Scenarios on clones on their own roots and theory of rejuvenation

[jujubemulberry]

@JinMA

I’m understanding correctly, the terms “juvenile” and “mature” refers to types of growth (non-flowering vs. flowering), and not (or at any rate not precisely) to age or degree of vitality/senescence. In fact, as the passage I just quoted observes, the oldest part of an adult tree will be the most juvenile, while the newer growth will be the most mature.

oh i see now, and yes, we are in agreement on that one

@JinMA

In other words, with respect to your point above, it seems (to me) that the key factor is not only the vitality (notice that I’m avoiding the word “juvenility”…) of the rootstock, but the suitability of the scion. (And that this suitability has less to do with time-to-senescence per se and more to do with ability to form a graft union and achieve vigorous growth?)

scion on a rootstock does involve vitality of rootstock-- plus compatibility. For my intents and purposes though, am more interested on whether or not a clone(that is not papaya), will run parallel to a papaya’s projected lifespan if an airlayer was to be obtained from a much longer-lived species, say, jujube. I don’t know how old the cultivar honey jar is when it was first grown from seed, or obtained as a sport, but it seems like it struggles when grown as an airlayer/cutting treated with iba hormone-- but it will be so much more vigorous when grafted to seedling rootstock.

@JinMA

Growth from the OHxF rootstock I use will often have noticeable “spines.” Growth from scions grafted on the same roots will generally not (maybe exceptions but I can’t think of one).

i guess what applies to citrus applies to pear rootstock, when grown from seed. And similarly, scions from fruiting branches of certain citrus will have lost their thorny habits, even if grafted to seed-grown rootstock. Calamondin citrus is a reproducible and tangible study that would demonstrate this.

@JinMA

but given what you’ve said about the shortness of their life span, I wonder if the limited growth of air-layered plants is due not to senescence being “passed on” and more to the fact that the adventitious roots simply don’t have time to catch up with the stronger root system of a seedling before senescence starts to set in.

i actually think it is both, and that the age passed on to the clone will hold much more. From my experience, a clone will not have a projected lifespan longer than its mother tree(simply because the act of cloning makes the clone “younger”). This is not true as demonstrated by relatively short-lived papayas and avocados. An avocado in decline won’t even respond to airlayering(wont form roots) or to tissue culture hormones unless its stem is first grafted to a seedling. And if a stem from a 6 yr old(which is old for the species) papaya tree were airlayered, it will continue to behave like an old papaya tree, bearing small fruits, and senescing like its mother, and will not peak in production like its mother did when it was 3 yrs of age. But if i take self-rooted clones from a papaya seedling or a 1-2 yr old , the clones will still grow up and peak in production with large fruits, and then slow down in production with smaller fruits as they reach 5 yrs or more…

@JinMA

Total speculation (and possible misunderstanding) on my part!

hey,that is my expertise as well, lol

@JinMA

is an intriguing point and I wonder if there are situations where it might offer a useful way of enhancing fruit production. Quite possibly not, but fun to think about!

it does work, but can kill the tree if you do it on the main trunk, as the roots need to eat too!

@JinMA

Given the fact that papayas have only a very short lifespan while jujubes have a very long one, I also wonder how well the lessons gleaned from one can be applied to the other.

jujubemulberry:

it applies if one does not know the age of the original scion of a jujube. Honey jar seems to be a laggard on its own roots, probably because it is an old cultivar and that its ‘true age’ gets exhibited as soon as removed from young rootstock-- have had a couple of them that died on me on their own roots.