Michigan State scientist warns crop fungicide resistance poses One Health risks

Dr. Sydney Everhart, professor and chair of Plant, Soil and Microbial Sciences at Michigan State University, told the council that plant disease systems are an underappreciated part of One Health and a training ground for understanding resistance. She noted that in plant pathology fungi dominate many crop diseases and that fungicide resistance has been reported widely in agricultural pathogens — "over 203 have been reported," she said.

Everhart reviewed protectant versus systemic fungicides, mechanisms that drive both qualitative and quantitative resistance, and a case study showing a rapid shift in sensitivity to a DMI fungicide (Proline) after registration. She recommended nonchemical approaches when possible, optimized application timing, mode-of-action rotation and stacked mixtures (multiple FRAC groups) where appropriate, and improved modeling and apps to help producers apply products effectively and reduce selection pressure that can have downstream One Health consequences.