‖ oidium Bot.
(əʊˈɪdɪəm)
[mod.L., f. Gr. {wlenisisub}όν egg + -ιδιον dim. suffix.]
A form-genus of parasitic fungi, comprising species now regarded as the conidial stage of various fungi of the family Erysipheæ; they cause various diseases of plants, and of the human subject. spec. The species Oidium Tuckeri (Erysiphe Tuckeri), or the disease of the vine produced by this; grape-mildew.
| 1857 Berkeley Cryptog. Bot. §318 (L.) It has already been shown that these supposed species of oidium are not true moulds, but merely states of different species of erysiphe. 1859 Times 20 Sept. 8/3 The late rain has favoured the growth of the grapes which escaped the oïdium and the hail. 1868 Rep. U.S. Commissioner Agric. (1869) 571 The sulphur-cure for the oïdium, the most formidable disease that attacks the vine. 1882 Contemp. Rev. Dec. 956 The wet and sunless summer had brought on the oidium. |