Name (also Uncinula necator var. Necator, Erysiphe necator var. Necator or Oidium tuckeri) for the pathogen of powdery mildew, see there.
Name for two dangerous vine diseases caused by fungi. They originate from North America and were only introduced to Europe in the second half of the 19th century with contaminated vine material. Both types of fungi are biotrophic parasites, which means that they feed on the living cells of the infected host. The two powdery mildew diseases are often confused, not so much because of the disease symptoms, which are fairly obvious, but because of the confusingly similar names. There are powdery mildew fungi specific to plants, such as apples, peas, cucumbers, roses, spinach, and vines. The fungi are strictly host-specific, meaning they can live exclusively on their host.
Both are conventionally controlled with sulfur (powdery mildew) and copper sulfate or Bordeaux broth (downy mildew). Increasingly, however, special fungicides or plant strengtheners are also being used. Control often has to be carried out several times during the growing season. When new varieties are crossed, resistance to both types of fungus is nowadays also emphasized. It should be noted that some species of ladybird, which are among the most important beneficial insects in viticulture, feed exclusively on powdery mildew. However, this is of no importance in vineyard control.
Powdery mildew is also known as "Oidium" or "Oidium tuckeri" after the gardener William Tucker, who first discovered the fungus in England in 1845. The pathogen of the disease belongs to the tubular fungi (Ascomycota), the botanical name is "Erysiphe necator var. necator" or "Uncinula necator var. necator". The fungus was identified and described in North America as early as 1834. It was probably introduced into Europe via England as early as the early 1840s and subsequently spread rapidly throughout the continent. This, together with phylloxera, which also originated in North America a few years later, led to a true catastrophe in European viticulture. Large parts of the vineyards were destroyed in many countries. In 1854, only one tenth of the normal amount could be harvested in France due...