Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/23/2002
Publication Date: 12/1/2002
Citation: SCHISLER, D.A., KHAN, N.I., BOEHM, M.J., SLININGER, P.J. GREENHOUSE AND FIELD EVALUATION OF BIOLOGICAL CONTROL OF FUSARIUM HEAD BLIGHT ON DURUM WHEAT. PLANT DISEASE. 2002. v. 86(12). p. 1350-1356 Interpretive Summary: The disease Fusarium head blight (FHB) causes devastating losses to farmers who raise wheat and barley in the United States and around the globe. Durum wheat is used primarily to make high quality pasta; and in the United States, most durum wheat is grown in the upper Midwest. In addition to destroying the yield, the fungus that causes FHB on durum wheat can badly affect the color, and therefore, the quality of pasta. Control options for this disease are limited. Registered fungicides have residue and cost concerns and highly resistant durum cultivars are not available. In our laboratory, we have discovered biological control agents that have a great potential for combating this disease. In this study, we report on tests of our biocontrol microbes in the greenhouse and in the field. We discovered that bacteria biocontrol agents were effective in greenhouse studies with one microbe reducing disease severity on durum wheat by as much as 90%. Though the nutrients fed to microbes in the laboratory sometimes influence how well the microbes control disease, microbe diet did not influence its performance in controlling FHB in this study. We also discovered that yeast microbes were the best at reducing FHB in the field, even though these yeasts were not very effective in greenhouse tests. Our yeasts reduced FHB severity on durum in the field by almost 60%. With further research, we anticipate that these yeast biocontrol strains will provide an effective method for durum wheat growers to minimize the damage caused by FHB.
Technical Abstract: Fusarium head blight (FHB) is a devastating disease that causes extensive yield and quality losses to barley and wheat. In durum wheat, the pathogen-produced toxin deoxynivalenol (DON) is retained in semolina at ca 50%, and the causal agent of FHB, Gibberella zeae, has a strong adverse effect on pasta color. Two bacteria and two yeast strains with known efficacy against G. zeae on hexaploid wheats were produced in liquid culture and assayed on two cultivars of durum wheat in greenhouse bioassays. All antagonists reduced FHB severity on cultivar Renville and three of the four reduced severity on cultivar Ben with Bacillus subtilis strain AS 43.3 decreasing FHB severity by as much as 90%. In separate greenhouse bioassays, the carbon:nitrogen ratio of the medium used to produce antagonists did not influence antagonist efficacy. All antagonist/production medium combinations but one were effective in reducing disease on both durum cultivars. Of six antagonists tested at field sites in Peoria, IL, and Langdon, ND, Cryptococcus sp. OH 71.4, C. nodaensis OH 182.9 and Cryptococcus sp. OH 181.1 reduced disease severity by 55%. Relative performance indices for four antagonists calculated from greenouse and field results on the two durum cultivars demonstrated that the bioassay location, but not the cultivar of durum, influenced the relative performance of antagonists. Yeast antagonists OH 71.4, OH 181.1, and OH 182.9 have the best potential for contributing to the reduction of FHB on durum wheat.