Figure 2.
Variable importance in projection (VIP) graph showing the 15 most important VOCs in descending order. The degree of importance during each phenological stage is shown by the color gradient, in which red indicates a high correlation and green a low correlation. VIP score is a measure of a variable’s importance. (a) VIP var. Albion; (b) VIP var. Festival; (c) VIP var. Frontera.