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ALToronto
Guest
And what's the germination rate in nature? Flasking is probably the one area where emulating nature is not the best practice.
Macroelements/microelements must be a costant ratio?
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And what's the germination rate in nature? Flasking is probably the one area where emulating nature is not the best practice.
Stone
Well-Known Member
Hi Kirk, Yes I agree with that. Perhaps ''optimum'' was the wrong word. My point was that we cannot use nutrient availability in nature to determine correct concentrations in the lab. Particularly when we are dealing with asmybiotic germination.
Eg: I often wonder just how much copper or zinc or whatever a twig epiphyte on the tip of a branch overlooking a revine recieves. No throughfall from the canopy only what is in rain or dust. Probably close to undetectable. Yet somehow they manage. We cannot use these tiny amounts with success in the flask (that I know of). Rather than optimum, maybe ''the best we have come up with so far''
Myxodex, good stories you tell, but you should be careful With eating mushrooms that you are not 100% familiar with. Not that they contain caesium (they still do), we got a lot of that from Tsjernobyl 29years ago and mushrooms are still full of the caesium. But as long as you do not eat it every day there is no worry.
Generally, at least in Norway, there has been a reluctancy in the population to eat mushrooms. Traditionally it has been regarded as dangerous and people do not take the risk. Nonsense of course if you know what you are doing. But there is one precaution, most of the poisonings in Norway happen with immigrants. Particularly from far east but also from eastern Europe. It seems that some of the common culinary mushrooms in Eastern Europe (does not grow here) are mixed up with a rather similar but poisonous species growing in Norway. So, be careful in new countries.
Generally, at least in Norway, there has been a reluctancy in the population to eat mushrooms. Traditionally it has been regarded as dangerous and people do not take the risk. Nonsense of course if you know what you are doing. But there is one precaution, most of the poisonings in Norway happen with immigrants. Particularly from far east but also from eastern Europe. It seems that some of the common culinary mushrooms in Eastern Europe (does not grow here) are mixed up with a rather similar but poisonous species growing in Norway. So, be careful in new countries.
They don't manage only on what is in the rain or dust they get nutrients from the living organisms that grow associated with them.
This is the reason to consider nutrient amounts and ratios that don't conform with previously published knowledge. It is the reason to consider that some common nutrients may cause problems when used at previously accepted levels. We do not yet know the optimum levels in-vitro or in-garden and we can come up with better than we have so far.
I have to question whether the discussion about complexing agents is even relevant to this discussion, if for no other reason than the extreme dilution levels we're dealing with in our solutions.
You can mix fertilizers and stuff like potassium silicate (Dyna-Gro ProTekt) in dilute solutions with no issue; mix them up in their concentrated forms, and they'll "complex" themselves into insoluble compounds quite readily.
You can mix fertilizers and stuff like potassium silicate (Dyna-Gro ProTekt) in dilute solutions with no issue; mix them up in their concentrated forms, and they'll "complex" themselves into insoluble compounds quite readily.
Back to the original question....
As you see one knows the positive answer.
The hobby is very complex because of the complexing agents that complex themselves when we make it too complex.
:evil:
:sob:
:noangel:
As you see one knows the positive answer.
The hobby is very complex because of the complexing agents that complex themselves when we make it too complex.
:evil:
:sob:
:noangel:
To answer Ray; preparing stock solutions necessitates stable solutions not too diluted. This applies for those of us that use proportioners. For others, it may be beneficial to have a homogenous solution instead of a powder mix, particularly when addition levels get down to low three digits ppm levels. E.g. 300mg/gal.
D
DavidCampen
Guest
Also, the discussion in this thread about complexing agents had nothing to do with using them in an attempt prepare non-precipitating concentrated solutions.
The discussion in this thread had started as someone wondering if the citric acid that he was using to adjust pH would significantly affect the bioavailabilty of micronutrients. My response was that, in my opinion, citric acid was a sufficiently weak complexing agent that it would _not_ significantly affect the availability of the micronutrients.
