An Estimation of Individual Leaf Area in Cabbage and Broccoli Using Non-destructive Methods

Accurate and nondestructive methods to determine individual leaf areas of plants are useful tools in physiological and agronomic research. A determination of the individual leaf area (LA) of such species in Brassicaceae family as red cabbage (Brassica oleracea var. cappitata L. f. Rabra), cabbage (Brassica oleracea var. cappitata L. F. Alba) and broccoli (Brassica oleracea var. Italica L.) involves measurements of leaf parameters including leaf length (L) and width (W), or some combination of these parameters. This research was carried out during 2008 (on eight cabbage, six broccoli, and three red cabbage genotypes) under open field conditions, to see whether an equation could be developed to estimate leaf area of cabbage and broccoli across their genotypes. Regression analysis of LA vs. L and W revealed several equations that could be used for estimating the area of individual cabbage and broccoli leaves. A linear equation having W as the independent variable provided the most accurate estimate of red cabbage as well as ordinary cabbage LA. The linear equation (LA= a+b W2) exhibited a high accuracy and precision in estimating red cabbage and non-red cabbage LA. For broccoli a linear equation having LW as the independent variable provided the most accurate estimate of LA, but required twice the time needed for leaf area measurement.