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.
- 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
- 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.
- Apply slow-release fertilizers in early spring or late fall after growth has ceased.
- Treat for sucking insects such as aphids, leafhoppers, plant bugs, and pear psyllid that wound tissue, permitting entry of bacteria.