Jujube fruit set if you don't have hot dry summers

[BobVance]

Correction for my post from 10 days ago: One of the other grafts, other than the Honey Jar is still holding a fruit. I don’t know much about it (Zang Huang Da), but the fruit is much longer than the So fruit on the same tree.

It’s not as strange a shape as the R4T3 from the above pic. I’ve also grafted this one, so I’m interested to see how the thinner fruit (higher skin to flesh ratio?) affects flavor. Here’s another pic of it, from Cliff England.

Zang Huang Da (my wife translated the “Da” part as meaning “Big”, but wasn’t sure about the rest- possibly a location):

[jujubemulberry]

those streamlined jujus remind me of russian ammunition.

[jujubemulberry]

i guess many young ones have tasted jujus unawares. They serve this in many school districts, and is first juice product have seen with juju as ingredient being sold in usa.
quite sure it is merely for flavor, as jujus aren’t exactly juicy.

[Derby42]

I saw it listed on the ingredients list on some juice at the store just this weekend. I thought that it was for added sweetness maybe, as I recall it was for juice that was no suger added.

[jujubemulberry]

now that is good news!

the more, the merrier, as jujus don’t require much water and need no pesticides.
characteristics the younger generations need to exploit and appreciate. And hopefully the older generations too, who may not be accustomed to drought conditions, and who grew up using pesticides.

crossing my fingers the trend leads to a more mainstream path.

I thought that it was for added sweetness maybe, as I recall it was for juice that was no suger added.

you’re probably right about added sweetness, as certain jujus have high sugar contents. One of the few fruits which don’t need artificial means to preserve itself into a dried fruit, with little chance of rotting.

[BobVance]

My first of the season:

Texture was the biggest difference I noticed, though the So has a sweet-tart component that the Sugar Cane lacked. I need a bigger sample size to make up my mind. But, I won’t get that this year, as the Sugar Cane only set 2 fruits (2nd should be ready in a few days). Only 1 of the many fruit on So were ready, so Sugar Cane may be slightly earlier.

Both are considerably more juicy than the ones I’ve been getting from Roger Meyers in CA (I ordered 30 lbs of them, as my trees are still young). The CA ones are very sweet (some max out my refractomer, which goes up to 32) and reasonably firm (only the larger ones, a different variety I think, are a bit spongy), but are still much dryer.

[jujubemulberry]

The CA ones are very sweet (some max out my refractomer, which goes up to 32) and reasonably firm (only the larger ones, a different variety I think, are a bit spongy), but are still much dryer.

jujus approach or may even exceed sugar beets and sugar canes in sugar content. This is why it preserves itself into dates with no processing whatsoever.

btw, in my locale, contorteds and sugarcane jujus are also both early, and start turning brown at about the same time, but contorted’s need to be fully brown to be sweet enough. And yes, the contorted is more dense and dry. When shriveled into dates, the contorted reminds me of raw molasses(smoky!). It would make an awesome barbecue seasoning, lol. Sugarcane jujus turn into dates with a pleasant apple overtone.

[tonyOmahaz5]

I found a video of large jujube tree in Oklahoma loaded with fruits on Youtube. This tree was very productive and am not sure what variety.

Tony

https://www.youtube.com/watch?v=tfdPFa1gd5c

[jujubemulberry]

thought i’d bring this up again for @scottfsmith and others whose juju fruit production plummeted after a few years , when–presumably, the rootstocs had grown deep, far and wide, and may have reached a continuous source of moisture, which then enhanced vegetative growth BUT compromised fruit set.

girdling is a way of simulating water deprivation, but this is a delicate scenario which borders on fatal outcomes, which is why was proposing to raise them in elevated planters or in large barrels if one is raising them where mother earth is very moist.

