Theses and Dissertations

Issuing Body

Mississippi State University


Allen Jr., Thomas Ward

Committee Member

Henn, R. Alan

Committee Member

Bond, Jason Aaron

Committee Member

Irby, Jon Trenton

Committee Member

Tomaso-Peterson, Maria

Date of Degree


Original embargo terms

MSU Only Indefinitely

Document Type

Graduate Thesis - Campus Access Only


Plant Pathology

Degree Name

Master of Science


College of Agriculture and Life Sciences


Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology


Frogeye leaf spot (FLS), caused by Cercospora sojina Hara, is a foliar disease of soybean (Glycine max (L.) Merr.). FLS has re-emerged as an important disease due to the widespread QoI-resistant fungal population in Mississippi. Growers have transitioned from a stand-alone QoI fungicide to a multi-mode of action fungicide. One disadvantage of certain MOA’s is phytotoxicity. Phytotoxicity is a concern among soybean growers as to whether or not yield is lost. Disease, phytotoxicity, green stem, yield, plant morphology, and grain quality were analyzed to determine the impacts of fungicide phytotoxicity. Yield was significantly and negatively correlated as a result of phytotoxicity. Numerical differences in phytotoxicity severity were observed among all cultivars. Phytotoxicity severity were greatest in the Hornbeck 4950 LL with an average of 26.9%. Tank-mixing dodine with Manniplex B Moly, Megafol, and Veritas decreased phytotoxicity by 8.5, 2.7, 11.4% compared to dodine as a stand-alone treatment, respectively.



Foliar Nutrient||MBC||SDHI||DMI||QoI||phytotoxicity||Frogeye leaf spot