I have had some calls about the tips of fruit trees dying back. Fire Blight has been a widespread problem this year.
Fire Blight is a very destructive, highly infectious disease caused by the bacterium Erwinia amylovora.
The disease affects plants in the Rosacea family that includes trees and shrubs in orchards, nurseries and landscape planting. It especially preys upon: apple, crabtree, plum, cherry, flowering quince, pyracantha, rose, serviceberry, etc.
Symptoms of the disease are young twigs and branches die from the terminal end and appear burned. Dead leaves and fruit remain on the branches.
Disease management is therefore key for fighting Fire Blight.
Prune out infected branches 8 inches below the sight of damage. Dip pruning tools in isopropyl alcohol wash and oil shears when you are finished. These practices avoid spreading the pathogen.
Chemical control is not always effective and needs to be applied preventively. Next year when warm, humid wet weather coincide with flowering and leaf emergence, spray plants with a fungicide containing basic copper sulfate or an antibiotic (ex. Agrimycin).
Applications of Agrimycin need to begin at the start of blooming and continue every 3-4 days during the bloom period. Application of copper sulfate should begin at bloom and continue every 7 days during bloom.
Plant resistant varieties include: Pyracantha – Leland’s firethorn; Pear – Kieffer, Moonglow, Orient; Apple – Enterprise, Freedom, Liberty and Crabapple – Adams, Dolgo, Jewelberry.