New host for Erwinia amylovora found in the USA
During recent years Crataegus aestivalis, a small native tree to southern USA, has increasingly been found to develop blighting symptoms in Georgia (US). The trees which produce edible fruits and which are potentially useful for landscaping were showing symptoms which resembled those of fireblight in other Rosaceae. Investigations on the causal organism showed that the disease was indeed caused by Erwinia amylovora (EPPO A2 quarantine pest). This is the first record of Crataegus aestivalis as a host for E. amylovora. The author believes that, due to the more intense cultivation of the trees, fireblight might become a serious disease of C. aestivalis.
Sources
Carter, S.M. (1993) Fire blight caused by Erwinia amylovora on mayhaw in Georgia.
Plant Disease 77, 1262.