Tomatoes rotting on vine not BER or blight?

[marchogaeth]

After a goggle and search on here, I've drawn a bit of a blank so ideas, please.
Basics
Variety - Amish Paste e.g. Amish Paste tomato | Baker Creek Heirloom Seed Co
Position - poly tunnel among lots of other varieties none of which are doing this.
Home saved seed growing in rings sitting on the soil.

Three of the fruit so far have reached the orange ripe stage and then gone mushy and brown towards the top of the fruit. I have only noticed it when it starts to look like a bruise coming out for want of a better description. I have had one ripe tomato from these plants so far and the plants look completely healthy and are growing well.

So any ideas? I will go and dig the latest one out of the bin later and take a photo but it's actually quite hard to see.

Diolch.

[Zelenina]

Does it look like any of these?
Disorders of Ripe Tomato Fruits | Vegetable Resources

or these?
Disorders of Green Tomato Fruits | Vegetable Resources

[Scarlet]

Have you got any problems with the stems of leaves of your plants? It could be botrytis/grey old but you would also see it on the stems or leaves.

[PyreneesPlot]

Could it be tomato hornworm damage?
I've only had it once in a greenhouse in Devon but the fruit showed no damage (there was a tiny, tiny hole at the top) until they rotted around the stem and then dropped revealing the caterpillar inside.

[marchogaeth]

Well, unfortunately it looks like Cottony Leak so thanks for the link. However, I only water through bottle towers and none of the fruit are anywhere near the soil. The other alternative might be sun scald but why only the Amish Paste?? The worst of it is these are the best I've ever got this variety to do - really big fruit.

I think if another one goes I might try picking them green and ripening in a cupboard.

By the way what great names - could be on the real ale name thread!

[marchogaeth]

Have you got any problems with the stems of leaves of your plants? It could be botrytis/grey old but you would also see it on the stems or leaves.

Could it be tomato hornworm damage?
I've only had it once in a greenhouse in Devon but the fruit showed no damage (there was a tiny, tiny hole at the top) until they rotted around the stem and then dropped revealing the caterpillar inside.

Thanks for these suggestions, I will have a targeted inspection tomorrow - when it is raining again!