Theses and Dissertations

Issuing Body

Mississippi State University


Wilkerson, Teresa H.

Committee Member

Allen, Thomas W., Jr.

Committee Member

Irby, Jon Trenton

Committee Member

Aboughanem, Nina

Date of Degree


Document Type

Graduate Thesis - Open Access


Plant Pathology

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology


Southern Blight (SB), caused by the fungus Athelia rolfsii, has increasingly impacted Mississippi soybean production with estimated economic losses in recent years rising from $181,616 in 2016 to $9,508,412 in 2021. Currently, there are no recommended fungicides and no known commercially available cultivar resistance. Eleven cultivars were evaluated for their response to the presence of Athelia rolfsii in the 2021 field trial. An in vitro fungicide assay was conducted to evaluate the efficacy of five fungicides to determine the respective EC50. These fungicides were then evaluated in combination with three cultivars, one mild, one moderate, and one severe in the 2022 field trial and in the growth chamber trial. A rapid and quantitative method was developed to evaluate the response of these commercially available soybean cultivars in combination with fungicides to SB. Determining effective management options has the potential to decrease disease losses for Mississippi Soybean growers.