This experiment was aimed at evaluating the precision of digital photos in estimating the leaf area of watermelon plants and to find mathematical models that estimates leaf area as a function of leaf linear measurements at different growth stages. All odd leaves of eight plants were photographed after being established on the field using a digital camera that resulted in 4,188 photos in which length and width were measured using a Sigma Scan Pro v. 5.0 Jandel Scientific software. In order to estimate the precision of the digital photos method, a sample consisting of 40 leaves was taken and leaf area measured using the standard leaf disks and the photo method. A 0.99 correlation coefficient was detected between the two methods. Therefore digital photos can be used to estimate leaf area of watermelon plants and estimation of leaf area per growth stage presents higher precision. The larger variability in leaf area was observed during reproductive growth. Maximum leaf width is the measure that best estimates leaf area.
Cucumis melo L; leaf area; non destructive method; regression
