Plants self-regulate uptake of ions; they control it, not us, unless we overdo ferts - Cannabis Botany and Advanced Growing Science - International Cannagraphic Magazine Forums

spurr · 10-02-2010, 07:09 PM

Plants can self-regulate uptake of N, P, Ca, Mg, etc, etc. Thus they control what they absorb by the amounts of certain amino acids in the phloem. For N, plants can not self-regulate uptake of ammoniacal N, which is why ammoniacal N can cause phtyotoxicity (if the plant can't move enough sugar to the roots to convert the ammoniacal N).

The way it works is uptake of nitrate (for example) means increased amino acids in plant because the ions (ex. nitrate) are converted to amino acids inside the plant, thus once a critical level of amino acid is present in phloem the plant will reduce/stop uptake of nitrates. And AFAIK, if one adds too much nitrates to the water they can bypass the plant self-limitation due to osmotic factors, thus causing phytotoxicity.

I am currently study the effects of various mixes of GH flora series ferts upon microbes in aerated compost tea and upon microbes from soil extracts. I am studying the GH mix's of G3h's formula, the Lucas formula and of my own GH formula of 6ml/6ml/6ml (G/M/B) with 5 ml Calmag+, 2.5 ml ProTekt, 5 ml kelp extract and 5 ml hydrolyzed fish. I do not use chem ferts to grow cannabis, but there is much debate about chem ferts effects upon soil biota, thus I hope to get some data and show what is, and is not happening to microbes from application of chem ferts.

Because I use amino acids and proteins from the kelp and hydrolyzed fish (aka fish hydrolysate) I thought I should post some info about how plants can use those sources of DON (Dissolved Organic Nitrogen) directly without microbes breaking them down into ions:

"Nutrient Media for Plant Tissue Cultures"
University of Florida, Horticultural Science Dept.
https://www.hos.ufl.edu/mooreweb/Tiss...Medium%20I.doc

Quote:

One of the first decisions that must be made when developing a tissue culture system is what medium to use. Nutrient media for plant tissue culture are designed to allow plant tissues to be maintained in a totally artificial environment. Many different tissue culture media have been developed, but only a few have found wide-spread use, e.g. MS (Murashige and Skoog, 1962). SH (Shenck and Hildebrandt), and Gamborg's B5. One of the most successful media, devised by Murashige and Skoog (Murashige and Skoog, 1962) was formulated by analyzing the inorganic components in tobacco plants and then adding them to medium in amounts similar to those found in the plants. Not only did they find that the ions themselves were important, but the forms in which the ions were supplied were critical as well.

In addition to mineral elements, the macro- and micronutrients that are similar to what is found in fertilizers, nutrient media also contain organic compounds such as vitamins, plant growth regulators, and a carbon source.

...

Nitrogen may also be added to medium in an organic form, as amino acids such as proline or glutamine, hydrolysates (such as casein hydrolysate), or, as above, as organic acids. Organic nitrogen is already reduced, i.e. in the form in which most nitrogen exists in the plant, and so may be taken up more readily than inorganic nitrogen. The organic forms are often added to media that do not contain ammonium. However, almost always, some inorganic nitrogen is present.

10-02-2010, 07:19 PM

Per your request I edited the thread, spurr.

ibjamming · 10-02-2010, 09:03 PM

Forgive my ignorance...my botany class was 30+ years ago...

Are ALL essential's picked up that way? By attaching to another molecule? Like hemoglobin for o2 with animals? All amino acids? All different? Does the root hair act like lung avoli (sp)? I need to read more about plants!

spurr · 10-02-2010, 09:39 PM

Quote:

Originally Posted by Guest

Per your request I edited the thread, spurr.

spurr · 10-02-2010, 09:40 PM

I am not sure what you are asking, I wrote this thread just as a FYI for folks because most ppl do not know plants control uptake of many ions. Many growers think they are in control of what the plant takes in, because they are the ones providing ferts, but that's not the case unless they provide a lot of ions which can bypass the plant regulation and cause phytotoxicity. Many growers think that if they put ions in the water (ex. hydro) the plant will take up the soluble ions no matter what, but that's not the case, plants self-limit uptake via. levels of amino acids in phloem.

