Aristocrat Pear Fire Blight: Identification and Management

Diagnosing Fire Blight on Flowering Pear

An 'Aristocrat' pear (Pyrus calleryana 'Aristocrat') with scattered branches turning dark brown to black from the tips backward is showing classic fire blight symptoms—a bacterial disease (Erwinia amylovora).

Key Identification Features

• Random, scattered branch involvement (not uniform)
• Leaves turn brown/black but remain attached (flagging)
• Twig tips often curl into a "shepherd's crook"
• Progresses from tips toward main stems
• Most active in warm, humid spring weather during bloom

Management Strategy

1. Prune out infections 12–18 inches below visible symptoms. Only in dry weather. Disinfect tools between every cut (10% bleach or 70% alcohol).
2. Remove pruned material from site—burn or bag.
3. Avoid nitrogen fertilizer—promotes succulent growth highly susceptible to infection.
4. Consider resistant replacements if tree is severely affected. 'Aristocrat' is moderately susceptible.

Chemical Control (Limited Effectiveness)

• Streptomycin or copper sprays only during bloom protect flowers.
• No cure for existing infections—pruning is primary control.
• Homeowner products have limited efficacy; commercial applicators have better options.

Resource

Fire Blight Fact Sheet: UAEX FSA-7534

Fire blight is manageable but requires vigilance. Sanitation and cultural practices are your best tools.