Sensitivity of Venturia inaequalis, the Causal Agent of Apple Scab, to the Fungicide Pyribencarb in Hokkaido

Abstract

Pyribencarb is a fungicide used to control the apple scab disease in Hokkaido. It functions as a quinone outside inhibitor (QoI). QoI-resistant strains of Venturia inaequalis, carrying the G143A mutation, have recently been identified in Hokkaido. This mutation affects mitochondrial cytochrome b in V. inaequalis. The sensitivities of the V. inaequalis isolates collected from Hokkaido to pyribencarb and trifloxystrobin were compared. Isolates carrying the G143A mutation exhibited reduced growth on a medium containing pyribencarb than on that containing trifloxystrobin.