The measurement of leaf area in apple trees

SummaryAnnual measurements of leaf area on a spacing trial of Golden Delicious/M.9a revealed that although the leaf area of an apple tree could be estimated from a regression on girth squared, this regression showed considerable variation from year to year due not only to seasonal factors but to a general curvilinear relationship between leaf area and girth with time. For young trees with a high proportion of leaf area on extension shoots, total shoot length was a better variate to use in the regression than girth. Cultivars differed in both mean leaf size and its variability. The variability in leaf size also depended on the time of year. In dense plantings mean leaf size tended to be larger at the bottom of the tree than at the top.