Fungus on Fruit Trees
- Fruit trees are susceptible to a range of fungal diseases.over-laden fruit tree image by Alfonso d'Agostino from Fotolia.com
Growing fruit trees in the home orchard is a rewarding task, but requires special attention to important cultural practices. These include selection of weather appropriate varieties, fertilization, pruning and training and pest and disease control. It is not uncommon to find insects and diseases ruin the entire season's crops. In severe instances, the entire tree may be damaged with no chances of recuperation. Many fruit trees are prone to diseases caused by fungi. For optimal disease control, fungicides are best applied before rainfall. - Phytophthora foot rot or foot rot is also referred to as brown rot gummosis. The disease is common in citrus trees and is caused by the species of the fungus Phytophthora. Foot rot affects the root system of the infected tree and the trunk right above or below the soil surface. As the disease progresses, it starts to adversely affect the foliage, blossoms, branches and fruit of the tree. The fungus is more active during rainy seasons. Trees grown with the bud union close to the soil surface, and those in poorly drained ground are most susceptible to foot rot. Preventative measures include using resistant varieties, planting in well-drained soil, and avoiding wounding the tree.
- Powdery mildew is a fungal disease in apples caused by Podosphaera leucotricha. The spores of the fungus are produced in spring and are spread to young tree tissues. The disease is characterized by the appearance of white, felt-like patches of fungal growth on the foliage, shoots, blossoms, buds and fruit. Leaves are likely to crinkle and curl along the leaf margins and can start to fall off as disease progresses. Tree growth is gradually stunted. Cultural management strategies include the use of resistant varieties and reducing the level of humidity in the tree canopy to allow air and light into the tree. Use recommended chemicals in cases of severe infections.
- Black knot is a common fungal disease of cherries and plums caused by Apiosporina morbosa and appears mostly on the branches of plums and cherries, according to Cornell University's Plant Disease Diagnostic Clinic. Trees grown close to wooded areas containing wild cherry are most susceptible to the fungus. Preventative measures include pruning the knots out as soon as they appear and using recommended fungicides every seven to 10 days. The wart-like black galls range in size from 1/2 inch to nearly 12 inches in length. The younger twigs and branches die within a year of infection while the larger branches can survive with the galls for many years. Tree health continually declines as disease progresses.
