Fire Blight Description:

Fire Blight is a bacterial disease affecting apples, pears, and some other members of the family Rosaceae. It is a serious concern to apple and pear producers. Under the right conditions, it can destroy an entire orchard in a single growing season.


Crabapple, apple, cotoneaster, firethorn, hawthorn, mountainash, pear, and quince are plants most commonly damaged.

Biology, Signs & Symptoms:

In the spring, during wet weather, the bacteria is splashed onto blossoms by rain or pollinating bees. The pathogen travels down into the shoots and into fruit spurs.

Symptoms include:

  • Wilt and blackening of leaves and twigs which form a “Shepherd’s crook”
  • Small, slightly sunken, and brown cankers (Older cankers are dark brown and sunken with brown tissue under the bark.)
  • Branch dieback and death of the plant
  • Bacteria ooze from the blossoms and fruit during wet, humid weather


  1. Remove infected wood several inches below cankers during the dormant season, if applicable. During the growing season, place pruned material in a container and cover it before leaving the area. Do not toss clippings around as this spreads the bacteria. Sterilize between each pruning cut.
  2. Apply slow-release fertilizers in early spring or late fall after growth has ceased.
  3. Treat for sucking insects such as aphids, leafhoppers, plant bugs, and pear psyllid that wound tissue, permitting entry of bacteria.

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