The physical and mechanical properties of plantation grown teak in difference ages from Kakum in Central Region of Ghana

Abstract

The increasing demand for timber in Ghana has placed much pressure on some of the species whose technical information is known. The incumbent trend of deforestation has posed a threat on sustainability of the country’s timber resource in the near future if adequate measures are not put in place to curb the problem. To this effort many exotic species have been introduced into the country and raised in plantation both on and off reserves to supplement the timber in the natural forest. Among these exotic species is the Tectona grandis (Teak). Despite the establishment of these hardwood species in plantation, wood users do not have adequate information which will encourage the maximum utilization of the species. The study was undertaken to evaluate the physical and mechanical properties of Teak wood at ages 10, 15, and 20-years grown in Jukwa in Hemang Lower Dankyira District. Six trees were selected from the plantation for the study. These trees were cut into three height portion (butt, middle and top) and wood samples selected for the test. Eighteen pieces of Teakwood were taken for the sample. Six pieces each for 10, 15 and 20 year-old teakwood. Twelve samples each were taken along the radial direction of the stem (heartwood and sapwood). The heartwood and sapwood were clearly sawn from the Teakwood. The sapwood samples were taken from 3 cm from the bark of the trees whereas the heartwood samples were taken from the range of 5 cm to the pith of each portion of the woods. The findings show that, maximum compressive strength, hardness and shear strength of the teak wood were found to increase with age of species. Teak wood at age 10 and 15 did not show any significant differences with respect to air dry density. On average, MoR of 20 years old Teak wood was 106 N/mm2, which was about 33% and 38% higher in the 20- year-old Teak wood than the 15 and 10 year old respectively. Modulus of elasticity (MoE) was 9% and 32% higher in 20 year than in the 15 and 10-year-old teak wood respectively. Relationship between teakwood properties and age of tree was not apparent. This suggests that other factors may influence the wood properties of teak tree. In general wood properties of 10 and 15-year- old Teak were not inferior to ones from 20-year-old Teak.