Tomato cracking can appear due to extreme fluctuations in water supply and temperature. It is more common on soil-grown crops and can be avoided by maintaining a consistent soil moisture status. Crop nutrition affects tomato cracking as well.
Crop Nutrition and Tomato Cracking
Boron has a positive influence on the level of cracking and shelf life of the tomato fruit. Any cracks on the fruit shoulder increases water loss and susceptibility to pathogen attack. Potassium and Calcium deficiencies also increase the risk of cracking in tomatoes.