Disease Note

Bradford Pear (Pyrus calleryana), a New Host of Botryosphaeria dothidea. J. M. Mullen, Cooperative Extension Service, Alabama Agricultural Experiment Station, Auburn University, AL 36849. A. K. Hagan, Cooperative Extension Service, and G. Morgan-Jones, Alabama Agricultural Experiment Station, Auburn University, AL 36849. Plant Dis. 69:726. Accepted for publication 22 April 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-726b.

In the spring of 1983, a canker disease was observed on Bradford pears (Pyrus calleryana Decne.) in a landscape planting in Mobile County, Alabama, Small, elongated, dark brown to maroon lesions were observed on lateral branches and main trunks of trees, along with mild foliage chlorosis and premature leaf drop. Trees with large, cracked, sunken cankers on large branches and main trunks were in a severe state of decline. Peridermal peeling often occurred at canker margins, and some large cankers were surrounded by a wide zone of dark discolored bark. The surface of large cankers was covered with numerous pseudothecia of Botryosphaeria dothidea (Moug. ex Fr.) Ces. & de Not. Pathogenicity of isolates recovered from cankers was established by wound-inoculating containerized Bradford pear trees. This is the first report of B. dothidea canker on Bradford pear or other Pyrus spp.