Durio zibethinus seedling girth size at first flower

[cassowary]

What was the girth of your durian seedling tree when you saw the first flowers?
Please share

I don’t think time is the factor that decides when a durian tree becomes mature, I think it is the girth of the main trunk and/or the girth of the lateral branch that is the most deciding factor of maturity.

I’v got a few durio zib seedlings that have about 100mm trunk diameter and 30mm branch diameter

[Finca La Isla]

That’s an interesting question, and well put, wanting to know about the trunk and branch girth.  More commonly people only ask about the tree age.
I’ve only had one seedling flower of zibethinis and it was a long time ago.  I don’t remember. That tree is now 35m tall and a heavy producer.
 I just had a Kutejensis seedling flower for the first time.  The trunk girth is about 12-13cm and the branch is about 5cm.  No set and I’m wondering if it needs cross pollination.
Peter

[Gone tropo]

cassowary great question and I think you are correct with your thinking,  I have a grafted tree that must be a bit over 100mm trunk girth I was really really hoping for flowers in the recent dry spell but so far none. I see a seedling tree up the road with trunk girth of 150-200mm and it doesn't have flowers either.

Seems there is plenty of flowers on trees around cairns.

[tongmuan]

In another thread, drymifolia said that for avocado, the trigger for a tree becoming mature (and so starting to flower) might be total biomass or number of leaf nodes:
https://tropicalfruitforum.com/index.php?topic=53083.0

I like the trunk and branch girth idea better though, in that case pruning seedling trees to a more manageable size would not delay flowering

One more related thought - could we graft scions of smaller seedlings to a bigger seedling tree that's about to reach maturation, and get mature scions of the younger seedling genetics from the resulting branches after the bigger tree's first flowering?

[cassowary]

Some good input here from you all

Seams like kutjensis requires less girth then zibethinus to be mature.
I will see how thick our kutjensis are when they mature. Will be interesting to see.
I wounder too if it needs cross pollination, zibethinus x kutejensis hybrids excist so they can pollinate each other but maybe zibethinus pollen isn’t as good as kutejensis pollen for kutejensis. Are there other kutejensis trees around?


I think age can be missleading because i have a few trees that are the same age but not same size, some are double the size. And when I asked people long ago usually good farmers said 5 years from seed to first harvest and casual gardeners gave me 8-10 years probly because their trees don’t grow as well and does not get to maturity size as fast as the good farmers trees.
If we know dimnesions for maturity then we can plan easier or change practices.

Hypothetically, if I knew that 250mm girth and 5cm branch is enough to make a tree/branch mature then if I have a zibethinus tree at 250mm girth 1m above the soil with plenty of 5cm branches  but no flowers then I would know there is something i need to correct. Maybe not enough sun, to much or to little water or low EC soil or to high EC soil or some deficiency.


Tropo, Maybe over 200mm for zibethinus is a fair estimate, if the tree has good sun, water and decent soil. None if mine at 130-150mm have flowered.
Would be good with some solid data on this.

Interesting that it might be biomass or leafnodes that can help detmine how far of to maturity in avocado trees. Avocado flowers are born on the end of branches which is different from zibethinus so this might not be applicable to zibethinus.

Peace

[Finca La Isla]

I have a kutejensis that just flowered for the first time.  The tree is only about 6 years old. The trunk has a diameter of about 15cm and the only branch that really flowered is 5cm. There was no set but the flowers were beautiful!
I have a very old and quite large seedling zibethenis but I can’t really recall the trunk size from when it first dropped fruit but I think it was pretty big. That tree is now about 33 years old and some 35m tall. We call it ‘Isla’ after our farm. Isla produces hundreds of fruit that I say tastes like vanilla cookie dough. Very pleasant flavor, while not so interesting for a conosouir, it’s the best for introducing durian to the uninitiated.
The rest of the durians I have that are in production are all grafted trees.
Peter

[Gone tropo]

Peter your "isla" tree sounds awsome I would love to get that here in australia, I have heard from others who have tasted your isla who rate it highly as well.

