Fire Blight

Characteristics

Fire blight is a type of bacteria that affects apple trees, crabapples, pears, hawthorns, cotoneasters, quince trees, and mountain ash. The severity of infection depends on 3 factors: the presence of bacteria, a susceptible host, and favourable weather conditions. 

Fire blight bacteria are capable of existing in trees without any symptoms. However, in warm temperatures with high humidity, the bacteria multiply rapidly and begin to spread. As the growing season progresses, cankers develop in the bark, and infected tissue becomes dark red or brown.

Fire blight overwinters in a host tree. During spring, as temperatures increase, bacteria spread from infected bark tissue. The bacteria can be relocated by splashing rain and insects.

Signs & Symptoms

Infected trees often have dead blossoms, shoots, and branches. Shoots first appear water-soaked but quickly turn brown or black. Fire blight often progresses into the tree limbs and trunks.

Fireblight produces cankers and depressions on the bark and branches of infected trees. Trees with multiple cankers will display branches with die back and an oozing opaque liquid. The bacterial ooze dries out and remains as a gummy substance or completely on canker surfaces. Severe infection will cause trees to die.

Treatment & Recommendations

The best way to treat Fireblight is to control it. Prune diseased twigs and branches to prevent further infection into healthy tissue. Proper nutrition and watering practices can help keep trees healthy and aid in prevention.

Give us a call if you think your tree appears to display signs and symptoms of fire blight.