Final diagnosis


Myrothecium roridum

Several incipient spots caused by <i>Myrothecium roridum</i> are clearly visible on this melon leaf.
Many spots dot this melon leaf. They are brown, of variable shapes, and show concentric patterns. The limbus at the periphery of the lesions is chlorotic. <i>Myrothecium roridum</i>
Detail of lesions caused by <i><b>Myrothecium roridum</b></i> on melon leaf.
The spots gradually necroticized and dried out on this melon leaf. The altered tissues have decomposed and fallen off, giving the blade a holey appearance. <i>Myrothecium roridum</i>
Detail of well evolved lesions: the decomposed central tissues split, disintegrate and fall. Note that the leaf blade of this melon leaf is rather chlorotic. (<i>Myrothecium roridum</i>)
Appearance of lesions observed on the lower face of the limbus. Some are greasy and/or located on the ribs. <i>Myrothecium roridum</i> are clearly visible on these weathered melon leaf tissues.
On this evolved spot on the upper side of the lamina, the sporodochia are more numerous. The conidia en masse constitute the upper, black part of the sporodochia. (<i>Myrothecium roridum</i>)
Two sporodochia of <i><b>Myrothecium roridum</b></i> are clearly visible on these altered leaf tissues.
Detail of a sporodochia of <i><b>Myrothecium roridum</b></i>.
Numerous phialides make up part of each sporodochia; they form at their extremity cylindrical conidia, hyaline to slightly olive-coloured. <b><i>Myrothecium roridum</i></b>
Detail of the cylindrical, hyaline to slightly olive-colored conidia of <b><i>Myrothecium roridum</i></b>.