Screening Of Alternatives To Decrease Copper Dependency For Plasmopara Viticola Control In Organic Grape Production

Summary

Downy mildew caused by Plasmopara viticola is a major pest in viticulture worldwide. Organic viticulture is highly dependent of copper-based product to control this disease. Because copper has negative environmental impact, strategies to decrease dependency to copper-based products are needed. In that context, during 2005-2017 period, we have assessed the efficacy of 35 compounds to control downy mildew on-farm. This study present a selection of our results. The screening showed that several formulated products and compounds have an efficacy to control the downy mildew when they are compared with the untreated control, but none at an efficiency similar to copper. When alternatives compounds are associated with a low copper dose, significant additional effect are rarely observed over the whole season.