Cornell University plant pathologists have discovered a strain of fire blight that is resistant to a traditional control measure—streptomycin.
For the past 50 years, apple and pear growers have used the antibiotic to control the disease, according to a news release.
The researchers found the streptomycin-resistant strains in four locations in Wayne and Ontario counties.
Herb Aldwinckle, a plant pathology professor, and Extension specialists are developing growe guidelines to reduce the treat.
Fire blight is caused by the bacteria Erwinia amylovora. It is harmless to humans but can cause a scorch appearance on infected leaves and branches.
The organism also can blacken flowers and young leaves, resulting in crop loss and even tree death.
This isn't the first time that strep-resistant fire blight has been confirmed. It was first identified in California in 1971 and has since been found in Washington, Oregon, Missouri and southwest Michigan.
Aldwinckle advises all growers to inspect their recently planted trees, particularly those from New York and Michigan nurseries, for fire blight symptoms.
He also is exploring other ways to treat fire blight including kasugamycin, a not-yet- registered antibiotic.