Question
what cause the splits in cherry tomatoes when they are ripe.

Answer
Sandy, when tomatoes split, it is always a sign of irregular watering. This is normally caused by days of no rain and then periods of heavy rain.

Although there is little that can be done to protect vegetables from rain, you can amend the soil with organic matter to improve drainage. I personally use raised beds with a soil level of 10 inches. My soil is composed primarily of compost, peat moss, shredded leaves, and aged
manure. Since using this method, I rarely experience problems related to excessive rain or poor drainage, similar to the problem you have described.

I hope this answered your question.  Please write again if I can ever be of assistance.

Regards,

Mike