Effect of Humic Acid and Ascorbic Acid on Seed Germination and Growth of Cucumber (Cucumis sativus L.) under Salinity Stress

Abstract

The aim of this study was to investigate the effects of Humic Acid (HA) and Ascorbic Acid (AsA) on cucumber growth under different levels of soil salinity. The experiment was designed as a factorial, using a completely randomized design in the laboratory of Samangan University in Afghanistan. The levels of salinity stress were set at (0, 50, and 100mM sodium chloride) while AsA and HA were set at (0, 30, and 60mM and 0, 1 and 2. L-l) respectively. The results of the analysis showed that the effect of all factors were significant on all studied traits. The highest mean daily germination (19%), root length (56.22mm), shoot length (39,06mm), fresh shoot weight (183.7mg), and seed vigor index were obtained from the (0mM salinity+60mM AsA+ 2g.L-l HA) treatment. Also the most germination percentage (95%), fresh root (45.88mg) and dry root (13.76mg), observed in (50mM salinity+0mM AsA+ 2g.L-l HA) treatment. However, the combined amounts of (60mM AsA+ 2g.L-l HA) were more effective for reducing different levels of salinity and increasing the growth characteristics of cucumber. Also, 2g L-l HA and 60mM AsA alone, were more effective. Treatments without AsA and HA showed the lowest growth in most traits. These findings suggest that the application of HA and AsA can help to improve cucumber growth under salt stress conditions.