Also, of note, is that ammonium (the main type of ammonicial-N ion found in cannabis ferts) will hinder uptake of nitrates. And cannabis, along with many plants, prefer a majority of N to come from nitrates. When ammonium is first taken up by roots it helps uptake of nitrate, but after a few hours the ammonium hinders uptake of nitrates. My hypothesis is that ammonium increases the amino acid level in phloem which triggers the plant to reduce uptake of nitrates.

In general plants, grass and bacteria prefer most N to be nitrate; and trees, shrubs and fungi prefers most N to be ammonium.

Greyskull · 10-02-2010, 09:45 PM

is this why canna suggests using equal parts of their coco A/B thru veg and flower and explain that the plants will take what they need from the nutrient solution?

ive got to look for where i saw it... it was on a site of Canna's i am sure but i dont know if its now a restricted site for me to visit....

spurr · 10-02-2010, 09:56 PM

Quote:

Originally Posted by Greyskull

is this why canna suggests using equal parts of their coco A/B thru veg and flower and explain that the plants will take what they need from the nutrient solution?

Not sure, I have not seen that claim, but it sounds like they are referring to what I am writing about. An exception is ammonicial-N, mostly provided by chem ferts as ammonium. Plants can't self-regulate uptake of ammonium. That is why if you add 25 ppm of ammonium and 25 ppm of nitrate to a hydro rez the ammonium will be used to near 0 ppm while nitrates will not (during the same time frame). The plant limits uptake of nitrates but not ammonium. Also, plants can more efficiently/quickly absorb ammonium than nitrates.

Plants must be able to move enough sugar into the roots (from photosynthesis) to convert ammonicial-N (like ammonia NH3- and ammonium NH4-) into useful forms within the roots. If plants can not move enough sugar into the roots fast enough to convert the absorbed ammonicial-N the roots will burn causing phytotoxicity. This is another reason why ammonicial-N makes up only a small fraction of the N in chem ferts. And of that small fraction of ammonicial-N in chem ferts most (if not all) is in the from of ammonium.

Quote:

ive got to look for where i saw it... it was on a site of Canna's i am sure but i dont know if its now a restricted site for me to visit....

If you find it let us know.

Greyskull · 10-02-2010, 10:01 PM

i know i read it and i know it was something from Canna ...
it was unique and that why it stick with me... and thats why i was comfortable using a 2 part/1 part food thruout the whole entire grow - becasue the plants ability to pull out what it needs/wants for growth.

I AM ON A MISSION...

spurr · 10-02-2010, 10:25 PM

Quote:

Originally Posted by Greyskull

i know i read it and i know it was something from Canna ...
it was unique and that why it stick with me... and thats why i was comfortable using a 2 part/1 part food thruout the whole entire grow - becasue the plants ability to pull out what it needs/wants for growth.

I AM ON A MISSION...

I am looking forward to what you find. You seem to have a very good grasp of this matter, and you and I agree 100%: let the plant take what is wants, don't overfeed

I wrote a long and very well referenced thread elsewhere a while ago about cannabis tissue assays for nutrients and why less P is needed than is most often used, etc. I could post up some info in a different thread someday if your interested.

Mudita · 10-02-2010, 10:53 PM

interesting to see it stated, but i think i knew it intuitively.
To me that's the whole point of balancing a nutrient solution so that elements are in a proper ratio, and of running lower concentrations. As long as everything is there in ratios that don't cause lockout and within the pH range that doesn't lock anything out, the plant can take what it needs as it needs it.

