Is this statement correct or not?

[Dusko]

Hi all,
I had a discussion today with one of my customers.

He claims that 99% of all aquatic plants uptake nutrients like NPK and traces, exclusively through the root system and NOT with leaves.
Leaves, he said, uptake only CO2 and light.

As well as that, he said that plants CAN'T uptake any other form of C except as CO2.
We were discussing the organic C, like Easy Carbo and Excel, and he claims that they, in touch with water become CO2!

Are these statements correct???

Thanks a million.

Kind regards, Dusko.

 

[VaughnH]

No, they are not correct. If the first one was correct no one could grow healthy plants in a neutral substrate with EI fertilizing. And if the second were true Excel would not work as it obviously does. Plants take nutrients from where ever they can, the roots or the leaves or both.

 

[Tom Barr]

Dusko, this person is very wrong(to the point of painfully so).

I can give you several references, that clearly show what they claim to be FALSE.
I can also give references which lead some hobbyist believe such mumbo.

I think the Cedergreen and Madsen paper is pretty obviously clear and a good paper(and they are close to you folks).

Madsen, T.V., Cedergreen, N. 2002, 'Sources of nutrients to rooted submerged macrophytes growing in a nutrient-rich stream', Freshwater Biology, vol. 47, pp. 283-291.

They cut the roots off the plants............they still had the same relative growth rates even without roots...so....how can that be unless they get their nutrients from the leaves and stems?

Magic?

http://person.au.dk/en/[email protected]/pub

Plant's use of HCO3.......
This is well known.

Madsen, T.V., Maberly, S.C. 2003, 'High internal resistance to CO2 uptake by submerged macrophytes that use HCO3 -: measurements in air, nitrogen and helium', Photosynthesis Research, vol. 77, pp. 183-190.

ScienceDirect - Aquatic Botany : Use of bicarbonate ions as a source of carbon in photosynthesis by Callitriche hermaphroditica

ScienceDirect - Aquatic Botany : The metabolic cost of bicarbonate use in the submerged plant Elodea nuttallii

Submersed plants are subjected to constraints on photosynthesis in comparison to terrestrial plants. Owing to the 104x slower diffusion rate of carbon dioxide in water than air, efficient use of bicarbonate ion as a dissolved inorganic carbon source is an important competative characteristic for existence in the aquatic environment. Hydrilla can use free carbon dioxide from surrounding water when it is available and can switch to bicarbonate utilization when conditions favors its use i.e., high pH and high carbonate concentration (Salvucci and Bowes 1983). These conditions occur in highly productive waters during warm water and high photosynthesis conditions. Under these conditions, hydrilla can also switch to C4-like carbon metabolism, characterized by low photorespiration, and inorganic carbon fixed into malate and aspartate (Holaday and Bowes 1980).

Regards,
Tom Barr

 

[Tom Barr]

No, they are not correct. If the first one was correct no one could grow healthy plants in a neutral substrate with EI fertilizing. And if the second were true Excel would not work as it obviously does. Plants take nutrients from where ever they can, the roots or the leaves or both.

What the plant eventually takes in and converts is still CO2..............HCO3 or Excel..........but this is internal, not external, sometimes at the cell surface(Excel), or both with bicarb.........

But plants can live on "sugar" in culture also.......they do not need to make their own if it's supplied.........

Regards,
tom Barr

 

[Sintei]

what doeas excell actually do? The info is pretty vague on this subject. Glutaraldehyde etc.

 

[paludarium]

What the plant eventually takes in and converts is still CO2..............HCO3 or Excel..........but this is internal, not external, sometimes at the cell surface(Excel), or both with bicarb.........

But plants can live on "sugar" in culture also.......they do not need to make their own if it's supplied.........

Regards,
tom Barr

Do you mean that aquatic plants will utilize Excel dirrectly witout any help from the bacteria in the substrate or in the filter?

Regards,
Erich

 

[Tom Barr]

what doeas excell actually do? The info is pretty vague on this subject. Glutaraldehyde etc.

I am the world's expert actually.
They have no such studies of the mechanism of action as a herbicide nor as a carbon source.

I'm the first to do so......even SeaChem cannot do this.
I'll leave the study for other's to dig up and if Seachem choses to market the results.
I'm not sure being not vague will really help any aquarist.

Paludarium,
The plants take Excel in at the cell surface, no, there's no secondary effect from bacteria(well, some, I suppose). what I measure is in sterile culture(no bacteria or decomposition)

Regards,
Tom Barr

 

[paludarium]

I am the world's expert actually.
They have no such studies of the mechanism of action as a herbicide nor as a carbon source.

