EFFECT OF MULCH AND DIFFERENT LEVELS OF SULPHUR AND BORON ON THE GROWTH AND BULB YIELD OF ONION

Abstract

A field experiment was conducted at the research farm of Sher-e-Bangla Agricultural University, Dhaka-1207 during the period from October, 2018 to March, 2019 to find out the growth and yield of onion as influenced by sulphur and boron with mulch materials. The experiment consisted of two factors: Factor A: Four doses of Sulphur and Boron fertilizer viz. F 0 = S 0kg B 0kg/ha (Control), F 1 = S 20kg B 1kg/ha (Sulphur 40 kg/ha and Boron 2 kg/ha), F 3 (Sulphur 20 kg/ha and Boron 1 kg/ha), F 2 = S 60kg B 3kg/ha (Sulphur 60 kg/ha and Boron 3 kg/ha) and Factor B: Four types of mulch viz. M 0 = No mulch and no irrigation, M 1 = Black polythene, M 2 = Water hyacinth and M 3 = Rice straw. There were 16 treatment combinations and experiment was setup in Randomized Complete Block Design (RCBD) with three replications. In case of Sulphur and Boron treatment, the highest plant height at 60 DAT (53.38 cm), maximum leaf number (10.48) at 60 DAT, highest bulb length (4.83 cm), maximum neck diameter (1.31 cm), longest root length (7.78 cm), highest dry matter content (15.98%), highest fresh leaf weight (26.82 g), dry matter content of leaf (24.74 %), single bulb weight (39.93 g), yield per plot (0.80 kg) and yield per hectare (9.98 t) were obtained from F 3 treatment. Similarly, among the mulch materials, highest plant height at 60 DAT (52.51 cm), maximum leaf number (10.19), highest bulb length (4.52 cm), highest bulb diameter (5.74 cm), maximum neck diameter (1.26 cm), longest root length (7.39 cm), the highest fresh leaf weight (25.61 g), dry matter content of leaf (23.35 %), single bulb weight (39.05 g), yield per plot (0.78 kg) and yield per hectare (9.76 t) were obtained from M 1 treatment. In combined effect, highest plant height at 60 DAT (55.54 cm), maximum leaf number (11.47), longest bulb length (5.51 cm), highest bulb diameter (6.68 cm), maximum diameter of neck (1.42 cm), longest root length (7.90 cm), highest fresh leaf weight (29.30 g), dry matter content of leaf (27.48 %), single bulb weight (42.40 g), yield per plot (0.85 kg) and yield per hectare (11.21 t) were obtained from F 3 treatment. The highest gross return (Tk. 3,36,300/ha), net return (Tk. 1,88,934/ha) and benefit cost ration (2.28) was obtained from the treatment combination F 3 M 1 (S 60kg/ha + B 3kg/ha with black polythene mulch) compare with the rest of the treatment combinations. For growth, yield and economic point of view, it is apparent the F 3 M 1 treatment was suitable for onion cultivation.