My tomato pathology book says that Early Blight can also appear on the stems AND petioles so I would assume that what you see on the sepals could be just extension from there.

Do you see any lesions on the petioles?

Another good possibility is that the sepals have become infected just due to heavy rain and rain transmitted EB spores that germinate on the sepals and infect.

Carolyn

Thanks for responding Carolyn. No, I haven't seen any lesions on the petioles. This is the first time I've seen them on sepals and it had me a bit concerned. I think you are correct that EB spores directly infected the sepals becuase the lesions did not appear to "travel" up the stems to the flower. As you might imagine, none of the affected sepals/flowers has produced fruit. Thank you again.

Teresa