MODELLING TO ESTIMATE THE SPECIFIC LEAF AREA OF TOMATO LEAVES ('PANNOVY')

The determination of leaf area is essential to understand the interaction between plant development and prevailing environmental factors during the growing season. In particular, the precise estimation of the leaf area index (LAI) is a prerequisite for modelling of canopy energy and mass fluxes, especially of canopy transpiration. Therefore, various non-destructive methods were established to calculate the leaf area of different plants, especially using leaf area estimation models. In this study, a model was developed to estimate the specific leaf area of tomato leaves in respect to the cultivar ‘Pannovy’ using simple linear measurements. During an experimental period of 2 years, the recorded measurements of leaves were randomly separated into two data sets which were used for calibration and validation of different models. The results showed that the leaf area can be accurately predicted when leaf length and width are used as independent variables (R²=0.885), whereas the leaf area estimation was limited when either leaf length (R²=0.755) or width (R²=0.856) was used as parameter in the respective models. Significant differences in the accuracy of the determination of leaf area occurred between a general leaf area estimation model based on different genotypes (including ‘Pannovy’) and the model developed in this study. These facts confirmed that for each cultivar of tomatoes a separate model should be developed to obtain the specific leaf area of single leaves.