Relative Contribution of Various Leaf-Sampling Factors on the Mineral Composition of Mango Leaves

The contribution of leaf age, sampling direction, position of leaves on the shoot and sampling height of leaves of mango cv. Chausa were studied by fitting stepwise regression equations and using dummy variable technique. N and P levels were explained by a quadratic fit upto an extent of 75.36 and 95.65 per cent respectively. K contents decreased and Ca contents increased linearly with leaf age having 72.52 and 89.00 per cent respectively as r² values. S and Mn levels were affected by leaf age and sampling direction. Mg level was explained by leaf age, sampling direction and position of leaves on the shoot. Mg, S and Mn had Cobb-Douglas relation with leaf age where age contributed 65.67, 74.86 and 68.04 per cent respectively. The contribution of sampling height of the leaves was negligible towards the variation in nutrient levels. Zn content was not affected by any of the 4 factors studied.