Modelling individual leaf area of cress and radish using leaf dimensions and weight

Abstract

Leaf area information is required in various horticultural and physiological studies. Leaf area measurements require easy, quick and possibly non-destructive methods. The objective of this study was to establish equations to estimate leaf area (LA) using length (L), width (W), fresh weight (FW) and dry weight (DW), length×width (L×W), length + width (L+W), width/length (W/L), length2 (L2) and width2 (W2) of cress (Lepidium sativum L.) leaves as a leafy vegetable and radish (Raphanus sativus L.) as a root vegetable. A soilcultured experiment was carried out in 2010 under greenhouse conditions to study relationship between leaf dimension and weight with LA of these two vegetable plants. Observed LA was obtained by an automatic measuring device and leaf dimensions were measured by a ruler. Regression analyses of LA versus L, W, FW, DW, L×W, L+W, W/L, L2 and W2 led several models that could be used for estimating the area of individual cress and radish leaves. A linear model employing FW as an independent variables [LA=0.295 (Fresh W.)+ 1.430] resulted in the most accurate estimate (R2 = 0.912, RMSE = 1.52) of cress LA. For radish, a linear model using W as an independent variable [LA=22.50 (W) + 7.46] showed the most accuracy (R2 = 0.874, RMSE = 11.26) estimating LA. Validation of the regression models showed that the correlation between measured and simulated values using these equations were quite acceptable (R2 = 0.922, 0.876).