Blisters at the base stem
I have noticed a common symptom on some of my tomato plants. They have one thing in common in that I started them myself, all at around the same time. I am new to seed starting, and I think I started these a little too early. They go kind of big, but it was still too cold to put them into the ground (till now).
Some of my plants with these symptoms were started from my saved seeds seeds (from 2008), and some from store-bought seeds.
Each of the plants have a series of firm bumps at the base of the stem, almost like blisters. There is a small amount of curling of the bottom leaves, and some of the older leaves turned yellow and died. But there is new growth that looks very normal. Overall, the plant doesn't look horrible.
Any, are these plants diseased? If so, which disease?
Thanks in advance.