Identification, symptomatology, and epidemiology of fire blight on Le Conte pear in the Nile Delta of Egypt.
The first outbreaks of fire blight (Erwinia amylovora) in Egypt since 1962 were associated with heavy rainfall during bloom in 1982, rainfall combined with wind storms during bloom in 1983, and one 2-d rain during bloom in 1984. The severe occurrence of the disease, expressed mainly as flower blight, caused a loss of flowers 10-75%/tree. Of 24 bacterial isolates from blighted pear tissues tested for colony morphology, pathogenicity and fatty-acid composition, 22 were E. amylovora and 2 appeared more virulent than 2 standard American cultures used for comparison. However, fatty-acid profiles of the Egyptian isolates matched those of the standard cultures in the E. amylovora library.