Influence of Humic Acid on Growth, and Leaf and Root Mineral Elements of Sabrina Strawberry under Salinity Stress

Salinity is one of the most brutal environmental stresses limiting the productivity of agricultural crops. In order to determine the effect of humic acid on some morphological and physiological characteristics and uptake of elements by strawberry (Fragaria ananassa Duch. cv. Sabrina) under salinity stress, a greenhouse factorial experiment was conducted with three factors including two treatment methods of humic acid application (spray and drench), three humic acid levels (0, 300 and 600 mg/L) and three salinity levels (0, 20 and 40 mM NaCl) in a completely randomized design with four replications. Results revealed that in the salinity level of 40 mM, the dry weights of shoot and root were reduced by 36.65 and 26.85 percents compared to control. With increasing the salinity level, the Na+ concentration increased and the K+, Ca2+ and Mg2+ concentrations in leaves and roots decreased. In the presence of 40 mM NaCl in external media, application of 600 mg/L humic acid increased root Ca2+ concentration by 65 %. However, application of humic acid mitigated the Na+ concentration in leaves and roots and improved the Fe2+ and Zn2+ concentrations. According to the results of this study, application of humic acid (especially at 600 mg/L) ameliorated the deleterious effects of salt stress in strawberry cv. Sabrina