Comparison of Fungal Efficacies of Commercial Preservatives using the E22 Soil Block, Deck/Flower Pot, and Standard E7 and E8 Versus Accelerated E7 and E8 Tests

摘要

Outdoor ground-contact and above-ground testing of potential wood preservatives is a lengthy and costly endeavor. We are studying accelerated laboratory and field tests where the results could possibly provide faster and more reliable fungal efficacyresults. Some of the tests we have recently examined are the harsh soil block test where longer exposure times than typically employed are used [but this method meets the Standard E22 protocol] until decay is observed in one or more treated sets. Anotheraccelerated concept employs ground-contact stake and post tests, where replicate samples are installed in both AWPA Standard E8 or E7 test plots and an adjacent accelerated plot where fungal-infested wooden feeder stakes are placed in contact with the treated samples. An above-ground accelerated test was developed based on the observation that many residential decks have flowerpots and the wood underneath and near these pots would be expected to have a high biodeterioration potential. A final ground-contact test is based upon the general knowledge that soil rich in nutrients and moisture-holding organic matter often gives faster wood decay than soils poor in organic matter and nutrients. Tests are currently underway with commercial copper-treated lumber, and stakes treated with pentachlorophenol formulated using two different carriers or treated with copper working preservative solutions obtained from commercial plants. The initial results obtained with these accelerated versus Standard E7 and E8 field tests with matched copper-treated samples, along with published Standard field E7 stake test results, suggest that efficacies obtained from these relatively short-term accelerated outdoor tests may be applicable to results obtained from long-exposurestandard field tests. The outdoor tests are continuing to be inspected to obtain more definitive fungal efficacy data.