If the fruit are open to direct sunlight you can find the skin sets and the fruit can't then grow. One heavy watering and they split. It's one reason to shade your tomatoes.
I haven't shaded my outdoor tomatoes and although those in the greenhouse were covered with fleece during hot weather when the plants were small, I haven't managed to get any shading up in the greenhouse. :P :-[
The aubergines are thriving in it though!! ;D ;D
Having consulted a book it looks as tho it may be caused by heavy watering after the soil has been allowed to dry out. The sudden growth causes the skin to split. To stop it from happening the roots need to be kept evenly moist
Looks like erratic watering to me
Thank you for your replies. The tomatoes photographed were from a plant in a pot in the greenhouse. There are other fruits on the same plant and although small, they look OK so I didn't think it was likely to be a disease or they would probably have been affected the same way.
I also have some other Costoluto Fiorentino tomatoes growing outside, also in pots but against the fence in one of the vegetable beds. These too have some tomatoes that are looking like those in the photo. Fortunately I went mad with my sowing and have quite a few plants so should still get some good ones. :D
Erratic watering and scorching seems to be the general opinion with what is wrong with them and this is probably why it is only those in pots that are affected as they are drying out too quickly. However, they do look as if they have a type of rust on them.
It only seems to be the Costoluto Fiorentino that are producing these abnormal fruits but then they are a beefsteak variety. Has anyone else had problems with this variety?
I would like to thank you all for your commiserations but be assured I have got five other varieties that seem to be going along all right. ;D
