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Growth Stress In Eucalyptus Dunnii, Timothy N. Murphy, Michael Henson, Jerome K. Vanclay
Growth Stress In Eucalyptus Dunnii, Timothy N. Murphy, Michael Henson, Jerome K. Vanclay
Professor Jerome K Vanclay
Growth stress in 9-y-old plantation-grown Eucalyptus dunnii was assessed by measuring longitudinal growth strain. Strain varied considerably (370–1560 ìm–1) and was sufficiently heritable (h2 =0.3–0.5) that tree breeding may be an effective way to reduce the incidence of growth stress in this species. Although the formation of longitudinal growth strain appears to be under strong genetic control (P = 0.0015), there was a tendency for tall thin trees to exhibit higher stress than short thick trees (P = 0.025 for height:diameter ratio). Two provenances and three families identified in this study show potential as superior material for further tree breeding.
Spiral And Interlocking Grain In Eucalyptus Dunnii, C Thinley, Graeme Palmer, Jerome K. Vanclay, Michael Henson
Spiral And Interlocking Grain In Eucalyptus Dunnii, C Thinley, Graeme Palmer, Jerome K. Vanclay, Michael Henson
Professor Jerome K Vanclay
Spiral grain in 181 trees from a 9-year-old plantationgrown Eucalyptus dunnii was normally distributed with mean −0.33 degrees (to the left) and standard deviation 1.7 degrees, and was affected by family and by crown asymmetry. Interlocking grain was common, exhibiting a mean amplitude of 3.4 degrees (standard deviation 1.5◦) and a mean wavelength of 39 mm (standard deviation 12 mm). The relatively large amplitude of interlocking grain means that most trees will have spiral grain that alternates between left and right during each year. The wavelength of interlocking grain is influenced by tree size, but amplitude of interlocking is under …