Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 3, 2005
Publication Date: July 20, 2005
Citation: Schisler, D.A., Boehm, M.J., Slininger, P.J. 2005. Dosage requirements and combinations of choline metabolizing strains and antagonist Cryptococcus nodaensis OH 182.9 for reducing FHB of wheat [abstract]. American Phytopathological Society Annual Meeting. Phytopathology 95:S93. Technical Abstract: Combining two or more microbial antagonists has proven fruitful in enhancing the efficacy and consistency of biocontrol against a variety of pathogens. Several studies suggest that choline and betaine, found in wheat heads and anthers, stimulate germ tube growth of Fusarium head blight (FHB) pathogen Gibberella zeae. In the present studies, yeasts and bacteria were isolated from wheat anthers. Several choline metabolizing strains (CMS) were discovered that reduced FHB in greenhouse and field trials. Prior to conducting trials of combinations of CMS and the non-CMS yeast antagonist C. nodaensis OH 182.9 (NRRL Y-30216), dose response trials were conducted with three CMS strains to determine the relationship between dose and biocontrol efficacy. Fully colonized broths that were diluted to one-quarter strength were frequently effective in reducing FHB, but further diluting broths of CMS antagonists often reduced efficacy below the P=0.05 significance level. Combining CMS antagonists with C. nodaensis OH 182.9 resulted in a modestly enhanced disease reduction effect compared to OH 182.9 alone in repeated greenhouse trials. Combinations of OH 182.9 and CMS antagonists will be field tested on soft red winter wheat in 2005.