ha) and potassium (137.5 kg/ha). Results showed that hand weeding thrice and application of Pretilachlor (0.75 Kg a.i/ha) with safener fb Bispyribac-sodium (250 ml/ha) fb 2,4-D were found equally effective in reducing grassy, broad leaved weeds and sedges population as well as dry matter accumulation of weed at all growth stages of rice. The rice establishment methods did not differ significantly in yield attributing characters, yield and economics. Among weed control methods, hand weeding thrice recorded significantly higher effective tillers (274/ m 2 ), panicle length (23.80 cm), 1000 grain weight (23.9 g),filled grain (99/ panicle), grain yield (4763 kg/ha) as well as straw yield (5690 kg/ha) as compared to rest of the treatments but at par with Pretilachlor + safener fb Bispyribac-sodium fb 2,4-D. The application of Pretilachlor + safener fb Bispyribac-sodium fb 2,4-D having net return (Rs.52530/ ha) and benefit: cost ratio (2.71) which was at par with Pretilachlor + safener fb Bispyribac-sodium but significantly superior than rest of the treatments. Hence, application of Pretilachlor+Safener fb Bispyribac-sodium fb 2,4-D in direct seeded rice was most appropriate weed control method for producing higher yield, net return and benefit: cost ratio.