Cercospora nicotianae

(Cercosporiose)

Frog-eye

Cercospora nicotianae is a fungus causing cercospora leaf spot (or frog-eye) on tobacco. The symptoms of this disease are small round spots of about 1 cm, pale beige, with a parchment-like appearance (figures 1 to 3).
 
The spots are sometimes covered with tiny black structures formed by clusters of conidiophores and conidia of the fungus (figure 3). Note that the spots are usually larger on mature leaves and that they are more susceptible to cercospora leaf spot. One can observe affected plants in nurseries, in the field and during curing.

 For further information on Cercospora nicotianae, see the fact sheet of this pest.