Obovoid is calculated from the maximum width (W), the height at which the maximum width occurs (y), the average width above that height (w1), and the average width below that height (w2), and a scaling function scale_ob as: Obovoid = 0.5 * scale_ob(y) * (1 - w1/W + w2/W) If Obovoid > 0, subtract 0.4. Otherwise, Obovoid is 0.
The youngest, fully developed leaf from the primary stem was collected at anthesis and scanned on a flatbed scanner, at a resolution of 300 dpi. A size and colour standard was included in each picture. For morphometric measurements, colours were inverted in Adobe Photoshop to increase contrast. Images were analyed using Tomato Analyzer (Rodrigues. et al. 2010); leaf boundaries were manually adjusted when necessary.