NITROGEN, WEED AND IRRIGATION MANAGEMENT FOR MAXIMIZING GROWTH AND YIELD OF BORO RICE (cv. BRRI dhan29)

Abstract

Two consecutive field experiments were conducted at the Suapur Union of Dhamrai Upazila, Dhaka. The experimental field is located at 23 88´N latitude and 90 0 14´E longitude and AEZ-12, during the period of 2014-2015 and 20152016

to find out nitrogen, weed and irrigation management for maximizing growth and yield of boro rice (cv.BRRI dhan29). The experiment comprised three factors; Factor A: Nitrogen management (4 levels), N : No urea (control), N 1 : Urea super granules-USG (77 kg N ha -1 ), N 2 0 : Prilled urea at recommended dose (150 kg N ha -1 ) and N 3 : ½ of the recommended dose (75 kg N ha ); Factor B: Weed management (4 levels), W 0 : No weeding (control), W : Two hand weeding (20 and 40 DAT), W 2 0 1 : Pre emergence herbicide (Butachor) and W : Post emergence herbicide (Prityloclor); Factor C: Irrigation management (4 levels), I 1 : Irrigating all time, I 2 : Irrigating 3 days after drying, I : Irrigating 5 days after drying, I : Alternate wetting and drying (AWD) method. The experiments were laid out in split-split-plot designs with three replications. Data on different growth characters, yield components and yield of BRRI dhan29 were recorded. Statistically significant variation was observed for different nitrogen, weed and irrigation management and also for their combined effect. For nitrogen management, on an average of two consecutive years, the highest grain yield (6.01 t ha 4 -1 ) was recorded from N 1 3 , while the lowest (4.35 t ha ) from N 0 . In weed management, the highest grain yield (5.92 t ha -1 ) was recorded from W 2 , while the lowest (4.49 t ha -1 ) from W . In case of irrigation management, the highest grain yield (5.88 t ha -1 0 ) was found from I 4 -1 , while the lowest (4.70 t ha ) from I 1 . For the combined effect of different nitrogen and weed management, the -1 3 -1 highest grain yield (6.80 t ha -1 ) was recorded from N iii

1 W , whereas the lowest (3.85 t ha -1 ) from N 0 W 0 2 . Due to the combined effect of different nitrogen and irrigation management, the highest grain yield (6.36 t ha -1 ) was recorded from N 1 I 4 , whereas the lowest (3.80 t ha -1 ) from N 0 I . In case of combined effect of different weed and irrigation management based on pooled data, the highest grain yield (6.52 t ha -1 ) was recorded from W 2 I 4 1 , whereas the lowest (3.85 t ha ) from W 0 I . Due to the combined effect of different nitrogen, weed and irrigation management, on polled basis the highest grain yield (6.99 t ha 1 -1 ) was recorded from N 1 W 2 I 4 , while the lowest yield (3.18 t ha -1 ) from N 0 W 0 I . The treatments having significantly high grain yields over others were N 1 1 W 1 I ), N 1 W 2 I 4 (6.99 t ha -1 ), N 1 W 3 I 4 (6.90 t ha -1 ), N 2 W 2 I 4 (6.70 t ha -1 ),N 2 4 (6.61 t ha W ), N 3 W 2 I 4 (6.54 t ha -1 ) and N 3 W 3 I 4 (6.61 t ha -1 ), which were identical among themselves.