VIEW ARTICLE

Resistance

Decay Resistance and Susceptibility of Sapwood of Fifteen Tree Species. Wallace E. Eslyn, Research Plant Pathologist, Forest Products Laboratory, Forest Service, U.S. Department of Agriculture, Madison, Wisconsin 53705; Terry L. Highley, Research Plant Pathologist, Forest Products Laboratory, Forest Service, U.S. Department of Agriculture, Madison, Wisconsin 53705. Phytopathology 66:1010-1017. Accepted for publication 10 February 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1010.

Twelve softwoods and three hardwoods were tested for resistance or susceptibility to decay above-ground by (i) soft-rot fungi: Papulospora sp., Monodictys sp., Graphium sp., Dactylomyces crustaceous, Penicillium sp., Thielavia terrestris, and Allescheria sp.; (ii) white-rot fungi: Coriolus versicolor, Phanerochaete chrysosporium, Lentinus tigrinus, Ganoderma applanatum, and an unknown basidiomycete; and (iii) brown-rot fungi: Gloeophyllum saepiarium, G. trabeum, Poria placenta, and Lentinus lepideus. All woods except the hardwoods and two of the softwoods underwent little weight loss (0-10%) when tested against soft-rot fungi by the serial-block method.White- and brown-rot fungi were used in an agar-block test designed to promote a relatively slow rate of decay. With white-rot fungi, all hardwoods were very susceptible to decay (45% or more weight loss); all but two of the softwoods sustained 11-24% weight loss. Five woods were very susceptible to decay (45% or more weight loss) by brown-rot fungi, nine were less susceptible (weight loss of 25-44%), while Eucalyptus was very resistant (0-1% weight loss). A measure of the relative importance of each of the test fungi, based on overall decay capabilities, is provided. Additionally, host preferences and deviations from preference trends are discussed for each of the fungal groups.