Fruit tree diseases can be injurious, if not fatal, to a fruit tree if left untreated. Even the most harmless disease can weaken a fruit tree over a long period of time. Being able to recognize a fruit tree disease can greatly improve the chances addressing the issue before it begins to destroy your tree.
Fruit tree diseases are generally fungal or bacterial. Some of these diseases, such as powdery mildew and anthracnose, are transported by fungal spores. These spores develop on dead and decaying debris, tree stumps and other necrotic materials that lie around the fruit tree. Once active, the spores are transported onto the fruit tree by wind and rain.
Other fungal and bacterial diseases, such as verticillium wilt and fusarium wilt, are soil-borne diseases that can thrive in the soil for many years, with or without a host. These diseases infect the fruit tree through the root system, infecting the tree from the inside out.
Fruit tree diseases can have a vast number of effects on the tree. Infected fruit trees may experience common symptoms such as wilt, leaf curl, leaf spots and discoloration. More severe disease symptoms include growth stunt, twig and branch dieback, and heavy defoliation. Soil-borne disease cause extensive tissue damage and weakening of the tree's overall structure and strength. Disease symptoms may be immediate or delayed. The severity of the symptoms is usually dependent upon the health of the fruit tree prior to infection. Vigorously growing trees are better able to resist disease than stressed fruit trees.
The process of preventing disease in your fruit tree begins before your fruit tree arrives. Even before you select a well-drained, sunny location for your fruit tree, you must select a healthy, disease-resistant fruit tree. Your selected fruit tree should be one that thrives well in your hardiness zone and micro-climate. Your planting area must be free of disease to avoid passing disease onto a newly transplanted tree. In addition, fruit trees should receive plenty of water and even amounts of fertilizer. Over-watering and drought conditions, as well as too much or too little fertilizer, will stress the tree and make it more susceptible to disease. Since most fungal and bacterial diseases thrive on decaying debris, it is important to keep your fruit tree's growing area free of defoliated debris. A clean growing area greatly reduces the potential of infection.
It is important that you treat your fruit tree's infections immediately to avoid permanent injury to the tree. The infected areas of the tree should be pruned away. This will redirect the tree's energy to more viable areas. Apply fungicidal treatments in a timely fashion, according to the directions, and repeated if necessary. Speak with a horticultural or nursery specialist for assistance in identifying your fruit tree disease and developing a treatment schedule.
Not every fruit tree disease is curable with pruning and chemical treatments. Some diseases--such as verticillium wilt, fusarium wilt and bacterial canker--are resistant to chemical treatments, and are fatal to fruit trees. A tree that has been infected with a fatal fruit tree disease should be removed and properly discarded. The stump and roots of the fruit tree should also be removed, and the soil throughout the planting location should be fumigated.