Pulping qualities of six year old clones of eucalyptus tereticornis, SM

Cell size and relative fiber dimensions have a major influence on the quality of pulp and paper products and solid wood products. Since many of the wood properties are strongly heritable (Zhang and Jiang, 1998), there is a possibility for improving these traits through tree improvement programmes. Eucalyptus tereticornis is commercially planted as a source of paper pulp yet the wood properties show considerable variation among the clones. The present study was mainly intended to understand the wood properties of different clones and their suitability for pulping. The clones were compared for the pulping indices like Felting coefficient, Runkel’s ratio, Isenberg coefficient, coefficient of fiber flexibility, inverse of fiber diameter and the amount of solid cell wall materials in the fibers. Clones were categorized based on their suitability for pulping. The clones Et 027, Et 093, Et 147, Et 148, Et 086, Et 082, Et 006 and Et 122 were identified as superior clones for good quality paper production due to their longer and thinner fibers. Clones Et 001, Et 128, Et 003, Et 142 and Et 071 were highly inferior in terms of pulp production due to their shorter and thicker fibers but they are suitable as a source of fuel wood. The clones like Et 111, Et 135, Et 114, Et 032, Et 084, Et 004 and Et 137 were having thinner but shorter fibers while Et 099, Et 105, Et 130, Et 100, Et 007, Et 010, Et 138, Et 132, Et 074 and Et 052 were having longer but thicker fibers. Correlation studies showed a significant positive correlation between height with fiber length and fiber wall thickness and a negative correlation with lumen diameter. Diameter also showed a significant positive correlation with fiber length but an inverse relation with fiber diameter and lumen diameter. The results indicate that during plus tree selection programme due importance must be given to growth traits that would definitely improve other desirable wood traits.