Evaluating Potential Decay Control Agents With A Small Block Test

A small-scale test was developed to evaluate the ability of fungicides to control decay fungi established in wood. The test, which uses blocks 2.5 x 2.5 x 10 cm, tests the ability of a chemical to migrate from the middle of the block to control a previously established decay fungus, Poria carbonica. The effect of block size, degree of fungal development, chemical exposure period, and aeration during exposure were evaluated on chemicals previously shown to be effective for remedial control of decay. The method was then used to evaluate potential decay control chemicals. Highly volatile chemicals proved to be most effective, while water-soluble and oil-borne chemicals produced much poorer control. The small block tests appear to provide a simple, rapid, and accurate method for predicting how chemicals will control established decay fungi in wood