Tree selection with high performance for paper recycling in eucalyptus globulus

The industrial recycling rate is limited to about three times; however, tree breeding program has never aimed for paper recycling. The first purpose of our study here was to examine the feasibility of selection of trees with high performance for kraft paper recycling from plantation trees even showing similar growth and pulp properties after digestion in Eucalyptus globulus as a model tree. The recyclability was assessed by non-linear regression of tensile index curve depending on recycling same and subsequent normalization of all samples to be the recyclability to be three times. A selected elite tree provided 1.85 times higher volume (growth), 0.97 higher pulp yield and 2.37 times higher recyclablity compared with the average of utilized 31 individuals. On the other hand, tree selection is preferably performed by a non-destructive way. The second purpose was to develop a rapid and non-destructive method for elite tree selection aiming paper recycling together with an automatic instrument FT-Raman spectroscopy. The statistical results were; correlation coefficient (r): 0.996, root mean square error of calibration: 0.16 in calibration, and r: 0.918, root mean square error of prediction: 0.70. This was the first successful non-destructive quantitative calibration of recyclability using vibrational spectroscopy combined with multivariate data analysis.