Effect of crop establishment methods and weed management practices on weed flora and yield of direct-seeded rice (Oryza sativa)

A field investigation was conducted during the rainy (kharif) season of 2011 and 2012 at Varanasi, Uttar Pradesh, to study the effect of crop-establishment methods and weed-management practices on weed flora and yields of direct seeded rice (Oryza sativa L.). Among crop-establishment methods, bed planting of directed seeded rice (DSR) markedly reduced weed density of various weed flora and their dry weight than zero-till and conventional planting, thus resulting in the lowest weed index. Bed planting markedly improved grain weight/panicle but recorded significantly lowest number of tillers/m² at harvesting among all the crop-establishment methods. Consequently, crop-establishment methods failed to influence grain and straw yields and harvest index at significant level. Integration of brown manuring practice (knock down of Sesbania at 25 days after sowing (DAS) by 2, 4-D @ 0.5 kg/ha) with either pendimethalin @ 1.0 kg/ha or bispyribac-sodium @ 0.025 kg/ha or both was significantly superior in suppressing weed infestations with lesser weed index and higher weed-control efficiency, yield attributes, yields and harvest index. No-till method and integrated weed-management by pendimethalin followed by brown manuring of Sesbania had higher remuneration among the crop-establishment methods and weed-management practices respectively.