A Wood Soil Contact Culture Technique for Laboratory Study of Wood-Destroying Fungi, Wood Decay and Wood Preservation

ABORATORY tests for evaluating fungicides are often used as a means of predicting field results and for investigating the action of cellulose and wood-destroying fungi. Of the several laboratory procedures hitherto devised for these purposes, however, none has been entirely adequate. This has led to incorrect interpretation of laboratory assays of fungicidal compounds, with attendant misapplication of preservatives. The confusion and misunderstanding concerning the use of preservatives have been further increased by the misapplication of the laboratory procedures themselves. A brief review and explanation of some procedures and their application will clarify these statements. Minute quantities of toxic agents and growth-promoting substances which are not readily detected by known chemical analyses may be determined by bio assay methods, the value of which depends upon a prior determination of the reaction of one or more organisms to known quantities of these substances. Another bio assay is the so-called "acceptance test" for fungicides, by which the fungus resistant qualities of materials impregnated with fungicides may be determined. Since fungus resistant qualities are the primary concern in such a test, the identity and quantity of the preservative are of only incidental interest. However, the identity, fungusproof qualities and quantity of fungicidal compounds are important when 102 WOOD SOIL CONTACT CULTURE TECHNIQUE 103 laboratory procedures are devised for comparing effectiveness in the development of different preservatives.