Effect of Deficit Irrigation on Common Bean (Phaseolus vulgaris L.) Under Conventional, Fixed and Alternate Furrow Irrigation Systems at West Wellega, Ethiopia

Improving water use efficiency is one important strategy for addressing future water scarcity, which is driven particularly by increasing human population. Enhancing agricultural water productivity is a critical response as it is by far the main consumer of global fresh water. This study investigated the response of common bean (Phaseolus vulgaris L.) to moisture deficit under conventional, alternate and fixed furrow irrigation system over a three years period. A field experiment was conducted at Haru Agricultural Research sub-center. A randomized complete block design (RCBD) with three replications was used. nine treatments which combined and imposed at all growth stages were used. The three years combined result indicated that there were a highly significant (P<0.01) variation among treatments for grain yield, above ground dry biomass yield, plant height and water productivity. The grain yield of common bean was significantly (P<0.01) affected due to moisture deficit and irrigation methods. Accordingly, the highest grain yield was obtained from conventional furrow 100% ETc irrigating all growth stage treatment followed by conventional furrow 75% ETc and 50% ETc. The highest water productivity of 0.84 kg m -3 was obtained from alternate irrigation system at 75% ETc but the yield loss is not tolerable. conventional furrow 75% ETc and conventional furrow 50% ETc gave a better yield with a moderate water productivity. Therefore, for better water productivity without a significant yield loss, it is recommended to use conventional furrow irrigation with 75% ETc and conventional furrow irrigation 50% ETc. In addition, if the water resource is not scarce in the area, it is recommended to use conventional furrow irrigation with 100% ETc throughout the whole growth stage to obtain optimum yield. Keywords; Water productivity, Deficit irrigation, ETc, Furrow irrigation system, common bean DOI : 10.7176/JNSR/9-1-04