Here are some possibles I got from the IL extension site:
Verticillium and fusarium wilts are soilborne diseases that cause yellowing of the leaves, wilting and premature death of
plants. These diseases persist in gardens where susceptible
plants are grown. Once they build up, the only practical control is the use of resistant (VF) varieties.
Early blight is characterized by dead brown spots that usually start on the lower leaves and spread up the
plant. Upon close inspection, you can see concentric rings within the spots. Although early blight is most severe on the leaves, it sometimes occurs on the stems and can cause severe defoliation. Certain varieties (Roma and Supersonic) are more tolerant of early blight than others.
Septoria leafspot is characterized by numerous small black spots on the leaves. The centers of these spots later turn white and tiny black dots appear in the white centers. The disease starts on the bottom leaves and may become severe in wet weather.