Selecting dry fiber weight for higher and better quality jack pine fiber production

Sixteen-year-old half-sib jack pine (Pinus banksiana Lamb.) families planted in New Brunswick were evaluated for wood density, growth traits (DBH, tree height, and bole volume), and dry fiber weight (wood density x bole volume). The variation and inheritance of these traits and their relationships were studied. The implications of these genetic parameters for optimum gains in wood quality and wood quantity (bole volume) were discussed. The results indicate that wood density and tree height exhibit considerably less phenotypic variation but a remarkably higher heritability compared to DBH and bole volume. Dry fiber weight shows the largest phenotypic variation but a moderate heritability. There exists a positive genetic correlation between wood density and all growth traits. This suggests that selection for growth traits would not necessarily lead to a reduction in wood density in this species. Compared to traditional selection for bole volume, however, selection for dry fiber weight would result in higher genetic gains not only in dry fiber weight (+12.9% vs. 9.9%), but also in wood density (1.8% vs. 0.8%) and bole volume (9.8% vs. 8.2%). Therefore, this selection strategy would achieve both higher and better quality fiber production compared to traditional selection for volume alone.