Septoria leaf spot
Figure 1. Septoria leaf spot of tomato is more severe on older leaves. Thus, older leaves are often the first to show symptoms.
Figure 2. Lesions of Septoria leaf spot are often dark brown on the inside margin.
Figure 3. Septoria leaf spot of tomato. Note brown margin and gray center of lesions.
Figure 4. Septoria leaf spot of tomato. Note gray center of lesion and gray margin. Dark, fungal bodies may visible in the lesion center with 10X hand lens.
Figure 5. Septoria leaf spot of tomato.
Figure 6. Lesions of Septoria leaf spot on a very susceptible variety. Look for dark fungal bodies in center of lesion.
Figure 7. Septoria leaf spot of tomato.