Overview
Fire Blight is a bacterial disease caused by Erwinia amylovora that affects members of the Rosaceae family, including apple, pear, crabapple, mountain ash, and cotoneaster. It's one of the most destructive diseases of these plants in Colorado.
Signs & Symptoms
- Blackened or brown shoots with scorched appearance
- Wilted flowers that remain attached
- Shepherd's crook shape of affected branch tips
- Oozing cankers on branches or trunk
- Necrotic twigs and branches
- Dark discoloration under bark
Transmission & Spread
Fire Blight spreads through contaminated pruning tools, insects (especially bees), and wind-blown rain. The bacteria enters plants through open flowers, wounds, or natural openings, then spreads through the vascular tissue.
Treatment & Management
Cultural Control
- Prune infected branches 12 inches below visible symptoms
- Sterilize pruning tools between cuts (10% bleach solution)
- Destroy all infected plant material (burn or bag)
- Avoid overhead irrigation during bloom
- Reduce excess nitrogen fertilization
Chemical Control
Antibiotic sprays or bactericides applied during bloom can help prevent infection. Treatment must be timed precisely and may require multiple applications.
Why Choose Earth-Wise?
Fire Blight requires accurate identification and prompt action. Our ISA Certified Arborists can diagnose Fire Blight, implement proper pruning techniques, and develop a comprehensive management plan to protect your valuable fruit trees.