Influence of Exogenous Application of Silicon and Potassium on Physiological Responses, Yield, and Yield Components of Salt-Stressed Wheat

To investigate the effect of exogenous application of silicon and potassium on some physiological responses, yield, and yield components of two wheat cultivars (Pishgam and Alvand) grown under salt-stress conditions, a field experiment was conducted at the Agricultural and Natural Resources Research Centre in East Azerbaijan, Iran, during 2012 and 2013 growing seasons. The experiment was arranged in factorial design based on randomized complete blocks design with three replications in each year. Wheat seeds were sown in saline soil (10 dS m(-1)) and irrigated with saline water (4 dS m(-1)). The plants were sprayed with silicon and potassium solutions at 0, 2, and 4 mM and 0, 100, 200, and 300 mM concentrations, respectively. The results demonstrated that silicon and potassium application improved antioxidant enzyme activity, chlorophyll content, photosynthesis rate, potassium uptake, yield, and yield components in both wheat cultivars. Although silicon and potassium had significant effects on all studied traits, there was a great interactive effect between them. When these two elements were applied on plants, the positive effect was more pronounced. Among all treatments, the most effective treatment was 4 mM silicon and 300 mM potassium. The greatest enzyme activity, chlorophyll content, photosynthesis rate, potassium uptake, yield, and yield components and the lowest proline, malondialdehyde, and sodium accumulations were observed in this treatment.