Threshold Values of Plant Water Status for Scheduling Deficit Irrigation in Early Apricot Trees

Irrigated agriculture is facing a serious problem of water scarcity, which could be mitigated by optimizing the application regulated deficit irrigation (RDI) strategies. For this reason, aim our study was to determine thresholds based on direct status indicators apricot trees under RDI maximize productivity. Three treatments were tested: (i) Control (CTL), irrigated at 100% crop evapotranspiration (ETc) during entire cycle; (ii) RDI1, as CTL, except fruit growth stages I–II when reduced 20% and late post-harvest, with an threshold moderate stress −1.5 MPa stem potential (Ψs); (iii) RDI2, but post-harvest using severe −2.0 Ψs. As scheduling RDI1 RDI2 did not affect yield quality, productivity increased 13.2 25.6%, respectively. This corresponded 1124 2133 m3 ha−1 saved for RDI2. A integral 30.2 day considered optimal since 41 accumulated, vegetative 35%. The non-sensitive periods delimited accumulation growing degree days (GDD) from full bloom, end 640 °C GDD, beginning 1840 GDD.