Splitting appears to be most closely related to extreme fluctuations in temperature, humidity, soil moisture, and possible fertilizer levels, and most likely caused by a combination of these factors instead of a single cause.  

In short, reasonable cultural practices to avoid extreme fluctuation in soil moisture and fertilization levels throughout the growing season may help to minimize fruit split. Regular irrigation is key.

As the tree requires more water, it takes from the fruit, which in turn becomes soft and the tree leaves begin to cup. If a large amount of water is added soon after, the fruit swells beyond the skin's capacity and splitting occurs.