Effects of organic mulches on growth and yield of winter onion (Allium cepa L.) cultivars

An experiment was conducted to study the effects of cultivars and household organic mulches on growth and yield of onion at the Horticulture Farm of the Department of Horticulture, Bangladesh Agricultural University, Mymensingh during the period from October 2020 to March 2021. The experiment consisted of three winter onion cultivars of Bangladesh viz. Taherpuri, BARI Piaz-1 and BARI Piaz-4, and five organic mulches, viz. Control (no mulching), vegetables wastes, rice straw, banana leaf and water hyacinth. The two-factor experiment was carried out in Randomized Complete Block Design with three replications. Results revealed that the parameters under study showed significant variation among onion varieties and mulching. BARI Piaz-4 gave the highest plant height, number of leaves, fresh weight and gross yield of bulb compared to BARI Piaz-1 and Taherpuri. The application of water hyacinth increased plant height, number of leaves, fresh weight of bulb, bulb length and diameter, and bulb yield compared to other treatments. Mulching with water hyacinth showed the best results in respect of on all the parameters under study. The highest bulb yield (12.72 t/ha) was recorded in T4 and the lowest bulb yield (8.97 t/ha) was found in T0. The effect of household organic mulches on yield were in order of water hyacinth> vegetables wastes> rice straw> banana leaf> control (no mulching). Among the treatment combinations water hyacinth mulch in combination with BARI Piaz-4 gave the highest plant height (47.85 cm), number of leaves (14.01), fresh weight of bulb (52.87 g) and gross yield of onion (18.24 t/ha), whereas, the lowest plant height (36.13 cm), number of leaves (6.53), fresh weight of bulb (17.08 g) and gross yield of onion (5.74 t/ha) were was obtained from Tahepuri caultivar having no mulch. Therefore, the combined application of water hyacinth along with BARI Piaz-4 was found to be the best in respect of growth and yield of onion.