SALT STRESS EFFECT ON NUTRIENT ABSORPTION IN MANGO TREE

The effect of salt stress on the dry mass, absorption and transport of nutrients was evaluated in mango cultivars 'Haden', 'Palmer', 'Tommy Atkins', and 'Uba' grafted on rootstock 'Imbu'. Plants were grown in modified Hoagland solution in aired static hydroponic system containing 0, 15, 30, and 45 mmol L-1 NaCl. The dry mass of the roots, the stem of the rootstock and the stem of the scion as the dry mass of the leaves has decreasing at concentrations from 15 mmol L-1 NaCl. There was a significant reduction of N, P, K+, Ca+2 and Mg+2 in the leaves of cultivars 'Haden', 'Palmer' and 'Uba' respectively. Cultivar 'Tommy Atkins' showed no change in the content of N, P, K+ and Ca+2 in the leaves. The levels of N, P, K+, Ca+2 and Mg+2 decreased with the increase of the NaCl in the root system of all cultivars. The external concentration of the ion Na+ has occupied the site of absorption of K+ and Mg+2 and the ion Cl- acted at the absorption site of N and P by inhibiting their absorption due to competitive mechanisms.