The Effect of salicylic acid treatment on some physiological indicators of cucumber plants under different levels of water stress

Abstract

The study was conducted during the year 2021. The aim was studying the effect of salicylic acid (SA) treatment on some physiological indicators of cucumber plants under different levels of water stress. It was performed at Urah Research Station/ Sewida Agricultural Scientific Research Center/ General Commission for Scientific Agricultural Research/ Syria. Cucumber seeds (cucumis sativus cv, Baladi) were treated with different concentrations of Salicylic acid (0, 1, 50, 150 mg/L) for 24 hours at room temperature, and exposed after cultivation to different levels of water stress (60, 80, 100% from field capacity). The results showed a decrease in the soluble sugars and relative water contents as the applied irrigation levels decrease. The treatment with SA at a concentration of 50 mg/L showed a significant difference compared to the control in the contents of soluble sugars and proline at all field capacities. The previous concentration achieved a significant difference compared to the control in relative water and total chlorophyll contents at the capacities 80 and 60%. The highest relative tolerance value for the total standards studied was recorded at a concentration of 50 mg/L (764.15, 461.01%) in both 80 and 60% capacities, respectively. Whereas the concentration 1 mg/L (89.45, 85.24%) showed the highest relative value of drought tolerance for productivity in the 80 and 60% capacity, respectively. Followed by the concentration 50 mg/L (86.06%) at the 80% capacity. The results of the cluster analysis, depending on the relative value of drought tolerance, showed the separation of the tested treatments into two groups, one included the treatments with the highest relative value of drought tolerance (50 and 150 mg/l), while the other group included the treatments with the relative value of the lowest tolerance (control, 1 mg/l). In conclusion, the study revealed that the treatments of seed priming with salicylic acid, especially at a concentration of 50 mg/L,

achieved a noticeable improvement in most of the studied indicators in response to water stress at the field level.