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<Ol> <LI> Taxonomic and ecological investigations of plant pathogenic fungi will be conducted using morphological features correlated with molecular methods. <LI> Evaluate fungicides and biological controls for foliar and soilborne pathogens of corn and soybeans. <LI> Determine the importance of soybean plant nutrition on toxin production and disease severity by M. phaseolina. <LI> Using molecular methods, evaluate corn hybrids for resistance to A. flavus comparing colonization potential or population densities by the fungus. <LI> Cultural and tillage practices will be evaluated for their effects on diseases. <LI> Points 2-5 will be integrated where appropriate to reduce producer input costs and increase yields.
NON-TECHNICAL SUMMARY: Several projects are ongoing and will be continued or be initiated from 2005-2010. 1) Continue the research on the biology and epidemiology of the charcoal rot pathogen. After summer 2005, data will be analyzed comparing visible symptom severity and percent root infections to nutrient changes in plants and toxin production. Specifically, the work is being conducted to understand disease initiation and establishment of the charcoal rot pathogen, Macrophomina phaseolina; 2) In 2004, primers for identification of Aspergillus flavus become available for use in real-time PCR. Research will focus on evaluating varieties for resistance to this mycotoxin forming fungus. Specifically, to begin research on methods to determine resistance in corn hybrids by quantification of DNA using Real-Time PCR; and 3) Fire ant research will continue to identify the associate microflora on fire ant mounds and their potential for control of the ants. Continue to evaluate the isolates for antagonistic or biological control potential in controlled conditions; and 4) Investigations on fungal systematics of pathogenic and mycorrhizal fungi will be conducted using traditional and molecular approaches.
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APPROACH: 1) Advance breeding lines and crosses will be evaluated for resistance using newly developed molecular methods. 2) Different pesticide (e.g. fungicide) chemistries will be tested for control of corn and soybeans. 3) Research to determine exact physiological changes (nutrient) in soybean plants will be obtained for comparison with fungus toxin production levels and disease severity. 4) Cultural and tillage practices will be evaluated for their effects on diseases. 5) Points in 1-4 will be integrated where appropriate to reduce producer input costs and increase yields.