I grew them here in Arizona. Low chill, early bloom. For the first few years, I had two plums on a huge tree grafted on Mariana -- so it needs a pollenizer if you want more than a few plums. It definitely has an acidic/tart aftertaste that I didn't care for, which is probably why it was never a commercial success.

You can also buy a tree on-line rather than wait years for that seedling to bear.

Inca Plum

I grew inca also. Never got over 4 or 5 plums every year. It was probably 10 feet from my self pollinated beauty plum that would have hundreds of plums every year. I pulled it out. Liked the plum, but would not produce for me. My opinion is it did not care for all this humidity down here.

I have zero humidity here. I honesty think it was a shy bearer. Eventually, I grew two pluots that bloomed at the same time -- Emerald Drop and Splash -- that were three trees over and both did nothing to improve the crop numbers.

I have had a tree for 4 years, it's a nice size (8' pruned) and only a handful of plums in all those years. I have Flavor King pluot next to it. Looks like I'm going to be grafting it over....