Production of decay-resistant sapwood in response to injury

Summary Mechanical injury to the sapwood of Quercus alba, Robinia pseudoacacia, and Maclura pomifera resulted in the formation of discolored tissue which was more resistant to decay fungi than the adjacent uninjured sapwood but usually less resistant than the heartwood. Considerable tree-to-tree variation in response to injury, as measured by subsequent variations in decay resistance, was noted. The exact cause for this induced decay resistance is unknown, but it appears to be due to fungistatic substances produced in situ by the dying parenchymous cells in the xylem.This work was supported by Grants GB-5313 and GB-7550 from National Science Foundation. Michigan Agricultural Experiment Station Journal Article No. 4925.