Spraying Maize with Salicylic and Ascorbic Acids to Improve Physiological Traits and Productivity Under Water Stress Conditions

A field trial was performed at El-Gemmeiza Agricultural Research Station El-Gharbia Governorate, Egypt, which is situated between Latitude 30° 58′ 56′′ N and Longitude 30° 57′ 8′′ E during the two successive summer seasons of 2020 and 2021 to examine how salicylic (SA) and ascorbic (AA) antioxidants could mitigate the negative influences of water stress and their effects on physiological traits and yield of maize plants (Single Cross 168).Irrigation treatments were applied at 50, 65 and 80 % of available soil moisture depletion (AVSMD) and foliar spraying with SA and AA at the concentration of 100 or 200 ppm.Increasing soil moisture depletion up to 80 % of AVSMD, diminished significantly shoot dry weight plant, plant height, leaf area index, leaf area duration, chlorophyll (chl.) a and b, leaf relative water content (LRWC), ear length, No. of grains row,100grain weight and grain yield. Whereas, osmotic potential (OP) and chl. a/b increased significantly. Irrigation at 65 % of AVSMD significantly increased water use efficiency (WUE), chl. a and b compared to other irrigation levels. The foliar spraying of SA or AA (200 ppm) significantly increased most of the studied traits compared to untreated plants, except for OP and Chl. a/b which were significantly reduced by SA foliar spraying at 200ppm. It can be concluded that irrigation of maize plants at 65 % of AVSMD with foliar spraying with 200 ppm SA or AA activate maize plant ́s growth and improved WUE also enhancing biosynthesis of photosynthetic pigments and then improving yield.