Phrag kovachii culture!

[Rick]

but just had this thought that people using RO only might have a deficiency.

:wink: There's always a good chance you are correct on this Bjorn.

I started out as a strict RO user, and while still on my old "weakly, weekly" campaign with MSU fert I noticed a bump in culture when I started cutting in some of my well water.

A baby step compared to cutting out most of the K, but noticeable. Problem is I don't know if I can attribute to adding back in some sodium or silicates or sulfates or chlorides (or all of the above):sob:

I would guess that the above mineral additions are getting to some fine tuning at this point, but I might let someone else take up the torch for those items. Did you already get bored with the silicate angle??

 

[Stone]

If you pile on the K they will stunt and become Ca deficient (no matter how much oystershell you put in the pot).

Just a couple of questions Rick.

What would you call ''piling''on the K. You often make this claim but how do you know there is an actual Ca deficiency? What are the symptoms? How would you prove the deficiency without leaf analysis if there are no obvious symptoms? Or are there? Please share them if there are....I don't think it is fare to make recommendations to others on a hunch without proof.

My kovachii has been recieving about 25 to 30 ppm K (at each watering) and similar N. Is that piling? I don't see any ''stunting'' though.
(I may reduce the total EC even further in the future down to about 15ppm N and K)

Ca deficiency often first manifests as browning root tips followed by root death. But I don't see that either. So what does the Ca deficiecy you speak of do? I don't think you can have good root growth AND a Ca deficiency AND vigorous young growth.


I believe you don't have to worry about the K factor. (with any PLANT at all for that matter let alone orchids, unless you are being rediculously foolish with your fertilizing habits) But if you keep the total EC low, keep the roots wet, and hold the pH around 7, kovachii will not have a Ca deficiency and grow as well as any other orchid. In fact it seems easier than many Paphs.
I also think the proplem with a lot of us is/was feeding the poor things when they are not receptive. I have discovered thet the worst thing you can do is to feed a plant when it is not growing. Stop feeding all together and eventually it gets going again. Only then can it take a balanced nutrition. Too much N stops root growth more surely than does too much K.

 

[naoki]

Mike, I remember that there were a couple papers showed some trends in negative correlation between K and Ca from leaf analyses, which Rick pointed out. So there is a possibility, but we don't know the causal relationship, though. But I'm guessing that you wanted to see the data from Phrag.

It is an interesting point about the fertilization when the plant isn't growing. The relationship between the root growth and lack of N is observed frequently.

Bjorn, here is a bit of info from the time when I looked into this info (mostly from Marschner's). There are some plants which accumulate Na in leaves (called natrophiles), but I don't know if there is any orchids which does this. Na is essential for some halophyte (plants growing in brackish area), and beneficial for some.
1. Relatively recently, it's been shown that Na can enhance C4 plants growth (but no orchids are C4).
2. Also if K is limited, some plants (not all plants) can substitute K with Na. So in these plants, leaf analysis can show negative correlation between K and Na. But this doesn't mean that K will cause Na deficiency.
3. Then it was shown that some plants supplied with Na can close the stomata quicker than plants with only K. K is important in controlling the stomata. This indicates that Na could be beneficial in the environment where there is irregular rain fall (and plants experience sudden drought). So there is a possibility that Na could be beneficial for some epiphytes. It would be interesting to see if there is any research about Na and orchids.

 

[gonewild]

It is an interesting point about the fertilization when the plant isn't growing. The relationship between the root growth and lack of N is observed frequently.

Just to continue on your comment.... I disagree with the idea that plants only need nutrients when they are growing or when the roots are actively growing. The only time this is true is when the plant is truly in or entering a stage of true dormancy.
If nutrients are available in correct ratios and amounts and environmental conditions such as temperature and light are adequate the plant will grow.
You may not be able to see it getting bigger but metabolism is active and it is growing. During periods when the light is too low and temps are too low plants may be stalled in growth and appear to be not growing but the moment the light comes on and temp rises above the minimum they will grow. Don't get caught at this moment with no food available. Supplying nutrients when a plant is not visibly growing does no harm but on the contrary if you have withheld nutrients and the sun comes out the plant cant grow.

A root does not have to have an active growing tip to take in nutrients so thinking the plant does not need fertilizer when there is no active root growth is wrong. Even when the plant has no live roots it can still benefit from nutrients absorbed through the foliage and stem, also the stubs of old roots can have active cells.

Seems logical that when a plant is struggling to recover from root loss that application of additional nutrients will make nutrient access easier.

 

[Stone]

A root does not have to have an active growing tip to take in nutrients so thinking the plant does not need fertilizer when there is no active root growth is wrong. Even when the plant has no live roots it can still benefit from nutrients absorbed through the foliage and stem, also the stubs of old roots can have active cells.

Not correct. Calcium, Iron and probably various other nutrients are taken up at or just behind the active growing root tip. Feeding the plant when they are not present is the good way of inducing imbalances.
Plain water is best in this situation.

 

[gonewild]

Not correct. Calcium, Iron and probably various other nutrients are taken up at or just behind the active growing root tip. Feeding the plant when they are not present is the good way of inducing imbalances.
Plain water is best in this situation.

Where is the published research for this on orchid roots?

 

[naoki]

Lance, as you said, there could be the other side to it. But I think that it is an interesting idea to "hack" the plant physiology. Plants have highly-tuned (but could be imperfect), internal programs, and we can manipulate these programs in some degrees. So this is a part of the reasons that natural data could be a good start point, but imitating the natural condition may not be the ultimate method in horticulture which uses artificial environment in my opinion.

