Non-destructive estimation of leaf area in hairy fleabane (Conyza bonariensis)

Hairy fleabane (Conyza bonariensis) is a widespread and troublesome weed in agricultural systems, and estimating its leaf area (LA) is essential for growth analysis and weed management studies. This study aimed to develop equations to estimate the LA based on the linear dimensions of leaf blades. The relationships between the LA and the dimensional parameters of leaf blade (length and width) were studied in C. bonariensis var. angustifolia and C. bonariensis var. bonariensis. Both linear and power regression models were tested, and their performance was assessed using Root Mean Square Error (RMSE), index of agreement (dw), BIAS index, Pearson’s linear coefficient (r), and index of confidence or performance (c). The best-performing model used the product of length and width (L×W), yielding the highest r values and the lowest RMSE for both botanical varieties. Specific models provided better estimates than the general model. The linear equations LA = 0.6578 × (L×W) and LA = 0.5896 × (L×W) for C. bonariensis var. angustifolia and C. bonariensis var. bonariensis, respectively, were the most accurate for estimating their LA. These equations offer reliable, non-destructive tools for estimating LA in studies involving each variety, contributing to improved precision in weed science research.