Integrated weed management in dry direct-seeded rainy season rice (Oryza sativa)

A field experiment was carried out during rainy season (kharif) of 2006 and 2007 at Pundibari, West Bengal to work out integrated weed management practices and their economics in dry direct-seeded rice. The weed flora emerged during experimentation were: grasses like Cynodon dactylon and Echinochloa colonum; sedges like Cyperus rotundus, C. iria, and Fimbristylis miliacea; and broad-leaved weeds like Ludwigia parviflora, Ageratum conyzoides, Spilanthes paniculata, Eclipta alba and Enhydra fluctuans. In integrated weed-management practices, butachlor @ 1.5 kg/ha as pre-plant surface application + brown manuring with Sesbania rostrata + 2,4-D @ 0.50 kg/ha recorded the highest grain yield (3.00–3.88 t/ha), which was significantly on a par with that obtained from season-long weed-free situation (3.14–3.98 t/ha). The highest net returns (Rs 11,889 and 19,029/ha) and benefit: cost ratio (0.74 and 1.19) were also recorded in this treatment. Therefore, this integrated weed management practice could become effective in dry-direct seeded kharif rice under foothill (terai) agro-climatic region of West Bengal.