GROWTH, YIELD ATTRIBUTES AND YIELD OF WHEAT AS INFLUENCED BY DOSE AND APPLICATION TIME OF MANNITOL

Abstract

An experiment was carried out at the Agronomy Research Field, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur during December 2022 to April 2023 to evaluate the effect of dose and application time of mannitol on growth and yield of wheat (BWMRI Gom1). The experiment was comprised with two factors namely, Factor A: Doses of mannitol viz. D₁ = 0 ppm of mannitol (control), D2=75 ppm of mannitol, D3=150 ppm of mannitol and D4=225 ppm of mannitol and Factor B: Application time of mannitol viz. T₁ = 25 days after sowing (DAS); T2 = 50 days after sowing (DAS) and T3 = 75 days after sowing (DAS). The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. The total plot number was 36 in the experiment. The area of the unit plot was (2.5m × 2 m). All parameters except a few were statistically significant.The highest results were recorded in plant height (106.80 cm) from D4 at 80 DAS. For other parameters, the highest results from D3: length of spike (16.40 cm), number of spikelet spike-1 (16.56), no. of grain spikelet-1 (2.70), grain spike-1 (44.97), weight of 1000-grains (53.19 g), grain yield (3.67 t ha-1), straw yield (4.50 t ha-1),biological yield (8.17 t ha-1), and harvest index (44.58%). And the lowest results were found from control treatments D1 such as; Length of spike (14.06 cm), number of spikelet spike-1 (14.21), grain spikelet-1 (1.99), grain spike-1 (28.29), weight of 1000-grains (46.17g), grain yield (2.61 t ha 1 ), straw yield (3.87 t ha-1), biological yield (6.48 t ha-1), and harvest index (40.24 %).The effect of different time of application of mannitol was recorded highest from T2 i.e. at 50 DAS from all parameters like; plant height (76.63, 95.06 and 107.30 cm), length of spike (15.87 cm), number of spikelet spike-1 (16.02), no. of grain spikelet-1 (2.50), grain spike-1 (40.51), weight of 1000-grains (51.47 g), grain yield (3.41 t ha-1), straw yield (4.26 t ha-1), biological yield (7.68t ha-1), and harvest index (44.11%). The lowest results were recorded from T1 (25 DAS): length of spike (15.16 cm), number of spikelet spike-1 (15.31), no. of grain spikelet-1 (2.26), grain spike-1 (34.89), weight of 1000-grains (48.56 g), grain yield (2.94 t ha 1 ), straw yield (4.15 t ha-1), biological yield (7.09 t ha-1), and harvest index (41.49%). For combined effect, maximum results of were recorded from D3T2; length of spike (17.03 cm), number of spikelet spike-1 (17.16), no. of grain spikelet-1 (2.93), grain spike-1 (50.38),weight of 1000-grains (55.16 g), grain yield (4.00 t ha-1), straw yield (4.60 t ha-1), biological yield (8.60 t ha-1), and harvest index (46.21 %). Lowest results were recorded from D1T1= 0 ppm of mannitol. It can be concluded that for the better growth and yield exogenous application of mannitol @150 ppm at 50 DAS (D3T₂) can be used as combined treatment.