Seems as if this fruit was not destined to make the long haul. There will be many different reasons for all splits. At least I can explain why this one did. After cutting her open to retrive the seeds the evidence was there. The cut was made just above the blossom. The darker green line marks the internal crack & where she eventually split open. There were many other internal cracks, all running parallel with the ribs. Calcium should not have been an issue with this fruit. I fear that this was due to a shortage of potassium. This was a new patch and the salts were very high. Mg, K & Ca ratios were no where near optimum. No additional K was added during fertilization.