Effects of Salicylic Acid, Melatonin, and Mycorrhizal Fungi on the Growth and Physiological Responses of Wheat Under Varying Water Irrigation Stress Levels

Abstract

The current study was carried out in Shandaweel Agricultural Research Station in Sohag governorate, Egypt, during the two growing seasons 2017/2018 and 2018/2019. The purpose of this research is to investigate the influence of melatonin(30 ppm), salicylic acid (200 ppm), mycorrhizal fungi inoculation (250 spores), and the combination of melatonin (30 ppm) + mycorrhizal fungi inoculation (250 spores), and salicylic acid (200 ppm) + mycorrhizal fungi inoculation (250 spores) treatments on growth parameters and physiological activitiesof wheat (Triticum aestivum L cv. Shandaweel1), which subjected to three water irrigation levels (5476 (I100%), 4380 (I80%) and 3285 (I60%) m3 ha-1 compared to the control (untreated plants). The results showed that the decreasing irrigation water amount from 5476 m3 ha-1 (I100%) to 3285 m3 ha-1 (I60%) caused a significant decrease of relative water content, membrane stability index, leaf area duration, crop growth rate, relative growth rate and net assimilation rate of wheat in both seasons, respectively. According to our findings, the use of melatonin, salicylic acid, and mycorrhizal fungal treatments singly or in combination reduced the deleterious effects of water stress on all of the aforementioned parameters.