Allometric model for leaf area estimation in Bougainvillea genotypes
Accurate estimates of leaf area (LA) are an urgent need for modeling eco-physiological processes within urban greening. LA can be measured by direct or indirect methods. The direct methods are fast, but require leaf excision and it is therefore not possible to make sequential measurements. An alternative tool would be to develop allometric models that relate the individual LA to the linear measurements of leaf length (L) and maximum width (W). The development of an unbiased allometric model from linear measurements to predict individual LA of Bougainvillea irrespective of genotypes is still lacking. The models were built using LA, L, and W data measured in 600 leaves collected from four Bougainvillea genotypes: B. glabra LSQUOCrimson LakeRSQUO, B. spectabilis LSQUOLady WilsonRSQUO, LSQUOMary PalmerRSQUO and LSQUORubianaRSQUO. Model validation was performed on 150 Bougainvillea leaves collected from another genotype (B. spectabilis LSQUOFucsia colorRSQUO). LA prediction models based only on L or W measurements were not suitable for estimating LA of Bougainvillea. A linear model having the product L×W as independent variable (LA = -1.36 +0.63 LW) provided the most accurate estimate highest r2 (0.95), smallest MSE, smallest prediction sum of squares (PRESS), and to the reasonably close PRESS value to error sum of squares. In the model validation, correlation coefficients showed that there was a highly reliable relationship between the predicted and the observed LA values with an underestimation of 3.7%. The LA model using L×W as independent variable can be successfully adopted in research on Bougainvillea, since it provides an accurate, simple non-destructive estimation of LA across Bougainvillea genotypes avoiding the use of any expensive device such as electronic leaf area meters and plant canopy analyzers.
Fascella, G., Rouphael, Y., Cirillo, C., Mammano, M.M., Pannico, A. and De Pascale, S. (2018). Allometric model for leaf area estimation in Bougainvillea genotypes. Acta Hortic. 1215, 449-452
estimation model, leaf dimensions, leaf shape, model validation, non-destructive measurement