BTW,I read thru the paper https://www.hos.ufl.edu/mooreweb/Tiss...Medium%20I.doc
and it does mention that plants can absorb nitrogen in an organic form, but it does not say 'how plants can use them directly without being broken down by microbes first' it only states that they can.

would you please do us the favor of posting up the data concerning precisely how?

10-02-2010, 07:19 PM	#2
Guest 18340 Guest Posts: n/a	Per your request I edited the thread, spurr. Last edited by Guest; 10-02-2010 at 08:34 PM..
	Quote

10-02-2010, 09:40 PM	#5
spurr Banned Join Date: Aug 2010 Location: https://www.scirus.com/ & https://www.google.com/schhp?hl=en Posts: 2,431	I am not sure what you are asking, I wrote this thread just as a FYI for folks because most ppl do not know plants control uptake of many ions. Many growers think they are in control of what the plant takes in, because they are the ones providing ferts, but that's not the case unless they provide a lot of ions which can bypass the plant regulation and cause phytotoxicity. Many growers think that if they put ions in the water (ex. hydro) the plant will take up the soluble ions no matter what, but that's not the case, plants self-limit uptake via. levels of amino acids in phloem. Also, of note, is that ammonium (the main type of ammonicial-N ion found in cannabis ferts) will hinder uptake of nitrates. And cannabis, along with many plants, prefer a majority of N to come from nitrates. When ammonium is first taken up by roots it helps uptake of nitrate, but after a few hours the ammonium hinders uptake of nitrates. My hypothesis is that ammonium increases the amino acid level in phloem which triggers the plant to reduce uptake of nitrates. In general plants, grass and bacteria prefer most N to be nitrate; and trees, shrubs and fungi prefers most N to be ammonium.
	Quote 1 members found this post helpful.

10-02-2010, 09:45 PM	#6
Greyskull Twice as clear as heaven and twice as loud as reason Join Date: Mar 2010 Location: Maui NO KA 'OI Posts: 3,381	is this why canna suggests using equal parts of their coco A/B thru veg and flower and explain that the plants will take what they need from the nutrient solution? ive got to look for where i saw it... it was on a site of Canna's i am sure but i dont know if its now a restricted site for me to visit.... __________________ This body holding me reminds me of my own mortality. Embrace this moment. Remember. We are eternal. All this pain is an illusion.
	Quote

10-02-2010, 10:01 PM	#8
Greyskull Twice as clear as heaven and twice as loud as reason Join Date: Mar 2010 Location: Maui NO KA 'OI Posts: 3,381	i know i read it and i know it was something from Canna ... it was unique and that why it stick with me... and thats why i was comfortable using a 2 part/1 part food thruout the whole entire grow - becasue the plants ability to pull out what it needs/wants for growth. I AM ON A MISSION... __________________ This body holding me reminds me of my own mortality. Embrace this moment. Remember. We are eternal. All this pain is an illusion.
	Quote 1 members found this post helpful.

10-02-2010, 09:03 PM	#3
ibjamming Banned Join Date: Oct 2007 Posts: 1,617	Forgive my ignorance...my botany class was 30+ years ago... Are ALL essential's picked up that way? By attaching to another molecule? Like hemoglobin for o2 with animals? All amino acids? All different? Does the root hair act like lung avoli (sp)? I need to read more about plants!
	Quote

10-02-2010, 10:53 PM	#10
Mudita Member Join Date: Jan 2010 Location: Where life is the way is should be Posts: 104	interesting to see it stated, but i think i knew it intuitively. To me that's the whole point of balancing a nutrient solution so that elements are in a proper ratio, and of running lower concentrations. As long as everything is there in ratios that don't cause lockout and within the pH range that doesn't lock anything out, the plant can take what it needs as it needs it. BTW,I read thru the paper https://www.hos.ufl.edu/mooreweb/Tiss...Medium%20I.doc and it does mention that plants can absorb nitrogen in an organic form, but it does not say 'how plants can use them directly without being broken down by microbes first' it only states that they can. would you please do us the favor of posting up the data concerning precisely how?
	Quote