Impact of crop establishment and different weed management practices on crop economics of direct seeded rice in north region of Bihar

A field experiment was undertaken during kharif season of the year 2011-2012 at the Research Farm of Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), Bihar to study the effect of crop establishment methods and different weed management practices on growth, yield, economics, and uptake of N, P and K under direct seeded rice. The drum seeded in puddled condition obtained the significantly highest yield attributes, yield, profitability and uptake of N, P and K as compared to wet seeded and dry seeded rice. Rice established by drum seeded in puddled condition had improved the grain yield by 8.80% to 20.36%, and benefit cost ratio by 1.07 times to 1.16 times as compared to wet and dry seeded rice. Applications of pre-emergence pendimethalin and post-emergence bispyribac (W₆) showed maximum increment in yield attributes, viz. plant height (8.03%), no. of tillers (39.11%), plant dry matter production (32.16%), and crop growth rate (447.2%) over weedy check (W₈). Treatment, W₆ maintained the highest value of grain and straw yield i.e. 35.55 q ha^-1 and 52.57 q ha^-1, respectively. On the basis of benefit cost ratio the weed management practices, W₃ (pre-emergence application of pretilachlor @ 0.75 kg ha^-1) maintained the highest benefit cost ratio (1.29) and lowest was recorded with hand weeding (W₇).