Please chec the pdf below for the rationale.

http://horticulturejournal.usamv.ro/pdf/2015/art5.pdf

“CONCLUSIONS
From our preliminary results it has been
showed that girdling treatments significantly
reduced the flowering time and enhanced
inflorescence development for the studied
Chinese date genotypes. Similar observations
have been reported by Khandaker et al. (2011)
in wax apple and Arakawa et al. (1997) in
apple.
The fruit weight on girdled branches was
slightly higher than on control ones. Girdling
can be an effective technique for improving
fruit weight.
The girdling improved substantially some
fruit characteristics (size and weight) beside
fruit set percentage and ripening period.
Girdling determined a fruit diameter increase
by 3 to 5 mm, earlier harvest by 3 up to 10
days.
and a reduced number of pickings because of
a more synchronized fruit maturation.
The results related to the effect on the total
yield was the most encouraging: an increase
in fruit production of more than 50% was
registered on girdled trees.
Varietal response to this practice, however,
was quite variable. Preliminary results
showed that almost all varieties showed some
response: substantial in some and almost
unnoticeable in others.”

[tonyOmahaz5]

I saw some videos on YouTube but too afraid to try. This method was done on both jujube and Asian persimmon (to prevent fruits drop). I harvested a few Li Jujubes today.

Tony

[jujubemulberry]

I saw some videos on YouTube but too afraid to try

growing mine where summers are very hot and dry, so girdling could be lethal in an instant. And there’s really no need for me to do it since my trees dry out in between waterings-- which seems to be main reason why they are very productive, the xerophytes that they are.
in the tropics where there’s plenty rain and humidity, one could grow many varieties of opuntia cacti, which could be weedy when planted on the ground(as long as there’s good drainage), but NOT inclined to flower and bear fruits. Only way of inducing them to flower in great numbers is to plant in pots and grown under greenhouse conditions. Getting plenty of light but not an inch of rain(it rains there for days on end). Watering them on a limited basis mimics desert conditions evidently. The humidity is higher inside a greenhouse, but they will still bloom due to the water deprivation.
i could surmise the same exact thing is what jujus need when grown in moist and humid conditions, but since a greenhouse is typically not in the budget of most people, girdling would be the cheaper alternative.

partial girdling, that is. Circumferential girdling is too risky.

as for your li jujus, i just found out they are just as early as the other ‘early’ varieties. Main reason why yours ripened just now is primariy due to our temp differences…
Sherwood and silverhill flowers at the same time as other jujus, but waits a while to produce actual fruits.

[fruitnut]

Girdling doesn’t cut off water to the top. It cuts off downward flow of carbohydrates to the root. By keeping carbs near the fruit; quality, size, and earliness may be enhanced. Grapes and stone fruit are sometimes girdled in summer and the top doesn’t die unless it is overdone to the point of damaging the roots.

[jujubemulberry]

Girdling doesn’t cut off water to the top. It cuts off downward flow of carbohydrates to the root.

while i agree re cutting downward flow of carbohydrates to the root, i totally disagree about it not cutting off water to the top.

girdled stems(aka cuttings–which happen to be suspended in midair, and NOT dipped in water) will survive for a while, relying on the moisture from the sapwood, and maybe even the heartwood, simply because solute content and proteins are higher within the cambium, so water gradient is in favor of the living parts of the plant. Either that or the live parts of the plant, the meristem and cambium, have physiologic pumps capable of extracting water even against gradient. But once all that water has been extracted from the wood and lost to transpiration, the top part will die. There is just no way a circumferentially girdled stem could extract substantial moisture from air.

also, all plants don’t thrive on water alone, but need roots at some point to channel vital ions from the soil–nitrogen, phosph, potash, etc. They may survive on whatever ions they have within their systems already, but that will run out quicly, because growth requires more ions. The heartwood and sapwood cannot do that efficiently, if at all. Maybe the submerged cambium can, but not as efficiently if the callus has not differentiated into roots. The cambium above ground may develop callus, but without access to soil, the above part will die.

