Fig. 7

Principal Component Analysis (PCA) of the VOC blends of P. xylostella-damaged cabbage (CA), broccoli (BR), turnip (TU), and B. stricta (BA). Top panel: score plot of the samples. The ellipse defines the Hotelling’s T2 confidence region (95%). Bottom panel: loading plot of the two components of the PCA, showing the contribution of each of the compounds toward the model