In-ground evaluation of a copper azole wood preservative (Tanalithâ E) at a tropical Australian test site
J W Creffield, J A Drysdale, N Chew
A field trial to determine the in-ground termite and decay resistance of Pinus radiata D. Don impregnated with a copper azole formulation, TANALITHâ E, has been established at a tropical site in the Northern Territory of Australia. Four retentions of TANALITHâ E, containing 1.54, 2.08, 2.92 and 4.30 kg/m³ of Cu, are being evaluated. For comparison, Pinus radiata specimens treated to two retentions (0.56 and 1.18 kg/m³ of Cu) of the benchmark CCA preservative TANALITHâ C, have also been included in the test. Treated specimens (including controls) have been assessed for degrade by subterranean termites and fungal decay, after 4, 7, 16 and 27 months of exposure, using a scale ranging from 4 (sound) down to 0 (failed). Over the duration of the trial, specimens have been contacted by the economically important species of termites Mastotermes darwiniensis Froggatt, Coptotermes acinaciformis (Froggatt), Schedorhinotermes spp. and Heterotermes spp. After 27 months of exposure, the mean termite and decay scores for replicate test specimens indicate that the performance of TANALITH â E is comparable to CCA.