Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 2, 2009
Publication Date: December 7, 2009
Citation: Schisler, D.A., Boehm, M.J., Paul, P., Dunlap, C.A. 2009. Colonization of wheat heads by Fusarium head blight antagonist Cryptococcus flavescens OH 182.9 when applied alone or in combination with prothioconazole and the treatment effect on FHB disease development in field-grown wheat. Proceedings of the National Fusarium Head Blight Forum. p. 80-84. Technical Abstract: The use of yeast biological control agent Cyptococcus flavescens OH 182.9 (NRRL Y-30216) as part of an integrated management strategy against Fusarium head blight (FHB) of wheat is understudied yet has considerable potential for significantly contributing to the reduction of FHB and deoxynivalenol (DON). The fungicide prothioconazole (PTC) is effective against FHB but cannot be applied later than wheat anthesis. A PTC-tolerant variant of OH 182.9 (OH 182.9 3C) in a tank mix with the fungicide or applied after flowering, could be especially useful in limiting the total DON content in harvested grain by establishing populations that combat new DON producing infections by F. graminearum that can occur during early to late grain development. Experiments were conducted to quantify OH 182.9 3C colonization of wheat head tissues when the biocontrol agent was applied alone or in combination with PTC either at or seven days after wheat flowering. Populations of OH 182.9 3C were not affected by the presence of PTC and, after rain events, made up 40-95% of the total microbial population recovered from glume tissues from 8 to 12 days after flowering. FHB disease reduction associated with the various treatments supported the observation that the population of OH 182.9 C3 on infection court tissues was not inhibited by the presence of PTC and that treatments that contained both OH 182.9 C3 and PTC provided the greatest arithmetic reduction in FHB symptoms and DON. Additional experiments to further evaluate the potential of integrating strain OH 182.9 and fungicide treatments to enhance the level of FHB reduction on wheat are warranted.