If you are talking about the spots just under the skin then it is called Cloudy Spot and is caused by stink bugs. If you mean the hard white cores inside the tomato, 'hard core' can be caused by weather heat extremes causing uneven ripening, low K fertilization, and some varieties are more prone.

As for composting infected foliage - it depends. Some say never, some say the composting process will deal with it fine. IMO it all depends on if one actively or passively composts. Hot, cooking, frequently turned and moisture controlled compost - no problem. adding it. Passive cold composting - I wouldn't.

Dave

Thanks Dave. By white spots, I mean when I take the skins off, there might be white spots in various places on the tomato meat. Some have a lot, some have none. They are a little hard. I've seen very few stink bugs this year (Yay!). Sorry if I'm having trouble understanding your answer. So do you think these spots on the meat, when I take the skins off are from stink bugs?

Oh........and we have 35 acres. Could I dump these skins and rotten ones out in the field, or would the leaf spot find it's way back? ;)

If you haven't seen stink bugs, the other reason is more likely - weather. Have you had some big variations in highs and lows lately?

No, no big variations, but it hasn't rained much, but I have raised stock tanks for my veggies, and I water them every 2-3 days. If it is from stinkbugs, what are those spots? Will it hurt anything if some of them get frozen with the rest of the tomatoes?

If they aren't visible on the skin itself (often yellow) then it wouldn't be Cloudy Spot from stink bugs. A photo of them would be a big help.

Cloudy Spot pics

but could be some other sucking pest. If they are white circular like small smoke rings then it is Ghost Spot

Ghost Spot pics

Sure you can dump them out in a field somewhere. It only over-winters on living tissue.

Dave

Thanks Dave. It looks a bit like a couple of those Cloudy spot pics......but that's when I can see the spots through the skin. Oh! I just remembered that I still need to throw out the skins and some of the bad ones, so I'm running to take a picture.........

Here it is. No skin. I've had these in the past, but they seem worse this year. Fortunately, I have a ton of tomatoes, and I don't need these. Like I said, they seem to be a bit tough in those spots.

Yeah that looks just like stink bug damage to me.

Dave

But what are those spots? It's not eggs or poop or anything is it?

No eggs, no poop. . Stink bugs just suck the juice out. I don't think that they lay eggs in tomatoes. What happens is that some juice is taken out and some air gets in.

Sey

Just Google stink bugs to learn all about how they work and Cloudy Spot for all the details. The injuries aren't deep and you can just cut off the damaged areas and the rest is fine. But with that much damage on just one tomato the odds are you have lots of stink bugs and need to treat for them.

Dave

Hmmm.......this is an enigma to me. Yes, it looks like some of the pictures of stink bug damage, but I'm pretty aware of things happening in the garden. I'm there every day, and I just have never seen the stink bugs this year. 2 years ago they were horrible on my pole beans. But this year, they're just not around. Shouldn't I see some skin dark spots where they've penetrated the skin...and maybe skin infection/rotting and maybe some drainage out the penetration holes? I have these white things on a fair number of the tomatoes.....especially the Romas. How can I explain this if I never see stink bugs? Do they work at night?

I really don't know what to tell you about not seeing them other than they are not an obvious pest and most diagnose their presence by the damage done, not a bug head count. They live and work deep within the plant hidden well by foliage. And that is classic stink bug damage. No you don't normally see rotting or infection or drainage from any penetration holes. That isn't how stink bugs are built or work nor the symptoms of their damage.

Whether you'd see some skin spots or not depends on several factors. Perhaps it is primarily being done by immature stinkers where the external damage isn't nearly as obvious as from adults. Perhaps they were there early and did the damage while the fruit was still very green and have since moved on. I can't say.

Dave

Thanks for your help Dave.

Stink bugs actively hide. They will walk around the tomato to avoid being seen. Some glare at me.

I read in the internet that Bacterial Canker can cause similar damage.