Every tomato on our bushes showed some evidence of cracking or splitting. I had seen this before after a rain and in late season tomatoes that lost foliage. In this instance we still have a lot of foliage on the plants and experienced a week of intermittent rain showers after a drought. I wrongly attributed the cracking to rain. That is not exactly correct.Cracks are caused by irregular watering. What happens is that the rainfall or extra water tomato plants receive makes the interior of the fruit plump up faster than the external skin can grow - thus the split. Some varieties are more resistant to splitting.
Different kinds of cracks that can indicate what is causing them to occur. Cracked and split tomatoes are still very much edible but not very pretty and will not last as long once picked.
Use of regularly metered drip irrigation offers the best chance of getting nice uniform growth. Maybe next year.
