Efficacy testing of novel organic fungicides and elicitors: from the lab to the field

Summary

Novel organic fungicides and elicitors against downy mildew on grapevines were evaluated on grapevine seedlings in a series of indoor screening experiments under controlled conditions and, if they have shown a good efficacy indoors, in a screening vineyard under field conditions.
From 39 products tested under controlled conditions 10 were further examined under field conditions.
All of the new products tested under field conditions showed at least partial efficacy. However, the efficacy was not good enough to protect grapevine plants sufficiently from downy mildew. For a complete re-placement of copper in plant protection against downy mildew on grapevine in organic agriculture, additional new products are needed.