Abstract In stone fruits, the pit hardening period is usually one of slow fruit growth that is considered relatively insensitive to an imposed moderate water stress. For this reason, this period is commonly employed for a first phase of reduced water input in regulated deficit irrigation (RDI) strategies. However, in previous studies with the Japanese plum cv. 'Angeleno', the identification of a period of slow growth just before harvest suggested the need to reconsider the most suitable RDI strategy for this cultivar. In this 3-year study (2014, 2015 and 2016) three irrigation strategies were compared: Control (CON) designed to meet tree water requirements throughout the season; Regulated Deficit Irrigation (RDI) with two separate periods of water deficit, one preharvest with no irrigation inputs during an intermediate period of fruit growth (pit hardening period), and the other postharvest with a 30 % reduction of the CON inputs; and Preharvest + Regulated Deficit Irrigation (RDP) with a single period of deficit irrigation initiated before harvesting and extended until the end of the irrigation campaign. Both deficit irrigation treatments were found to be effective at controlling tree vigor, with lower trunk cross-sectional area growth and pruned wood weight than in the CON treatment. Average water savings with the RDI and RDP strategies over the three years of the study were 24 % and 18 %, respectively, compared to CON, with no impact on yield and no carry-over effect. Fruit size in the RDP treatment was similar to the CON. The differences in fruit firmness, soluble solids concentration (SSC), acidity, lightness (L), hue (ho) and chroma (C*) of the skin were only slight or inconsistent over the three years. Our results confirm the suitability of moderate pre- and postharvest water stress (RDP strategy) in this cultivar, with greater water productivity than the traditional RDI strategy.

中文翻译：

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日本晚熟李子品种‘Angeleno’不同亏缺灌溉策略的评价

摘要 在核果中，核硬化期通常是果实生长缓慢的时期之一，被认为对施加的适度水分胁迫相对不敏感。出于这个原因，这个时期通常用于调节亏缺灌溉 (RDI) 策略中减少水输入的第一阶段。然而，在以前与日本梅花 cv 的研究中。'Angeleno' 在收获前发现了一段缓慢的生长期，这表明需要重新考虑最适合该品种的 RDI 策略。在这项为期 3 年的研究（2014、2015 和 2016）中，对三种灌溉策略进行了比较： 对照 (CON) 旨在满足整个季节的树木用水需求；有两个不同时期的缺水期的调节亏缺灌溉 (RDI)，一个收获前在果实生长中期（坑硬化期）没有灌溉投入，另一个收获后减少 30% 的 CON 投入；收获前 + 调节亏缺灌溉 (RDP)，在收获前开始单次亏缺灌溉，并延长至灌溉活动结束。发现两种亏缺灌溉处理都能有效控制树木活力，与 CON 处理相比，树干横截面积增长和修剪的木材重量更低。与 CON 相比，RDI 和 RDP 策略在研究的三年中平均节水分别为 24% 和 18%，对产量没有影响，也没有结转效应。RDP 处理中的果实大小与 CON 相似。果实硬度、可溶性固形物浓度 (SSC)、三年来，皮肤的酸度、亮度 (L)、色调 (ho) 和色度 (C*) 只有轻微或不一致。我们的结果证实了该品种的适度收获前和收获后水分胁迫（RDP 策略）的适用性，其水分生产率高于传统的 RDI 策略。