Effect of planting geometries and weed-management practices on weeds, crop performance and economics of direct-seeded aerobic rice (Oryza sativa)

Abstract

A field experiment was conducted in a factorial randomized block design during the rainy (kharif) season of 2013 at Pantnagar, Uttrakhand, to study the influence of different planting geometry and weed-management prac- tices on weed and crop dynamics in direct seeded aerobic rice (Oryza sativa L.). Continuous drilling at 20 cm with pendimethalin as pre-and bispyribac-Na as post emergence herbicide supplemented with 1 hand-weeding 45 days after sowing provided excellent results. Echinochloa colona (2.04 +0.71) recorded the maximum summed dominance ratio. Among the planting geometries, continuous drilling at 20 cm and among weed-control practices, pendimethalin (1,000 g a.i./ha) + bispyribac-Na (25 g a.i./ha) + 1-hand-weeding 45 days after sowing (DAS) pro- vided the higher weed-control efficiency (87.4%), productivity ( 4.79 t/ha) and net benefit ( 40,633/ha).