Effect of foliar application of salicylic acid on some of Physiological characteristics of corn (Zea mays L.) under drought stress conditions

IntroductionDrought stress is one of the most important environmental factors that regulate plant growth and development, and limit plant production. Salicylic acid is a growth regulation which its role was investigated in plants tolerance to environmental stresses such as drought stress. Therefore, the objective of present research was to evaluate the effect of foliar application of salicylic acid on response to drought stress in maize.
Materials and methodsIn order to evaluate some physiological and biochemical responses of maize hybrid SC704 to foliar application of salicylic acid under drought stress conditions, this field experiment was carried out at the green house of College of Agriculture, University of Shahid Bahonar, in 2013 in a factorial using completely randomized block design with six replications. Experimental treatments were salicylic acid (0 and 1 mM) and drought stress. Evaluated traits were including plant height, plant fresh weight, plant leaf area, electrolyte leakage, relative water content, photosynthetic pigments and antioxidant enzymes (including ascorbate peroxidase, catalase, peroxidase).
ResultsThe results showed that drought stress (70 and 50% F.C.) significantly reduced relative water content, chlorophyll a, b and total chlorophyll, fresh weight, length and leaf area of maize. However, the effect of 50% F.C. was more pronounced. Furthermore, results of this experiment also showed that drought stress increased electrolyte leakage as well as antioxidant enzymes such as catalase, peroxides and ascorbate peroxides of maize leaf. In contrast, foliar application of salicylic acid significantly increased relative water content, chlorophyll a, b and Total chlorophyll, fresh weight, length and leaf area of maize as well as catalase, peroxides and ascorbate peroxides and also reduced electrolyte leakage. Furthermore, salicylic acid caused the reduction of 20 percent in electrolyte leakage at the highest level of drought stress.
ConclusionSalicylic acid with the maize plant protection against drought stress caused growth improvement and increasing of tolerance to stress and finally, with regard to the cost and availability of salicylic acid, the application of this exogenous protection compound can be a method to cultivate maize plant in drought stress regions.