Greening, Paula Red, Rome, and many crabapple varieties. (Apples: Ida Red, Fuji, Gala, Cortland, Jonathan, Jonagold, Lodi, R.I. Fire blight is most severe on highly susceptible varieties. This bacterial ooze may also be observed on young fruits or infected blossoms. In the spring, a cream or light yellow-colored liquid may ooze from the margins of the cankers. When the bark is removed from these cankers, there is a sharp line of distinction between white healthy wood and infected reddish-brown wood. The cankers enlarge slowly and may eventually girdle the limb. The cankers are often separated from healthy bark by narrow cracks. Infected fruit turn brown (apple) or black (pear) and eventually shrivel and become mummified.ĭark, sunken cankers usually form on the larger branches. Infected blossoms shrivel, and as infections move into the twigs, the leaves on the twigs wilt and turn brown. The first symptoms are usually observed following the blossoming period. The dead leaves remain attached to the twigs, giving the tree the appearance of having been scorched by fire hence the name “fire blight”. A characteristic symptom of terminal blight is the bending of the blighted terminal to resemble a “shepherd’s crook”. Symptoms include sudden wilting followed by shriveling and blackening of the blossoms and young shoots. Blossoms, twigs, leaves, and young fruit can all be infected. Credit: A.L.įire blight is most damaging during warm (70☏), humid weather. Fire blight on apple shoot note Shepard’s crook at shoot tip.

Fire blight treatment for pear tree