I'm the first to do so......even SeaChem cannot do this.
I'll leave the study for other's to dig up and if Seachem choses to market the results.
I'm not sure being not vague will really help any aquarist.

Paludarium,
The plants take Excel in at the cell surface, no, there's no secondary effect from bacteria(well, some, I suppose). what I measure is in sterile culture(no bacteria or decomposition)

Regards,
Tom Barr

Hi,

for a long time I assumed that excel or glutaraldehyde were metabolized by the bacteria and then were biotransformed to CO2. SpringerLink - Journal Article I also supposed it was CO2 that the plants take in. So Seachem is correct about the mechanism that the plants uptake excel dirrectly without decomposing it into CO2, right?

Regards,
Erich

 

[Tom Barr]

Hi,

for a long time I assumed that excel or glutaraldehyde were metabolized by the bacteria and then were biotransformed to CO2. SpringerLink - Journal Article I also supposed it was CO2 that the plants take in. So Seachem is correct about the mechanism that the plants uptake excel dirrectly without decomposing it into CO2, right?

Regards,
Erich

Well, if there is no bacteria, it's kind of hard to have secondary decomposition
Isolated studies that do not have plants in the system(such as the above), really do not answer much.

That study has mainly a sediment's effect on the chemical.
Bacteria tend to go after those two ends of the molecule, same with plants.
This detoxifies the chemical.
Then, it's taken it and processed.
Note: this is speculation, but the chemical is well known and C14 studies can show what and where, as well as the products of oxidation that are radio labeled.
Unless you are a certified research facility, no radioactive products are available.

I am and have access to such a lab here at UCD and at the weed lab here, as well as the Rice Herbicide lab and perhaps a couple of others outside my committee.
C14 has a long 1/2 life, so we do not like it it getting loose.

Plants can take it in directly, but they chop it up.
Then use it.

Give me a few months. I'll know and confirm then.
I plan on using Egeria and Hydrilla which Excel acts as a herbicide and then Myriophyllum which is able to process Excel and use it as a carbon source.
We do this submersed obviously.

Regards,
Tom Barr

 

[swylie]

You'll announce it here when you publish that study, right?

 

[Tom Barr]

It'll be in UCD's archives.

Regards,
Tom Barr

 

[paludarium]

Well, if there is no bacteria, it's kind of hard to have secondary decomposition
Isolated studies that do not have plants in the system(such as the above), really do not answer much.

That study has mainly a sediment's effect on the chemical.
Bacteria tend to go after those two ends of the molecule, same with plants.
This detoxifies the chemical.
Then, it's taken it and processed.
Note: this is speculation, but the chemical is well known and C14 studies can show what and where, as well as the products of oxidation that are radio labeled.
Unless you are a certified research facility, no radioactive products are available.

I am and have access to such a lab here at UCD and at the weed lab here, as well as the Rice Herbicide lab and perhaps a couple of others outside my committee.
C14 has a long 1/2 life, so we do not like it it getting loose.

Plants can take it in directly, but they chop it up.
Then use it.

Give me a few months. I'll know and confirm then.
I plan on using Egeria and Hydrilla which Excel acts as a herbicide and then Myriophyllum which is able to process Excel and use it as a carbon source.
We do this submersed obviously.

Regards,
Tom Barr

Hi,

I've been using 2.5% glutaraldehyde as the sole carbon source in my planted tank sicne Feb. The plants were growing well in the past 37 weeks.

Four weeks ago I cleaned my canister filter and put a branchlet of sea almond tree, Terminalia catappa, into the aquarium. To my surprise, the growth rates of most stem plants reduced dramatically. Some of the Rotala macrandra even showed broken old leaves and stunted, which were probably due to insufficient CO2 or carbon sources. I speculated that glutaraldehyde penetrated the reduced biofilm in the filter and killed the bacteria, in addition, the sea almond tree secreted some chemicals like tannins that also reduced the growth of the bacteria.

Ten days ago I romoved the branchlet and did an 80% water change. Well, the plants regained their previous growth rates! I just wonder, without any help from the bacteria, how fast do the planst take in the glutaraldehyde or excel dirrectly and chop it up?

Regards,
Erich

 

[Tom Barr]

Hard to say what did what.

Simply cleaning filters can do this (or a lack of not doing the cleaning).
Almond leaves might have some effect.

Who knows without isolating it.

Regards,
Tom Barr