Cercospora nicotianae

Ellis & Everh. (1893)

Frog-eye
 

- Frequency and severity of disease incidence

Cercospora nicotianae is prevalent in many countries and particularly severe in tropical areas, in India and in many Asian and African countries. It has not been observed currently in France.

- Symptoms

Frogeye lesions are small, circular, about 1 cm, light beige and parchment-like (figures 1 and 2). They can be covered by tiny black dots composed of clusters of conidiophores and conidia (figure 3). The spots are larger on mature leaves. They can develop during curing.

- Biology

The fungus develops during wet periods with free water on leaves. Favourable temperature for its development ranges from 18 to 27°C. It can survive on plant debris and other host plants including weeds (Physalis angulata...). Infections are iniated by conidia (figure 4).

- Protection Methods

Only healthy seeds should be used.

No product is approved for control frog-eye in France.