Calcium deficiency (plant disorder) - Wikipedia, the free encyclopedia
Yep, that's pretty much what it looks like. Glad to know it's not contagious. It says calcium deficiency can be caused by overapplication of nitrogen and potassium fertilizers. I did apply it liberally, but there aren't any clear instructions on how much is too much.
It's also brought on by drought. Yep! It went a few (hot, hot, hot) weeks without significant rain, and lots of folks' plants are suffering. I irrigated, but not consistently.
Corrective action: apply lime, irrigate consistently, apply less fertilizer next year. I should be able to save most of my crop this year, but not all of it. I think I'll amputate all the affected tomatoes now.
I don't want gangrenous spots to attract bacterial, fungal, and animal parasites.
Oh, and awesome: I get to go buy saltpeter now. Hopefully all the oxidizers in my garage won't raise too many eyebrows.