Effect of water and weed management in Boro rice (cv. BRRI dhan28) in Bangladesh

Abstract

The experiment was conducted at the Farm of Farm Management Division, Bangladesh Agricultural University, Mymensingh during December 2012 to June 2013 to find out the effect of water and weed management in Boro rice (cv. BRRI dhan28). The experiment consisted of three irrigation systems viz., conventional flood irrigation, Alternate wetting and drying (AWD) and System of rice intensification (SRI) and four weed management practices viz., No weeding, hand weeding thrice at 20, 35 and 50 days after sowing, blade weeding + hand weeding once at 20 DAS; and pre-emergence herbicide (Panida 33 EC) @ 2.5 l ha^-1 + hand weeding once at 20 DAS. Crop characters, yield components and yield were significantly influenced by water and weed managements, and their interaction. The highest plant height (91.51 cm), total tillers hill^-1 (15.49), grains panicle^-1 (86.87) and grain yield (4.02 t ha^-1) were obtained in SRI method and corresponding lowest values were found in conventional flood irrigation while all parameters showed intermediate values in AWD. The highest plant height (93.45 cm), total tillers hill^-1 (16.53), effective tillers hill^-1 (12.88), grains panicle^-1 (86.14), grain yield (5.47 t ha^-1) and straw yield were found in pre-emergence herbicide (Panida 33 EC) @ 2.5 l ha^-1 + one hand weeding at 20 DAS while all the parameters showed lowest values in weedy check. Weed infestation reduced 80.07% yield compared to application of pre-emergence herbicide (Panida 33 EC) @ 2.5 l ha^-1 + one hand weeding at 20 DAS. In case of interaction, the highest total tillers hill^-1 (20.93), grains panicle^-1 (102.3) and grain yield (5.86 t ha^-1) were found in SRI method with pre-emergence herbicide (Panida 33 EC) @ 2.5 l ha^-1 + one hand weeding at 20 DAT while the lowest total tillers hill^-1 (10.97), grains panicle^-1 (61.46) and grain yield (0.91 t ha^-1) were found in conventional flood irrigation having no weeding treatment. The above results concludes that SRI method with pre-emergence herbicide (Panida 33 EC) @ 2.5 l ha^-1 + one hand weeding at 20 DAS appeared as the promising technique for appreciable grain yield of Boro rice (cv. BRRI dhan28).