Variation in anisotropic shrinkage of plantation-grown Tectona grandis (Linn) Wood

Abstract

This study investigated anisotropic shrinkage of 15-year-old Tectona grandis wood to assess axial and radial variation. Four trees with clear bole and similar diameter were purposefully selected and felled from the plantation of Federal University of Agriculture, Abeokuta, Nigeria and used for this study. Wood samples were systematically collected from the outer, middle and inner wood sections of the radial direction and axially at base (25%), middle (50%) and top (75%) of the merchantable height. The mean value of wood weight was 29.77% while the mean values for longitudinal shrinkage, radial shrinkage, tangential shrinkage and volumetric shrinkage were 3.56%, 3.25%, 3.01% and 9.82% respectively. Variations in both axial and radial directions were statistically significant (p≤0.05) for all the properties evaluated except tangential shrinkage. This study showed that within tree and within species variation existed in the shrinkage properties of 15-year-old Tectona grandis. The variations have implications on dimensional stability of the species and therefore on the utilisation potentials.

Keywords: Tectona grandis wood, Axial and radial directions, Radial shrinkage, tangential shrinkage, volumetric shrinkage