The first signs can be brown spots on the leaves. In severe cases the whole leaf and stem can become infected and the whole plant decay and collapse. Injury to plants, like frost or hail will make it easier for Botrytis spores to enter the leaf; spraying is highly advisable soon after injury and is only effective when foliage is dry.
Spray ACUROSIL NANO+ @1.5ml/ltr
After Bud setting, apply ACUROSIL NANO+ @2ml/ltr