Fire Blight
Fire Blight .jpg) Fire blight can be easily confused with sooty mold, a relatively harmless, black leaf fungus that rubs off easily. Fire Blight bacteria enter the tree at the growing tips. They may travel down towards the roots killing the whole treeSusceptible Plants- Fire blight, caused by the bacterium Erwinia amylovora,concerns orchardists as a serious disease of apple and pear. However, it also occurs on many landscape trees and shrubs, in the rose family. Besides attacking apple and pear trees,including flowering crabapple and callery pear, fire blight appears commonly on several, species of cotoneaster , hawthorn, and mountain ash . It also occurs on firethorn, and less commonly on serviceberry , flowering ,quince , cultivated quince , Christmas berry , flowering plum, spirea , rose, (Rosa spp.), and on Rubus species, such as red and black raspberry and thorn-less blackberry. Symptoms The earliest symptoms of fire blight in the flowers can be seen only by careful examination of infected spurs, which reveals dark and wilted individual flower bases or pedicels. As the infected bloom collapses, the infection spreads rapidly into the other flowers in the spur, causing the entire spur to wilt suddenly and die. Thus, growers often first notice that blossoms and leaves of infected terminals and spurs wilt suddenly and then turn dark brown to black as if scorched by fire. Diseased tissue usually remains firmly attached to the tree. From there, infections from fire blight frequently spread to the supporting spurs and branches to form cankers. These cankers continue to increase in size as long as conditions remain favorable for disease development. The cankers have a shrunken surface and appear dark brown to purple in color. If a canker girdles a stem, the whole stem can die. At first the tissues appear water-soaked and dark green; soon, however, they become brown to black in color. Twig infections can spread back into their supporting limbs and cause cankers. Infections of basal sprouts (suckers) can rapidly kill a tree when the fire blight infection moves into the root collar area and restricts the vital flow of nutrients and water into the crown
Prevention and Control- Plant resistant cultivars, or choose fruit trees grafted onto blight-resistant rootstock. Do not prune susceptible woody plants too severely or overfeed then because both of these practices discourage succulent growth on mature trees.
Grow grass right up to the trunk of the tree. If needed allow the grass to grow longer than normal. Prune out infected branches, along with 6- 12in( 15-30 cm) of healthy tissue .Good gardening hygiene is the most effective method of preventing fire blight. Fungicidal Control- BI-Carb Organic Fungicide. has some control of fire blight fungus, Erwinia. Cease a Fungicidal Product offers some control of the fire blight fungus, Erwinia. Cease™ works two ways. First, the bacterial spores occupy space on the plant surface and compete with the pathogens; then active compounds called lipopeptides produced by each bacterium disrupt the germination and growth of invading pathogens. Due to this, resistance is not likely to develop. Cease™ can be used in combination and/or rotation with other products and as part of an effective resistance management program..
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