I supposed this is the way the plant excludes and prohibits pests and diseases from entering the wounds, much like our blood clot preventing infection to set in.
Anyway, remember the separate nectarines and flowers that I mentioned before? The few inflorescences were developing and they have not taken on the vibrant scarlet or orange colour yet. But the larger inverted cup-shaped nectarines and the smaller unopened floral buds directly below it were obvious from some of these photos. And there was an ant trying to get to the nectar?