Quote:
Originally Posted by treevet  Maybe the wall does not require to have callus but callus is part of the wall (including chems within). Where the chems fail (through attack) their is no callus. Success of invading pathogens define the wall.
You must lay up in bed at night staring at the ceiling thinking about this shit. Just keep trees healthy and make an appropriate NTP cut and everything else is money. |
I apologize for that last paragraph, I do not want to be like that.
I d like to add to last post. "Wall 4 is a boundary that separates wood present at time of wounding from the new wood that continues to form."
Callus is not wood. It has little or no lignen.
I d like to quote a section of Shigo "Tree Pruning"
"After wounds injure wood in living trees, a long series of physiological and anatomical events take place. The first response is an electrical one. Then chemical changes take place. Stored energy reserves in living parenchyma cells are converted through long biochemical pathways to substances that are inhibitory to most wood inhabiting microorganisms. The substances form a boundary that resists the spread of microorganisms into the wood. The boundary also defends the liquid transport, energy storage, land mechanical support systems of the tree. This boundary is the reaction zone.
Then the cambial zone about the wound resumes growth, the newly formed cells differentiate to form a boundary that separates the wood present at the time of injury from new wood that will form after the boundary is completed. That separating boundary is called the barrier zone.
On the margin of the wound, the cambial zone produces large, undifferentiated, nonlignified, homogeneous cells called callus. As callus production continues, some of the cells begin to differentiate to form transport cells-vessels, tracheids- and fibers. When these cells become lignified, then we have woundwood.
It does not say that after the barrier zone is formed then (then) callus is formed. It may be formed at the same time and be part of the zone. Also I have read that callus contains inhibitory chemicals, too, giving credence to the possibility that it may be an aspect of wall 4 (when one forms when injury occurs as none may occur if energy reserves are low or nonexistent).
PS I could lay up at night thinking about this
