Every year the same thing happens, about this time some of my tomato plants start having branches with brown and crumbly leaves. I can't say what they look like early in the process because I don't notice anything until I see the brown leaves. Right now only a few are showing on each plant, eventually there will be more.

I'm trying to post multiple images but so far I haven't seen any instructions on how to do that. The first three photos are an Early Girl, the last is a Heinz Super Roma.