Botrytis grey mould and other fungal diseases frequently cause grape yield losses, particularly in growing seasons when rain falls close to harvest. Management late in the season is problematic due to a lack of fungicide options. While canopy manipulation and other viticultural practices such as variety and site selection can reduce the incidence of bunch rots, disease losses still occur in those seasons where there is high disease pressure. In difficult vintages where fungal rots are widespread, decisions on when or even if to harvest need to take into account the likely impacts fungal rots will have on subsequent wine quality. This webinar will discuss Botrytis grey mould and some of the other fungal diseases responsible for bunch rot of grapes. The effect of Botrytis, Aspergillus and Penicillium rots on wine quality will be reviewed. Recent data on establishing vineyard thresholds for grey mould contamination of grapes and impacts on wine quality will also be presented.