Leaf area constant model in optimizing foliar area measurement in plants: A case study in apple tree

• Measured leaf area based leaf dimensions, is a useful and non-destructive method.
• Area constant KA contributes to increase the accuracy of leaf area calculation.
• Leaf Area Constant Model (LAC Model) allows to obtain optimal values of KA.
• Predicted leaf area using KA ensures a high degree of safety.
• LAC Model can be used to determine the KA at different plant species.

Non-destructive methods of determining plant leaf area are useful instruments in physiological, ecological and agronomic research. Determining individual leaf area (ILA) in plants based on leaf size parameters – length (L) and width (W) – suppose the use of an area constant (KA) as a factor of correction in increasing calculus precision. These studies suggest a model for the high accuracy calculus of the area constant (KA) and of leaf area in plants based on leaf size on five apple tree cultivars. Measuring leaf area was done in parallel with for each leaf through measured leaf area (MLA) and scanned leaf area (SLA) in 1,500 leaves. Area constant (KA) was calculated and validated through the comparison of measured leaf area (MLA) and scanned leaf area (SLA) under minimum error (ME) and minimum value RMSE conditions. Based on research, was obtained a Leaf Area Constant Model (LAC Model) to calculate KA whose optimum value facilitated the accurate prediction of leaf area based on L and W in the five apple tree cultivars we studied (R2 = 0.987 to R2 = 0.995). The suggested LAC Model was used with high precision to calculate KA in apple tree making possible its extension to other plant species also.