Effect of potassium nitrate (KNO3) on some morphological and physiological characteristics of two tropical lawn (Cynodon dactylon L. and paspalum vaginatum L.) under salinity stress condition

High level of sodium chloride is known to be the most widespread cause of saline soil environmental stress in dry and semi dry lands that ceases growth and yield of crop species. An experiment was conducted to examine the effect of potassium nitrate on certain morphological and physiological characteristics of two tropical lawn, Cynodon dactylon and Paspalum vaginatum, under salt stress through 1390-91at the Research Farm Station of Horticultural at the Shahid Chamran University, Ahvaz. Plants were treated with four different concentrations of potassium nitrate (0, 5, 10, 15 ml) and four different concentrations of sodium chloride (0, 4, 6, 8 des/m). Results of this experiment showed that salinity significantly effects growth parameters at the probability level of 1%. It was observed that when salt stress increased, the saline soil significantly reduced leaf length and width, LAI, length and diameter of stem and stolon, fresh and dry weight of shoot and root, RWC and chlorophyll content, whereas proline and electrolyte leakage increased due to accumulation of salt within the soil. Amung (KNO3) treatments, application of l0 ml was recognized as the best treatment that (p≤0.01) showing positive interaction effect on the plant cheracters except total chlorophylls and leaf area.