Winter and the Relationship Between Leaves and Roots, etc.

[tmjudd1]

If I'm understanding things correctly... the leaves nourish the roots, and in exchange for the favor, the roots respond by nourishing the leaves. Sounds like a sweet relationship, however. What happens during the winter when the leaves aren't getting as much sun, etc.? I'd suspect that everything balances out, naturally, and the relationship continues, only at a much slower rate, however. (Question #1) What about 'Deciduous' trees with 'no' winter foliage remaining to offer the roots anything? Should these types of trees 'NOT' be fertilized, at all, during the winter... in order to keep things in their proper, natural balance? (Question #2) What about 'Evergreens' who still have foliage, but less sunlight, and less nourishment for the roots? Should they be fed 'something', during the winter... seeing hows they still have leaves?
The reason for me asking these questions is due to lots of mixed info. Some folks say to not feed at all, only keep watered. Others say to feed 0-10-10. Others yet, recommend 20-20-20 claiming that the trees will store the excess nitrogen for the next growing season, and everything else will promote aggressive root growth during the off-season. Personally... "I'm now confused as hell!" I'm in zone 8a, for whatever that's worth...

 

[Gustavo Martins]

Sun drives photosynthesis which produces the ‘food’ that plants need. Less sun, less photosynthesis, less food, less growth. Since growth is minimal, fertilisation which you could think of as a supplement, won’t do much. Also, since plant evapotranspiration is minimal, there won’t be much uptake anyways. As such, there’s little role for winter fertilisation. Even ifthey are active, they likely won’t need it since They produce their own food.

 

[Shibui]

Nutrients travel from roots up the trunk along with water. Water only moves up the tree as it evaporates from the leaves so dormant deciduous trees can't move water. Nutrients (N,P,K, and other micro nutrients) are converted to sugars by photosynthesis in the leaves then moved back around the tree to wherever they are needed. No leaves means no photosynthesis so nutrients cannot be converted.

Even ifthey are active, they likely won’t need it since They produce their own food.

Fertiliser supplies the basic nutrients that are used to make plant 'food' Plants cannot make 'food' unless they have access to the nutrients provided by fertiliser.
No leaves means that fertilising deciduous trees in winter is a complete waste of time and resources. Worse, leftover nutrients are washed away and end up polluting rivers and groundwater.
Evergreen plants can still take up and use nutrients because they still have leaves. In recent years we showed that feeding pines through winter made a big difference in subsequent spring and summer growth. Our climate is quite mild compared to much of USA so I'm not certain how evergreen trees in really cold climates manage nutrients in winter.

0-10-10 is supposed to prepare plants for winter by slowing growth and hardening cells, etc. I don't think it is supposed to be used all winter. In my climate there is no need for winter hardiness so we don't switch to low N before winter. My trees get the same fert any time of year. Dallas is 8a so probably just a bit colder than here. You may also not need to promote 'winter hardiness' and maybe some fert over winter will do your evergreens some good. A trial would be the way to go to find out.
20-20-20 and other higher N fertilisers are designed for growth. Trees cannot store nitrogen directly. It must be converted in the leaves first so without leaves excess N is wasted but evergreens may be able to utilise some fert.

Take home message: Don't feed deciduous plants when they have no leaves. Reduced levels of fert may be beneficial for evergreens in some (warmer) climates.

 

[Wires_Guy_wires]

Another take home message:
Photosynthesis products are fuel.
Nutrients are the building blocks that can only be used when there is fuel to do so.

Keeping those two separated in your mind will help a lot in figuring stuff out. A lot of people tend to interchange the two in written text.

 

[Gustavo Martins]

Fertiliser supplies the basic nutrients that are used to make plant 'food' Plants cannot make 'food' unless they have access to the nutrients provided by fertiliser.

This is actually incorrect. Plant food is glucose (C6H12O6) and they don’t need anything other than water and CO2 plus the energy of the sun to make it.

 

[0soyoung]

• Energy (i.e., carbohydrates) are stored as starch grains in the vacuoles of living cells distributed throughout the tree. These starch grains can be converted back into sugar 'as needed'.
• Cellulose, which is the primary constituent of wood, is just a sugar polymer. IOW glucose is more than food.
• ATP is the basic currency of 'energy' in living cells. It is made by an enzymatic reaction. Enzymatic reaction rates decline with temperature.

