A non-destructive method for quantifying Cu, monitoring its residues, and downy mildew incidence on grapevine leaves after the application of copper-based antifungals

Perennial crops such as grapevine are often sprayed with copper-based antifungals against one of the most important diseases in viticulture, downy mildew (DM), which is caused by the biotrophic oomycete Plasmopara viticola. Although the European Union has limited the use of copper-based fungicides in organic farming since 2002, the likely negative effects on the environment, human health and wine quality, as well as soil contamination from diffuse sources in some agricultural regions, should be taken into account. The aim of this work, funded by the INTAVIEBIO project (PSR - FVG), was 1) to minimise the copper use by studying the variance of Cu coating on vine leaves and 2) to develop a non-destructive and rapid method to detect Cu on treated leaves using a new chemical probe that can detect the presence of Cu by image analysis.