Teak (Tectona grandis L.f.)is the most preferred timber species in the tropics for saw-log and veneer production from plantation forestry. To evolve a system for end-use classification of a large number of tropical hardwoods, using teak as standard (reference species), comparative suitability indices/coefficients have been derived. With the renowned durability and decorative values of heartwood, teak has proved eminently suitable for multiple end-uses including construction, furniture and cabinet, railway sleepers, decorative veneer, joinery, boat and vehicle body-building, mining, etc.
The important property requirements of end-users in fast-grown teak obviously include straighter bole with least taper (cross grain) and knots, lower proportions of juvenile and tension wood, higher proportion of heartwood, optimum wood density and strength. As more research data are forthcoming, the earlier notion that fast-grown teak yields inferior timber is slowly diminishing. Now that there is new evidence for unaltered heartwood-sapwood ratio or even increasing heartwood percentage and wood density with faster growth. The strength properties were reported to be often independent of growth rate. These results are strongly in favour of solid wood-user's requirements. However, the growth-property-product relationships are quite complex, as the wood formation pattern differs markedly between the silvicultural practices and genetic selection which aim at enhancing the growth rate.
The impact of faster growth due to various factors incl. insect defoliation control on end-user's requirements is discussed. The data available at present are inadequate for property manipulation by intensive management practices but presuppose such a possibility if international cooperative research is strengthened with the Teak Wood Task Force.
Key words: growthpropertyproduct relationships, tropical hardwood, heartwood, mechanical properties.
Correspondence: K.M. Bhat, Wood Science Division, Kerala Forest Research Institute, Peechi 680 653, Thrissur Dist. Kerala, India
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