Variations in volume and dimensions of rays and their effect on wood properties of teak

Six teak (Tectona grandis L.) trees were sampled from two districts in Bangladesh. Ray proportion and dimensions of rays (ray area, ray height, and ray width) on tangential sections were measured, and the influence of ray volume on longitudinal and radial compression strength was investigated. Ray proportion remained more or less constant from pith to bark. Number of rays/mm(2) and dimensions of rays became constant at about ring 10 from the pith. Ray proportion and dimensions showed characteristic values from tree to tree and were not affected by growth rate. The trees that had the highest ray volume showed higher specific gravity and higher radial compression strength. It can be considered as the influence of the rays. Hence it may be advisable to breed teak with a high ray proportion.