Then there was a bit of a discussion about if very strong chelating agents such as EDTA would significantly affect the bioavailabilty of the micronutrients. It is my opinion that very strong chelating agents such as EDTA likely do reduce the bioavailabilty of the micronutrients. I believe that someone else also made a similar comment.
I gave up trying to make a single bottle liquid concentrate to use with a Dosmatic injector (for use at something like 1:50 or 1:100). I did not want to use strong chelating agents like EDTA and so I could not get enough calcium and sulfate in my concentrate without precipitation. I gave up on using the Dosmatic pump and now prepare a two bottle liquid concentrate that I add to a stock tank to make the final diluted watering solution.
Many commercial fertilizer formulations do provide the minor elements as chelates with very strong chelating agents (some even stronger than EDTA). I think that this not necessary for fertilizers that will be used on epiphytic orchids (or even Paphiopedilums) and is likely counterproductive.
David, that is why I bought a second Dosmatic a couple of years back. Then I can inject Ca to the water without precipitation. I use the miniDos, at 1:100 and 1:500. Guess the ideal would have been to have Three; one for macro elements except Ca, one for Ca and one for micros
But that gets excessively expensive.
There seems to be results in literature that citric acid helps iron to enter the plant through the epidermis, at least for citrus.
But that gets excessively expensive.
There seems to be results in literature that citric acid helps iron to enter the plant through the epidermis, at least for citrus.
myxodex
Well-Known Member
Interesting point that raises for me a tangential question. I wonder how much silicate precipitation goes on in the medium during the drier part of the watering cycle? Given that Ca is the cation with highest concentration (of those with insoluble silicates) , I wonder whether a small amount Ca silicate precipitation occurs and could then act as an antacid in the media, could be a potentially useful side effect of using proTekt ? I have wondered whether there are any insoluble or conditionally (pH) insoluble minerals that would buffer pH only when it drops into the low 5's ... that could be very useful.
When the medium is dry, ALL dissolved solids have precipitated.
Which drops out of solution first is dependent upon their relative solubilities and interactions with other species as the concentration increases with evaporation of the solvent.
Along this though path...
As the soil moisture dries up different nutrients drop out of solution leaving an imbalance of nutrients in solution. That imbalanced solution is what the plant has access to. As well, as the compounds are close to dropping out of solution aren't they supper saturated in solution at that point?
As the moisture dries what are the ppms of each remaining nutrient?
I hadn't thought of that...
Not necessarily, as that means the concentration has actually exceeded the normal solubility limit, which is unlikely in all but undisturbed systems, but yes, that normal limit is approached.
It's going to approach the percentages of the solute, less whatever has been absorbed already. If you dissolve a 30-10-10 fertilizer in pure water, then let the water evaporate without any other interaction, you end up with your 30-10-10 again.
D
DavidCampen
Guest
David, that is why I bought a second Dosmatic a couple of years back. Then I can inject Ca to the water without precipitation. I use the miniDos, at 1:100 and 1:500. Guess the ideal would have been to have Three; one for macro elements except Ca, one for Ca and one for micros
But that gets excessively expensive.
There seems to be results in literature that citric acid helps iron to enter the plant through the epidermis, at least for citrus.
I had thought about buying a 2nd MiniDos but then I discovered that I was having trouble getting consistent metering from the MiniDos (and a MicroDos was even more problematic). I use a watering wand with a very fine spray head (made from a pesticide applicator spray wand), with the spray head removed so that the solution could flow freely I would get the metering rate that I expected but with the spray head on (which would increase the backpressure and reduce the flow rate) the proportion of concentrate being injected would be greatly reduced. So I decided to abandon using an injector and instead use a stock tank (where I mix the ready to use watering solution) and electric pump. As a bonus I can now use the stock tank with electric pump for pesticide and fungicide applications.
Yes, iron is the one element that has to be complexed. Fe(II) sulfate is water soluble but it quickly oxidizes to insoluble Fe(III) oxide/hydroxide but Fe(III) ammonium citrate (green form) is nicely soluble and stable if it is not left standing in sunlight and additional citric acid improves the stability.
