Mohmmad Hossein Aminifard - Assistant Prof, Department of Horticultural Science and Special Plants Regional Research centre, College of Agriculture, University of Birjand, Iran
Hassan Bayat - Department of Horticultural Science, Faculty of Agriculture, University of Birjand, Iran.
Mehdi Khayyat - Department of Horticultural Science, Faculty of Agriculture, University of Birjand, Iran.

Purpose: 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), width/length (W/L) of cress leaves as a leafy vegetable and radish  leaves as a root vegetable. Research method: An experiment was carried out under greenhouse conditions to study the 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 and W/L led several models that could be used for estimating the area of individual cress and radish leaves. Findings: A linear model employing FW as an independent variable [LA=0.295 (Fresh W.)+ 1.430] resulted 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) for estimating LA. Validation of the regression models showed that the correlation between measured and simulated values using these equations was quite acceptable for radish and cress (R2 = 0.922, 0.876), respectively. Research limitations: Evaluation of more leafy vegetables possibly had better results. Originality/Value: The results showed that cress and radish LA could be monitored quickly, accurately, and non-destructively by using the leaf FW and leaf W models, respectively.

independent variables, Lepidium sativum, non-destructive method, Raphanus sativus, regression models