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Disease Note. Tubercularia Canker of Honeylocust in North Dakota. J. A. Walla, Department of Plant Pathology, North Dakota State University, Fargo 58105. R. W. Stack, Department of Plant Pathology, North Dakota State University, Fargo 58105. Plant Dis. 72:734. Accepted for publication 13 April 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0734B.
A stem and branch canker disease was found on honeylocust (Gleditsia triacanthos L.) in landscape and experimental plantings in eastern North Dakota. Stem cankers were associated with dead or pruned off branches and basal wounds. When branches were cankered, tip dieback were observed. Black erumpent sporodochia on dead bark of the cankers were identified as those of Tubercularia ulmea Carter. Other fungi that commonly cause cankers on honeylocust in other states were not found. Pathogenicity of two T. ulmea isolates was confirmed by inoculating colonized wheat kernels onto twig wounds (1) of several 8-to 14-mm-diameter branches and two of 20 wounded but noninoculated branches. Sporodochia of T.ulmea developed on cankered branches within 7 mo. T ulmea has been reported to cause cankers on other woody hosts in North Dakota. Identification of Tubercularia canker on honeylocust is significant as documentation of a disease that should be considered when cultivars of honeylocust are tested for planting in the northern Great Plains. |