Katherine L. Stevenson

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ABSTRACT The effects of partial host resistance, temperature, leaf wetness duration, and leaf age on infection and lesion development of pecan scab were evaluated. Trees of cultivars Wichita (susceptible) and Sumner (resistant) were inoculated with conidia of Cladosporium caryigenum and placed in mist chambers set at 15, 25, or 35 degrees C. The trees were(More)
ABSTRACT Epidemics of early leaf spot of peanut (Arachis hypogaea), caused by Cercospora arachidicola, are less severe in strip-tilled than conventionally tilled fields. Experiments were carried out to characterize the effect of strip tillage on early leaf spot epidemics and identify the primary target of suppression using a comparative epidemiology(More)
BACKGROUND Didymella bryoniae has a history of developing resistance to single-site fungicides. A recent example is with the succinate-dehydrogenase-inhibiting fungicide (SDHI) boscalid. In laboratory assays, out of 103 isolates of this fungus, 82 and seven were found to be very highly resistant (B(VHR) ) and highly resistant (B(HR) ) to boscalid(More)
Systemic acquired resistance (SAR) can be elicited by virulent and avirulent pathogenic strains and SAR against plant-parasitic nematodes has been documented. Our objective was to determine whether co-infection of cotton by Meloidogyne incognita and Rotylenchulus reniformis affects the population level of either nematode compared to infection by each(More)
Systemic acquired resistance (SAR), which results in enhanced defense mechanisms in plants, can be elicited by virulent and avirulent strains of pathogens including nematodes. Recent studies of nematode reproduction strongly suggest that Meloidogyne incognita and Rotylenchulus reniformis induce SAR in cotton, but biochemical evidence of SAR was lacking. Our(More)
ABSTRACT Amplified fragment length polymorphisms (AFLPs) were used to estimate phylogenetic relationships within Magnaporthe grisea and determine the genetic structure of M. grisea populations associated with tall fescue and St. Augustinegrass in Georgia. Sixteen clonal lineages were identified in a sample population of 948 isolates. Five lineages were(More)
Background Azole resistance in isolates of the fungus Aspergillus fumigatus has been associated with agricultural use of azole fungicides. Environmental isolation of resistant isolates has been reported in Asia, Africa, Europe and South America. Objectives To determine whether A. fumigatus isolates containing TR 34 /L98H or TR 46 /Y121F/T289A can be found(More)
Pecan scab, caused by the plant pathogenic fungus Fusicladium effusum, is the most destructive disease of pecan, an important specialty crop cultivated in several regions of the world. Only a few members of the family Venturiaceae (in which the pathogen resides) have been reported sequenced. We report the first draft genome sequence (40.6 Mb) of an isolate(More)
Venturia effusa is the most important pathogen of pecan in the southeastern United States. Little information exists on the population biology and genetic diversity of the pathogen. A hierarchical sampling of 784 isolates from 63 trees in 11 pecan orchards in the southeastern United States were screened against a set of 30 previously characterized(More)
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