... discuss.

 

[Zach Smith]

Plants are very complex organisms (as all are). The fact that they need "NPK" fertilizer plus a lot of trace minerals is a clue. Dormancy is also a lot more complex than it appears at first blush.

 

[bonsaichile]

Nutrients (N,P,K, and other micro nutrients) are converted to sugars by photosynthesis in the leaves

That is simply NOT TRUE. Sugars (and carbs in general) DO NOT contain N, P, or K. Sugars are made of carbon hydrogen and oxygen atoms in different combinations. To say that a tree "transforms" N, P or K into sugars is false and misleading. That is not what fertilizers work.

 

[Kendo]

Nutrients (N,P,K, and other micro nutrients) are converted to sugars by photosynthesis in the leaves then moved back around the tree to wherever they are needed.

6CO2 _6H2O+light"e"=C6H12O6+O2

I dont see the NP OR K in Photosynthesis.

Hai

 

[Kendo]

• 
  
• ATP is the basic currency of 'energy' in living cells. It is made by an enzymatic reaction. Enzymatic reaction rates decline with temperature.

... discuss.

ATP is the result of Calvin Cycle, not only enzyme reaction. Hai


he steps in the cycle are as follows:

1. Grab: A five-carbon carbon catcher called RuBP (Ribulose bisphosphate) catches one molecule of carbon dioxide and forms a six-carbon molecule.

2. Split: the enzyme RuBisCO (with the energy of ATP and NADPH molecules) breaks the six-carbon molecule into two equal parts.

3. Leave: A trio of carbons leave and become sugar. The other trio moves on to the next step.

4. Switch: Using ATP and NADPH, the three carbon molecule is changed into a five carbon molecule.

5. The cycle starts over again.

 

[Kendo]

dd

 

[Kendo]

Essential thought for information bonsai is location. SOme is saying, but is not same as you. This we must thinking about sources. Hai

We cannot just saying winter is 1 action. Hai

If we using fertilizer on something late season, we can kill or make sick for future. This can make the problems. Hai

I thinking best information is coming from experience and time your location and style growing. each is different, even if small. Hai

Another consideration is education. We take information from Sensei for learning. Hai

Thank you.

Akio/Kendo San

Thank you.

 

[0soyoung]

ATP is the result of Calvin Cycle,

No. It is made by ATP-synthase.
It powers the Calvin cycle. Otherwise, yes; this is how photosynthesis works.

Now, what about the Kreb's cycle?
Where does it happen vesus where does the Calvin cycle occur?

 

[Kendo]

No. It is made by ATP-synthase.
It powers the Calvin cycle.

Now, what about the Kreb's cycle?
Where does it happen vesus where does the Calvin cycle occur?

Sorry morning is early for me. I make thinking backward. Hai

This is in the Mitochondria matrix.

 

[Kendo]

For consideration of NPK

• Every amino acid contains nitrogen.
• Every molecule making up every cell's membrane contains phosphorous (the membrane molecules are called phospholipids
• Potassium makes up 1 percent to 2 percent of the weight of any plant and, as an ion in cells, is essential to metabolism.

^Thank you.

 

[0soyoung]

Sorry morning is early for me. I make thinking backward. Hai

This is in the Mitochondria matrix.

And maybe we should also say that every living cell has mitocondria?

Making inferences, one might think that cells in roots might be warm when the rest of the plant (above ground) is cold. So roots could grow when the rest of the plant is dormant, using stored starch as fuel and material to grow.

But wait, wouldn't they need some minerals to make more cells?

 

[Wires_Guy_wires]

• Energy (i.e., carbohydrates) are stored as starch grains in the vacuoles of living cells distributed throughout the tree. These starch grains can be converted back into sugar 'as needed'.
• Cellulose, which is the primary constituent of wood, is just a sugar polymer. IOW glucose is more than food.
• ATP is the basic currency of 'energy' in living cells. It is made by an enzymatic reaction. Enzymatic reaction rates decline with temperature.

... discuss.

