Fire Blight is a contagious bacterial disease affecting members of the Rosaceae family including apple and pear trees. This can be a very aggressive disease capable of destroying an entire orchard in a single season. The name comes from the appearance of affected trees, as the disease resembles leaves scorched by fire. The bacteria can be spread by insects, birds, rain, and wind. Blighted leaves will often remain attached to the tree, even after normal autumn leaf loss. Suckers at the base of trees are often rapidly infected providing a perfect pathway to the root structure resulting in total tree loss in as little as one season.
The disease enters the tree through leaf stomata resulting in necrotic lesions and blackening of leaves. The lesions will leak a red-brown, sticky, fluid that contains the bacteria and can spread to other sections of the tree or other individual trees. The bacteria reproduce rapidly once temperature reaches about 65 degrees, but is dormant in the winter. The bacteria overwinter in the cankers of bark and branches. Once infected, many parts of the tree can ooze bacteria-containing fluid including, leaves, flowers, and fruit.
Treatment regimes for Fire Blight can be complex and based largely on the situational factors including severity of infection, time of year, daily temperature and humidity, and others. Proper fertilization can greatly increase a trees ability to avoid Fire Blight, but excessive nitrogen application can actually make a tree more prone to infection. Let the plant healthcare professionals at Walker Tree Care help you devise a strategy for avoiding or treating Fire Blight before it takes its toll.