Peronospora destructor (Berkeley) Caspary, 1860

downy mildew of onion

on Allium

gall

The leaf shows rather large, yellowish-brown spot, often with a dried centre; at their underside a greyish-violet fungal bloom, consisting of erect conidiophores that apically several times are dichotomously branching, each branch ending in an elliptic conidium.

host plants

Amaryllidaceae, monophaag

Allium ampeloprasum, ascalonicum, cepa, fistulosum, x proliferum, sativum, schoenoprasum, scorodosoprasum.

synonyms

>Peronospora schleideni Unger, 1847.

notes

serious pest in onion cultivation.

references

Belbahri, Calmin, Pawlowski & Lefort (2005a), Brandenburger (1985a: 718), Chater, Woods, Stringer, ao (2020a), Choi, Constantinescu & Shin (2007a), Cunnington (2008a), Doppelbaur, Huber & Poelt (1965a), García-Blázquez, Constantinescu, Tellería & Martín (2007a), Göker, García-Blázquez, Voglmayr ao (2009a), Gustavsson (1991a), Jage, Klenke, Kruse ao (2017a), Klenke & Scholler (2015a), Kruse (2014a), Mułenko, Piątek, Wołczańska ao (2010a), Müller (2015a), Müller &a Kokeš (2008a), Negrean & Anastasiu (2006a), Porta-Puglia & Mifsud (2006a), Săvulescu (1948a), Scheuer & Bechter (2012a), Sert & Stimbtil (2003a), Thines & Choi (2016a).