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Official Journal of the Japan Wood Research Society

Journal of Wood Science Cover Image
  • Note
  • Open Access

Radial modulus of rupture in radiata pine measured by individual rings

  • 1Email author,
  • 2,
  • 2 and
  • 2
Journal of Wood ScienceOfficial Journal of the Japan Wood Research Society200147:BF01171227

  • Received: 11 January 2000
  • Accepted: 9 June 2000
  • Published:


New equipment was developed to measure the strength of individual annual rings in green wood under predominantly tensile stress. This equipment was then used to assess the variation of the radial modulus of rupture (rMOR) in thirty-six 25-year-old radiata pine trees taken from three sites in New Zealand. The rMOR for individual rings ranged from 4.2 to 12.7 MPa and was calculated on the assumption that during bending of the specimens fracture was caused by the tensile force in the radial direction (i.e., perpendicular to the tangential-longitudinal plane). No consistent trends were observed in rMOR from pith to bark; nor was there any evidence of differences between the three sites. However, there was substantial between-tree variability that manifested mainly in different average rMOR values for the trees rather than in variations from pith to bark. These results indicate that there are no concerns with respect to splitting resistance for the juvenile wood of radiata pine. It will be of interest to investigate whether splitting resistance is under genetic control.

Key words

  • Radiata pine
  • Modulus of rupture
  • Within-tree and between-tree variation