SUSCEPTIBILITY AND RECOVERY POTENTIAL OF HYBRID RICE VARIETIES TO DROUGHT STRESS AT DIFFERENT GROWTH STAGES

Abstract

An experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Dhaka-1207 during the boro season of the year 2017-18 to evaluate the susceptibility and recovery potential of five hybrid rice varieties to drought stress at different growth stages. The two factorial experiment was laid out in a split plot design with three replications. Factor A: Different levels of drought stress [T 0 = Drought stress at 40-45 days after transplanting (tillering), T 2 = Drought stress at 80-85 days after transplanting (flowering)] and Factor B: Hybrid rice varieties [V 1 = BRRI dhan29, V 2 = Nobin, V 3 = Heera2, V 4 = Moyna, V 5 = BRRI hybrid dhan3]. Significant variation was observed on growth, yield and yield contributing parameters. In case of drought stress, the highest plant height at different days after transplanting (29.84 cm, 49.77 cm, 69.60 cm and 89.42 cm respectively), leaves hill -1 (75.05), leaf area index (4.13), tillers hill -1 = Control, T 1 (6.40, 9.87, 12.87 and 14.13 respectively), effective tillers hill

(12.60), panicle length (24.37 cm), filled grains panicle -1 (161.43), 1000 grain weight (31.39 g), grain yield (7.26 t ha -1 ), straw yield (8.42 t ha -1 1 ) and chlorophyll content (48.83) were recorded from T 0 ), biological yield (15.68 t ha and lowest from T 2 . In case of hybrid rice varieties, the highest plant height at different days after transplanting (25.83 cm, 43.97 cm, 61.72 cm and 78.07 cm respectively), leaves hill (59.89), leaf area index (4.25), tillers hill -1 (5.08, 8.42, 11.00 and 12.75 respectively), effective tillers hill -1 (10.67), panicle length (22.57 cm), filled grains panicle -1 (156.53), 1000 grain weight (29.67 g), grain yield (6.88 t ha -1 ), straw yield (7.98 t ha ), biological yield (14.86 t ha -1 ) and chlorophyll content (41.89) were recorded from V 3 and lowest from V 2 . In interaction, highest plant height at different days after transplanting (31.77 cm, 50.77 cm, 70.80 cm and 90.23 cm respectively), number of leaves hill (90.67), leaf area index (4.68), tillers hill -1 (7.33, 11.67, 14.67 and 16.33 respectively), effective tillers hill -1 (15.33), panicle length (26.50 cm), filled grains panicle -1 (173.30), 1000 grain weight (31.07 g), grain yield (8.58 t ha -1 ), straw yield (9.96 t ha ), biological yield (18.55 t ha -1 ) and chlorophyll content (49.33) were recorded from T 0 and lowest from T 2 V 2 . Thus, V 3 (Heera2) showed better performance under drought stress and V 2 (Nobin) showed comparatively more susceptibility to drought stress. -1 -1 -1 -1 V 3 -1