Good morning, everyone!

We are already in spring and summer is approaching! During this season, the most dreaded potato disease appears: mildew.

In summary, mildew is a cryptogamic disease, i.e. a disease caused by a fungus. It is the main enemy of potato crops, it is widespread throughout the world and it has the ability to spread very quickly, in just a few days it can spread over entire fields. It can cause production losses of up to 80%!

Conditions that favour its propagation are mild temperatures, high humidity above 75% and the presence of water on the foliage. The risk periods are April, May, June, July, August and September.

The inactive fungus can be stored in potato debris or affected tubers that gives new infected plants, but can also be stored in soil and will directly contaminate plantations. Mildew is characterized by brownish, oily spots on the upper part of the potato leaves and white down on the lower part. As for the tuber, brown spots appear on the epidermis and dry rot is found inside.

Some potato varieties are resistant to mildew, their crop is abundant and they do not need treatment. This is the case, for example, of the Sarpo Axona and Sarpo mira varieties whose seeds are marketed in England. The other varieties that have a strong resistance are: Carolus, Gasore, Bleue d’Artois, Limousine, Vitabella, Tentation, Sarpo Bleue du Danube.

As the fungus spreads, it is important to destroy waste and regrowth to avoid the risk of primary contamination. Another solution for controlling mildew is the use of fungicide until harvest, which prevents or prevents the development of fungi.

Be vigilant the mildew season is coming!