GROWTH AND YIELD OF WHEAT AS INFLUENCED BY IRRIGATION LEVELS AND GIBBERELLIC ACID

Abstract

The experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka during the period from November 2011 to March 2012 to find out the growth and yield of wheat as influenced by irrigation levels and gibberellic acid. BARI Gom-21 (Shatabdi) was used as a test crop of this study. The experiment comprised of two factors; Factors A: Irrigation (4 levels)- I0: No irrigation i.e. control condition; I1: Irrigation at crown root initiation (CRI) stage (18 DAS); I2: Irrigation at pre-flowering stage (45 DAS) & I3: Irrigation at CRI and pre-flowering stage and Factor B: Gibberellic acid (3 levels)- G0: No GA3 i.e. control condition; G1: 100 ppm GA3 & G2: 200 ppm GA3. The experiment was laid out in Split Plot Design with three replications. In case of irrigation, at 50, 60, 70, 80 DAS and harvest, the tallest plant (48.26 cm, 61.63 cm, 76.21 cm, 84.69 cm and 92.36 cm) was recorded from I3 and the shortest plant (42.82 cm, 50.63 cm, 63.25 cm, 70.88 cm and 78.10 cm) from I0. The highest number of filled grain spike-1 (30.76) was recorded from I3, whereas the lowest number (24.49) from I0. The highest grain yield per hectare (3.93 ton) was recorded from I3, while the lowest grain yield (2.95 ton) from I0. The highest straw yield per hectare (4.88 ton) was recorded from I3, again the lowest straw yield (3.83 ton) from I0. For gibberellic acid, at 50, 60, 70, 80 DAS and harvest, the tallest plant (49.24cm, 59.99 cm, 74.40 cm, 83.23 cm and 89.85 cm) was observed from G2, again the shortest plant (42.08 cm, 51.30 cm, 63.71 cm, 72.29 cm and 79.30 cm) from G0. The highest number of filled grain spike-1 (30.43) was found from G2, again the lowest number (26.08) from G0. The highest grain yield per hectare (3.94 ton) was observed from G2, whereas the lowest grain yield (3.13 ton) from G0. The highest straw yield per hectare (4.60 ton) was recorded from G2, whereas the lowest straw yield (4.20 ton) from G0. Due to interaction effect of level of irrigation and gibberellic acid at 50, 60, 70, 80 DAS and harvest, the tallest plant (54.04 cm, 68.58 cm, 84.11 cm, 93.39 cm and 98.05 cm) was observed from I3G2, while the shortest (39.92 cm, 46.76 cm, 57.79 cm, 66.08 cm and 75.67 cm) was recorded from I0G2. The highest number of filled grain spike-1 (34.47) was recorded from I3G2, while the lowest (22.40) was found from I0G0. The highest grain yield per hectare (4.41 ton) was found from I3G2, again the lowest grain yield (2.85 ton) from I0G0. The highest straw yield per hectare (5.40 ton) was observed from I2G2, again the lowest straw yield (3.56 ton) from I0G2. Irrigation at CRI and pre-flowering stage and 200 ppm GA3 performed superior in growth, yield contributing characters and yield of wheat.