Foliar Selenium Application to Improve the Tolerance of Eggplant Grown under Salt Stress Conditions

Sea level rise is one of the most risky climate change impacts under Egyptian conditions to increase the salinity of northern Delta. Increasing the tolerance for salinity in current and future crops is strongly desirable. The current experiment was carried out in the experimental station at Agriculture Research Centre, Egypt, during the summer seasons of 2014 and 2015, to evaluate the effect of selenium foliar applications (0, 5, 10, 20, 30 µM Na2SeO3) on eggplant grown on a sandy soil and irrigated with different concentrations of saline water (0, 30, 60, 120 mM NaCl). The results showed that the Se supplement with 20 µM showed the best effects on vegetative growth and yield of eggplants under different salinity levels of irrigation water. Increasing salinity resulted in increasing N and P contents in the leaves and fruits of eggplant, but K decreased as a result of some sort of antagonism with Na; in spite of that, N, P and K contents in leaves and fruits increased with increasing Se supplements up to 20 µM to be at higher concentrations then decreased. Regarding K/Na ratio in leaves, the treatment of ECw 13.5 dS m-1 without Se supplements gave the lowest value (0.52); treatment of Se 30 µM under 0 mM NaCl irrigation water gave the highest one (1.71). Also, chlorophyll contents in plant leaves increased with increasing salinity level of irrigation water, but decreased with increasing Se supplements. Regarding the proline contents in fresh leaves, the treatment of ECw 13.5 dS m-1 without Se supplements gave the highest value (51 mg g-1), but the lowest one (30.9 mg g-1) was observed with control treatment.