Grapes and stone fruit are sometimes girdled in summer and the top doesn’t die unless it is overdone to the point of damaging the roots.

again, i disagree—i have it the other way around. The top will die first. Most obvious way of illustrating this would be something you and i are familiar with— the respective survival rates of scion wood and rootstoc over winter(when both have been denied the benefits of photosynthesis for months) Chances of scion wood dying when it is grafted onto a healthy roostoc even in optimum conditions is much higher, and much faster, compared to the rootstoc below. The scion may already have died for various reasons, but the rootstoc won’t mind, and will continue to send up shoots several times before it finally starves. This is because most dicot roots evolved “survival mode” functions and not just specialized with their anchorage and absorption functions. Carrots and yams being exaggerated examples of energy storage specialization.

https://faculty.unlv.edu/landau/roots120.htm

"Functions and structure of roots

1.          Absorption � roots absorb large amounts of water and dissolved minerals (nitrates, phosphates, and sulfates) from the soil.
   

2.          Anchorage � to locate water and minerals, roots permeate the soil. �In doing so, they anchor the plant in one place for its entire life.
   

3.          Storage � roots store large amounts of energy reserves, initially produced in the leaves of plants via photosynthesis, and transported in the phloem, as sugar, to the roots for storage, usu as sugar or starch, until they are needed."

[fruitnut]

You can completely girdle a tree by removing a ring of bark down to the cambium in 110F heat and the leaves won’t wilt because you haven’t cut off the water from the roots. Water travels up the wood not the bark.

I’ll try to link a picture:

https://search.yahoo.com/yhs/search?p=tree+anatomy&ei=UTF-8&hspart=mozilla&hsimp=yhs-002

That didn’t get to picture I wanted. But look at the picture of a tall tree titled “basic tree anatomy”. It shows location of water transport inside the cambium, ie xylem or sapwood.

When air rooting figs some people ring the limb, ie remove bark all the way around the limb. The wounded area is then pack with moist material to form roots. The part above the wound doesn’t drop it’s leaves. If water were cut off the leaves would wilt in hours and drop in days.

[jujubemulberry]

It shows location of water transport inside the cambium, ie xylem or sapwood.

i guess i wasn’t clear, what i meant by girdling jujubes was deep girdling, where the sapwood TOO, is severed immensely.
Because the main intent was simulating dehydration.

[tonyOmahaz5]

Fn, Jujus,

I want to do an experiment by using a hose clamp and tighten the screw over my jujube and persimmon trees to have a girdling effect without having to scorching the trunks. What are your thoughts?

Tony

[fruitnut]

I imagine that would have at least some effects of girdling. Try it on smallish limbs. You might also girdle smallish limbs as pictured in Juju’s link above. Make the girdle to bark but not too long so that it heals in a couple months.

In grapes they use a special knife and make a spiral cut that goes all the way around the trunk but isn’t connected.

[jujubemulberry]

sounds good to me, way safer than deep girdling, lol!

you could try that on a branch, and not on the main trunk if you want some peace of mind.
and if you have plenty branches to spare, i’d recommend the standard girdling fruitnut brought up,
while also try deep girdling another branch, where a large amount of sapwood is sawed off, to induce a bit of dehydration. Sapwood is basically dead, so no need to girdle wide, just a bit deep.
wish i could do that experiment where am at, but the soil here is bone-dry, that my trees are literally deep-girdled by default!.

[jujubemulberry]

Make the girdle to bark but not too long so that it heals in a couple months.

quite curious also if Tony tried a really long/wider girdle, making it last longer than a couple months, since it is only just a limb, and will not starve the rootstoc since rootstock is still fed by other ungirdled branches.

[forestandfarm]

Tony,

Weren’t you trying something similar for hard to root trees with air layering? I recall something about using wire on persimmons for some amount of time and then trying to air layer the branch. Did that ever work out? Seems similar in principal to the technique described in the previous series of posts but for a different objective.