Mostly used abbreviation for Botrytis cinerea (synonym Botryotinia fuckeliana) for the mould from the genus Botrytis, which is called grey mould rot (also grey rot, grey mould, sour rot) or positively as noble fungus or noble rot. It is a tubular fungus and spreads vegetatively via the so-called conidia (spore form). Depending on the stage of ripeness or the infected areas on the vine, it is also called vine botrytis, stalk botrytis or grape botrytis. It was already described in the 18th century and occurs in all temperate climate zones of the world. Wine-growing regions with particularly favourable geographical and climatic conditions for infestation are Sauternes (France), Rheingau (Germany), Neusiedlersee (Austria) and Tokaj (Hungary). More than 200 host plants are known. Flower bulbs, vegetable species, ornamental plants and grapevines are particularly affected. In young grapes, the infestation is necotrophic (lethal), in older grapes it is biotrophic (host organism stays alive longer).