Effects of foliar application of salicylic acid on growth characteristics of lolium grass under salt stress condition

in agriculture, increase of water and soil salinity represents a main challenge. Salinity affects plant growth and productivity in various ways. On the other hand, compounds such as salicylic acid through signaling systems, can result in some resistance in plants. In this study, the effects of foliar application of salicylic acid with different concentrations on lolium growth and development were investigated under various salinity levels. This study was done as a factorial based on completely randomized design. Salicylic acid was sprayed on plants in 4 concentrations of 0, 100, 200 and 300 mg/L, and soil salinity was applied at 3 levels of 3-4, 6-7 and 9-10 dS/m using NaCl. Different plant growth and development factors were evaluated at two periods of middle and end of experiment. The results of present experiment showed that salinity as well as spray of salicylic acid was effective on many morphological and physiological traits of lolium plants. At the first harvest, the highest shoot fresh and dry weight were observed in treatments with high salinity, while chlorophyll index and plant height decreased by increasing salinity levels. In the second harvest, plant height and other growth-related traits were distinctly decreased by increasing salinity levels. Spray of salicylic acid resulted in higher root fresh and dry weight as compared to control plants, while it showed no effects on shoot fresh and dry weight. It was concluded that application of salicylic acid could reduce salinity effects on lolium plants.