What is Lithothamne? Well, it’s a natural product used by organic growers in their battle against downy mildew.
Talking with Bernard Fouquet in Vouvray today he was explaining that he uses it in the vineyard and is pleased with the results.
But what actually is it?
Well, it’s an algae that is roasted and ground to a fine powder. The powder is sprayed over the vines and it absorbs humidity, the culprit when it comes to mildew spreading in the vineyard.
It’s a bit like talcum powder and is used as a preventative treatment in the vineyard rather than using copper (which is also permitted in organic viticulture but is toxic to the soil).
A mixture of copper and sulphur is used as a preventative in the vineyards although sulphur can have an adverse effect upon the natural yeast population present on the grapes. That something that organic producers want to avoid so they often treat with Lithothamne about 15 days before picking with no harmful effects to the grapes or to us.
