Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/5/1999
Publication Date: N/A
Technical Abstract: Fusarium head blight (FHB), primarily caused by Gibberella zeae, is a devastating disease of wheat in humid and semihumid regions of the world. In the first 8 years of this decade, FHB incited losses of over 2.6 billion dollars in the United States alone. Methods for reducing this disease are few as highly resistant varieties are not available, and labeled fungicides sare not consistently effective. In durum wheats, the pathogen-produced toxin deoxynivalenol (DON) is retained in semolina at approximately 50%, and G. zeae has a strong adverse effect on pasta color when G. zeae damaged kernels make up as little as 2% of a lot. In this work, we evaluated whether microbial strains that we previously discovered to be effective in reducing Fusarium head blight on hard red spring and soft red winter wheats would also be effective in reducing the disease in greenhouse and field tests on durum wheats. In greenhouse testing of FHB antagonists on durum cultivars Renville and Ben, all four of the antagonists tested reduced disease severity on cultivar Renville compared to the pathogen control, and three of the four reduced disease incidence. Bacterial antagonist AS 43.3 decreased disease severity by >90% and disease incidence by >75%. Three of four antagonist treatments reduced FHB disease severity on cultivar Ben in greenhouse tests, and two of four reduced FHB disease incidence. Bacterium AS 43.3 and yeast OH 182.9 significantly reduced disease severity on cultivar Renville in field tests despite unfavorable conditions for FHB disease development. With these results, the considerable potential for applying these microbes to reduce the severity of FHB on durum wheat has now been demonstrated.