Final diagnosis


Golovinomyces cichoracearum var. cichoracearum (Erysiphe cichoracearum, powdery mildew)

Several small powdery, white spots dot the upper surface of the lower leaves of this lettuce. <b> <i> Golovinomyces cichoracearum </i> var. <i>cichoracearum</i> </b> (powdery mildew)
In fact, the spots are made up of the superficial mycelium of the fungus and a profusion of conidiophores and conidia forming in a chain. <b> <i> Golovinomyces cichoracearum </i> var. <i>cichoracearum</i> </b> (powdery mildew)
A few white powdery spots dot the leaf blade of this lettuce leaf. <b> <i> Golovinomyces cichoracearum </i> var. <i>cichoracearum</i> </b> (powdery mildew)
The fungus <b> <i> Golovinomyces cichoracearum </i> var. <i>cichoracearum</i> </b> (powdery mildew), obligate parasite, disrupts the functioning of plant cells which die after a certain time. This results in the appearance on the blade of fairly diffuse chlorotic sectors, becoming greyish to light brown.
Oidium1
Oidium6
Oidium4
Oidium2
Oidium3
A superficial mycelial network covers the oidized tissues. There are young conidiophores. <b> <i> Golovinomyces cichoracearum </i> var. <i>cichoracearum</i> </b> (powdery mildew)
Detail of a young conidiophore producing its first conidia. <b> <i> Golovinomyces cichoracearum </i> var. <i>cichoracearum</i> </b> (powdery mildew)
<b> <i> Golovinomyces cichoracearum </i> var. <i>cichoracearum</i> </b> (powdery mildew) in its imperfect form commonly produces chains of hyaline, cylindrical to doliform conidia (25-45 x 14-26 µm), located at the end of short conidiophores.