Date of this Version
This NebGuide tells how fire blight is spread among apple, pear and woody ornamentals. It describes the disease cycle and offers advice for treatment and protection.
Fire blight, caused by Erwinia amylovora, is the oldest, most serious bacterial disease of apple and pear. It was first reported in the late 18th century in the Hudson River Valley in New York. The disease is indigenous to North America, and probably occurred on native American plants such as crabapple, hawthorn and mountain ash and then spread to susceptible cultivated apples, pears and woody ornamentals planted by the early American pioneers. As the settlers moved west, so did fire blight. By the early 1900s it became established as a serious threat wherever apples and pears were grown in North America.