Fire blight disease on pears was reported for the first time in Iran in Baraghan region of Karaj . This bacterial disease was subsequently reported on other host plant in Ghazvin and west Azarbaijan province .In 1994, Fire blight infections were spread and caused heavy losses on apple, pear and quence orchards in Karaj. Early this year (1995) . This disease has become extremely severe due to continuaus rainfalls and high moisture. Currently, fire blight disease has spread through most of the orchard farms in karaj with high severity.
The most sensitive cultivars are quience, pear trees with quience root stocks pear and golden and red delicious apples. Symptom development and bacteriological properties of 34 isolates from karaj region based on physiological , biochemecial and pathogenicity tests identified the diseased - causing agent to be Erwinia amylovora. Because karaj is a major fruit - hrowing region it is probable that almost all host plants sensitive to this disease will be eliminated if appropriate measures are not taken to control the spreaed of this disease. In addition , because the pathogen is spreading to a new region every year, it is possible that the disease will become epidemic through out the orchard trees of Iran in near future.
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