Effects of exogenous selenium application for enhancing salinity stress tolerance in dry bean

Excess salinity is one of the most important abiotic stress that negatively affect plant growth and development. Like many other leguminous crops, dry bean (Phaseolus vulgaris L.), is classified as salt-sensitive plant. Researches related to the use of selenium to reduce salinity stress have been increasing in recent years. However, no study has been found in the world literature that shows the effects of this element on reducing salinity stress in dry bean. The main purpose of this study was to determine whether the negative effects of salinity stress on growth, yield, and organic compounds of dry bean could be reduced by foliar selenium applications. Three different foliar application dosages of selenium (0, 5 and 20 ppm) under four different irrigation water salinity levels (control0.6, low-1.6, moderate-3.0 and high-4.8 dS/m) were tested in the study. It has been shown that the foliar application of selenium, which is suggested to be used to reduce salinity stress in many plants, did not show, in general, a statistically positive trend for almost all growth, yield, and quality parameters in dry bean. Compared to the control salinity treatment, it was revealed that the application of 20 ppm selenium did not affect the salinity threshold value at a significant level, but this application had a very low positive effect on the slope value, which expresses the decrease in yield after the threshold salinity. In general, it was concluded that foliar application of selenium under studied concentrations had a minor effect than expected in improving the tolerance of salinity stress in dry bean.