A theory linking the change in the cold susceptibility of the cambial tissue in the early spring with the development of a stem canker on Acer. saccharum Marsh. has been postulated. With crushed dry ice wrapped in burlap, selected areas on the boles of a number of sugar maples were artificially frozen on March 15, and on May 9, 1962. Subsequent microscopic examination and comparison revealed that the May-freeze areas and "maple cankers" were similar in cross section and the March-freeze areas were similar to areas of normal growth. This indicated that "killing frosts" in the spring could be the causation of the stem cankers.
Document Type: Journal Article
Associate Professor of Forestry, The Pennsylvania State University, University Park, Pa.