Extensive group of microorganisms (lat. Fungi) with about 100,000 species. After they were for a long time attributed to the plant kingdom, they are now considered a separate kingdom due to their physiological and genetic characteristics and are more closely related to animals than plants. Unlike almost all plants, they can exist without chlorophyll and, like animals, feed on organic nutrients from their environment. Fungi therefore do not develop by photosynthesis (and therefore do not need light), but must live as rot-dwellers, parasites or as symbionts of dead or living organic substances. They often enter into a mutually beneficial symbiosis with the host plants. Yeasts, which are important for fermentation, are also fungi. A large group is summarized under molds. The growth of many fungal species is favored by high relative humidity from about 70%.
On the vine, various types of fungi can be the causative agents of numerous diseases such as anthracnose, botrytis (noble rot, grey rot), esca, eutypiosis, green rot, true and false mildew, Petri's disease, pink rot, red rot, black rot, black spot disease (excoriosis), black foot disease, white rot and wilt. They are mostly controlled by various fungicides. Many grape varieties have to be treated with them five to ten times within one vegetation cycle (year). However, certain fungal species are also vital for the vine to thrive due to the decomposition of decomposing substances in the soil and the improved supply of nutrients to the vine in symbiotic coexistence with the host plant (see also Mycorrhiza). In the breeding of new grapevine varieties today, it is an important breeding goal to achieve a high resistance against various fungal species. Such varieties are particularly in demand in organic viticulture and are known as PIWI varieties (fungus-resistant). See also under vine enemies.
Oidium: From Maccheek to English Wikipedia, CC BY-SA 3.0, Link
Esca: From farmer Karl - Own photo, CC BY 3.0, Link
Eutypiosis: INRA Science & Impact - Photo P. Lecomte
Botrytis: By Tom Maack T.o.m. CC BY-SA 3.0, Link