Effects of plant extracts on downy mildew of vine-Laboratory and field experiments

Summary in the original language of the document

Extracts made from leaves, bark, flowers or roots of 23 different plant species using water, alcohol or acetone were tested against downy mildew of vine in laboratory, glasshouse and vineyards. Highest effects were found for Hedera helix (leaves in water), Quercus spec.(bark in alcohol), Primula veris (roots in water), Rhamnus frangula (roots in alcohol), Solidago spec (leaves in alcohol), Salix spec. (bark in water). Extracts of Rhamnus and Primula had significant curative effects (30 - 35%). In the laboratory and glasshouse test protective effects were much better (70- 90% reduction of infection) than the results in field experiments (30 - 40%). Single use of these extracts is insufficient for practical use in viticulture. The use in combinations with stone-meals and low doses of copper should be tested in future.