Water Use of Micro-Sprinkler Irrigated Apple Trees Under Full Irrigation and Regulated Deficit Irrigation

Apple trees grown in a loam soil, were irrigated under two different treatments: 80% of E-pan all seasons (full irrigation treatment) and 40% of E-pan (Regulated Deficit Irrigation-RDI) during slow fruit growth stage plus 80% of E-pan during the rest periods. Compared with full irrigation, RDI treatment saved 17%～20% of water and kept almost the same yield and shoot growth reduced. Similar results were obtained for both years of the study. The annually averaged crop factors were 0.61 and 0.55 for full irrigation and RDI treatment, respectively.