EFFECT OF NITROGEN AND WEED MANAGEMENT ON GROWTH AND YIELD OF BRRI dhan46

Abstract

A research work was carried out at the Agronomy Farm, Sher-e-Bangla Agricultural University, Dhaka-1207 during the period August to December 2008 to determine the suitable nitrogen dose and weeding method to cultivate transplanted Aman rice variety BRRI dhan46 with higher yield harvest. The experiment comprised five doses of nitrogen viz. N 1 = 50 % lower nitrogen than recommended dose, N = 25 % lower nitrogen than recommended dose, N 3 = Recommended dose of nitrogen, N = 25 % higher nitrogen than recommended dose, N = 50 % higher nitrogen than recommended dose and three weeding methods viz. W 5 1 2 4 = Control (No weeding), W

= Hand weeding at 20, 35 and 50 DAT and W = Weeding with Japanese rice weeder at 20, 35 and 50 DAT. The experiment was set up in a split-plot design with three replications. Experimental Results indicated that nitrogen doses had the significant effect on plant height, tillers hill -1 3 , weight of dry matter hill -1 , weed dry matter weight m -2 , effective tillers hill -1 , panicle length, filled grains panicle -1 , grain yield, straw yield and harvest index. Nitrogen dose 25 % higher than recommended dose (N ) showed the highest grain yield (5.34 t ha -1 ) that mainly attributed by the highest effective tillers hill -1 and highest filled grains panicle -1 . Among the weeding methods hand weeding treatment gave the highest grain yield (4.73 t ha -1 ) and it was mainly attributed by the highest effective tillers hill -1 , filled grains panicle -1 and 1000- seed weight. Combination of nitrogen doses and weed management methods did not significantly influenced the yield of rice.

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