Publication Date


Document Type


Committee Members

Songlin Cheng (Committee Member), Don Cipollini (Advisor), David Goldstein (Other), Thomas Rooney (Committee Member), Joseph F. Thomas, Jr. (Other)

Degree Name

Master of Science (MS)


Garlic mustard is an invasive Eurasian biennial that has rapidly spread throughout the United States. In Southwestern Ohio, many garlic mustard populations are infected with the powdery mildew Erysiphe cruciferarum that can reduce the growth and fitness of garlic mustard. E. cruciferarum was assessed using a Decision Tree in regards to its potential use as a biological control agent. I determined the distribution of E. cruciferarum on garlic mustard and I determined the potential risk of E. cruciferarum to native Brassicaceous species and selected crops. I surveyed 19 parks in Southwestern Ohio and recorded the number of diseased garlic mustard and aspect at every population and then made a distribution map of disease incidence of E. cruciferarum on garlic mustard using GIS ESRI (ArcMap) software. My distribution survey showed a random distribution of E. cruciferarum infection on garlic mustard with disease incidence decreasing away from Dayton, Ohio. Aspects with higher disease incidences were level and facing southeast and were significantly different than northwest facing aspects. Five native spring ephemeral species were surveyed in the field and then obtained from local wooded areas in May 2008. Individual plants were transplanted in the greenhouse and then exposed to infected garlic mustard plants. The native plants surveyed showed no obvious signs of E. cruciferarum infection in the field. All of the native plants subjected to powdery mildew under greenhouse conditions became mildly infected with E. cruciferarum. Twelve crops in the family Brassicaceae along with 2 crops in the Fabaceae and Solanaceae families were planted and inoculated with E. cruciferarum and only one cultivar, Savanna Mustard (Brassica juncea), became infected with powdery mildew. A distribution survey showed the distribution of E. cruciferarum infection on garlic mustard with disease incidence decreasing away from Dayton, Ohio. Populations located on level ground or facing southeast had significantly higher disease incidence than northwest facing aspects. Results from the greenhouse study show that under optimal conditions, some native spring mustard species can become infected with powdery mildew. However, E. cruciferarum likely poses little threat to native Brassicaceaeous plants because the phenology of native plants allows them to escape infection. E. cruciferarum poses a slight threat to cultivated crops since only one crop became infected and Savanna Mustard is not a common cultivated variety in Ohio.

Page Count


Department or Program

Department of Biological Sciences

Year Degree Awarded


Included in

Biology Commons