Wood color variation in undried and kiln-dried plantation-grown lumber of Vochysia guatemalensis

Abstract

Vochysia guatemalensis has been planted over large tropical areas to obtain lumber products. However, compared with naturally-grown material variations in wood color have been noted. In the current research, trees from two 8-year-old fast-grown plantations were sampled from different climatic conditions in order to identify the causes of color variation. The study evaluated the heartwood presence, grain pattern, distance from pith, height within the tree, and effect of drying schedules. The wood color was measured by CIEL*a*b* systems. Wood color of Vochysia guatemalensis is a combination of different tonalities of lightness (L*), redness (a*), and yellowness (b*), however, the lightness and yellowness components were the dominant tones. The color of heartwood and sapwood were different before and after drying. A negative relationship was found between a* and L*, and a* and b* in the undried state, but no relationship was found between L* and b*. The L* index is only correlated with heartwood presence in undried wood. In dried wood, only a relationship between a* and L* is maintained, while other color parameters were affected by climate, drying schedule and heartwood presence, the L* parameter being the most affected. The dried wood displays a lighter surface than the wood before drying. The variations in the dried wood suggest that it is useful to establish dried lots of lumber according to the drying schedule, source and presence of sapwood and heartwood. Keywords: Fast growth plantations, tropical species, CIElab color systems, wood quality.