Fig. 8

Correlation analysis between the fit (predicted) and true values for biomass component content in sugarcane stalks. Offline NIRS calibration for dry biomass of sugarcane stalks upon sugar content (A), residues (B) and ratio between them (C); D–F online NIRS calibration for dry biomass of sugarcane stalks upon sugar content (D), residues (E) and the ratio (F); online NIRS calibration for fresh biomass of sugarcane stalks based on moisture content (G), sugar content (H) and residues (I). The red and black colors represent calibration and internal cross validation, respectively