Probst, I'm guessing this is
root knot nematode damage.
I used to use Bacillus Thuringiensis on my soil to reduce the nematodes, but there are problems associated with this treatment. Another way to discourage nematodes is to enrich the soil with vegetative matter. Some people swear by planting marigolds, but that hasn't helped me that I've noticed.
Planting in a different location may help for a year or two, but the nematodes will spread.