Gilat Research Center, Agricultural Research Organization, Volcani Institute, M.P. Negev 8528000, Gilat, Israel.
Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Institute, Rishon LeTsiyon 7505101, Israel.
Sci Rep. 2022 Jul 22;12(1):12563. doi: 10.1038/s41598-022-16839-3.
With climate change, spring heatwaves have become frequent in the Mediterranean region. High temperatures combined with wind and low humidity are problematic for subtropical crops adapted to high humidity and mild climate. Avocado is a valuable crop-nutritionally and economically-and many new orchards are planted in Mediterranean areas. Spring heatwaves increase avocado fruitlets dropping, severely decreasing yields. Addressing and solving the problem are necessary to maintain the crop's profitability. This study presents a sprinkler-based canopy cooling method that uses the existing pressurized irrigation system. The study aimed to test the system's performance during spring heatwaves, after the flowering season, in avocado orchards cultivated in a semi-arid region. The experiments examined the effect of various sprinkler types with varying flow rates and installation methods: sprayers, sprinklers and pulsing sprinklers, on foliage temperature, stem water potential, salt accumulation in the leaf, fruitlet survival and yield. The system reduced leaf temperatures by approximately 10 °C, significantly decreasing the trees' drought stress and increasing yields by 8-12%. Using low-quality water is possible, but requires adjustments to avoid salt damage to the leaves. The system can mitigate heat stress, and provides a relatively simple solution for handling spring heatwaves. The evaporative cooling system is modeled for semi-desert and desert conditions; the dry, windy climate contributes to the method's effectiveness.
随着气候变化，地中海地区的春季热浪变得越来越频繁。高温加上风和低湿度，对适应高湿度和温和气候的亚热带作物来说是个问题。鳄梨是一种有价值的作物——在营养和经济上——许多新的果园都种植在地中海地区。春季热浪会导致鳄梨幼果掉落，严重降低产量。解决这个问题对于保持作物的盈利能力是必要的。本研究提出了一种基于喷头的树冠冷却方法，该方法利用现有的加压灌溉系统。该研究旨在测试该系统在春季热浪期间（开花季后）在半干旱地区种植的鳄梨果园中的性能。实验研究了不同类型喷头（喷雾器、喷头和脉冲喷头）、不同流量和安装方法对叶温、茎水势、叶片盐分积累、幼果成活率和产量的影响。该系统将叶片温度降低了约 10°C，显著降低了树木的干旱胁迫，并将产量提高了 8-12%。使用低质量的水是可能的，但需要进行调整以避免盐分对叶片的损害。该系统可以缓解热应激，为应对春季热浪提供了一个相对简单的解决方案。该蒸发冷却系统针对半干旱和沙漠条件进行了建模；干燥多风的气候有助于提高该方法的效果。
