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In the garden: A happy oak (?)

Quercus rubra? I don't have an acorn, but perhaps the happy growing tips -- maybe Dromaius has another ____ tropic word, here -- will give clue.

All my close=ups of the Cinquefoil -- I really do believe that's what it is -- turned out lousy, alas. I'll try again letter.

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Submitted by Dromaius on

My tropic words are phototropism are geotropism which are growth toward the light, in response to gravity. Right now, the number of daylight hours and the the predominant color of the light, as well as the external temperatures and moisture conditions are all causing the plant to produce lots of auxins. Auxins promote vertical growth (apical dominance) and are in a push-me-pull-you regulatory relationship with cytokinins, which promote axillary growth.

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Submitted by nippersdad on


I had hoped to never hear those words again after the test.

Along with:
anion exchange capacity
cation exchange capacity
field capacity
gravitational potential
matric potential
osmotic potential
redox potential

You must have been the guy sitting at the front of the class. We were the ones in the back row saying, Please God, make it stop. :)

Submitted by lambert on

.... I want to say mechanism, but that's not the word, that cause a tree to grow toward its tips, and not all of its tips. This is, as I understand it, what pruning controls (beneficially to the plant).

Submitted by Dromaius on

Also, read this quote from my link:

"The apical bud produces an auxin (IAA) that inhibits growth of the lateral buds further down on the stem towards the axillary bud. It was first discovered that the plant hormone auxin likely regulates apical dominance in 1934"

Submitted by lambert on

Phrase-maker! More from that source:

When the apical bud is removed, the lowered IAA concentration allows the lateral buds to grow and produce new shoots, which compete to become the lead growth. Pruning techniques such as coppicing and pollarding make use of this natural response to damage to direct plant growth and produce a desired shape, size, and/or productivity level for the plant. The principle of apical dominance is manipulated for espalier creation, hedge building, or artistic sculptures called topiary.

And this is a really cool page I wish I had time right now to understand.

nippersdad's picture
Submitted by nippersdad on

I didn't mean to imply that Dromaius was in any way wrong, just that all of the chemistry involved in my horticulture classes were sheer drudgery, from my perspective.

He is absolutely right about the hormones involved. Knowledge of how they work is pretty critical when one is doing cuttings......