Chapter 7: Distribution and Intensification of Bur Oak Blight in Iowa and the Midwest ( Project NC-EM-B-10-01)

Abstract

A new, late-season leaf disease on bur oak (Quercus macrocarpa) had been observed in southern Minnesota, southwest Wisconsin, eastern Nebraska, and Iowa since the mid-1990s. Symptoms of the new disease included necrosis of the leaf tissue along the veins and death of entire leaves, usually starting in late July (Pokorny and Harrington 2011). Branches in the lower crown were generally the most severely affected, and severity of the disease tended to increase year to year in individual trees. Distinctive fruiting bodies (conidiomata) of a fungus were found along the veins of affected leaves, and the fungus was tentatively identified as Tubakia dryina. However, the cause of the disease had not been established before this project, and the incidence of the disease appeared to be increasing

Parent Publication

• Forest health monitoring: national status, trends, and analysis 2015

Citation

Harrington, Thomas C.; McNew, Douglas L. 2016. Chapter 7: Distribution and Intensification of Bur Oak Blight in Iowa and the Midwest ( Project NC-EM-B-10-01). General Technical Report SRS 213. USDA-Forest Service, Southern Research Station. 6 p.