Early Blight -- Now that we are nearing the height of gardening season, we are seeing a lot of tomato samples being brought by with early blight. This disease is caused by the fungi Alternaria tomatophila and A. solani and is first observed on the plants as small, brown lesions mostly on the older foliage. Spots enlarge and concentric rings in a bull’s-eye pattern may be seen in the center of the diseased area.