Author Topic: Citrus juvenility and internode count  (Read 614 times)

deRoode

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Citrus juvenility and internode count
« on: June 07, 2022, 02:51:34 PM »
Hi!

I am quite interested in citrus juvenility. There are some studies that suggest after x amount of plant internodes, the seedling will become adult. One study observed flowering earliest at around the 50th internode up until 120ish internodes. In my opinion, genetics clearly play a role, especially considering precociousity.

Does any one of you have experience with the number of internodes required for flowering? I am especially interested in yuzu, and when to expect flowering in my seedlings  ;D


kumin

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Re: Citrus juvenility and internode count
« Reply #1 on: June 07, 2022, 03:49:52 PM »
There's clearly a genetic component to first flowering/fruiting. I have propagated a number of grafts from young seedlings. The seedlings and the grafted clones initially flower/fruit very close to the same time. Unrestricted apical growth is helpful, top pruning delays initial flowers.

poncirsguy

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Re: Citrus juvenility and internode count
« Reply #2 on: June 07, 2022, 09:48:07 PM »
Seed grown Meiwa kumquats flower well at around 40 nodes and the Fukushu starts after about 60 nodes

Millet

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Re: Citrus juvenility and internode count
« Reply #3 on: June 07, 2022, 09:58:02 PM »
 Length of time to flower from planting the seed. Most oranges and grapefruit require 7 - 10 years. Calamondin & Key Lime 2 to 3 years.  Mandarins 3 to 5 years. Yuzu I do not know the time required until flowering.

pagnr

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Re: Citrus juvenility and internode count
« Reply #4 on: June 09, 2022, 06:05:34 PM »
I have a Yuzu seedling that just started to flower from seed, last season. It has 2 main stems, so would be about 2 metres tall and slightly bushy with side branches.
Haven't counted the nodes, but would be the same for any 2 m tall citrus, not overly vigorous with normal bud spacing.
The plant is in a pot, and has been on the back burner. It is well over 10 years old, but has been neglected over the years, until now it started flowering.
As I recall Yuzu is not one of the faster types to fruit from seed.
Anything that can be done to speed up the growth rate to achieve node count will be helpful., i.e. extending the growing season with protection or heat or repotting as required.
A friend in Cairns, tropical Queensland had a grapefruit seedling that came into full production about 3 years old.
He was gardening in the rainforest and the plant was 20 feet tall in that short time.

brian

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Re: Citrus juvenility and internode count
« Reply #5 on: June 09, 2022, 10:06:05 PM »
I am becoming skeptical of the node count explanation as I have a few rootstocks that fruited after the scion died, and the rootstocks probably have only a hundred or so nodes though they are a few years old and trunks >1in diameter.  One was a pummelo (likely Cuban Shaddock as it was a FourWindsGrowers tree) and the other I think is c-35 citrange. 

It may be simply that node count is a reflection of tree size. 

pagnr

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Re: Citrus juvenility and internode count
« Reply #6 on: June 10, 2022, 04:05:57 AM »
I am becoming skeptical of the node count explanation as I have a few rootstocks that fruited after the scion died.

Generally I would agree, some plants seem to flower or fruit despite the node count theory.
However in the case of a formerly budded rootstock, was node count achieved by the whole grafted plant,
and flowering maturity transferred to the rootstock ??
Another possibility is flowering hormones from the mature grafted scion influencing the rootstock.

poncirsguy

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Re: Citrus juvenility and internode count
« Reply #7 on: June 10, 2022, 07:36:19 AM »
My four winds cuban shaddock's scion died and it flowered and produced fruit.  the rootstock was a rooted cutting.

brian

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Re: Citrus juvenility and internode count
« Reply #8 on: June 11, 2022, 11:05:51 PM »
My four winds cuban shaddock's scion died and it flowered and produced fruit.  the rootstock was a rooted cutting.

I hadn't consideres that the rootstocj itself might be a cutting.  Is that common?  I thought most citrus are hard to root.

deRoode

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Re: Citrus juvenility and internode count
« Reply #9 on: June 12, 2022, 05:01:14 AM »
I have a Yuzu seedling that just started to flower from seed, last season. It has 2 main stems, so would be about 2 metres tall and slightly bushy with side branches.
Haven't counted the nodes, but would be the same for any 2 m tall citrus, not overly vigorous with normal bud spacing.
The plant is in a pot, and has been on the back burner. It is well over 10 years old, but has been neglected over the years, until now it started flowering.
As I recall Yuzu is not one of the faster types to fruit from seed.
Anything that can be done to speed up the growth rate to achieve node count will be helpful., i.e. extending the growing season with protection or heat or repotting as required.

Very interesting! I will be trying to speed up the growth of my seedlings

I am becoming skeptical of the node count explanation as I have a few rootstocks that fruited after the scion died.

Generally I would agree, some plants seem to flower or fruit despite the node count theory.
However in the case of a formerly budded rootstock, was node count achieved by the whole grafted plant,
and flowering maturity transferred to the rootstock ??
Another possibility is flowering hormones from the mature grafted scion influencing the rootstock.

Normally after achieving the necessary node count, all new growth will be adult and can flower. I would agree with you that the rootstock is likely a cutting.

There are some studies were a gmo rootstock was able to induce flowering in a juvenile scion, so it could surely be possible, although the likelyhood of it being a mature cutting would make more sense.


My four winds cuban shaddock's scion died and it flowered and produced fruit.  the rootstock was a rooted cutting.

I hadn't consideres that the rootstocj itself might be a cutting.  Is that common?  I thought most citrus are hard to root.

There are some good protocols for rooting citrus out there, this one for example:
https://crec.ifas.ufl.edu/extension/citrus_rootstock/rootstock-literature/2017.%20K.D.%20Bowman,%20U.%20Albrecht.%20Efficient%20propagation%20of%20citrus%20rootstocks%20by%20stem%20cuttings.pdf

 

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