Effect of salicylic acid on morphological and physiological characteristics of vetiver grass under water deficit stress conditions

This experiment was conducted in order to investigate the morphological and physiological responses of vetiver grass (Chrysopogon zizanioides L. Roberty), to water deficit stress and salicylic acid application in department of horticultural sciences at the University of Zanjan in 2015. After 6 months of planting transplants into pots, three soil available water levels (40, 70 and 100%) and salicylic acid concentrations (0, 1 and 2 mili Molar) were applied in a factorial experiment based on completely randomized design with three replications for 6 weeks. salicylic acid applied through foliar spray weekly. Generally, water deficit reduced root and shoot dry weight and leaf chlorophyll content. Root length, total phenol, proline and electrolyte leakage of leaves was increased by reducing the amount of available water. Salicylic acid application improved negative effects of water deficit in all attributes and its effect was more pronounced in 40% available water treatment. In all available water levels, there was no significant difference between 1 and 2 mili Molar salicylic acid treatments in root dry weight and leaves total phenol whereas in other factors, 2 mili Molar salicylic acid application had better result and plants in this treatment had higher shoot dry weight, proline and chlorophyll content and less electrolyte leakage than 1 mili Molar salicylic acid treatment, suggesting that in order to increase water deficit tolerance of vetiver grass, higher concentration of this plant growth regulator must be evaluated.