early blight of tomato
Early blight-One of the most common tomato diseases in the Midwest. Note older leaves are more severely affected. Concentric ring lesion is typical. Common in field production, but not difficult to manage. Less common in high tunnels.
Figure 1. Early blight lesion on tomato leaf. 
Figure 2. Petiole lesion of early blight of tomato. 
Figure 3. Early blight lesions on tomato leaf. Note cracked lesions. 
Figure 4. Early blight lesion on tomato leaf. Note lesion is restricted by vein. 
Figure 5. Lesion of early blight of tomato. 
Figure 6. Early blight lesion on tomato. 
Figure 7. Older leaves are more susceptible to the early blight fungus. Therefore, tomato plants may appear to be dying from the ground up. 
Figure 8. Note ring structure of early blight of tomato lesions. 
Figure 9. Clear ring structure of early blight lesion on tomato. 
Figure 10. Early blight lesions of tomato. This is an heirloom variety and perhaps especially susceptible. Note bulls-eye lesions.