EFFECT OF DEFICIT IRRIGATION LEVELS ON YIELD AND WATER USE EFFICIENCY OF GARLIC (Allium sativum L.) UNDER DIFFERENT FURROW IRRIGATION TECHNIQUES AT HIGHLANDS OF DEBRE BIRHAN, AMHARA REGION, ETHIOPIA

Abstract

In the current time of overpopulation pressure and climate change, the competition for water resource is increasing over time and space. The improvement of irrigated agriculture is an important national issue. The experiment was conducted at Debre Birhan Agricultural Research Center to investigate the effect of deficit irrigation levels on yield and water use efficiency of garlic (Allium sativum L.) local cultivar under different furrow irrigation techniques. It was laid out in Randomized Complete Block Design with three replications with four irrigation levels (100, 85, 70, and 55% ETc) and three-furrow irrigation techniques (AFI, FFI and CFI). The amount of water applied was based on the soil water depletion. All collected data was subjected to ANOVA in SAS statistical software. The result obtained revealed that different irrigation levels had a highly significant (P<0.01) effect on yield and WUE of garlic. A smaller reduction of irrigation levels would not have brought significant yield reduction. Similarly, yield and WUE were highly significantly (p<0.01) affected by furrow irrigation techniques. AFI techniques gave a higher WUE with 10% yield reduction in comparison to CFI and 29% yield advantages over FFI. Moreover, the interaction effect of deficit levels and furrow techniques had highly significantly (P<0.01) affected yield and WUE of garlic. The maximum yield of 9.1 t/ha was obtained with the application of 100 % ETc under CFI, while the maximum WUE of 4.1 kg/m3 with the application of 55 % ETc under AFI. The application of 85 % ETc under AFI resulted in statistically no significance difference in yield and WUE of 100 % ETc under AFI. In areas where there is abundant water, garlic could be irrigated with seasonal irrigation water of 592 mm (100% ETC) under CFI techniques in F.C state. The application of 85 % ETc under AFI techniques save irrigation water without having yield penalty, and this saved water could possibly produce an extra yield of 9.9 t/ha, save water usage and attain optimum garlic production. Therefore, the application of 85% ETc levels under AFI is the best choice under the conditions of the study area