from what am seeing here, ga-866 is more stingy than sherwood, porterville, gi-1183, and autumn beauty(although autumn beauty can be precocious as new grafts), so probably even less reliable ‘outside of its element’. The cultivars ma ya zao and r4t3(which are reportedly productive in TN) are kind of similar to ga-866, and in my opinion better in flavor, so those might be a better fit for your growing conditions. Both were also precocious on li interstem. R4t3 was also precocious on contorted.
am thinking some jujus might change into biennial or triennial bearers in subpar conditions, but that is just a hypothesis. Our lang was a biennial the past four years, not producing flowers for some reason. Ant admire has been an incredible annual performer here, btw.
hormonal inhibitory effects of multi-grafts may also occur, but that hypothesis is difficult, if not imposible to prove. The incredible diversity of spinosa-type rootstock evidently also play a huge part in juju well-being, especially in subpar conditions. Unlike apples and drupes where named rootstock(gisela, m1, etc) are used specifically, the nurseries selling jujus seem to just graft their named varieties to random rootstock suckers or random seedlings. I have noticed manganese/iron deficiency-type symptoms on some of our trees here(common problem in alkali soils), even though juju trees a couple of feet away are verdant, lush, and loaded with fruits. If variances occur on our trees here, quite certain those would be amplified in less favorable conditions. Possible that some rootstock are better extractors of nutrients from the soil than others.
in the rainy tropics you cannot get certain cacti to flower unless you grow them under an umbrella, limiting the amount of water they get, and letting the pots dry out in between. Many native xerophytes in the southwest(tepary beans/cacti/succulents) need periodic dehydration to flower and fruit.
dry conditions may play a part in triggering hormonal effects, but also may ‘increase’ fertility of soil not by adding minerals to the soil, but by removing a great deal of the diluent. A crude and admittedly sophomoric analogy could come up with would be that one of the first lines of treatment for dangerously high blood sugar among diabetics is hydration. A couple of bags saline rapid iv infusion. The acidotic gradient typical of the condition decreases by mere dilution, so conversely with removal of excess water from the soil, the gradient increases in favor of absorption. If soil nutrition is something to rule out, growing jujus in pots(or dumpsters with wheels) might be too much work, but perhaps worth experimenting with since you could pretty much use 100% miracle gro potting soil and avoid leaching by not watering too much.
i agree, longevity and hardiness are good traits to have, but inutile if productivity is negligible or nil…