Deficit irrigation strategies and their impact on yield and nutritional quality of pomegranate fruit

Introduction – The cultivation of drought tolerant crops and the application of deficit irrigation (DI) strategies are necessary agronomic measures for sustainable agriculture in arid regions of the world and in areas that are experiencing recurrent water shortages (i.e., Central California). Pomegranate is a drought tolerant fruit tree and is extensively cultivated in arid and semi-arid regions of the world. The objective of this study was to evaluate the physiological response of pomegranate trees subject to DI for two years relative to fruit yield and quality. Materials and methods – In this 2-year study, pomegranate trees (Punica granatum L. ‘Wonderful’) grown in Central California were treated with four different DI treatments [35, 50, 75 and 100% evapotranspiration (ET_lys)] and tree physiological responses were evaluated relative to fruit yield and nutritional quality (including pH, soluble solids, total phenolic compounds, anthocyanin and non-anthocyanin compounds, and mineral elements). Results and discussion – The DI strategies, as low as 35% Et_c, did not significantly affect the yield, fruit color, pH, concentration of soluble solids, total phenolic compounds, anthocyanin and non-anthocyanin compounds, and mineral elements. Conclusion – Longer-term studies are needed to better predict physiological responses to water deficit management at orchard and individual tree level relative to productivity and nutritional quality of the pomegranate fruit.