Disease Agent and Injury Control

From Bugwoodwiki

Leaf spot, Septoria spp.

The fungus overwinters on dead leaves; spores are wind disseminated to young leaves in the spring. Small round spots with straw colored centers may be numerous; red oaks are preferred; defoliation may result in growth loss but no mortality.

Powdery mildew, Microsphaera alni and Phllactinia guttata.

These fungi overwinter on dead leaves, and their spores are spread by the wind to healthy leaves. White, powdery mold patches on leaves and buds; leaves may be distorted, stunted and dropped prematurely.

Twig canker, Dothiorella quercina.

The fungi overwinter on dead tissues; in the spring, spores are wind disseminated to wounds and twigs. Small sunken branch cankers and twig dieback

Spot anthracnose, Elsinoe, quercus – falcatae

The southern red oak is preferred host; spreads by wind disseminated spores. Very small spots on leaf upper surfaces starting about mid-summer.

Smooth patch, Aleurodiscus oakesii.

The fungus survives on the bark surface and releases spores which continues its spread. Often regarded as a threat to stand by owner, but it is of minor importance; control rarely needed.

Iron – deficiency chlorosis

Iron deficiency may be a common problem with pin and willow oaks in some of the less acid soils. Yellow-green discoloration between veins; leaves may curl, turn brown along margins and between veins.

References

J. D. Solomon, F. I. McCracken, R. L. Anderson, R. Lewis, Jr., F.L. Oliveria, T.H. Filer, and P.J. Barry