Infected branches may be girdled, resulting in loss of the entire branch. Inside these droplets are millions of bacteria, which may cause new infections.įire blight bacteria can move from blighted spurs and shoots through the vascular system into larger limbs and tree trunks. Pearly or amber-colored droplets of bacterial ooze are often present on diseased blossoms, fruit, and leaf stems, on succulent shoot stems, and on the exterior of infected fruits. A characteristic symptom of shoot blight is the bending of terminal growth into the shape of a shepherd's crook. The leaves wilt rapidly, turn dark, and remain attached as in the case of spur blight. It may occur any time during the season while the shoots are still growing and when environmental conditions are most favorable for the disease. Shoot blight begins with the infection of the young, succulent growing tip. Some remain even after normal leaf fall.įire blight's two main symptoms are shoot blight and cankers on limbs. The blighted flowers and leaves remain attached for much, if not all, of the growing season. The leaves wilt, turning brown on apples and quince and dark brown to black on pear.

Here they follow the midrib and main veins, which soon darken. Bacteria may move through the pedicel to the fruit spur and out into the leaves. Infected blossoms wilt rapidly and turn light to dark brown. The disease gains entry to the tree through two main points, blossoms and new shoots, and often appears first in spring as blossom, fruit spur, and new shoot blight. Some susceptible varieties include Braeburn, Crimson Crisp, Fuji, Gala, Granny Smith, Jonathan, Rome, Yellow Transparent, and Idared.

Certain varieties of apples are more susceptible than others. In fruit trees, the disease can kill blossoms, fruit, shoots, limbs, and tree trunks. Fire blight also occurs frequently on pyracantha, spirea, hawthorn, and mountain ash.

Fire blight sprays