Integrated Irrigation Management for a Pear Orchard Under Mediterranean Semi-Arid Conditions

This study evaluated the effect of an integrated irrigation practice (IP), including reg-ulated deficit irrigation (RDI), managed through an IoT-based platform, on a pear or-chard (Pyrus communis L., cv. ‘Krystali’) compared to the farmer’s standard practice (FP). Tree response was evaluated through the measurement of tree water relations, leaf physiological functions, biochemical parameters, fruit growth and quality, pro-duction, and aerial multispectral NDVI imaging. IP achieved 15.8% water savings, sig-nificantly enhancing water-use efficiency and increasing yield per tree. However, IP trees exhibited higher crop water stress index - CWSI values and lower midday stem water potential -Ψstem than FP, particularly by late July, indicating progressive water stress. Leaf-level responses revealed morphological and biochemical alterations to drought, including increased leaf mass per area (LMA), dry matter content (DM), and accumulation of proline, alongside declines in chlorophyll pigments. Despite these stress indicators, gas exchange parameters were maintained in IP, possibly due to fruit load modulating source–sink relationships and surpassing stomatal limitations. IP re-duced vegetative growth, as evidenced by lower winter pruning material mass, but this did not result in improved fruit quality. IP produced smaller fruit with lower an-tioxidant activity, polyphenolic content and soluble solids content/acidity ratio, alt-hough fruit firmness was improved. NDVI did not detect differences between the treatments on vegetative growth, or on canopy greenness, suggesting that IP trees maintained adequate photosynthetic capacity or that water stress was moderate for NDVI detection. The study highlights the need for integrating irrigation management with fruit thinning and careful scheduling to optimize both water productivity and marketable fruit quality in water-scarce pear production systems.