Another connection to water.
Splitting is often caused by erratic watering. Perhaps when the fruiting plant has been allowed to get too dry and then flooded with compensatory water.
The water travels up through the plant, swells the fruit but at a rate too fast for the outer skin to adjust to, causing the fruit to split. The split usually occurs on one side and from top to bottom.
The split in itself may not render the fruit ruined but the split can be a wound through which infection can enter and this can cause the fruit to be ruined.
