Fig. 1. Calculated leaf area fractions (F) as a function of downward leaf rank (L) for eight data sets. Each data set represents eight different corn cultivars. Cultivar names are found in the figures. The fitted model is F = F0exp[–0.5(L – L0)2/k2] (Eq. [5]), where F = individual leaf area/plant leaf area, L0 is the downward leaf rank with the maximum area fraction of F0, and k is a constant. R is the multiple correlation coefficient from model fitting.