How can I tell if my tomatoes have a fungus? The leaves are turning yellow with black spots. It's starting at the bottom of each plant and is working its way upward. I've been removing each branch as they become infected but am afraid the plants will die if I can't get rid of or control this. They are in a raised bed with brand new soil mix this year.
From your description it does sound like it is Early Blight Alternaria. There is no cure and the plants should be destroyed.
Read through the articles below and check all the symptoms of the disease listed.