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The research was carried out at Abu Jerash Farm/Faculty of Agricultural Engineering, University of Damascus, Syria, during the years (2020-2021) and (2021-2022) to study the effect of soaking treatment with gibberellic acid and foliar spraying with abscisic acid on growth and productivity of two varieties of lettuce (Kbous and Shanchar) under salt stress conditions. Four levels of salt (0, 50, 10, 150 mM) were used, the seeds were soaked with gibberellic acid (0, 50, 100 ppm), then seedlings were foliar sprayed with abscisic acid (0, 5, 10 ppm). The results showed that the gradual increase in salt levels resulted in negative effect on most of the studied indicators (morphological, physiological, and productivity), meanwhile soaking treatment with gibberellic acid and foliar spraying with abscisic acid improved all studied indicators compared to untreated plants under all studied salinity levels. On the other hand, the interaction treatment between soaking with gibberellic acid (50 ppm) and foliar spraying with abscisic acid (10 ppm) achieved the best values at the lowest salt concentration (50 ppm) compared to the rest of the treatments. In addition, the same treatment gave the best results for the studied physiological indicators (wet and dry weight, relative water content, proline content, activity of antioxidant enzymes, concentration of nitrogen, phosphorus and potassium, productivity) compared to the other treatments at high salt concentrations (100, 150 ppm).
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