Soft rot studies on CCA treated eucalypt power transmission poles
IRG/WP 1132
L E Leightley
Initial results found for sixty CCA treated eucalypt poles, from a soft-rot survey are discussed. Retentions of CCA within above and below ground pole samples were variable. The variation was attributed mostly to biodegradation and effect of soil environment, rather than leaching. Bacterial decay was found in many poles and was severe in some cases. Although found in the presence of soft-rot decay, bacterial attack also dominated in regions of the CCA treated sapwood. Timber suffering such attack was appreciably softened. Extracellular layers have been observed around fungal hyphae from agar cultures and within soft-rot cavities. Fungal isolates were used to produce such polysaccharides. This material was used to observe the effect of addition of copper and quaternary ammonium compound. Solutions of extracellular polysaccharides exhibited some ability to bind copper and remove it from solution. In the presence of a quaternary compound polysaccharide was precipitated from solution.