Growing macadamia nut trees continues to gain popularity due to the delicacy and nutritional value associated with the nuts. These evergreen trees are grown in areas where rainfall quantity and distribution is often inadequate to sustain optimum yields. As a result, irrigation is often required to meet demands and achieve maximum profits. However, there is little detail on the minimum volume of water required during different growth stages to obtain optimal yields. This paper reviews existing studies on the plant-water relations of macadamia nut trees from the perspective of understanding their impacts on water resources. Macadamia trees have been found to use an average 75 L tree⁻¹ day⁻¹ in Australia, while values range between 4 and 71 L tree⁻¹ day⁻¹ for trees grown in South Africa. Macadamia trees are characterised by strict stomatal control, enabling them to maintain a favourable water status for prolonged periods under water stressed conditions. However, stress during the premature nut drop and oil accumulation stages decreases yield and quality. On the other hand, imposing stress at floral initiation increases yield. Therefore, stress manipulation may be a useful management tool for improved water use efficiency in commercial orchards. This requires accurate measurements of the thresholds for the maximum stress and minimum water required at these critical stages. Yield response to irrigation has been difficult to determine with confidence. Due to the cyclical nature of macadamia yields, it has been recommended that a minimum of five years is required to establish a relationship between water use and yield. There has been a limited amount of work done on the impacts of macadamia production on water resources and financial constraints are likely to limit this in the future. However, based on the rapid development of commercial macadamia orchards, future water-related research needs to consider macadamia production beyond tree and orchard scales, viewing macadamia as part of a socioecological system where orchard water use may impact on the availability and quality of water for other users, including the environment.

由于与坚果相关的美味和营养价值，种植澳洲坚果树继续受到欢迎。这些常绿乔木生长在降雨量和分布通常不足以维持最佳产量的地区。因此，经常需要灌溉来满足需求并实现最大利润。然而，关于在不同生长阶段获得最佳产量所需的最小水量的细节很少。本文从了解澳洲坚果树对水资源的影响的角度回顾了现有的关于澳洲坚果树植物-水分关系的研究。已发现澳洲坚果树在澳大利亚平均使用 75 L 树^-1天^-1，而值范围在 4 到 71 L 树^-1天之间⁻¹用于南非种植的树木。澳洲坚果树的特点是严格的气孔控制，使它们能够在缺水条件下长时间保持良好的水分状态。然而，坚果过早脱落和油积累阶段的压力会降低产量和质量。另一方面，在开花开始时施加压力会增加产量。因此，压力控制可能是提高商业果园用水效率的有用管理工具。这需要准确测量这些关键阶段所需的最大压力和最小水量的阈值。很难自信地确定灌溉对产量的反应。由于澳洲坚果产量的周期性，建议至少需要五年时间才能建立用水量和产量之间的关系。在澳洲坚果生产对水资源的影响方面所做的工作有限，未来可能会受到财政限制。然而，基于商业澳洲坚果园的快速发展，未来与水相关的研究需要考虑超越树木和果园规模的澳洲坚果生产，将澳洲坚果视为社会生态系统的一部分，其中果园用水可能会影响水的可用性和质量。其他用户，包括环境。