Effect of planting geometry and weed-management practices on yield of scented rice (Oryza sativa) varieties

A field experiment was conducted at the Shaheed Gundadhur College of Agriculture and Research Station, of the Indira Gandhi Krishi Vishwavidhyalaya, Jagdalpur, Chhattisgarh during rainy season (Kharif) of 2019, to evaluate the effect of planting geometry and weed-management practices in transplanted scented rice varieties. Treatments consisting combination of 2 varieties, 2 planting geometry and 4 weed management practices were replicated thrice in a split-split plot design. The dominant weeds in transplanted rice were: Ludwigia peploides (Kunth) P.H. Raven., Spilanthes acmella (L.) C.B. Clarke ex Hook. f., Echinochloa colona L., Cyperus difformis L., Cyperus iria L., Commelina benghalensis L. and Fimbristylis miliacea (L.) Vahl. Significantly lowest population of different weed species, and the highest grain and straw yields, and harvest index were found with variety, ‘Tarunbhog Selection 1’ while the maximum test weight was observed with ‘Dubraj Selection 1’. The planting geometry of 20 cm × 20 cm recorded the minimum weed population and the highest yield and benefit cost ratio. Application of pyrazosulfuron ethyl 10% WP @ 20 g/ha at 3 Days after transplanting (DAT) + 1 hand weeding (HW) at 25 DAT was found the most effective for broad-spectrum weed control and increased the rice grain yield. The highest net returns and benefit cost were recorded with the pre-emergence application of pyrazosulfuron ethyl 10 % WP @ 20 g/ha.