Hardwood Leaf Diseases of Minor Importance |
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| Insects and Diseases of Trees in the South. 1989. USDA Forest Service - Forest Health Protection. R8-PR16. 98 pp. Taken from http://fhpr8.srs.fs.fed.us/forstpst.html |
| Disease Agent |
Injury |
Control |
| Powdery mildew, caused by Microsphaera spp., Phyllactinia spp. and others. These fungi overwinter on dead leaves. Spores are windblown to healthy leaves.
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A white, powdery mold occurs on leaves and buds. Leaves may be distorted, stunted and fall prematurely.
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2, 3
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| Leaf blister, caused by Taphrina spp. This fungus overwinters on bud scales. When buds expand, infection of new leaves occurs. Spores produced on leaves are disseminated by wind.
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Yellowish-green to purple blisters appear on leaves. Blistered leaves remain on the tree.
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1, 2, 3
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| Leaf spots, caused by various fungi. Fungi overwinter in leaf tissue; spores are disseminated by wind and rain.
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Small round to angular spots, variable in size and color appear on leaves. Defoliation may occur in extreme cases.
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1, 2, 3
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| Nutrient deficiencies. These physiological conditions are soil related. Soil condition, such as pH, may make nutrients unavailable to plants, or the soil may be exhausted of some nutrients.
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Leaf tissue turns yellow to brown; often this happens first along the veins. Some leaf fall may occur. Dieback may occur later if uncorrected.
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4 |
Leaf blister on oak. |
Leaf spots |
| Controls for Urban Trees |
- Rake and destroy fallen, infected leaves.
- Maintain high vigor through cultural practices.
- Control with chemical fungicide.
- Control with appropriate fertilizer.
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| Pesticides |
| There are EPA registered chemicals for the control of these leaf diseases. Consult a specialist if the damage appears to be unusually severe and chemical control is needed. |
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