Teak (Tectona grandis) is one of the most well known timbers of the world. Its timber qualities include attractiveness in colour and grain, durability, lightness with strength, ease of seasoning without splitting and cracking, ease of working and carving, resistance to termite, fungus, and weathering, etc. The species is native to the Indian-Burmese floristic region and found naturally in India, Myanmar, Thailand and Lao (Kaosa-ard, 1983); it is an old introduction to Indonesia (Kaosa-ard, 1981). Due to its high timber qualities, market demand, ease of domestication and cultivation, teak plantations have been widely established throughout the tropics from the 1850s (FAO, 1956, 1957). Teak has been successfully established as an exotic in many countries, e.g. Sri Lanka, Bangladesh and China in Asia; Ghana, Nigeria, Ivory Coast, Senegal, Togo and Benin in West Africa; Sudan and Tanzania in East Africa; Trinidad, Puerto Rico and Panama in Central America; Brazil and Ecuador in South America (FAO, 1957; Keogh, 1994; Hougs, unpublished data). The global teak plantation area recorded in 1990 was about 1.6 million ha (Hougs, unpublished data) which comprises 75 % of the high grade tropical hardwood plantations (Keogh, 1994). The main objective is to produce high quality timber trees with good growth.