Use of allometric models to estimate leaf area in Hymenaea courbaril L.

The indirect estimation of leaf area (LA) in plants using non-destructive methods is a useful tool in the biological and agronomic studies, to determining the size of the capture apparatus of light energy by plants. This study aimed to determine equations that better estimate the LA of Hymenaea courbaril L. using the non-destructive methods based on leaf maximum measurements (length and width). In addition, we intended to check the accuracy of LA reading when compared with destructive methods obtained by the image analysis software (ImageJ(A (R))) and leaf area meter (LI-3100 Li-Cor). About 1000 leaves were sampled from one year old plants. To validate the models, we used an extra sample of 500 leaves with distinct age, randomly selected and collected from different canopy levels of young and adult trees. The variability observed was extreme, with values of LA for each leaf ranging from 1650 to 14018 mm(2). The LA values obtained with the LI-3100 integrator were higher than those obtained by the ImageJ(A (R)) software at 2.7 % and with a high correlation between them. Among the models studied to estimate the LA based on non-destructive measurements, it can be said that linear and quadratic models as well as the ellipse formula can be safely used without differing significantly from the values obtained through the LI-3100 analyzer and ImageJ(A (R)) software. Thus, it is possible to use non-destructive measurements for estimating the LA of H. courbaril with accuracy using allometric models, as well as ensuring that the ImageJ(A (R)) software can replace the LI-3100 analyzer to determine the leaf area at the species investigated.