Effect of Different Amounts and Application Number of Salicylic Acid on Increasing Drought Tolerance of Fig in Rain-fed Conditions of Estahban Region

Today, the use of salicylic acid as one of plant growth regulator substances is a common way to increase plant resistance to stresses such as drought. This experiment was conducted in order to determine the effects of different concentration and different application number of salicylic acid on some morphological and physiological characteristics of fig in rain-fed conditions of Estahban region. Investigation was performed as factorial based on a randomized complete block design (CRBD) with three replications. The studied factors included salicylic acid in four levels (0, 0.5, 1 and 1.5 mM) and different number of foliar sparying in three levels (one, two and three times in three week intervals). The first foliar application of salicylic acid was carried out three weeks after caprification of trees. The parameters such as chlorophyll, carotenoids, proline, ion leakage, average leaf area, shoot growth, relative water content (RWC) and yield were measured. The results showed that the use of salicylic acid increased chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, relative water content, proline and yield, but, decreased ion leakage of the fig cv. "Sabz". Application of this compound did not significantly affect on shoot growth and leaf area. The effect of application number of salicylic acid on chlorophyll a, total chlorophyll and ion leakage was significant, but, had no significant effect on other traits. Generally, results indicated that application of salicylic acid significantly improved physiological characteristics and drought tolerance of fig in rain-fed conditions.