Can biodynamic grape growers spray their vineyards with copper and sulphur?
Yes. But again, the allowable levels are lower than those allowed for conventional viticulture. And again, in practice, most biodynamic growers keep sprays of copper and sulphur to a minimum, or don’t use them at all (especially in warm, dry seasons like 2006/2007), preferring to use whey or skim milk to prevent mildew, or compost teas to build up the vines’ resistance to mould.
