Final diagnosis


Leveillula taurica (Internal powdery mildew)

Leveillula1
A few bright yellow spots, sometimes angular, dot this leaflet. <b> <i> Leveillula taurica </i> </b> (internal powdery mildew)
Some of these chlorotic spots start to turn brown and necrode. <b> <i> Leveillula taurica </i> </b> (internal powdery mildew)
Ultimately, the invaded tissues end up dying. The spots then gradually necrosis in their center, and then appear brownish lesions sometimes concentric. <b> <i> Leveillula taurica </i> </b> (powdery mildew)
There is sometimes a discreet white down on the underside of the leaf blade of oidized leaflets. <b> <i> Leveillula taurica </i> </b> (internal powdery mildew)
<b><i>Leveillula taurica</i></b> ( powdery mildew)
<b> <i> Leveillula taurica </i> </b> (internal powdery mildew) fruit exceptionally on the upper surface of leaflets when climatic conditions are very favorable.
The white down is in fact made up of the numerous septate and more or less slender conidiophores of the fungus. At their end, conidia are formed. Note that the terminal conidia is characteristic because it presents a pointed apex, called <i> spearhead </i>. <b> <i> Leveillula taurica </i> </b> (powdery mildew)
The conidiophores of <b> <i> Leveillula taurica </i> </b>, an obligatory parasitic fungus that cannot be cultivated on artificial media, are long and sometimes branched. They exit through the stomata and bear conidia, isolated or in very short chains. Note that this fungus rarely forms cleistothecia. Powdery mildew
The first conidium is pus or less lanceolate and pointed at its tip. The second is more or less ellipsoidal to cylindrical. Their measurements are variable: 30-80 x 12-22 µm. <b> <i> Leveillula taurica </i> </b> (powdery mildew)La première conidie est pus ou moins lancéolée et pointue à son extrémité. La seconde est plus ou moins ellipsoïdale à cylindrique. Leurs mensurations sont variables : 30-80 x 12-22 µm. <b><i>Leveillula taurica</i></b> (oïdium, powdery mildew)