Avocado (Persea americana Mill.) is a subtropical tree, particularly sensitive to either an excess or a lack of water. Understanding this balance is crucial to determine the optimum water supply and enhance crop productivity. The rising shortage of water resources in semiarid producing regions and the need for irrigation optimization call for sustainable water savings. A 3-year monitoring study with avocado cv. “Hass” tested sustained-deficit irrigation strategies supplying 33, 50 or 75% of the estimated crop water demand. They were compared with a control strategy supplying 100% of the estimated crop water demand. The leaf water potential, stomatal conductance, tree growth, yield and several fruit quality parameters were evaluated. The yield, tree growth and fruit size were significantly and proportionally lessened by deficit irrigation treatments. Over the study, the average yields amounted to 31.6, 38.3 and 43.8 kg tree⁻¹ in the 33, 50 and 75% treatments respectively, which were significantly less than the yield of 47.5 kg tree⁻¹ measured in the control. The 33% and 75% sustained-deficit irrigation treatments increased the omega 3 and omega 6 fatty acids as well as the unsaturated fatty acids (oleic); however, the 33% deficit irrigation treatment significantly reduced the yield, size and fruit weight. We consider, therefore, that approximately 25% of the irrigation water can be saved without adversely affecting the avocado tree performance in short and medium terms and we recommend implementing the 75% sustained-deficit irrigation strategy. Here we show for the first time the key role of redesigning irrigation strategies in Mediterranean areas, focusing on the benefits of sustained-deficit irrigation, which can save water, encourage water use efficiency and enhance fruit quality. In order to save water, it is critical and necessary to implement such novel water shortage strategies, at the affordable cost of reducing fruit yield while enhancing its quality.

鳄梨（Persea americanaMill.) 是一种亚热带树木，对过量或缺水特别敏感。了解这种平衡对于确定最佳供水和提高作物生产力至关重要。半干旱产区水资源日益短缺和灌溉优化的需要要求可持续节水。一项为期 3 年的鳄梨 cv 监测研究。“Hass”测试了持续亏缺灌溉策略，可提供估计作物需水量的 33%、50% 或 75%。将它们与提供 100% 估计作物需水量的控制策略进行了比较。评估了叶水势、气孔导度、树木生长、产量和几个果实质量参数。亏缺灌溉处理显着并成比例地降低了产量、树木生长和果实大小。在学习期间，^{-1 分别}在 33%、50% 和 75% 处理中，显着低于 47.5 kg 树的产量^-1在控制中测量。33% 和 75% 的持续亏缺灌溉处理增加了 omega 3 和 omega 6 脂肪酸以及不饱和脂肪酸（油酸）；然而，33% 亏缺灌溉处理显着降低了产量、大小和果实重量。因此，我们认为，在短期和中期不会对鳄梨树的生长产生不利影响的情况下，可以节省大约 25% 的灌溉用水，我们建议实施 75% 的持续亏缺灌溉策略。在这里，我们首次展示了重新设计地中海地区灌溉策略的关键作用，重点关注持续亏缺灌溉的好处，它可以节约用水、提高用水效率并提高水果质量。为了节约用水，