Lentil is one of the main pulse crops of south west Asia including Iran that may experience some degree of salinity in many areas of production. Many studies denote the ameliorative effects of elevated Ca2+ and K+ concentrations in the growth medium of salinized plants. The interactive effects of salinity, calcium and potassium on physiomorphological traits of a local Lentil cultivar (Robbat) were studied in a green-house experiment. Treatments included 4 levels of NaCl (0, 15, 30, and 45 mM NaCl), 2 levels of CaCl2 (0 and 10 mM), and 2 levels of KCl (0 and 10 mM) that was added to the nutrient solution. Salinity higher than 15 mM substantially reduced the plant growth as reflected by a decrease in the plant height, leaf number, dry matter accumulation and seed yield. Application of supplemental calcium and potassium resulted in partially restoring the adverse effects of high salinity (not more than 30 mM) on plant growth, whilst simultaneous application of both of them imposed a negative effect on growth parameters. In many traits, additional calcium showed higher ameliorative effects than potassium on plant growth characteristics. Potassium could control the sodium accumulation at highest level of salinity, but Ca and combination of potassium and calcium could not reduce Na accumulation in leaves of lentil. By adding any type of cation to the growth medium, the leaf total cation concentration increased significantly but the average cation concentrations in different levels of NaCl and application of Ca or K or their combination were not significantly different. Based on our results, salinity higher than 30 mM is not recommendable for production of lentil even by application of Ca2+ and K+.

Keywords