Which scenario results in most thickening of base?

[eeeealmo]

Succinctly put, when trying to thicken a trunk or a branch, does ramification on the branch help or hinder the thickening? Should ramification be removed while one shoot is allowed to elongate, or should everything be allowed to grow free, even if it results in ramification?

I ask this because Bjorn alluded scenario A (below) resulting in the most thickening of the trunk/base and was unsure why that was the case. Thanks!

p.s. Sorry for poor drawing quality. Drawing with a mouse is awful.

 

[Cadillactaste]

Honestly...if Bjorn offered advice. We can't reason why he chose a specific one. Your best bet would ask one simple word...why? To him...to understand his reasoning.

 

[eeeealmo]

Honestly...if Bjorn offered advice. We can't reason why he chose a specific one. Your best bet would ask one simple word...why? To him...to understand his reasoning.

Well it's more so that I want to make sure I understood him correctly, and to see if there are any nuances in this idea.

Or, if 1 singular shoot elongating will always thicken the base faster than with any additional ramification.

 

[Forsoothe!]

All the leaves above a given point on a tree feed everything below that point. The larger the number of leaves and/or the total leaf surface feeds larger. 100 leaves feeds twice as much growth as 50 leaves, ad infinitum.

 

[Shogun610]

It depends on what species you’re trying to thicken. Growing out a sacrificial leader or sacrificial branch will always result in growth, along with methods of growing in ground, colander or grow bag in ground. The trick is to control the roots while thickening a trunk for growth , while also promoting development of side shoots / branches that will eventually be your silhouette for design once the sacrificial leader is cut off after desired trunk size is met.

 

[Mikecheck123]

Scenario A is clearly faster in practice.

I'm guessing that it's simply because the resulting tree has more plant mass above the base, which requires a thicker cambium to feed.

 

[eeeealmo]

All the leaves above a given point on a tree feed everything below that point. The larger the number of leaves and/or the total leaf surface feeds larger. 100 leaves feeds twice as much growth as 50 leaves, ad infinitum.

This is what I'd have thought as well, hence my confusion when Bjorn mentioned removing side branches on a developing maple to allow a singular apex to elongate to thicken faster.

 

[Deleted member 32750]

I suggest reading this and the answer may make more sense to you. https://courses.lumenlearning.com/wmopen-biology2/chapter/plant-growth/

But to summarize, the plant hormone Auxin is responsible for the growth in trees and is contained in meristematic tissue in the shoots. shoots grow because the the shoot apical meristem is adding tissue behind the shoot and propelling the shoot higher towards the sun (phototropism).

Scenario A results in all of that new tissue being created in a straight line down the the trunk (i.e faster growth)

In the other scenarios there is shoot apical meristematic tissue in the tips of the branches which will cause the branches to thicken as well as the whole base but it wouldn't be as fast or as dramatic as scenario A

 

[eeeealmo]

I suggest reading this and the answer may make more sense to you. https://courses.lumenlearning.com/wmopen-biology2/chapter/plant-growth/

But to summarize, the plant hormone Auxin is responsible for the growth in trees and is contained in meristematic tissue in the shoots. shoots grow because the the shoot apical meristem is adding tissue behind the shoot and propelling the shoot higher towards the sun (phototropism).

Scenario A results in all of that new tissue being created in a straight line down the the trunk (i.e faster growth)

In the other scenarios there is shoot apical meristematic tissue in the tips of the branches which will cause the branches to thicken as well as the whole base but it wouldn't be as fast or as dramatic as scenario A

Perfect. Thank you!

 

[Adair M]

Trunk thickening is NOT primarily affected by leaf mass!!!

It’s a commonly held mis-belief.

Trunks thicken by hormonal action. Most trees are genetically programmed to grow tall, to get to the sunlight (up) faster than their neighbors. To grow tall, the trunks have to be stout. A tall skinny trunk is too weak, and is subject to breaking or bending over if overly stressed.

The tallest actively growing bud or shoot on the tree produces the most auxin. Auxin flows downward from the growing tip to the roots. This glow of auxin stimulates the production of another hormone (sorry, I can’t remember the name, but I bet @0soyoung knows!) that stimulates wood growth. This is how trunks grow fatter than branches. It’s the auxin flow from the tip down to the roots.

I have highly ramified trees that have not produced much if any trunk thickening for years! That’s because I prevent active terminal growth, thus limiting the auxin. No auxin, no fattening!

To answer your question, to fatten the trunk, choose Option A. Once you get the low base fat, do a hard prune to shorten, choose a new twig to be the new leader, and let it grow unimpeded.

Repeat as necessary.

This is how you get trunks with girth and taper. This tree:



Has a base about 8 inches at the nebari. It only about 16 inches tall.

At one time, it looked like one of these:



It was 15 feet tall!

 

[Adair M]

This is what I'd have thought as well, hence my confusion when Bjorn mentioned removing side branches on a developing maple to allow a singular apex to elongate to thicken faster.

Forsoothe is absolutely wrong!

 

[0soyoung]

The tallest actively growing bud or shoot on the tree produces the most auxin. Auxin flows downward from the growing tip to the roots. This glow of auxin stimulates the production of another hormone (sorry, I can’t remember the name, but I bet @0soyoung knows!) that stimulates wood growth. This is how trunks grow fatter than branches. It’s the auxin flow from the tip down to the roots.

Ethylene causes enhanced radial growth.
Growth of wood
Growth of bark

When branches are wiggled around (say whips in the wind), living cells in the areas where they are flexed are damaged which induces the production of

ethylene
and the stem thickens faster than elsewhere.

An excess of auxin also induces the production of

ethylene

We observe this at the upper edge of air layer girdles (where auxin piles up)



Exactly why the highest branch tip winds up in charge for the whole tree (which is true for most species, but certainly for pines) is caused by something else. The phenomenon is called 'correlated inhibition' and the last I saw was that it is suspected to be due to strigalactone (welcome to the bleeding edge of modern plant physiology).