Abstract:
A study on the variation in wood basic density and dynamic modulus of
elasticity of teak (Tectona grandis L.f.) trees grown in tree improvement trials at
various locations in Kerala using destructive and nondestructive testing (NDT)
methods was conducted in the College of Forestry, KAU, Vellanikkara, Thrissur
during the period 2012-2015. The investigation focused on the variation in
physical and mechanical wood properties of teak, and to understand their
relationship with growth traits and evaluating the suitability of NDT methods as
predictors of timber properties under field conditions.
Pilodyn (6J) and Treesonic Microsecond Timer (FAKOPP) were the two
NDT equipments used in the study. Teak logs collected from a forest plantation
(Elival, Palakkad) were destructively analysed following nondestructive testing
with the above equipments. Discs and logs were analysed for within tree variation
in Pilodyn pin penetration depth (PPD) and were further subjected to various
mechanical tests using UTM as well. Significant variation in mechanical
properties, and Stress Wave Velocity (SWV) was observed between the trees
sampled. Most of the mechanical properties assessed destructively were found to
be highly correlated with SWV. PPD in the periphery of the trees was related to
the same in the middle portion of the trees. Pilodyn readings also correlated well
with the actual wood basic density analysed destructively. In general, both the
NDT instruments were found to be useful in estimation of the respective
properties using regression analysis.
In standing trees of a CSO (Walayar, Palakkad), an SPA (Nilambur) and
two clonal trials (Chettikkulam and Vellikulangara, Thrissur) non-destructive
evaluation was repeated. The study revealed high genetic divergence in the wood
traits and indicated greater scope for application in tree improvement trials.
Growth traits didn’t show any consistency or trend with the differing age of the
plantations, nor any convincing relationship with the wood traits. Clusters were
also identified for the clones at Walayar and Chettikkulam based on which
selection for further breeding programmes can be undertaken
