Stem and Branch Distribution of Wetwood and Relationship of Wounding to Bleeding in American Elm Trees. C. W. Murdoch, Postdoctoral Research Fellow, N.E. Plant, Soil, and Water Laboratory, USDA, ARS, University of Maine, Orono 04469. R. J. Campana, Professor of Botany and Forest Pathology, University of Maine, Orono 04469.. Plant Dis. 68:890-892. Accepted for publication 19 April 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-890.

Frequent bleeding from wounds made to inject chemicals into elm stems indicated a need to investigate the distribution and development of wetwood. A study was made to determine the location and distribution of wetwood in stems of varying ages and to evaluate the relationship of bleeding to types and depths of wounds made to inject chemicals. Cross-sectional area of wetwood, volume of wetwood per meter of bole, and surface-to-volume ratio of the wetwood cylinder were higher in injected trees than in noninjected trees. Frequency of bleeding increased with depth of injection wound. Topical application of a bactericide to wounds did not prevent bleeding.

Keyword(s):