What is the use of knowing these laws?
Understanding how a tree or shrub works makes it possible to intervene more accurately, planting pruning…
These few laws are universal and have virtually no exceptions.
In these explanations the word sap is not only understood as the liquids circulating in plants, but also as the vigor of the tree with which it is directly associated.
The main laws
The sap circulates in a tree according to the same principles as the circulation of any liquid, such as water for example. It is thus possible to evaluate the pressure drops of each branch.
1. The sap (vigor) is always attracted by the highest point of the tree (the only apparent exception, but which responds to the principles of osmosis. The raw sap rises, the elaborate sap descends). The terminal bud secretes a hormone which naturally slows down its competitors. So when we remove it by pruning we generate disordered reactions from the rest of the plant and in particular from the eyes located nearby.
2. It flows better when the section is big
Water suffers less “head loss” in large pipes
3. On the other hand, the distance increases the “head loss”.
4. Elbows and sharp turns are also pressure drop points, the straight line being the most profitable, in the absence of large radius curves.
5. Light being the main source of energy for chlorophyllous plants, it attracts the growth of branches which naturally orient themselves towards it.
– Jacques Ginet
Other laws complement these first principles:
C/N balance
Flowering and therefore fruiting occurs when the plant has reached a physiological equilibrium where the absorption of carbon by the mass of foliage compensates for the availability of nitrogen available and stored in the soil (a form of equilibrium C /NOT).
Severe pruning will force the tree to re-foliage instead of starting to bear fruit, so avoid trigemme pruning.
The strength of the tree’s frame.
Of course, the larger the branch section, the stronger it is, capable of bearing fruit.
But the insertion of the branch in its support (trunk or main branch) has a very important role and you should know that the more the angle of insertion is open (close to 90°) the more the fixation of the branch is solid.
Also important, the depth of the insertion is paramount, the closer the age of the inserted branch to the age of the supporting branch (trunk, main branch), the stronger this weld. We speak of anchoring the branch, the branch.
– Jacques Ginet
In summary,
Removing the terminal bud is not a trivial act because this act will generate a certain disorder in the growth of the tree for years and weaken the solidity of its crown in the long term. It will then be necessary to establish compensation actions.