Effect of different mulching materials on weed dynamics and yield of direct seeded rice in Chitwan, Nepal

An experiment was carried out at farmers ' field to compare the effects of live mulches and herbicide on weed growth and dynamics, yield, and economic performance of direct seeded rice under humid sub-tropical condition at Phulbari, Chitwan in 2009. The experiment was conducted in Randomized Complete Block Design with eight treatments and three replications. The treatments consisted of i) control, ii) three hand weeding, iii) herbicide application (bispyribac sodium @ 80 ml/ha) + one hand weeding, iv) wheat straw mulch @ 5t/ha + one hand weeding, v) Eupatorium mulch @ 5t/ha + one hand weeding, vi) brown manuring with Sesbania aculeata @ 30 kg/ha, vii) brown manuring with Sesamum indicum @ 2kg/ha, and viii) brown manuring with Crotolaria juncea @ 30 kg/ha. Weed dry matter accumulation was significantly lower with herbicide application (1.15 g/m2) than wheat straw mulch (6.75 g/m2). The treatments with brown manuring and Eupatorium mulch were found to be equally effective in suppressing the weed growth by reducing both dry matter content and weed density. Application of Eupatorium mulch one day after sowing produced significantly higher grain yield (3.5 t/ha) than control (1.77 t/ha), Sesamum brown manuring (2.97 t/ha) and wheat straw mulch (2.83 t/ha). Yield attributes like effective tillers/m2, panicle length and panicl