<Note>Classified Characters of Wood Quality in the Junvenile Stage of Cultivars of Japanese Cedar

Abstract

Nine wood quality indicators are compared with three groups of growth rates and three types of load-deflection curves in bending on 36 cultivars of juvenile Japanese cedar (Cryptomeria japonica D. Don). The fast-grown trees have shorter tracheids. In the load-deflection type having the large plastic region, tracheid length is shorter and fibrils lie more flatly and bending modulus of elasticity is lower on the same specific gravity as in other two load-deflection types. The trees in this type, therefore, seem to be more juvenile. Moreover, much proportion of the trees in this type belongs to the fast-grown group. Then, by all meams, the precise information of wood quality is necessary for the utilization of fast-grown cultivars.