http://tropicalfruitforum.com/index.php?topic=11876.msg152528#msg152528We discussed this plant a bit earlier, in the how to graft Jaboticaba (Myrciaria/Plinia) thread, which I posted above.
here is an updated picture of the tree, (M. dubia, grafted onto M. vexator, appox 2yr ago)



I believe this plant (graft combination) represents an opportunity for growers in South, FL, where the climate is good for growing Camu camu, but the soil is horrible (lime rock, with high pH), making it almost impossible to grow this species, without digging a big hole, and replacing the native soil with acid sand, or peat moss, and also drenching with chelated Fe.
The rootstock I've chose to employ, is the Blue jaboticaba (M. vexator). It can thrive in the native soils of South FL, as long as it's fertilized, and properly irrigated. In theory, this resistance for high pH (lime rock soil), should be imparted into the grafted tree, making the scion (M. dubia) more capable of surviving the adverse conditions of South FL soil. Although the trees will be more resistant to high pH, I'm sure they will still require periodic drenches with chelated Fe, until they are established...but the amount of product required to keep the plants thriving would be a fraction of what you'd have to use if you tried to keep M. dubia alive on it's own roots.
It would make me really happy to see a grove of Camu camu fruiting in the Redlands of FL (even if it's a very small grove, or just one tree! haha!)