Fungicidal Efficacy of Ammoniacal Copper and Zinc Arsenic Preservatives Tested by Soil-Block Cultures


  • J Rak
  • H Unligil


<i>Pinus resinosa</i>, fungicidal efficacy, ammoniacal preservatives, <i>Coniophora puteana</i>, <i>Poria monticola</i>, <i>Lenzites trabea</i>, Cu, Zn, As, soil-block tests, biodegradation, preservative's, water-borne preservatives


Three new preservative formulations-copper-zinc-arsenic-additive (CZAA), copper-arsenic-additive (CAA), and zinc-arsenic-additive (ZAA)—were tested in comparison with four other preservatives by soil-block culture on unleached red pine samples using test fungi Coniophora puteana, Poria monticola, and Lenzites trabea.

Threshold values (based on retentions of all oxides) of 0.1 pound per cubic foot (1.6 kg/m3) for CAA and 0.2 pound per cubic foot (3.2 kg/m3) for CZAA were comparable with threshold values of the commercial preservatives ammoniacal copper arsenate (ACA) at 0.1 pound per cubic foot (1.6 kg/m3) and eliminated copper arsenate type C (CCA-C) at 0.3 pound per cubic foot (4.8 kg/m3). The ZAA formulation had a relatively high threshold value [0.6 pound per cubic foot (9.6 kg/m3)]. Thresholds based on As2O5 retentions only indicated the fungicidal efficacy in decreasing order: ACA or CAA > CZAA > CCA-C > ZAA.

Coniophora puteana (A328, EFPL) was more resistant to all tested preservatives (except ZAA) than the standard strains of Poria monticola and Lenzites trabea.


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