Because of this resistance, new USDH active principles were registered for pre-harvesting inspections concerning B. cinerea and other top-fruit pathogens such as fluxapyroxad, penthiopyrad e fluopyram.
In the spring of 2015, researchers from the Washington State University conducted a study on apples affected by grey mould. They sampled produce from 65 packing warehouses in the State of Washington and obtained 1,600 isolates on which they tested sensitivity to different active principles.
A resistance to fluxapyroxad and fluopyram in B. cinerea populations in commercial apple orchards in the state of Washington emerged. Researchers reported that "these results suggest being careful when using these two fungicides to avoid a rapid selection of resistant B. cinerea populations."
Source: Amiri A., Mulvaney K. A., Pandit L. K., Angelis D. R., 'First Report of Resistance to Fluxapyroxad and Fluopyram in Botrytis cinerea From Commercial Apple Orchards in Washington State', Gennaio 2017, Plant Disease, dx.doi.org/10.1094/PDIS-09-16-1384-PDN
