作物科学と技術の進歩

抽象的な

Effect of Deficit Irrigation on Yield and Yield Components of Onion (Allium cepa l.) Cultivars in Horo District, Western Ethiopia

Worku A, Zerihun Jalata

Onion crop is widely is grown under irrigation by the small and large scale farming in Ethiopia However, its yield performance is limited due to scarcity of water resources and varietal influences. Hence, Deficit Irrigation (DI) improves water productivity and irrigation management practices resulting in water saving. Thus, an experiment was conducted using three onion cultivars (Bombay red, Red Creole and Adama red) as the main plot and four types of DI were applied at 3, 5, 7, and 9 days irrigation interval as a subplot and arranged in Split Plot Design with three replications at Horo District, Western Ethiopia. This study aimed to investigate the effects of deficit irrigation on the growth, yield, and yield components of onion cultivars, identify the sensitive onion variety(s) to the deficit irrigation and identify irrigation water use efficiency for onion cultivars. Analysis of variance showed highly significant (p<0.01) difference for the interaction effects of varieties (main plot) and deficit irrigation level (subplot) on plant height, leaf length, number of leaves per plant, pseudo-stem diameter, average bulb weight, marketable bulb yield, unmarketable bulb yield and total bulb yield except for day to maturity and bulb size. The result showed that the highest total bulb yield of 21.2 t/ha and crop water productivity of 44.8/kg/m3 /ha at three days deficit irrigation interval. The yield response factor (Ky) except for three days of DI interval ranged between 0.08 and 0.63. Considering the yield response factors (Ky) with water saved for varieties Bombay red, Red Creole and Adama red (Ky) values were 0.35, 0.08, and 0.33 at five days of DI, respectively, by saving 3244 mm of irrigation water.