Nondestructive method for estimating the leaf area of sapodilla from linear leaf dimensions

The leaf area is a parameter of fundamental importance in studies on plant growth and physiology. The objective of this study was to build allometric equations for the accurate and fast estimation of sapodilla leaf areas. In total, 250 leaves of different shapes and sizes were collected from sapodilla matrices trees growing at the Universidade Federal Rural do Semi-Arido, Mossoro-RN, Brazil. For each leaf, the length, width, product of length and width (LW), product of length and length, product of width and width, and leaf area were measured. Linear and nonlinear models were used to construct the allometric equations. The best equations were chosen on the basis of the following criteria: the highest coefficient of determination, Pearson's linear correlation coefficient, and Willmott's index of agreement; and the lowest Akaike information criterion and root mean square error. It was verified that the models that used the LW value presented the best criteria for estimating the leaf area. Specifically, the equations (y) over cap = 0.664 x LW1.018 and (y) over cap = 0.713 x LW, which use LW values, are the most suitable for estimating the leaf area of sapodilla quickly and accurately.