"Bill P" wrote

I have three breeds of tomato ripening in the greenhouse. Gardeners
Delight, New Girl and Ferline F1.
Problem is that as the tomato's ripen there are yellow patches at the top.
I have never experienced this before.


Sounds like Tomato Greenback. They believe it's caused by low levels of
potassium and phosphate and/or hot sunlight that damages the stalk end. So a
good tomato feed and shading in hot sunlight and don't remove too many of
the leaves which do provide shading to the fruit and keep the house
ventilated to reduce heat buildup.
--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK