Decay Resistance of Various Timber Species against Soft Rot Fungus, Chaetomium globosum KUNZE, in Accelerated Laboratory Tests

Abstract

Decay resistance of various temperate zone timber species (138 spp. of hardwoods and 44 spp. of softwoods) against a soft rot fungus, Chaetomium globosum KUNZE was estimated with reference to methanol extractives in wood in laboratory sand block tests. Morus alba, Morus bombycis, Robinia pseudoacacia, Picrasma quessioides, Ternstroemia japonica, Pieris japonica, Vacinum bracteatum, Ehretia ovalifolia and Paulownia tomentosa were designated as very durable hardwoods. Heartwoods of 14 species were classified in perishable class. Variances of decay resistance among species and families were considered not to be much different from those in the case of Basidiomycetes. Softwood species were slightly attacked and the greater part of species retained high resistance after treatment with hot methanol. In the case of Coriolus versicolor QUEL., a white rot fungus, extractiverich species of softwoods were more resistant to decay, and the greater part of such species became less resistant after the treatment. It may be possible to conclude that the role of extractives on the higher resistance of softwoods against soft rot fungi is generally poor.