The currently used downy mildew control strategies in vitis vinifera in Switzerland are based on the use of acidified clay products combined with copper and sulphur.
Data from 1997-2003 show that acidified clay products are a valuable alternative to control downy mil-dew of grapevine in conditions of medium rain fall, good spray timing and with a good application tech-nique. The limits of these products show under heavy rain conditions and when there is high disease pressure