In my 2 component concentrate formulations, Solution A contains calcium and magnesium nitrates along with all of the cationic trace elements - Fe, Mn, Zn, Cu, Co, and Ni which are also added as nitrates with the exception of the ferric ammonium citrate and the solution is then buffered to pH 5.5 - 6.0 with the addition of citric acid and citric acid salts. Solution B then contains potassium and ammonium nitrates along with phosphate, sulfate, borate and molybdate. Solution A is stored in amber bottles (actinic glass) to prevent light from converting the ferric ammonium citrate into a less soluble form.
Yes, injectors need a certain minimum flow to work properly. According to the manufacturer data that flow is rather high, cannot remember exactly, but think I found out that I made it with my half inch hose. Checking fertiliser level with the conductivity revealed that at least it was working approximately correct. Approximate is the right term dealing with mixture of citric chelates and urea trying to assess ppm by conductivity. Its not straight forward, but probably good enough knowing the compsition?
D
DavidCampen
Guest
What I would do is prepare a known concentration by, say for a 1:100 ratio, diluting 10 ml of concentrate measured using a small graduated cylinder to 1 liter using my RO water and a 1 liter graduated cylinder. Measuring this conductivity would give me the value that I would expect to see coming from the injector.
Sure that is a way to calibrate things. Should be more accurate, being away from analytical chemistry does these things to man. Unfortunately my lab conditions are far from beiing perfect, more like non existing for the time being. That is why I have not started with seed propagation i assume....
Rick
Well-Known Member
Rick
Well-Known Member
myxodex
Well-Known Member
So from the time of watering to the next watering the concentration of nutrients is obviously increasing. The idea of chelating all the cationic micros is to lengthen the time that they are available by reducing their propensity to precipitate as phosphates, increase their mobility in the medium and thus, hopefully, allow lower concentrations to be effective for longer. That is the idea at least, whether it actually works out this way in practice is another matter. There is a company that produces freeze dried amino acid chelates of micronutrients that they claim to be soluble and compatible with fertilisers. I'm not entirely convinced that the amino acid chelates that I use are necessarily going to stay intact that long in the medium as the microbial population in the mix is probably going to gobble up the amino acids anyway. Nonetheless, I'm trying this approach which is very similar to what David Campen has been doing, which I think is a good enough idea at least to try out.
We tend to focus on the inorganic compounds when looking at natural systems, but there is accumulating evidence that both the organic acids (eg. citric, malic, succinic, fumaric, oxalic) and amino acids (eg. aspartate, glutamate, histidine, and others) are present in easily detectable amounts in aboreal forest soils. Not much work on tropical forests that I could find. Fungi, including mycorrhizal fungi, are known to excrete organic acids to increase the availability of cationic nutrients, and some plants have genes that are involved in the export from roots of malic or citric acid. I seem to remember that mosses do something similar. So chelation is a natural strategy for both plants and fungi in the acquisition of cationic nutrients. Subsequent to uptake in plants, chelation of the cationic micros is essential to protect the plants from oxidative damage. A tomato mutant that is defective in the gene that synthesizes nicotianamine, an essential chelator for metal ion transport in plants, has all sorts of problems and can only be kept alive by application of chelated micros. Hyperaccumulators of Ni have constitutively high levels of histidine in their xylem, and their resistance to Ni toxicity can be partially conferred on sensitive plants by feeding histidine. The point I'm making is that chelation is not some exotic unnatural mechanism dreamt up by chemists in a lab (EDTA is, for sure, but that has been mentioned above). In what form do wild orchids get their micros from mycorrhizal fungi? I'm not sure this is known, but I'm willing to bet that due to toxicity issues the fungus is going to be transporting these as chelates of one form or another. It is likely that fungi growing in our orchid pots are excreting organic acids anyway and whether you are applying chelates or not, some of the micros being assimilated by your plants might well be in chelate form anyway. It's back to the story of beneficial micro-organisms and the interactions between the micro-ecology of the pot and the nutrients we apply.
So as the question about the relevance of chelation at high dilution, I would say chelation could just be a way of getting effective feeding at even higher dilutions, maybe even approaching that in natural environments by using a mechanism that exists in these environments.
