Effect of different levels of nano and typical potassium on yield and some Morpho-physiological characteristics of two wheat cultivars under salt stress

Potassium plays an important role in improving plant tolerance to abiotic stresses such as salinity stress. To evaluate the effect of potassium on salinity tolerance of two wheat cultivars, Kavir (as salt tolerant) and Qods (as salt-sensitive), a pot experiment was conducted, using a factorial experiment based on randomized complete block design with three replications in different treatments (Control, 150 mM NaCl, 150 mM NaCl with two levels of 300 and 450 mg potassium sulfate per 1kg soil and two levels 30 and 45 mg nano potassium per 1kg soil). Application of different potassium levels and sources in stress conditions led to mitigate the negative effects caused by salt stress, and hereby improved grain yield and its components, biological yield, plant height, stomatal conductance, and also reduced Na+ concentrations and increased K+ concentrations and the K+/Na+ ratio in flag leaf. It appears that the presence of potassium under salt stress in compare with the absence of it, through competition with sodium uptake by plant can lead to reduce the adverse effects of sodium accumulation in plants and through osmotic potential adjustment and improved stomatal conductance caused to maintain photosynthesis, and hereby reduce salt effects on yield.