Control measures
Control of the grey mould disease is possible but it is difficult and is rarely justified on potato.
In senescent cultures, which are very prone to Botrytis, treatments are not useful as they do not give any yield increase.
For high altitude crops, where the disease can be problematic, yield can be increased by the application of fungicides. However, as the growing season is relatively long (7 to 9 months), the crop must be protected for long periods and, as a result, plant protection is generally too expensive to be profitable.
Furthermore, prophylactic measures limiting the disease are to promote aeration of the foliage, to avoid the presence of water on the plants, to opt for the same reasons for an drip-irrigation system, avoiding to wet the foliage (unlike irrigation by aspersion), to use an adapted nitrogen fertilisation in order to avoid stress to plants leading to disruption in plant growth and to remove plant debris at the end of culture.