Longitudinal Growth Strains in Melia dubia

Abstract

Logs of many fast-grown tree species develop end splitting immediately after felling, and timber from such logs suffers from excessive warping and twisting on sawing. Such distortions are attributed to the presence of high magnitude of inherent growth stresses. This results in low recovery of quality sawn material and therefore devalues a tree species for timber purposes. For the efficient utilization of any timber species, prior knowledge on the intensity and distribution of growth stresses in trees is vital. Melia dubia is increasingly gaining popularity as the plantation species because of its fast growth and is becoming a preferred species for plywood manufacturing. For ensuring the suitability of the species as a timber for other applications, the propensity of growth stresses needs to be known. Since inherent growth stresses cannot be measured directly, in lieu longitudinal growth strains are measured by relieving the stresses. In this paper, magnitude of longitudinal growth strain measured in trees and logs of M. dubia from three age groups growing in different locations are presented. The longitudinal growth strains were measured using wire strain gauge method. The magnitude of growth strain was ranging from 56 to 730 microstrains. The observed growth strains are in the range which does not raise a serious concern in processing and utilizing this species as timber.