Development of Water - Yield Relation for Onion Production at Arba Minch, Southern Ethiopia

Abstract

In arid and semiarid areas where agricultural development is severely constrained by water scarcity and its mismanagement, the need to use the available water efficiently is unquestionable. This research was conducted aiming at development of water - yield relation for onion (Allium cepa L.) production. A field experiment was conducted at Arba Minch area district, Southern Ethiopia during 2017 dry cropping season. The experimental treatments consisted four irrigation levels (100, 75, 50 and 25% ETc) and three irrigation intervals (3, 5 and 7 days). The experiment was laid out according to randomized complete block design in factorial arrangement with three replications. Results of the analysis revealed that the interaction effects of irrigation levels and irrigation intervals showed highly (P<0.01) significant difference on marketable bulb yield and significant (P<0.05) difference on bulb diameter and bulb weight but non significant difference on unmarketable bulb yield. Maximum water productivity (4.6kgm^-3) was recorded from treatment receiving 75% ETc at 3 days irrigation intervals; followed by treatment combination of 75% ETc and 5 days irrigation interval this recorded (4.6kgm^-3). Treatment combination of 75% ETc with 3 days interval and 75% ETc with 5 days interval were save equivalent amount of irrigation water 155mm. This implies that it can bring 0.31 ha area of land in to production. no significant different on marketable bulb yield among them. In addition to that the highest number of irrigation event observed from treatment combination of 3 days interval with 75% ETc than treatment combination of 5 days interval with 75% ETc which leads to save labor cost, time and competition for irrigation water. Therefore, treatment combination receiving 75% ETc and 5 days irrigation interval seems economically productive when adopted by onion farmers in the study area. .

Keywords: water-yield relation, onion, Arba Minch