Tree diseases are many and complex, caused by many different things. As with people or animals, there are different treatments for different problems. Fungi cause many tree diseases, and some of those may be treated with different types of fungicides. Good tree care is more prevention than cure - once a problem is well established in a tree it may be too late to treat.
There are many different kinds of plant diseases that occur in different species of trees. Diseased branches are usually pruned away. Sometimes diseased trees need to be removed so as not to infect neighboring trees. With plant disease, pathologists usually look for the cause and try to prevent the disease from occurring at the start. For example, if a particular species is susceptible to disease when waterlogged, then actions are taken to prevent waterlogging of the soil, or not to plant that species of tree under such possible conditions. Sometimes a tree might appear to be diseased, but might be symptomatic of nutrient deficiencies such as a nitrogen or potassium deficiency in which cases, fertilizers can be applied in proper amounts and form to address the problem. There is no "miracle" medicine to treat disease in trees.
Tree diseases may have to be determined by a specialist. For free advice, many cities have departments that maintain trees on city streets and in parks. The U.S. Department of Agriculture has extension offices in most every county in the U.S. They may be able to diagnose the problem and recommend treatment. Some large nurseries have staff who are knowledgeable about the problem and may be able to help. In all cases, after phone contact, bring in a small branch so that they can see what the problem is.
Sources:
[1] Vince Calder, J. Elliott, Anthony Brach, "Medicine for Tree Diseases", Online posting. NEWTON BBS Ask a Scientist.
|