EFFECTS OF FREQUENCY OF IRRIGATION ON ONION (/Aiium capa L.) BULB PRODUCTION

Abstract

A field experiment was conducted at the Bangladesh Agricultural University Horticulture Farm, Mymensingh during Hovember 1989 to April 1890 to determine the optimum moisture level and optimum frequency of irrigation for bulb production of onion cv. Faridpur Bhati. There were five irrigation treatments viz. no irrigation, irrigation at 15, 30, 45 and 60% depletion of available soil moisture. The treatments were replicated three times in randomized block design. Irrigation significantly influenced the plant growth and yield of onion. Maximum number of leaves per plant (11.58) was j produced in 15% depletion regime. Irrigation at 30% depletion produced maximum plant height (43.03 cm) which was closely followed at 15% depletion (41.83 cm). Occurence of split bulb and bolting plant were higher under irrigated condition. The size of the bulb increased with irrigation. Highest yield of bulb (12.96 t/ha) was obtained in 15% depletion regime with a total water use of 195.2 mm.