EFFECT OF PLANTING DATES AND NiTROGEN DOSES ON THE GROWTH AND YIELD OF BORO RICE CV. BRRI dhan45

Abstract

The experiment was conducted at the experimental field of Sher-e-Bangla Agricultural University. Dhaka. Bangladesh during the period from November 2008 to May 2009 to study the effect of planting dates and nitrogen doses on the growth and yield of Boro rice. Cultivar BRRI dhan45 was used as the test crop in this experiment. The experiment comprised of two factors. Factor A: transplanting date: 3 dates; transplanting at 15 December 2008 - TI; transplanting at 30 December 2008 - T2 and 'l'ransplanting at 15 January 2009- T3. Factor B: Nitrogen level: 4 levels; 0 kg N ha4 (control) - NO; 80 kg N hi' - N,; 100 kg N ha1 - N2 and 120 kg N ha1 - N3. The experiment was laid out in Randomized Complete Block Design with three replications. Data on yield contributing characters and yield were recorded. At 30, 50. 70 and 90 DAT and at harvest, the tallest plant (25.59 cm. 41.88 cm. 59.58 cm. 75.75 cm and 94.44 cm) was recorded from T2, while the shortest plant (24.42 cm. 39.75 cm, 55.94 cm, 72.35 cm and 89.48 cm) was observed from T,. The maximum number of effective tillers hilr' (12.13) was observed from T2 and the minimum number (11.07) was recorded from T1 . The highest grain yield (5.91 t/ha) was found from T2, whereas the lowest yield (5.12 t/ha) was recorded from 1'3. At 30, 50. 70 and 90 DAT and at harvest, the tallest plant (27.09 cm, 43.84 cm. 61.21 cm. 78.38 cm and 95.36 cm) was observed from N3 again the shortest plant (21.98 cm, 35.49 cm, 52.23 cm, 66.00 cm and 82.72 cm) was recorded from No. The maximum number of etl'ective tillers hill' (13.27) was found from N3, whereas the minimum number (9.07) was obtained from No. The highest grain yield (6.44 t/ha) was obtained from N2, while the lowest yield (3.50 t/ha) was found from No. At 30, 50, 70 and 90 DAT and at harvest, the tallest plant (28.17 cm, 45.47 cm. 63.77 cm, 86.26 cm and 98.87 cm) was found from the treatment combination of T2N3, whereas the shortest (21.00 cm, 33.80 cm, 49.97 cm, 82.33 cm and 80.87 cm) was observed from the treatment combination of T1 N0. The maximum number of effective tillers hill' (13.93) was recorded from the treatment combination of T2N1. again the minimum number (8.40) was found from T,N0. The highest grain yield (6.83 t/ha) was recorded from the treatment combination of T2N2 and the lowest yield (3.26 t/ha) from T,N0. It may be concluded that the growth, yield and yield contributing characters of BRRI dhan45 were greatly influenced by planting dates and nitrogen doses. The planting at 30 December and application of 100 kg N ha1 may be recommended for maximum yield of BRRI dhan45 in SAU campus.