Internal Wounding Associated with Atrinal Injections in Norway Maple

Abstract

Ten Norway maple trees were examined to determine the internal injury (discolored wood) associated with trunk cankers induced by Atrinal injection. The trees were part of a study involving 225 trees injected with Atrinal in the Spring of 1984, in Westahester, New York. The amount of discolored wood associated with injection wounds varied from 7 to 38% at the injection site and up to 44% further away. The average volume of discolored wood at the injection site (10 inches above and below the injection point) was approximately 20%. The average volume of compartmentalization could be correlated with the size of external cankers. The pattern of internal compartmentalization was related to the size of the external canker. Internal decay begins after compartmentalized areas of trees are breached by a second wound. Current trunk injection practice involves trangential injections which greatly increase the probability of breaching existing compartmentalized areas. Actual wood decay was apparent in one tree of the ten examined. The results of this study demonstrate that injection of Atrinal or other growth regulators may cause extensive internal injury to trees.