Main Symptoms

At the beginning, greasy spots appear on mature leaves. They turn brown and black and quite quickly show concentric rings. When the conditions are very favorable, large areas of the lamina are affected (figures 1 to 5).

Note that spots can depreciate the quality of cured tobacco leaves (figure 6).

Some of the information on the worldwide distribution of the disease is obtained from surveys conducted by CORESTA (Cooperation Centre for Scientific Research Relative to Tobacco). The reliability of the information is not confirmed in all countries.