Wood quality traits in Eucalyptus hybrid in Tamilnadu for pulpwood

Abstract

Eucalyptus tereticornis is utilized mainly for paper pulp as it possess long fibers and fibers with wide overall diameter and thin walls. This paper elicits information on extent of variability, effect of stand age, order of coppice sprouts relative to the original tree and number of coppice sprouts per stool on wood properties of E. tereticornis.

This study conducted at two even aged plantations at Pudukkottai and Coimbatore in TamilNadu revealed maximum variability in the extractive contents followed by cellulose yield up to 36.5 per cent with site. Lignin, pentason, cellulose yield and specific gravity showed lesser variability. Rotation age did not affect cellulose and lignin content, while extracts increased progressively with rotation. From the stand point of cellulose yield, a new parameter, seven year old stand was superior and it recorded increased yields of 84 per cent and 26 per cent respectively over three and six year old plantations.

Wood properties barring specific gravity and calcium oxide varied significantly among various rotations. Rela tive to the original stand, cellulose content reduced in the second coppice stand. Between the two coppice stands, the second harvest possessed higher lignin content. Alcohol extract was markedly more in both first and second coppice stand. Cellulose yield of original and the first coppice stand were on par while it reduced by 25% in second coppice stand. Others like specific gravity, pentosan, cellulose content and alcohol extract did not vary due to number of shoots per stool in the coppiced stands, though the extractive contents increased with increasing number of coppice shoots, while results relating to lignin were inconsistent.