Fruit trees are highly susceptible to tree mildew that affects tree and fruit health. Identify fungal infection associated with fruit trees for easy recognition of problems and reliable control methods. Provide your tree with the particular care requirements it needs, as all fruit trees have specific preferences that result in vigorous growth.
Most fruit trees need abundant sunlight for successful growth of fruit. However, a citrus tree may have different requirements than an apple tree; so research the type of fruit tree you are growing for appropriate care. Identify appropriate sun exposure as well as the preferred soil including type, drainage concerns and pH level. For all trees, however, avoid waterlogged soil as it leads to tree decline and invites fungi germination.
The fungal infection powdery mildew affects many trees including fruit trees. Powdery mildew is caused by a wide variety of plant-specific fungi that spread sporadically on the wind or in water, according to the Cornell University Plant Disease Diagnostic Clinic. Fungi overwinter on plant parts or plant debris and form infections during the spring season and are most prevalent in high humidity.
Symptoms and Damage
Powdery mildew symptoms include the presence of a grayish white powder-like substance that resembles mildew on plant surfaces, according to the Cornell University Plant Disease Diagnostic Clinic. The first symptoms that lead to the mildew spread is the exhibition of small white spots that grow and join into a widespread coating. Damage includes diminished health, malformed plant parts including fruit, stunted growth and defoliation.
For natural control of powdery mildew on fruit trees, remove and destroy affected plant parts to inhibit disease spread. Keep wet conditions to a minimum on trees by avoiding overhead irrigation that causes extended periods of wetness on leaves. Maintain well-drained soil at all times. Always sanitize pruning tools after each cut and when moving from one tree to the next to avoid unintentional disease transfer.
In conjunction with natural control, chemical control provides greater management of tree mildew. If powdery mildew appears on fruit trees during the growing season, apply neem oil, fungicides with the active ingredient myclobutanil or sulfur-based fungicides, according to the Cornell University Plant Disease Diagnostic Clinic.