The Role of Selected Deuteromycetes in the Soft-Rot of Wood Treated with Pentachlorophenol

Authors

  • Jonathan D. Lew
  • W. Wayne Wilcox

Keywords:

Soft-rot, Trichoderma, Scytalidium, Fusarium, Douglas-fir, Pseudotsuga menziesii, poles, pentachlorophenol, liquefied petroleum gas, Deuteromycetes, fungi

Abstract

The severity of soft-rot in a group of Douglas-fir transmission poles treated with pentachlorophenol (PCP) carried in a liquefied petroleum gas (LPG) cosolvent system was assessed at the cellular level using phase contrast and polarized light microscopy. The principal fungi involved in the surface deterioration of the poles were isolated, identified, and tested for their tolerance to PCP in synthetic culture media and for their ability to produce weight-loss and/or soft-rot cavities in wood blocks treated with varying concentrations of PCP.

Two Deuteromycetes, Trichoderma spp. and Scytalidium spp., were common on the pole surfaces despite high retentions of PCP in the outer 1/4-inch zone. Fusarium spp. were isolated with less frequency. All three fungi demonstrated significant tolerance to PCP in agar-plate screening, but only a Scytalidium isolate produced soft-rot cavities under the conditions of the weight-loss test. Soft-rot attack was extremely superficial in these poles, despite the ubiquitous presence of PCP-tolerant Deuteromycetes. After 7-12 years of service life, the depth of degradation due to the action of soft-rot organisms was less than 1 mm in 90% of the poles studied. This observation suggests that this group of poles should provide excellent service life.

References

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Published

2007-06-27

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Research Contributions