Help to identify rootstock. Mandarin cleopatra?

[sanguinho]

I have an old mandarin tree that died a few years ago, the rootstock resprouted and although several years have passed, at least 5, it has never given any fruit. It seems strange to me since near there are two orange and lemon trees, I do not know if it is a question of incompatibility.



Before I graft it I would like to identify it, I think it could be mandarin cleopatra, but I'm not sure.

[kumin]

First question, has this tree been flowering? If it hasn't flowered it needs to transition to the mature, reproductive phase.

If it's repeatedly flowered profusely, then lack of effective pollination could be a factor, although many types of Citrus are capable of fruiting w/o pollination.

[sanguinho]

I don't know because it is not in a place I usually visit, not knowing the date when it might bloom doesn't help, although it seems strange to me that it doesn't bloom since it has been at least 5 years since the graft was lost, but the tree has been planted for more than 15 years. From my lack of knowledge I think it should not take as long as a tree growing from seed to flower, starting to count from the time the graft was lost. 5 years seems to me a long time to not have seen any fruit.

[sc4001992]

Not really long time. I have a rootstock that is growing tall for over 5yrs and it still has not flowered and I'm trying to determine the same thing (what it is).

[kumin]

The count toward rootstock maturity started when the scion was lost. The age of the scion doesn't have much bearing on rootstock shoots originating at soil level. The effective age at soil level is just a few months of age. Avoiding pruning any apical growth will help in the maturing process. Any apical growth removed needs to be regrown before the "timer" towards fruiting can be reset.

[sc4001992]

Oh rats, I just cut some of the taller branches on my rootstock growth. It was about 10 ft and I cut it back to 8 ft.

[ash]

Mar 7, 2021 17:10:16 GMT -5 kumin said:

The count toward rootstock maturity started when the scion was lost. The age of the scion doesn't have much bearing on rootstock shoots originating at soil level. The effective age at soil level is just a few months of age. Avoiding pruning any apical growth will help in the maturing process. Any apical growth removed needs to be regrown before the "timer" towards fruiting can be reset.

This is a little confusing
So what your saying is that the flowering stage of a plant grown from seed is not determined by how old the entire plant is..... Or are you saying that a heavy pruning can reset the ageing process or at least pause it for 20 years?

Do you know this from experience or from something you've read? Do you have any links you could give us to back up this theory?

I don't have any knowledge either way so I can't agree or disagree with you but I definitely would like some more information to back up this claim.

I tried looking up stuff about it myself but I didn't know what to search for and since few people grow fruit trees from seed it's very difficult to find out the information

[kumin]

Maturity of a tree in regards to being in a vegetative state vs a reproductive state is determined by more than simple age of the plant. The chronological age of the tree's tissues are almost the opposite of what might be expected.

As a tree grows, the base of the trunk, although the oldest chronologically, remains the most immature reproductively. The most mature tissue in a reproductive sense is found in the most distant tissue, highest in the tree. When maintaining woody plants for production of cuttings( stools) , they  are repeatedly pruned back near to the ground to keep them in a easy to root, vegetative state.

Cuttings taken from high positions, or older fruiting wood are much more difficult to root than basal cuttings.

link.springer.com/chapter/10.1007/978-94-017-0994-1_13

www.researchgate.net/publication/239921787_Juvenility_Maturity_and_Rejuvenation_in_Woody_Plants

In regards to personal experience, I had a small business of rooting hardwood plants in the past and relied on these principles for successful propagation.

[ash]

Thanks that makes sense.
I suppose that also explains why heavily pruning an old tree can result in the tree seeming much younger and is called rejuvenation of the tree

[mbmango]

To keep prospective plants more compact, would it work to continually graft terminal shoots down lower, thereby not having to maintain intermediate wood?

[kumin]

Grafting mature wood to lower trunk positions does indeed work, however, they may need to be forced in order to flush and compete with higher position branches.

One thing to keep in mind is that after high position branches cause the tree to transition from vegetative to reproductive phase, the effect is no longer limited to the very top of the tree.

Although the base remains juvenile and has thorny sprouts, etc. the entire canopy will convert to reproductive phase reasonably soon after the top growth initiates the phase change.

[mbmango]

Curious how much mature material is needed to initiate a phase change.  If one grafts mature wood onto a seedling, will the remaining seedling buds change once the mature wood grows to a certain size?  I guess this would depend on how much hormone can be produced and distributed, and whether that is a significant influencer of a phase change.

[millet]

mbmango wrote >>>> If one grafts mature wood onto a seedling, will the remaining seedling buds change once the mature wood grows to a certain size?<<<<

 No, the buds on the seedling below the mature wood graft, will forever remain immature. 

[mbmango]

Thanks Kumin & Millet!

[ilya11]

Mar 8, 2021 16:09:15 GMT -5 millet said:

mbmango wrote >>>> If one grafts mature wood onto a seedling, will the remaining seedling buds change once the mature wood grows to a certain size?<<<<

 No, the buds on the seedling below the mature wood graft, will forever remain immature. 

It  really depends on variety. Thomasville  and many C.ichangensis seedlings are first flowering on lower branches. For other varieties, the mature status is also changing over time, in two-three years after first flower, the whole plant is becoming mature.