www.IndianJournals.com Members Copy, Not for Commercial Sale Downloaded From IP - 220.225.236.59 on dated 9-May-2013 Performance of direct seeded rice under different integrated weed management and crop establishment practices in Indo-gangetic plains of India NIKHIL KUMAR SINGH, U.P. SINGH, J.M. SUTALIYA, C.M. PARIHAR AND S.L. JAT Directorate of Maize Research, Pusa Campus, New Delhi 110 012 Direct seeding of rice is a potential alternative to tradi- tional transplanting of rice as it reduces labour input and cost and maintain grain yields similar to that of trans- planted rice. Direct seeded rice (DSR) offers such advan- tages as faster and easier planting, reduced labour and less drudgery, earlier crop maturity by 7-10 days, more effi- cient water use and higher tolerance of water deficit, less methane emission and often higher profit in areas with an assured water supply. Labour requirements to establish rice by transplanting are high and increasing wage rates and labour scarcity because of off-farm migration are as- sociated with the move to direct seeding. Weeds are emerging as the most important cause of damage to direct seeded rice crop due to presence of weed seed banks in the soil, early crop weed competition and lack of standing water for suppressing the weeds. Besides chemical and mechanical weeding, other agronomic practices may also play vital role in weed management. Thus it is quite pos- sible that the emergence and growth of weeds under differ- ent crop establishment system might influence the compe- tition of weeds as also the efficiency of various weed con- trol measures. If weed emergence or weed seed bank checked by some suitable tillage alternatives, soil cover and residue intervention, it would be very useful in any weed management programme. METHODOLOGY The study was carried out for two consecutive years 2008 & 2009 at Agricultural Research Farm, Institute of Agricultural Sciences, BHU, Varanasi, U.P., India. The soil of the experimental site was Gangetic alluvial having sandy loam in texture with pH 7.2. The soil samples were analysed and it was observed that the soil is moderately fertile, being low in organic carbon (0.43%), available ni- trogen (198 kg/ha), medium in available phosphorus (24.6 kg/ha) and potassium (210 kg/ha). The experiment was laid out in split plot design consisting of three crop estab- lishment methods; [CE 1 -Zero-till DSR, CE 2 -Zero-till DSR with residue 40 cm anchored and CE 3 -Reduced tillage DSR (Zero Till-drill seeding)]. Seeding will be done with pre-sowing irrigation at by zero- till drill machines in all the crop establishment methods. Sowing will be done in the presence of 40 -45 cm anchored as well as lose residue similar to combine harvested fields in CE 2 - Sowing will be done under reduced tillage situation through 2-3 shallow ploughing by cultivator followed by one planking in CE 3 - After harvest of preceding rice, succeeding zero-till wheat was established in main plots and nine weed management treatment, viz. W 0 - Weedy check, W 1 - Weed free, W 2 - Hand weeding (20 and 40 DAS), W 3 - Glyphosate 1000 g/ ha (Pre-seeding) fb pendimethalin 1000 g/ha (Pre-em), fb 2,4-D EE 500 g/ha at 25 DAS, W 4 - Pendimethalin 1000 g/ ha (Pre-em) fb 2,4-D EE 500 g/ha at 25 DAS + one hand weeding (HW) at 40 DAS, W 5 -Pendimethalin1000 g/ha (Pre-em) fb metsulfuron+cholorimuron 4 g/ha at 20 DAS + one HW at 40 DAS, W 6 - Pendimethalin 1000 g/ha (Pre- em) fb azimsulfuron 35 g/ha at 15-20 DAS + one HW at 40 DAS, W 7 - Fenoxaprop with safener 56 g/ha + ethoxy- sulfuron 18 g/ha at 20-25 DAS + one HW at 40 DAS and W 8 - Bispyribac 25 g/ha at 20-25 fb one HW at 40 DAS in sub plots with three replication during both the years of investigation. RESULTS The higher grain and straw yield was observed under Zero-till DSR with anchored residue than the zero-till DSR and lowest in reduced till DSR during both the years of studies. Among weed management practices in DSR, pendimethalin 1000 g ha -1 (Pre-em) fb azimsulfuron 35 g ha -1 at 15-20 DAS + one HW at 40 DAS recorded maxi- mum grain and straw yield which was comparable to weed free, but significantly superior over rest of the treatments. Each weed management treatment showed maximum net return and benefit: cost ratio under zero-till DSR with an- chored residue than zero-till DSR and reduced-till DSR. In weed management treatments, the maximum net return Supplement 3 rd International Agronomy Congress on Agriculture Diversification, Climate Change Management and Livelihoods held at New Delhi, India on November 26-30, 2012 Extended Summaries: 3rd International Agronomy Congress, Nov 26-30, 2012, New Delhi, India