Increasing Water Use Efficiency in Date Palm Cultivation with Plant-Based Sensors

Date palm cultivation in Israel, particularly in the Arava Valley with its high evaporative demand, relies on high-frequency irrigation with saline water. Irrigation plays a crucial role in date palm growth, soil salinity, and yield quality. However, over-irrigation not only wastes water resources but also contaminates water bodies with agrochemicals. Plant-based sensors offer a promising avenue for real-time monitoring of plant physiological responses to water stress, providing valuable insights into plant water status. The objective of this study was to optimize irrigation scheduling by using plant-based sensors to monitor date palm responses to varying irrigation systems and amounts, thereby establishing threshold parameters for effective irrigation management. Sixteen fully mature date palm trees were irrigated under two irrigation systems: a larger irrigated area with fifty number of drippers (D) and a smaller area with two emitters per tree (E), both having the same flow rate; and two irrigation levels: 50% and 100%. Sap flux density, frond growth rate, and stem daily shrinkage were continuously measured by automated sensors, while frond growth rates were also periodically manually measured. Additionally, stomatal conductance was measured biweekly using the LI-600. The 100% irrigation treatment significantly increased the frond growth rate, stomatal conductance, and sap flux density compared to the 50% irrigation. However, the 50% irrigation treatment increased maximum daily shrinkage. There was no difference in yield between 50% and 100% irrigation. No effect of the irrigation systems on the measured parameters was seen. The integration of plant-based sensors, for measuring plant physiological processes, into date palm cultivation has the potential to enable real-time monitoring of the water stress effect, facilitating precise irrigation management.