Mineral Nutrient Balance Associated with the Different Degrees of Iron Chlorosis in Sugarcane Var. Co 740

Leaf samples of iron chlorotic sugarcane leaves from natural field were analysed for different mineral contents. The leaves were classified according to their colour; complete yellows-medium yellow, medium greet and complete green. It was discovered that the chlorosis is not due to the deficiency of Fe⁺² but due to, its inacitivation in the leaf tissues. The composition of Ca⁺², Mg⁺², and nitrogen was not disturbed, however K+ and P contents show a linear increase as the chlorosis became severe. At the same time Cu⁺², Zn⁺², Mn⁺², and Na+ contents decreased due to chlorosis. The high P/Fe ratio is possibly responsible for the inactivation of iron in the leaves and the balance of P/Fe, K/Fe, and K/Ca is brought to normal level following ferrous sulphate spray resulting in the greening of the chlorotic leaves.