Utilizing Deficit Irrigation to Enhance Growth Performance and Water-use Efficiency of Eggplant in Arid Environments

The objective of this research was to investigate the effects of deficit irrigation on physiological and agronomic terms of eggplant to maximize the Water Use Efficiency (WUE) without affecting the final yield and fruit quality parameters under arid environment. Therefore, two field experiments were conducted at two different sites: Ghor Al-Safi, Jordan Valley and Sail Al-Karak, Karak Valley, Karak Province, Jordan, using a common eggplant cultivar (Classic) using five irrigation levels: ۲۰, ۴۰, ۶۰, ۸۰, and ۱۰۰% based on field capacity. The most stressful Deficit Irrigation (DI) treatments (۴۰ and ۲۰%) resulted in significant effects on leaf area, leaf relative water content, leaf water potential and leaf mineral content. Biochemical parameters also showed an increase in proline and a decrease in chlorophyll content under water deficit conditions. Fruit weight and total yield decreased with DI. The control (۱۰۰% irrigation treatment) plants revealed higher nutrient contents than the water-stressed plants. The fruit TSS and titratable acidity were increased at both sites as the irrigation regime decreased from ۱۰۰ to ۲۰%. Fruit nutrient content decreased with increasing water deficit. However, the differences were not significant between the control (۱۰۰% irrigation treatment) and the ۸۰% irrigation treatment. The ۸۰% treatment showed high water use efficiency with relatively small effects on plant growth performance compared with the control. As a result, DI level at ۸۰% can be utilized to increase WUE without a significant effect on crop growth performance.