Weed management in rice (Oryza sativa)wheat (Triticum aestivum) cropping system under conservation tillage

A field experiment was conducted during 200910 and 201011 at agronomical research farm of Birsa Agricul- tural University, Ranchi with four tillage management viz. Zero till rice (Oryza sativa L.) and zero till wheat {Triticum aestivum (L.) emend. Fiori & Paol}; zero till rice and conventional till wheat; conventional till rice and zero till wheat and conventional till rice and conventional till wheat, in main plots and three methods of weed control prac- tices viz. weedy check; recommended herbicides butachlor @ 1.5 kg/ha pre emergence + 2,4-D @ 0.5 kg/ha post emergence for rice and isoproturon @ 0.75kg/ha +2,4-D @ 0.5 kg/ha post emergence for wheat and two hand weeding (20 and 40 DAS for rice and 25 and 50 DAS for wheat, in sub plots to assess the productivity and profit- ability of ricewheat cropping system under conservation tillage. Direct seeded ricewheat sequence with conven- tional tillage produced maximum rice equivalent yield 7.4 t/ha (3.1 t/ha rice and 3.6 t/ha wheat) and net returns ( 58,206/ha). Among weed control, ricewheat either with butachlor @ 1.5 kg/ha pre-emergence + 2,4-D @ 0.5 kg/ ha post-emergence in rice and isoproturon @ 0.75kg/ha + 2,4-D @ 0.5 kg/ha post-emergence in wheat or, with two hand weeding in both crops produced maximum rice equivalent yield (7.4 t/ha and 7.8 t/ha) and net returns ( 62,258/ha and 60,498/ha)