Ameliorating the deleterious effects of saline water on the antioxidants defense system and yield of eggplant using foliar application of zinc sulphate

To alleviate the harmful effects of NaCl salinity on the development, antioxidants defense system and yield of eggplant (Solanum melongena L.) using foliar application of zinc sulphate (ZnSO4), a pot experiment was conducted during two summer seasons 2017 and 2018 at the Experimental Farm, Faculty of Agriculture, Ain Shams University. Eight treatments were the combination of two sodium chloride levels of irrigation water 0 and 100 mM, and four levels of ZnSO4 0, 0.7, 1.5 and 3 mM. Results indicated that, under 100 mM NaCl concentration of the macronutrients (N, K, Mg and Ca) in leaves significantly decreased, while sodium concentration increased in both leaves and fruits which led to an increase in the concentration of malondialdehyde (MDA) which in turn reflecting on the reduction of vegetative growth, photosynthetic pigments, flowers number, fruits number, fruit setting and total yield of eggplant in both seasons. The foliar application of ZnSO4 alleviated the adverse effects of salinity by stimulating the growth, antioxidants defense system in the form of superoxide dismutase (SOD), total soluble sugars, proline, free amino acids and total soluble protein, which enhanced the flowers number, fruits number, fruit setting and total fruits yield. The most effective application that antagonized the adverse effects of salinity stress was 1.5 mM ZnSO4.