Researchers at USDA's ARS Bioprotection Research Unit in Peoria, Illinois hope this year they can replicate the same results last year's trials produced as they began studying what they are calling a beneficial yeast that tolerates fungicide. Their hope is that an improved variant of the yeast Cryptococcus flavescens can be used as a biocontrol agent against Fusarium graminearum - the fungal culprit behind Fusarium head blight - also known as scab.
According to ARS plant pathologist David Schisler Cryptococcus flavescens is better at preventing scab than its predecessor and can be applied to wheat either alone or combined with prothioconazole or other similar fungicide chemistries. In 2009 field trials 3C reduced scab by 30 to 70%. And when combined with prothioconazole 3C reduced kernel damage by 85%.
In susceptible wheat and barley varieties scab-afflicted kernels appear shrunken and chalky-white. The fungus can also produce a mycotoxin that can diminish the grain's value or make it less safe to eat. If the new variant works out it is hoped it will help control scab following flowering, which is the cut-off point for application of today's chemicals.