Wood Quality and Pulping Process Efficiency of Elite Eucalyptus spp. Clones Field-Grown under Seasonal Drought Stress

The objective of the present study is to evaluate the wood quality of five elite Eucalyptus spp. clones at 4 years of age from a clonal test installed in a region of seasonal drought stress in central-western Brazil focusing on pulp production. A total of 25 trees were systematically felled and disks and logs were obtained along the trunk. Wooden disks were used for density and fiber analyses and the logs were converted into chips for application in the pulping process. For the denser genotype, clone D (E. grandis x E. urophylla x Eucalyptus tereticornis), a thicker cell wall associated to thinner fibers results in a negative effect on the fiber quality. In contrast, clone B (Eucalyptus pellita x E. grandis), which has relatively inferior pulping performance, displayed the lowest wood density associated to wider lumen and fibers. The best growth performances in response to acclimatization and adaptation to the site strongly influences the pulp productivity, which is identified as the parameter of greatest variance between genotypes, and highlighting clone E (E. grandis x E. urophylla).