GROWTH AND YIELD OF BORO RICE AS AFFECTED BY WEED MANAGEMENT

Abstract

The experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka during the period from January to May, 2009 to study the growth and yield of Boro rice as affected by weed management. The experiment comprised two factors. Factor A: Variety: 2 levels; BRRI dhan29 – V 1 ;

Hira 1 – V 2 ; Factor B: Weed management: 5 levels; No weeding – M 0 ; 2 hand weedings – M 1 ; Application of herbiside – M ; Application of water hyacinth – M 3 and Application of rice straw – M 4 2 . The experiment was laid out in split plot design with three replications. Significant variation was recorded for data on weed population, different yield contributing characters and yield At 25 and 65 DAT, it was found that the maximum number of weeds (17.24 m -2 and 21.79 m ) were found in the Hira 1 cultivated plot whereas the minimum number (16.48 m and 20.92 m -2 ) was recorded in BRRI dhan29. At 30, 50, 70, 90 DAT and harvest the taller plant (22.83 cm, 29.37 cm, 43.13 cm, 58.16 cm and 82.92 cm, respectively) was recorded from V , whereas the shorter plant (21.68 cm, 28.14 cm, 41.80 cm, 55.82 cm and 81.79 cm respectively) from V 2 . The higher grain yield (6.62 t/ha) was recorded from V 2 1 , whereas the lower yield (6.04 t/ha) from V . At 25 and 65 DAT, the lowest dry weight of weed biomass (1.51 g and 1.29 g respectively) was recorded in M 1 and the highest weed biomass (1.59 g and 1.72 g) was found in the M plot. At 30, 50, 70, 90 DAT and at harvest, the tallest plant (25.06 cm, 32.08 cm, 45.53 cm, 63.18 cm and 89.65 cm, respectively) was observed from M 1 0 , while the shortest plant (19.90 cm, 25.53 cm, 39.12 cm, 50.37 cm and 74.58 cm, respectively) was recorded from M . The highest grain yield (7.56 t/ha) was observed from M , while the lowest grain yield (3.84 t/ha) was recorded from M 0 1 . The highest straw yield (7.78 t/ha) was observed from M 1 , while the lowest straw yield (4.53 t/ha) was recorded from M . At 25 DAT, the maximum (21.54 m -2 ) weed population was observed in V 2 M and the lowest (6.70 m -2 ) population observed in V 1 M 2 1 . At 65 DAT, the maximum (31.79 m ) weed

0 -2 3 -2 -2 0 population was observed in V 2 M . At 30, 50, 70, 90 DAT and at harvest the tallest plant (25.31 cm, 32.40 cm, 46.03 cm, 65.20 cm and 89.80 cm, respectively) was observed from V 2 M 1 0 , while the shortest (18.67 cm, 24.80 cm, 38.35 cm, 49.60 cm and 74.53 cm, respectively) from V 1 M . The highest grain yield (7.71 t/ha) was observed from V 2 M 1 0 , while the lowest yield (3.56 t/ha) from V .

1 M 0