If you really want to.. OK.
Energy is not always stored as starch and not in every location of the tree. There's glucose, fructose and a few other varieties of carbohydrates with similar functions that can be stored as well, it depends highly on the type of tree which type of carbohydrate it makes, how it's stored and where it's stored. Birches make different carbohydrates (xylitol, stored as liquid) than pines (glucose, stored as semi-solid or starch).
Cellulose is a sugar polymer, but it cannot be converted back to sugars by plants. To link glucose polymers, there are building blocks needed that can provide the enzymatic production. Without glucose as a source, and enzymes as katalysts, it's impossible to build structures. Both nutrients and fuel are needed. But.. Without the nutrients, glucose can still be made from existing processes, but it can't be processed into a structure if there's a lack of building blocks. I think together, we're covering almost the entire thing ;-)
Enzymatic reactions do not always decline with temperature, some increase exponentially. I've done a whole load of enzymatic reactions, many of which take place at below room temperature (activity increases when temperatures drop, like glycerol production in plants and many other cold-related functions). Some enzymatic reactions require temperatures up to 74 degrees C, like the thermophilus bacteria living in Yellowstone, which enzymes are used in DNA synthesis. As temperatures drop, these enzymes become inactive. Yet, there's a whole army of enzymes that stop working at any temperature above 20 degrees C (room temp). These are usually winter- or dormancy-related, or sometimes even immune-related because some pathogens are specialized in low temperature colonization. Our plants wouldn't survive a winter if these reactions wouldn't take place at a faster rate compared to the pathogen. It is true that most growth related reactions increase activity when temperature rises, but not all of them and not always.
If you mention ATP, please keep in mind it's tiny little brother ADP. Without ADP, there's no bank account to exchange the currency. The P is for porn.. ehh.. Phosphate. ATP needs N and P out of the nutrient spectrum. A few of the building blocks.


@Kendo Plants do not have cell membranes. They have cell walls.

 

[0soyoung]

Plants do not have cell membranes. They have cell walls.

I still think plants have both. Animals lack cell walls.

Energy is not always stored as starch and not in every location of the tree.

There are those (with whom I've chosen to align my view) who argue that these sugars aren't really in storage --> linguistics. But you are very much correct.

From chemistry, enzymatic reactions monotonically increase with temperature; rates may saturate at high temperatures but never decline. However, there may be regimes in which an enzymatic reaction consumes the output of another. One reaction may proceed faster at low temperatures than the other that dominates at high. It may be that an enzyme (a) affects special sugars being produced and that its reaction rate saturates at a low temperature. Another enzyme (b) may consume these sugars, but its rate is much lower at these low temperatures. Then the product of (a) seemingly is only produced in a (possibly narrow) range of low temperatures.

There are also other processes that do decline with increasing temperature that lead to optimum temperatures for growth, like oxygenation. Oxygen is required for growth, but oxygen must (1) dissolve in water and (2) diffuse in water to get to/into the living cell. The solubility of oxygen declines with increasing temperature whereas its diffusivity increases. The oxygen demanded by metabolic processes also generally increases with temperature and largely determines at what temperature there is a maximum in growth rate.

... just discussing
Thanks.

 

[TN_Jim]

This is actually incorrect. Plant food is glucose (C6H12O6) and they don’t need anything other than water and CO2 plus the energy of the sun to make it.

Plants actually need an array of micro and macro nutrients to conduct photosynthesis. For example, potassium is essential in regulating turgor pressure needed to open/close stomata. No potassium, no CO2 intake. It’s not just a+b=c.

Is there any evidence that feeding in winter does ANY harm?...aside from being washed down the drain?

Especially given the nature of well draining bonsai soils, is it not better to have these nutrients around consistently for when the tree happens to begin wake up simply need them?
<—I think these things are really what this thread was in-part trying to get at as well. However, I’m seriously happy to simply enjoy this rare bnut deep dive into the ins/outs of photosynthesis. Watched, thanks.

 

[bonsaichile]

Plants actually need an array of micro and macro nutrients to conduct photosynthesis. For example, potassium is essential in regulating turgor pressure needed to open/close stomata. No potassium, no CO2 intake. It’s not just a+b=c.
View attachment 220789
Is there any evidence that feeding in winter does ANY harm?...aside from being washed down the drain?

Especially given the nature of well draining bonsai soils, is it not better to have these nutrients around consistently for when the tree happens to begin wake up simply need them?
<—I think these things are really what this thread was in-part trying to get at as well. However, I’m seriously happy to simply enjoy this rare bnut deep dive into the ins/outs of photosynthesis. Watched, thanks.

They do need those nutrients. But to say that they are "converted" into sugars is patently false