Growth and Wood Properties of Sugi (Cryptomeria japonica) Cultivars Planted in the Kyushu Region

Abstract

This study examined growth and wood properties of sugi (Cryptomeria japonica D. Don) cutting cultivars planted in the Kyushu region. Sixteen cultivars (48 trees) which were identified based on MuPS (Multiplex-PCR of SCAR markers) types were used. Each cutting cultivar showed peculiar growth. The intra-cultivar variations in green moisture content of heartwood were small whereas the inter-cultivar variation was large. There were statistically differences in the L* and a* values of the heartwood color between cultivars, and a negative correlation of the L* value with green moisture content was found. There was also significant difference in wood density between cultivars, and the neutral and the late-growth type cultivars showed larger basic density than the precocious-growth type cultivars. A significant difference in dynamic Young's modulus was also found between cultivars, and there were two axial variation patterns. In one pattern the dynamic Young's modulus increased with stem height, and in the other it was almost constant except at the position of the butt log where it had the lowest value. The former was the neutral or late growth type and the latter was the precocious type. There was a significant difference in the bending loaddeformation curve of clear test specimens between cultivars or growth types. © 2005, The Japan Wood Research Society. All rights reserved.