In my limited experience, bumps low on the main stem and low branches are usually root buds. Mine get them later in the season when the weather is hot and dry. And If you mound up soil around it, it will send out new roots.View attachment 1418836 View attachment 1418838 View attachment 1418837 When I was finishing up pulling the grass out of the garden around my tomatoes I noticed two of my Martian giant slicers plants are having issues. Or maybe they’re not issues but not something I’ve seen before. One of them which is the first two pictures and very hard to see has these small odd bumps on the stem And a few days I noticed one of the branches had leaves that were turning brown and didn’t seem good they were just odd looking so I Snipped that branch off and today I noticed there was two more branches like that. So I’m not sure what’s causing that either or if the bumps on the other tomato plant or a problem.