Abstract

Differences in wood density, bark and heartwood, and fibre length were investigated in trees from 3-, 5-, 7- and 9-yr-old plantations at 3 sites in Kerala (Munnar, all ages; Vandiperiyar, 3- and 5-yr-old; Wynad, 9-yr-old). All plantations had a spacing of 2X2 m except for the one at Wynad (3X3 m). The required wood density for pulpwood was attained at 3 yr old, and there was no significant increase in density in older trees (although density was less in 5-yr-old trees). Within each age group tree growth (height, diameter) had no marked effect on wood density, fibre length or heartwood. Bark , however, was negatively correlated with tree growth. There was no appreciable difference in wood properties between the 3 locations, although fibre length andheartwood were slightly greater in the more rapidly grown trees at Vandiperiyar. An analysis of variance showed that wood density and fibre length varied significantly within, but not between, trees. Density decreased from stump to b.h., and thereafter increased towards the crown; there was a reverse trend in fibre length. Fibre length increased considerably from pith to bark in all age groups. Av. wood density for the tree could be predicted from density at b.h. in 5-, 7- and 9-yr-old trees, while stump density was a better predictor in 3-yr-old trees. Between-tree variation was small for fibre length and wood density, larger for bark, and greatest for heartwood