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Resistance

Decay Resistance of Red Pine Wood Chips Enriched with Oleoresin. Wallace E. Eslyn, Supervisory research plant pathologist, Forest Products Laboratory, USDA Forest Service, Madison, WI 53705; Karl E. Wolter, plant physiologist, Forest Products Laboratory, USDA Forest Service, Madison, WI 53705. Phytopathology 71:1248-1251. Accepted for publication 24 March 1981. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. DOI: 10.1094/Phyto-71-1248.

Red pine (Pinus resinosa) trees growing in Wisconsin were treated with paraquat to induce synthesis and deposition of high oleoresin contents (lightwood production), or with water (controls). The trees were harvested 2 yr later and wood chip samples containing average levels of nonvolatile oleoresins of 3.9 (controls), 9.7, and 15.9% were obtained. These samples were subjected to decay by the typical wood decay fungi, Phanerochaete chrysosporium, Poria subvermispora, Gloeophyllum trabeum, an unknown basidiomycete (ME-493), and by the soft-rot fungus, Papulospora sp. Weight losses caused by each of the test fungi were consistently less in the lightwood than in the normal wood chips. Generally, little difference in decay resistance was found between chips containing average nonvolatile oleoresin contents of 9.7 and 15.9%. Because of the greater decay resistance of lightwood, its initial dryness, and fewer living parenchyma cells, wood chip storage piles consisting predominantly of lightwood should undergo reduced biological deterioration and initial heating.