Influence of Rainfall, Irrigation and Age on the Growth Periodicity and Wood Structure in Teak (Tectona Grandis)

Growth periodicity was followed for two consecutive annual cycles to reveal the pattern of wood fonnation in plantation-grown teak at three different localities in India. Rainfall and age were the two important factors that influenced cambial activity. Cambial reactivation occurred during March-April in both years. The pre-monsoon showers broke the cambial donnancy at all three localities. Almost a month's interval was observed between bud break and initiation of radial growth . Irrespective of age and locality, a peak period of cambial activity occurred during June-July. Dormancy began during October-December, depending on the age of the trees and locality. Juvenile trees and those grown in relatively high rainfall areas had a prolonged cambial activity and retained foliage throughout the year. They produced wider rings with higher proportions of latewood. Irrigation of 5-year-old trees led to the loss of typical ring porosity of teak wood; their first three growth rings were more or less diffuse-porous. This is attributed to uninterrupted cambial activity resulting in production of rather uniform-sized vessels.