The Effects of Dwarf Mistletoe on The Wood Properties of Lodgepole Pine


  • Douglas D. Piirto
  • Donald L. Crews
  • Harry E. Troxell


Pinus contorta, modulus of elasticity, specific gravity, longitudinal shrinkage, microfibril angle, tracheid length, extractives content, static tests, flexural strength


The effects of dwarf mistletoe (Arceuthobium americanum Nutt. ex. Engelm.) on the wood properties of lodgepole pine (Pinus contorta Dougl.) were studied. The results indicate: a decline in modulus of elasticity, modulus of rupture, and work to proportional limit in both infected and noninfected wood from the infected trees; a higher specific gravity of the infected wood; a higher percentage of alcohol-benzene extractives in the infected wood; an increase in longitudinal shrinkage in both infected and noninfected wood from the same tree; a lower percentage of latewood in wood from infected trees; no significant difference in growth ring width between infected and control wood; narrower growth rings in the noninfected regions of infected trees; a decrease in tracheid length in both infected and noninfected wood from the same tree; an increase in microfibril angle in both infected and noninfected wood from the same tree.

This is the first study to show that both infected wood and noninfected wood from the same tree are definitely inferior to wood from noninfected trees in strength and longitudinal shrinkage characteristics.


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