Effect of crop establishment and weed management practices on weed growth and productivity of Basmati rice
A field experiment was conducted at village Binuria of the district Birbhum, West Bengal, India during rainy seasons (Kharif) of 2008 and 2009 to study the effect of crop establishment methods and weed management practices on weed growth and productivity of aromatic rice cv. ‘Basmati 370’. Three crop establishment methods viz. drum seeding (DS), system of rice intensification (SRI) and conventional transplanting (CTR) were assigned in main plots and six weed management practices, viz. weed-free check (WFC), unweeded check (WC), pyrazosulfuron-ethyl (PSE) at 20 g/ha, cono weeder (CW) twice at 15 and 30 DAS/DAT, combination of pyrazosulfuron-ethyl (PSE) at 20 g/ha and cono weeder twice (PSE + CW) and metsulfuron -methyl 10% + chlorimuron- ethyl 10% (Almix) at 4 g/ha in sub-plots, replicated thrice. Cynodon dactylon, Echinochloa colona and Oryza rufipogon under grasses, Hydrolea zeylanica, Ludwigia parviflora, Sphenoclea zeylanica, Monochoria vaginalis, Sagittaria sagitifolia and Marsilea quadrifolia among broad-leaved and Cyperus iria, C. difformis and Fimbristylis miliacea among the sedges were predominant weeds. Hydrolea zeylanica was the most pre-dominant species in SRI as well as conventional transplanting method while Fimbristylis miliacea in drum seeding. SRI recorded significantly lower number of total weeds at 60 DAT, the highest number of panicles (231/m 2 ), filled grains (98/panicle) and grain filling efficiency (84.79%) producing the highest grain yield (3.23 t/ha), 19.68 and 25.8% higher than that of CTR and DS methods respectively. Pyrazosulfuron-ethyl in combination with cono-weeder recorded the lowest weed population and dry weight at 40 DAS/DAT, higher grain yield (2982 kg/ha), 20.58% more over weedy check and was equivalent to sole application of pyrazosulfuronethyl and metsulfuron-methyl + chlorimuron-ethyl.