Methods for the very early selection of Pinus radiata D. Don. for solid wood products
- 265 Downloads
There has been an increasing interest in very early selection of radiata pine to reduce the breeding cycle for solid wood products. For such selection, new approaches are required to assess wood quality in wood from very young stems.
Nursery seedlings of clones of radiata pine were grown in leant condition using two leaning strategies for 18–20 months. Opposite wood and compression wood were isolated from the leaning stems and tested for dynamic modulus of elasticity, density, longitudinal shrinkage, volumetric shrinkage and compression wood area using new methods evolved for testing small size samples quickly and reliably. The methods were tested for their efficiency in differentiating clones by their wood properties.
Leaning of stems provided distinct opposite and compression wood for testing. Automated image analysis method used for compression wood area assessment was found to be a quick and effective method for processing large number of samples from young stems. Compression wood was characterised by high basic density, high longitudinal shrinkage and low volumetric shrinkage than that of opposite wood. Acoustic velocity in opposite wood had a strong negative association with longitudinal shrinkage. The study signifies the importance of preventing mixing of opposite wood with compression wood while assessing wood quality in young stems thus making leaning a critical strategy. The comparison of wood properties of opposite wood revealed significant differences between clones. Opposite wood of the clone with the lowest dynamic modulus of elasticity exhibited the highest longitudinal shrinkage.
Significant differences in measurable wood properties between clones suggest the prospects of early selection for solid wood products.
KeywordsEarly selection Leaning Radiata pine Tree clones Wood properties
Authors are thankful to Nigel Pink and Lachlan Kirk for helping in fabrication of micro-saw, shrinkage jig and processing samples. This work is a part of the Compromised Wood Programme (P2080) funded by Foundation for Research Science and Technology (FRST), New Zealand. Jimmy Thomas gratefully acknowledges funding for his PhD scholarship generously provided by Scion Ltd, Rotorua, New Zealand.
- Andrews M (2002) Which acoustic speed? The 13th International Symposium on Nondestructive testing of wood. University of California, CaliforniaGoogle Scholar
- Burdon RD (1975) Compression wood in Pinus radiata clones on four different sites. NZ J For Sci 5:152–164Google Scholar
- Evans R (2000) Measuring wood and fibre properties. In: WTRC Workshop 2000. Wood Technology Research Centre, University of Canterbury, New Zealand. pp 15–20Google Scholar
- Floyd S (2005) Effect of hemicelluloses on longitudinal shrinkage in wood. In: Entwistle KM, Walker JCF (eds) The Hemicellulose Workshop 2005. Wood Technology Research Centre, University of Canterbury, New Zealand, pp 115–120Google Scholar
- Halabe UB, Bidigalu GM, GangaRao HVS, Ross R (1997) Nondestructive evaluation of green wood using stress wave and transverse vibration techniques. Mater Eval 55:1013–1018Google Scholar
- Horvath B, Peszlen I, Peralta P, Horvath L, Kasal B, Li L (2010) Elastic modulus determination of transgenic aspen using a dynamic mechanical analyzer in static bending mode. For Prod J 60:296–300Google Scholar
- Huang CL, Lambeth C (2007) Stress wave velocity of loblolly pine seedlings. In: Walker JCF (ed) The compromised wood workshop. Christchurch, New Zealand, pp 37–50Google Scholar
- Kretschmann DE, Cramer SM (2007) The role of earlywood and latewood properties on dimensional stability of loblolly pine. In: Walker JCF (ed) The compromised wood workshop, Christchurch, New Zealand, 215–236Google Scholar
- Nakada R (2007) Within-tree variation of wood characteristics in conifers and the anatomical characteristics specific to very young trees. In: Walker JCF (ed) The compromised wood workshop, Christchurch, New Zealand, 51–67Google Scholar
- Ross R, Pellerin R (1991) NDE of green material with stress waves: Preliminary results using dimension lumber. For Prod J 41:57–59Google Scholar
- Timell TE (1986) Compression wood in gymnosperms, vol 1. Springer Verlag, Heidelberg, 706Google Scholar
- Wang X, Ross RJ, McClellan M, Barbour RJ, Erickson JR, Forsman JW, McGinnis GD (2000) Strength and stiffness assessment of standing trees using a nondestructive stress wave technique. Research Paper Forest Products Laboratory, USDA Forest Service (FPL-RP-585), 9 ppGoogle Scholar