Fire blight

Fire blight on Malus 'Honey Gold' in a Minnesota orchard

Fire blight is a bacterial disease that affects the following hosts:

  • apple
  • pear
  • loquat
  • quince
  • cotoneaster
  • hawthorn
  • photinia
  • pyracantha
  • some other ornamental plants.

There's no single effective treatment for fire blight.

See Plant Health Australia for more information.

Fire blight symptoms on apple sp.

Where fire blight is found

Fire blight seriously effects fruit production worldwide. It exists in:

  • New Zealand
  • North America
  • the United Kingdom
  • Europe
  • the Middle East.

Symptoms of fire blight

The following symptoms can indicate fire blight:

  • brown wilting of blossoms, shoots and leaves, with a scorched appearance
  • discoloured sunken areas or cankers on branches, limbs and trunks
  • bacterial ooze in warm, humid weather
  • red-brown discolouration of the sapwood
  • shoots and branches bent into a 'shepherd's crook' shape
  • leaves remain attached to stems.

Fire blight on shoot of apple showing twig blight with shepherd’s crook and water-soaked young leaves before turning black

The scorched appearance of a young twig with fire blight, note the blacked attached leaves, midrib necrosis and shepherd's crook

Bacteria oozing from young apple fruit infected with E. amylovora

Fire blight has spread down the twig into the main stem, where a canker has begun to form

Fire blight on pear fruitlet, showing blackened fruit with ooze

Fire blight on loquat (Eriobotrya japonica)

Fire blight on firethorn

Fire blight on cane fruit showing blight and death of fruit

Spread of disease

Plants can become infected in the following ways:

  • blossoms where the bacteria is transported by bees during pollination
  • surface injuries caused by insect feeding, hail or mechanical damage
  • bacterial exudate can be dispersed locally by wind, rain, insects and birds.

Control

There's no single effective treatment for fire blight.

Photo credits

Figure 1: Courtesy Jody Fetzer, Maryland National Capital Park and Planning Commission, Bugwood.org

Figure 2: courtesy of Rebekah D. Wallace, University of Georgia, Bugwood.org.

Figure 3: Courtesy of Mary Ann Hansen, Virginia Polytechnic Institute and State University; Bugwood.org

Figure 4: Courtesy of Guido Schnabel, © Department of Agriculture & Environmental Sciences, Clemson University.

Figure 5: A.L. Jones, Michigan State University.

Figure 6: Photo by Penn State Dept. of Plant Pathology & environment Microbiology Archives, Penn State University., Bugwood.org.

Figure 7: Courtesy of Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Bugwood.org

Figure 8: Courtesy of Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Bugwood.org

Figure 9: Courtesy of Florida Division of Plant Industry , Florida Department of Agriculture and Consumer Services, Bugwood.org

Figure 10: Courtesy of Brian Olson, Oklahoma State University, Bugwood.org

Page last updated: 20 Aug 2020