Modeling leaf area of Dracocephalum moldavica L. as a medicine plant using destructive and non-destructive methods

Leaf area (LA) is a key variable for physiological studies, therefore accurate and simple models determining leaf area of plants are important for many experimental comparisons. Measuring the leaf area of Dracocephalum moldavica L. either as a medicinal plant or a vegetable is one of the most important factors. For this purpose, an experiment was conducted at research greenhouse of Ferdowsi University of Mashhad. For estimation of leaf area of this plant, leaf dry weight, leaf fresh weight and leaf dimensions (width and length) were measured. Regression analyses of LA versus FW, DW, L and W revealed several models that could be used for estimating the area of individual leaves of Dracocephalum moldavica. Among all models studied in this experiment, LA = 0.510(L+W)0.946 and LA=0.510(L2×W2)0.473 provided the most accurate estimate (R2 = 0.887, RMSE = 0.655 and R2 = 0.887, RMSE = 0.656) of LA, respectively. It can be concluded that regressions using L×W and L2×W2 may better estimate the leaf area. However, leaf length and width solely didn’t display a good estimation of leaf area. Also these models were validated and showed that they could predict the leaf area of Dracocephalum moldavica quickly and precively.