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dc.contributor.authorThomas, Anna
dc.date.accessioned2014-03-04T20:22:55Z
dc.date.available2014-03-04T20:22:55Z
dc.date.issued2011-08
dc.identifier.otherthomas_anna_201108_ms
dc.identifier.urihttp://purl.galileo.usg.edu/uga_etd/thomas_anna_201108_ms
dc.identifier.urihttp://hdl.handle.net/10724/27619
dc.description.abstractBaseline isolates of Didymella bryoniae were tested for sensitivity to penthiopyrad, tebuconazole and difenoconazole using mycelia growth assay. Based on the sensitivity distribution, a discriminatory concentration of 3.0 µg/ml was selected for future monitoring of shifts in sensitivity. Cross-resistance between boscalid and penthiopyrad was identified in field isolates of D. bryoniae and a potential for cross-resistance between DMIs is observed based on baseline sensitivity profile. Field experiments were conducted to establish a relationship between frequency of resistance and fungicide efficacy in managing gummy stem blight (GSB). Tebuconazole and chlorothalonil were proved to be most effective in managing GSB. A consistent negative association was observed between the frequency of resistance and disease control in the field. Isolation of D. bryoniae resistant to thiophanate-methyl from commercial seedlots helped explain the unpredictable development of fungicide resistance in watermelon fields. Results from this study will help manage GSB with efficient use of fungicides.
dc.languageeng
dc.publisheruga
dc.rightspublic
dc.subjectCross-resistance
dc.subjectDidymella bryoniae
dc.subjectDifenoconazole
dc.subjectDMIs
dc.subjectFrequency of resistance
dc.subjectFungicide resistance
dc.subjectGummy stem blight
dc.subjectPenthiopyrad
dc.subjectTebuconazole
dc.subjectThiophanate-methyl
dc.subjectWatermelon
dc.titleSensitivity of Didymella bryoniae to DMI and SDHI fungicides and the relationship between fungicide sensitivity and control of gummy stem blight in watermelon
dc.typeThesis
dc.description.degreeMS
dc.description.departmentPlant Pathology
dc.description.majorPlant Pathology
dc.description.advisorDavid B. Langston, Jr.
dc.description.advisorKatherine Stevenson
dc.description.committeeDavid B. Langston, Jr.
dc.description.committeeKatherine Stevenson
dc.description.committeeRonald R. Walcott
dc.description.committeeRonald D. Gitaitis


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