Oidium may refer to:
*
''Oidium'' (genus), a genus of fungi in the family Erysiphaceae
*
Oidium (spore)
An oidium (plural: oidia) is an asexually produced fungal spore that (in contrast to conidia) is presumed not to constitute the main reproductive preoccupation of the fungus at that time.
The hypha breaks up into component cells/ small pieces and ...
, a type of fungal spore
*Oidium, a disease of grapes caused by the fungus species ''
Uncinula necator
''Uncinula necator'' (syn. ''Erysiphe necator'') is a fungus that causes powdery mildew of grape. It is a common pathogen of Vitis species, including the wine grape, ''Vitis vinifera''. The fungus is believed to have originated in North America ...
'' (
syn. ''Oidium tuckeri'')
{{Disambiguation