Base Lines for Judging Wood Quality of Loblolly Pine

Abstract Base lines for judging wood quality of Pinus taeda L. were established using measurements from 65 trees each from Coastal Plain soils near Georgetown, S. C. and Piedmont soils near Rockingham, N. C. Wood samples taken consisted of four 10-mm breast high increment cores from each tree. Laboratory measurements included age, specific gravity, percent summerwood, percent juvenile wood, alcohol-benzene extractives, and lignin. Determinations of pulp yield, permanganate number, fiber length, fiber width, cell wall thickness and fiber strength (zero-span tensile strength) were obtained from fibers isolated by a micropulping procedure. Highly significant positive correlations were obtained between age and specific gravity, percent summerwood, fiber length, cell wall thickness, pulp yield, and zero-span tensile strength. Highly significant negative correlations were obtained between age and percentages of juvenile wood, lignin, and alcohol-benzene extractives. Significant differences between the geographic areas resulted in the establishment of separate base lines for specific gravity, percent summerwood, alcohol-benzene extractives, pulp yield, and zero-span tensile strength.