Tomato Greenback and associalted problems

[Garden Manager]

My tomatoes have cropped really well this year and have generaly ripened nicely but have suffered a bit from greenback, which has also affected the flesh inside the fruits. This has resulted in areas of green rather inedible bits around the stalk area, which have to be cut out before eating.

I am wondering what might have caused this, what I can do in future to avoid it?

Thanks

[Garden Manager]

[saddad]

Some varieties are more prone than others and I tend to grow resistant heritage varieties so I don't know the cause, is it a deficiency?
???

[amphibian]

There is a gene in tomatoes which can predispose certain varities to greenback, though I am under the impression that environmental concerns such as too much heat, poor ventilation can worsen the problem.