THE RELATIONSHIP BETWEEN LEAF SIZE AND NUTRIENT CONCENTRATIONS OF LEAF SAMPLES IN ´GOLDEN DELICIOUS´ APPLES GROWN IN CHIHUAHUA, MEXICO

The objective of this study was to obtain the relationship between leaf size and the nutrient concentration of leaf samples in ‘Golden Delicious’ apple orchards grown in Chihuahua, Mexico. Leaf samples from about 300 mature apple orchards were obtained at different phenological stages from late June through end of August, 2003. Leaves were sampled from the middle part of current season shoots located on main branches at middle height of the tree; 30 to 40 leaves in a 5 ha block were collected to complete each sample and were divided in five categories according to leaf size from 1 to 5 (1 = the smallest, 5 = the largest); mineral nutrient content was measured in all samples, and correlation coefficient between leaf size and nutrient concentration was determined. Positive correlations between leaf size and concentration of N, K, Ca and Mg were obtained in some of the phenological stages. The correlation with P, Zn, B, Cu, Fe and Mn were nonsignificant. With these results it can be concluded that a better interpretation of the results can be obtained if leaf size is included in the final results.