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Bur oak blight and Tubakia species

My Old Homepages were taken down by the university in 2020. I am sorry for this loss of access, and I am trying to recreate some of this material on new pages, like this one. Please let me know ( if a link or broken or you have other problems accessing these publications.

Bur oak blight, caused by Tubakia iowensis

work conducted by Tom Harrington and Doug McNew at Iowa State University

funded by grants from the USDA Forest Service

Tubakia fruiting body with conidia


Bur oak blight in a cemetery



This is a link to a 2017 video (actually a powerpoint presentation) on bur oak blight, featuring potential management with fungicides. 

An overview of bur oak blight, including symptoms and disease cycle, can be found at: Harrington, T. C., and D. McNew. 2016. Bur oak blight. Pp. 16-19 In: Diseases of the Great Plains. A. D. Bergdahl and A. Hill, eds. U.S. Forest Service, Gen. Tech. Rep. RMRS-GTR-335.  Fort Collins, Colorado. (pdf of book chapter)

Trends on bur oak blight and a table other Tubakia species (then unnamed) on oak can be found at: Harrington, T. C., and D. L. McNew. 2016. Distribution and intensification of bur oak blight in Iowa and the Midwest. Pp. 105-110 In: K. M. Potter and B. L. Conkling, eds. Forest Health Monitoring: National status, trends, and analysis 2015. US Forest Service Gen. Tech. Rep. SRS-213. (pdf of book chapter).

A brief update and comparison of BOB with the invasive laurel wilt can be found here: Harrington, T. C. 2013. Exotic pathogens or shifts in climate? Luarel wilt and bur oak blight. pp. 39-41 In: Proceedings, 24th USDA Interagency Research Forum on Invasive Species. Pubication FHTET 13-01. Forest Health Technology Enterprise Team: Fort Collins, CO. 124 p. (pdf of manuscript).

The initial description of bur oak blight and Tubakia iowensis: Harrington, T.C., D. McNew and Hye Young Yun. 2012. Bur oak blight, a new disease on Quercus macrocarpa caused by Tubakia iowensis sp. nov. Mycologia 104: 79-92

We later described three new species of Tubakia on oaks: T. macnabbii, T. tiffanyae and T. hallii after Sande McNabb, Lois Tiffanyi and Richard Hall, our late colleagues at Iowa State University. These new species are generally not as serious as bur oak blight, but they can cause significant defoliation on some trees. Harrington, T. C., and D. M. McNew. 2017. A reevaluation of Tubakia, with three new species and six new combinations. Antonie van Leeuwenhoek

The last (as of Winter 2018) ISU distribution map of confirmed Tubakia iowensis is shown below as magenta counties superimposed on the gray distribution of Quercus macrocarpa. We think this BOB distribution roughly coincides with the distribution of Q. macrocarpa var. oliviformis. Thanks to Doug McNew, Jill Pokorny, and the numerous cooperators in Iowa and neighboring states for identifications and sending samples!

BOB distribution mapBack to Tom Harrington's homepage