Powdery mildew impacting on wine quality

摘要

Analysis of wines made from powdery mildew- affected grapes has revealed that even slight infection leads to compositional changes, an oily mouthfeel and undesirable fungal/earthy flavours when compared with wines made from disease-free grapes. Research has also found that powdery mildew is difficult to assess visually at low levels of infection, particularly in large consignments of fruit after machine harvesting. CRCV researchers have been examining the effects of powdery mildew as part of project 1.5.2—fungal contaminants and their impact on wine quality. Project leader, Dr Eileen Scott, (University of Adelaide), presented a summary of research conducted by Dr Belinda Stummer and Timothy Zanker (University of Adelaide) and Drs Leigh Francis and Bob Dambergs (AWRI) at a recent seminar in Griffith, organised by the CRCV, the National Wine and Grape Industry Centre and the Riverina Winegrape Growers Centre. Eileen said that before project 1.5.2 started, there was relatively little information available about the effects of known levels of powdery mildew on grape and wine quality, but wines made from powdery mildew-affected grapes had been reported to have lowered quality due to factors such as delayed ripening, increased acidity and reduced colour and phenolics in red varieties.