Growth Ring Structure and Specific Gravity Variation in Juvenile and Mature Wood of Natural-Grown Teak (Tectona grandis L.f.)

Abstract

The radial variation of specific gravity and growth ring structures was studied in juvenile and mature wood of Tectona grandis L. grown naturally in dry (Chandrapur) and moist (Thane) deciduous forests of Maharashtra, India. Five trees each from age group of 48–66-year from Chandrapur and 120–154-year-old trees from Thane were selected. The study revealed that the mean specific gravity of growth rings in juvenile wood was more than the mature wood from both the sites. The annual growth in juvenile and mature period was higher in dry site than moist site. Ring width of juvenile and mature wood was 4.45 and 2.30 mm with the latewood content of 85.70 and 72.97%, respectively, in dry site. The patterns of radial variation of ring width, latewood content and specific gravity demonstrated inconsistency in juvenile to mature wood in both the sites. The specific gravity of all the five trees from both sites showed a poor association between ring width and latewood content in juvenile wood; however, it was positive and strong in most of the samples from mature wood. Considering mean values, there was a positive strong association between ring width and specific gravity in both juvenile and mature wood of both the sites. However, the latewood content did not show strong association with specific gravity. The overall result showed that ring width, specific gravity and latewood content vary among individuals within and between two sites. It is also important that individual tree variation needs to be studied while breeding for higher specific gravity rather than mean variation of all the trees in specific site.