Effect of cultural and chemical weed management practices on yield, economics and nutrient uptake under zero-till direct seeded rice (oryza sativa l.)

Abstract

An field experiment was conducted during kharif seasons of 2013-14 at Varanasi, UP to evaluate the effect of weed management practices in zero-till direct seeded rice. Results revealed that weed free treatment resulted the highest yield; however, it was not economical due to high cost of cultivation. Pre-emergence application of pendimethalin (1.0 kg ha-1) fb (followed by) early post-emergence application of bispyribac (0.025 kg ha-1) at 18 days after sowing (DAS) was recorded significantly the highest number of effective tillers, grain yield (4290 kg ha-1) and straw yield (5750 kg ha-1), biological yield, harvest index (42.71 %) and NPK uptake as compared to Sesbania co-culture + residue incorporation, Sesbania co-culture fb 2, 4-D and pretilachlor fb hand weeding at 30 DAS and it were at par with the application of pendimethalin fb hand weeding at 30 DAS and pretilachlor fb bispyribac. Application of pretilachlor fb bispyribac at 18 DAS recorded maximum net returns ( 45586) and benefit cost ratio (2.7). None of the treatment as effective as weed free with respect to reduction of density and dry weight of weeds, crop growth, yield attributes and yield, and nutrients uptake.