Frog Eye Leaf Spot

Frog Eye Leaf Spot or Cercospora. nicotianae attacks all life stages of the tobacco plant and even harvested leaves during curing. The fungus causes lesions of about 2-15 mm diameter. The frog-eye shape of the lesions gives the disease its common name. Lesions are greyish-brown, with necrotic tissue like parchment in the centre. Conidia and short conidiophores are scattered in the centre of the lesion as minute black dots. Spots occur mostly on the lower leaves, near the ground, because old, mature leaves are more susceptible than young and apical growing leaves. In wet weather spots also occur on younger leaves. Near harvest time the middle to large leaves can show numerous, heavily necrotized spots.