In this study, the adaptation characteristics of orange trees, related to the application over a decade of deficit irrigation (DI) strategies, have been explored. To this purpose, the analysis of a minimal dataset composed of physiological information (stem water potential - Ψ_stem and sap flow - SF measurements), yield (fruits number and weight) and qualitative parameters (titratable acidity, TA; and total soluble solids, TSS) was performed with reference to the last irrigation seasons (i.e. 2018–19). The applied irrigation treatments were the following: sustained deficit irrigation (SDI); regulated deficit irrigation (RDI); partial root-zone drying (PRD), each distributing a water deficit of about 19%, 29% and 52%, respectively, compared to the control treatment (FI) supplying the full irrigation level (100% ET_c). In general, higher water use efficiencies (WUE) have been obtained in DI treatments, which guarantee greater water savings (up to 50%), without affecting yield and quality characteristics. In particular, the most stressed treatment (PRD), while reaching the lowest Ψ_stem values (− 1.8 to − 2.0 MPa), as also shown by SF versus Ψ_stem clusters, resulted in WUE values for yield (WUE_Y), TA (WUE_TA) and TSS (WUE_TSS) parameters of approximately 2.6, 2.9, and 3.1 times greater than FI, respectively. Overall, this study allowed identifying the cumulative adaptation characteristics of the orange trees under study to the application of long-term DI strategies and showing that trees were able to achieve yields and qualitative features similar to those obtained with FI, even after 10 years of application of deficient irrigation regimes.

在这项研究中，已经探索了橘子树的适应特性，该特性与十年来的亏水灌溉（DI）策略的应用有关。为此，对包含生理信息（茎水势-_茎）的最小数据集进行分析并参考最后一个灌溉季节（即2018-19）进行了汁液流量-SF测量），产量（果实数量和重量）和定性参数（可滴定酸度，TA；总可溶性固形物，TSS）。应用的灌溉方法如下：持续性亏缺灌溉（SDI）调亏灌溉（RDI）; 与提供完全灌溉水平（100％ET _c）的对照处理（FI）相比，部分根区干燥（PRD）分别分配约19％，29％和52％的水分亏缺。通常，在DI处理中获得了更高的用水效率（WUE），这可以确保更大程度的节水（最多50％），而不会影响产量和质量特性。特别是压力最大的治疗（PRD），而最低的是SF与Ψ的_茎簇也显示了_茎值（-1.8至-2.0 MPa），得出的WUE值（WUE _Y），TA（WUE _TA）和TSS（WUE _TSS）参数约为2.6、2.9，和FI分别大3.1倍。总体而言，这项研究可以确定所研究的橙树对长期DI策略的应用的累积适应特征，并表明即使使用10年后，橙树也能够获得与FI相似的产量和定性特征灌溉制度不足。