dc.contributor.author	Taylor, Kenyanna
dc.coverage.spatial	Georgia	en_US
dc.coverage.temporal	2020-2023	en_US
dc.date.accessioned	2024-04-29T16:50:54Z
dc.date.available	2024-04-29T16:50:54Z
dc.date.issued	2024-02-21
dc.identifier.other	7cd740c2-b469-4b27-8eba-3688d0cf9555	en_US
dc.identifier.uri	https://hdl.handle.net/10428/7163
dc.description.abstract	Early and late leaf spot, caused by the fungi Passalora arachidicola and Nothopassalora personata, are important foliar diseases of peanut that can lead to premature defoliation and yield loss if not controlled. In fields with a history of leaf spot, the diseases are managed using frequent applications of fungicides. Recently, mixtures of micronized elemental sulfur with tebuconazole, a demethylation inhibitor (DMI) fungicide, or azoxystrobin, a quinone outside inhibitor (QOI) fungicide, were shown to lessen defoliation caused by leaf spot. The objective of this study was to determine if sulfur mixtures reduce defoliation by causing fewer leaf spot infections or by increasing plant tolerance. Field studies conducted at the University of Georgia Coastal Plain Experiment Station in 2020 and 2021 exposed peanut plants to 7 applications of six fungicide treatments at recommended rates: (1) a nontreated control, (2) sulfur, (3) tebuconazole (DMI), (4) DMI + sulfur, (5) axozystrobin (QoI), and (6) QoI + sulfur. Disease was assessed weekly between 90 and 140 days after plating (dap) using the FL 1-10 scale, a visual estimation of defoliation and disease severity, and as the number of leaflets with leaf spot (leaflet incidence) and the mean number of lesions per leaflet (leaflet severity) for 10 lateral branches per plot. As expected, defoliation assessments were significantly lower for the sulfur mixture treatments than the DMI and QoI treatments alone in most cases (P<0.05). A similar pattern was observed for leaflet incidence and leaflet severity (P<0.05). There was a significant exponential relationship between cumulative leaflet severity (AUDPC severity) and final defoliation (R2 = 0.77; P<0.001) and AUDPC severity and AUDPC defoliation (R2 = 0.82; P<0.001). In most cases, sulfur effects on defoliation were insignificant when AUDPC severity was included as a covariate in the model (P>0.05). This suggests that the mechanism of reduced defoliation is due to fewer leaf spot infections rather than increased plant tolerance.	en_US
dc.description.tableofcontents	1.CHAPTER 1 LITERATURE REVIEW 6 2.CHAPTER 2 FIELD RESEARCH ON SULFUR SYNTHETIC FUNGICIDE MIXTURE EFFECTS ON LEAF SPOT DISEASE SUPPRESSION a.INTRODUCTION 14 b.METHODS 17 i Field Experiments Experimental design and treatment structure ii iii Disease Assessment iv Statistical Analysis c RESULTS 21 d DISCUSSION 31 3 CHAPTER 3 FIELD RESEARCH ON SULFUR SYNTHETIC FUNGICIDE MIXTURE EFFECTS ON PEANUT RUST SUPPRESSION a INTRODUCTION 33 b METHODS 35 i Field Experiments ii Experimental design and treatment structure iii Disease Assessment iv Statistical Analysis c RESULTS 38 d DICUSSION 40 4 CHAPTER 4 LAB RESEARCH ON SULFUR SYNTHETIC FUNGICIDE SULFUR MIXTURE EFFFECTS ON Nothopassalora personata GROWN ON PDA MEDIA a INTRODUCTION 42 b METHODS 44 i N personata Isolates and N personata Monocultures Treatment Production ii iii Lawn Production iv Conidia Acquisition v Evaluation c RESULTS 47 d DISCUSSION 51 5 REFERENCES 53	en_US
dc.format.extent	1 electronic record. PDF/A document, 53 pages, 2409271 bytes.	en_US
dc.format.mimetype	application/pdf	en_US
dc.language.iso	en_US	en_US
dc.rights	This dissertation is protected by the Copyright Laws of the United States (Public Law 94-553, revised in 1976). Consistent with fair use as defined in the Copyright Laws, brief quotations from this material are allowed with proper acknowledgement. Use of the materials for financial gain with the author's expressed written permissions is not allowed.	en_US
dc.subject	Academic theses	en_US
dc.subject	Biology	en_US
dc.subject	Epidemiology	en_US
dc.subject	Plant diseases	en_US
dc.subject	Defoliation	en_US
dc.subject	Peanut industry	en_US
dc.subject	Peanuts--Diseases and pests	en_US
dc.subject	Fungicides	en_US
dc.subject	Leaf spots	en_US
dc.title	Comparing The Effects of Sulfur-Synthetic Fungicide Mixtures On Leaf Spot And Rust Peanut Pathogens	en_US
dc.type	Thesis	en_US
dc.contributor.department	Department of Biology of the College of Science and Mathematics	en_US
dc.description.advisor	Culbreath, Albert
dc.description.committee	Cantonwine, Emily
dc.description.committee	Turco, Jennifer
dc.description.degree	M.S.	en_US
dc.description.major	Biology	en_US