Received these photos of leaf mold on tomato from Kenny Sharpe in Livingston Parish. This disease is caused by the fungus Fulvia (Cladosporium) fulva and is typically more of a problem on greenhouse tomatoes or transplants coming out of the greenhouse in early spring than on field-grown tomatoes. However, we do see it occasionally on field-grown tomatoes growing in areas with restricted air flow and high humidity. Fungicides containing either copper hydroxide or chlorothalonil will control this disease, but ensuring thorough coverage is important. improving air movement to reduce humidity is also important.
Donald M. Ferrin, Ph.D., Louisiana State University Agricultural Center, Baton Rouge, LA