Tomato greenback problem

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

 

Your GH was almost certainly too hot. Another possibility is too little potash though if you've been feeding with tomato fertiliser this is less likely.
Next year try improving ventilation and reduce sunlight with a mesh screen or glass paint.

 

I agree with DW but this some times occur at the end of crop cycle