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Apple tree with fire blight

Symptoms of Fire Blight

Want to know what to look for when it comes to This Deadly disease? You can Read further to properly identify the symptoms of fire blight.

Begin watching for fireblight infections in early spring during periods of wet weather. This is when the bacteria begin to produce ooze. Visual symptoms first appear on the flowers and then progress down the branch.

Symptoms of Fire blight

Infected blossoms appear water-soaked and wilt rapidly before turning dark brown; this phase of the disease is referred to as blossom blight. As the bacterial invasion progresses, leaves wilt, darken, and remain attached to the tree (see right); this gives the tree a fire-scorched appearance, thus the name “fire blight.”

symptoms of fireblight

Infected twigs darken, and branch tips may bend over, forming a “shepherd’s crook.”

During wet conditions infected tissue may exude creamy bacterial ooze in droplets or fine, hair-like strands. Infected fruits also exude bacterial ooze.

Rather than dropping from the tree, infected fruits gradually dry and remain attached to the branch.

Fire blight cankers on branches or stems appear as dark discolored areas that are slightly sunken, with a narrow callus ridge along the outer edge. The narrow callus ridge is diagnostic for differentiating fire blight cankers from fungal cankers. 

Under the bark associated with a canker, the inner bark turns from green to brown, but the appearance varies depending on plant variety. Droplets of bacterial ooze may appear on the canker.

A certified arborist will diagnose your tree according to the appearance of symptoms of fire blight and suggest a course of treatment – if your fruit tree is salvageable.

Get more resources on this disease from CSU extension here.

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