The Variation of Chemical Composition and Pulping Yield With Age and Growth Factors in Young Eucalyptus Globulus

The wood quality of 2-, 3-, and 6-year old Eucalyptus globulus trees was assessed in relation to chemical composition and pulping for two growth conditions: a control (C) and optimized growth (IL) through a weekly nutrient supply and irrigation.The wood chemical composition did not show statistically significant differences between C and IL trees. With age an increase was found for lignin and extractives, especially ethanol and water-solubles.The overall average pulp yield was 56.5% at a Kappa number of 15. No differences in pulp yield or delignification degree could be associated with fertilization and irrigation or with tree age. In these conditions, intensively grown trees and shorter rotations may be used for pulping without loss of raw-material quality