Engenharia de Sistemas de Irrigação e Drenagem

Onion seed production and water productivity under deficit irrigation in Oda Bultum District, West Hararghe Zone, Eastern Ethiopia

Abstract

Gamachu Ayala*, Ayana Bulti, Eshetu Ararso and Bayisa Muleta

In semi-arid areas where agricultural development is highly constrained by water scarcity and its mismanagement, the need to use the available water resources efficiently is important. The aim of the study was to evaluate the effect of different irrigation levels on seed yield, yield components and water productivity of onion (Allium cepa L.). The experiment was carried out on two farmer’s field on Midhagdu small scale irrigation scheme at Oda Bultum district, West Hararghe Zone during 2018/19 irrigation season. The experiment was laid out in a randomized complete block design with three replications of five irrigation levels (i.e.100, 90, 80, 70 and 60%) in combination of four growth stages (vegetative, bolting, flowering and seed formation) with non-deficit at all growth stages used as control. The combined result of deficit furrow irrigation techniques indicated that there were significance difference (p<0.05) between onion seed yield and water productivity but no significance difference (p>0.05) were observed on growth parameters. The highest mean seed yield and net return were gained from 20% deficit at vegetative stage with higher benefit-cost ratio indicating better onion seed yield is found with mild water stress and reduced with increase in water stress. Thus, the findings summarized that using deficit irrigation of 20% were economically profitable and saves water than full irrigation at all growth stages.