Effectiveness of five fungicides on grapevine grey mould and their effects on must fermentation

Abstract

In 1991, the effectiveness of fungicides iprodione (Rovral 50%), vinclozoline (Ronilan 50%), procymidone (Sumilex 50%), dichlofluanid (Euparen 50%) and folpet (Folpet 50%) in controlling grey mould on grapes was tested in field experiments. Fungicides were applied four times according to the phenological method. At harvest, the percentage of infection was evaluated. All fungicides gave a significant reduction in disease compared with the untreated control, but among them folpet showed a slightly inferior result. Unclarified musts were analysed for fungicide residues. The residue contents were below the prescribed tolerance. The highest amounts of residues in must were found in the must that contained iprodione. There was no significant difference among other fungicide residue contents in must. The influence of fungicides on the fermentation of musts was monitored for 3 years. Fermentation was strongly influenced by folpet. Iprodione, vinclozoline, procymidone and dichlofluanid showed no influence on fermentation.