Cassowary Iknow its not apple and apple comparison because you are talking about seedling tree but my biggest grafted tree P88 (D178) is 3 years old and i measured the trunk diameter the other day at approx 150mm above graft union as done on the zappala study (so not the base) and it is 80mm. The tree has some thick laterals which i didn't measure but can if you want because i have topped the tree multiple times sometimes quite severely it is only about 2 metres tall.  Im still hopeful of getting some flowers before the wet season but could be wishful thinking time will tell.

[cassowary]

Wow that sounds like a good Durian!

5cm hmm I’ll keep that in mind and see what the branch thickness will be when we get the first kutejensis fruit.

Yeah it would be interesting to see what the minimum branch size for grafted trees would be.
Peter sellareis in Cassowary (sorry for spelling his name wrong) would probobly know, he got some small grafted durian on his hill side trellises.

Tropo, have you tried to give it high P-K fertiliser with trace mineral foliar?
I saw this man in Thailand do that to his durian and he can get his harvest 1-2 months earlier compared to doing nothing.

2m, that’s good height for wind resistance!

Peter have you ever tried to induce earlier flowering with any of your practices?

I am keen on this because then I could possibly harvest most durian right before cyclone season.

https://m.youtube.com/watch?v=Tx8tvDwYWZ0

I am trying this on a few of the biggest of mine. But i am not sure if it’s kinda waste of resources if my trees aren’t “mature” yet.

[Mike T]

Meaning circumference not diameter.I think age and biomass are important and minimum size for opening the account varies with variety.

[Finca La Isla]

Our farm is certified organic so we don’t have every tool available to us for forcing flower induction. We use K-mag and apply an appropriate nutricional cycle for durian.
But really, my seedlings only get manures, biomass, and very frequent lactobacillus applications.

In Malaysia last year I saw 5 year old mustang king that were producing fruit. This was at a very large farm that I feel was pushing their trees pretty hard. I think they use a strong foliar application of potassium. Really, the fruit wasn’t that great.
Peter

[fruit nerd]

I am keen on this because then I could possibly harvest most durian right before cyclone season.

Yeah, early harvest would be great here. Last year, there was durian dropping from late Sept to Nov. Was excellent quality and fortunately before the cyclone. Durian in the Cairns/Daintree area are flowering now so looks like there will be durian in Jan which is pretty good I think.

[Gone tropo]

Sorry I meant my tree has 80mm Diameter not circumference probably should measure that too.

Cassowary nah I haven’t tried spraying anything on it yet.  The soil Is starting to get drier and I don’t water the trees at all so will see what happens.

Placobutrazol is used in SE Asia to bring on early flowers. It is also used widely in the mango industry in Australia. Don’t know how good it is for your soil though using it long term…..

[cassowary]

Peter, is that Langbeinite Sul-Po-Mag?

I just use a vernier caliper to measure diameter and can use c = πd to get circumference.
Your right mike Girth is circumference not diameter.

Yes it would be nice to be able to have majority of durian mature by Dec-nov.

Placobutrazol,
Paclobutrazol (PBZ) is the ISO common name for an organic compound that is used as a plant growth retardant and triazole fungicide.[2][3] It is a known antagonist of the plant hormone gibberellin, acting by inhibiting gibberellin biosynthesis, reducing internodal growth to give stouter stems, increasing root growth, causing early fruitset and increasing seedset in plants such as tomato and pepper. PBZ has also been shown to reduce frost sensitivity in plants.

It was assessed as being of moderate acute toxicity, mildly irritating to skin and eyes and unlikely to be genotoxic or carcinogenic to humans.[25] PBZ is relatively stable in water and soil. Under laboratory aerobic or anaerobic conditions, the half-life of paclobutrazol can be higher than one year.