These are my favorite Brandywine heirloom tomatoes. They crack at the stem and I get so much waste. They taste fine but I have to throw out a lot of it. The plant yellows at the bottom at a very early age and the leaves start to turn brown and work its way up. I get this every year .
Usually splitting of the tomato is from too much water my wife says. the yellowing almost sounds like your plants are dying from the bottom up? Perhaps because of too much water possibly attracting fungus gnats?
