Effect of viticultural practices and sprayer technology on the level of fungicide residues in grapevine berries, must and wine.

摘要

Producer and consumer demand for improved wine quality has driven substantial amendments in the application of good agricultural practices. To enable high quality production, removal of leaves within the bunch zone has become common practice to enhance sunlight exposure to the cluster zone. Therefore, bunches as target areas are now better exposed compared to previous viticultural practices. To date, the effect of these new production techniques on residues in berries and wine has not been thoroughly studied yet. The aim of this project was to evaluate the level of fungicide residues obtained under different grades of bunch exposure and under use of different spray application techniques. Additionally, residue level during different stages of wine production was to be assessed. Three different levels of leaf defoliation practices and two different commercial types of sprayers were included in this study. In all treatments active ingredients of the respective fungicides were detected on the berries. However, all samples were below the maximum residue level (MRL) defined for table grapes. The leaf removal treatments and the two air stream blower types showed different effects on the concentration of plant protection agents and their active ingredients, respectively. Concentrations of most agents declined below the detection level during the winemaking process, except for the active ingredients dimethomorph (control of Plasmopara viticola) und pyrimethanil (control of Botrytis cinerea), which were still detectable in the wine. However, the level of both was below the MRL.