In addition to the overall C assimilation rate, one of the program is how plant allocate the resources within a plant body. By limiting the nutrients and water, it will hack the program so the plants reallocate more resources toward roots (increased root:shoot ratio). Similar to how we use phytohormones to play with plant physiology. I think that it is probably case by case (and your logic may be more appropriate for some cases), but it is an interesting thing to try out to kick start these sleepers.

Mike, with other major nutrients, I thought that there are papers showing that pretty old roots of orchids can absorb nutrients at a little bit reduced rate (I vaguely remember that they used isotopically marked minerals to test this). Some Cattleya study I believe.

Another thing to consider is that water absorption is a passive process (mostly driven by transpiration), but most nutrient uptake by root is active (costs energy).

 

[Stone]

Where is the published research for this on orchid roots?

Still unpublished sitting someones draw.

 

[Stone]

but imitating the natural condition may not be the ultimate method in horticulture which uses artificial environment in my opinion.

A very good point. Also as I mentioned a while back, some orchids have an in-built genetic potential which is sometimes unrealized in the habitat. This can be seen by some specimens in cultivation out-performing their wild counterparts. eg. isabelia violacea which has 1 or 2 flowers in the habitat has 3 -5 in cultivation when well grown.

Mike, with other major nutrients, I thought that there are papers showing that pretty old roots of orchids can absorb nutrients at a little bit reduced rate

Yes I have no doubt that they can still take up NPK with old root back from the tip. But there will eventually be an imbalance with say....I don't know....Calcium and potassium? :evil:

 

[gonewild]

Yes I have no doubt that they can still take up NPK with old root back from the tip. But there will eventually be an imbalance with say....I don't know....Calcium and potassium? :evil:

There should not be an imbalance by applying nutrients when roots have reduced capacity because at some point the roots would start to grow again and pick up the missing nutrients. If the nutrients are not in the root zone because the grower has with held them that is when the imbalance can occur.

 

[gonewild]

Still unpublished sitting someones draw.

OMG

 

[Stone]

Mike, I remember that there were a couple papers showed some trends in negative correlation between K and Ca from leaf analyses, which Rick pointed out. So there is a possibility, but we don't know the causal relationship, though.

Naoki, I have been saying all along that the ''too much K'' thing leading to ''deficiency of Ca'' (except in extreme cases) was bogus.
I checked an old post from roth. (below) He did a leaf analysis of freshly collected emersonii and ''a lot of years later''

We all know that Roth uses very little Calnitrate, does not use K lite and does use ammonium. Given all that look at the K and Ca figures for before and after. (post #19) Statistically, no difference. So where is all the missing Ca? The fact is that it is not missing.
(emersonii is a limestone Paph)
You can check roths feeding program in another thread. Remember I'm not talking about B or Mo etc. Just the K and the Ca.

Pretty conclusive to me. There is so much evidence everywhere that there is no problem with the K and NO evidence that there is in the vast majority of cases. The only time this kind of thing may be a problem is for example, if you dump buckets of potassium sulphate on your lawn for a number of years without Calcium additions. And even then there would have to be very low Ca concentrations in the soil to begin with and or very low pH.
Really, what more proof does one need that using ''normal'' K/N ratios does not interfere with Ca uptake?

http://www.slippertalk.com/forum/showthread.php?t=7692&page=2

 

[Rick]

What would you call ''piling''on the K.

My kovachii has been recieving about 25 to 30 ppm K (at each watering) and similar N. Is that piling?

Well you are applying N and K at roughly 50X more than what they see in the wild (and growing better than in GH conditions BTW). So "piling" and "good growth" is in the eye of the beholder. I apply N at ~5 and K<1ppm daily and find Pk as fast growing as "easy" phrags like pearcei and longifolium. I seem to recall in the early years of Pk that seedlings of these guys were slow and died like flies on the typical balanced fert regime.

Ca deficiency often first manifests as browning root tips followed by root death. But I don't see that either. So what does the Ca deficiecy you speak of do?

By the time you are seeing black leaf tips and root tip burn you've already stunted the plant. Slow -stunted growth, susceptibility to disease come before leaf tip burn and root rot.

Part of Manola's talk espoused how the present culture regime that they used produced plants that flowered on growths almost 1/2 the size of their parents. However, he felt this was a benefit in producing "compact" Pks. Some people are pretty happy with plants like these, but then complain about short life span, erwinia rots, and then go back to all the temperature, light, and humidity games to explain the issues.

We all revert to the Mother Nature fantasies for light/temp/humidity when it doesn't work, and I just pointed out Mother Natures chemical regime supporting Pk in the wild. It's certainly up to you if you want to do something not eco-relevant like many of us did for years with bad results, but you can't claim that what you are doing is either natural or superior to what others are doing using a lot less mineral supplementation on their plants.

 

[Rick]

I made a table of available leaf tissue data since Stone brought up Xavier's 2008 post with some wild paph data. Note that the potassium discussions didn't start till 2010 - 20111. This table includes leaf tissue data on in situ PK and the Paph leaf tissue sufficiency standards from University of Hawaii (which is what you get if you "pile on" nitrate and potassium via balanced fertilizer application.



Note that wild plants should be dead from N and K deficiency compared to what U of H considers normal tissue concentrations of these nutrients.

 

[gonewild]

Based on the chart it looks like the Uni is under supplying Calcium or oversupplying everything else.

 

[Rick]

Based on the chart it looks like the Uni is under supplying Calcium or oversupplying everything else.

Keep in mind that the K ranges are inverse to Ca and Mg when you look at individual plant data (i.e the higher the K the lower the Ca/Mg).

So supplying more Ca doesn't put it into the plant if the K is high. (Remember the Cornell data??).

Another point of note is the effect of ammonium as opposed to nitrate. Once again there are references in the Cornell work and others that ammonium (which is a potent cation) is antagonistic to K, Ca, Mg. It seems to be the only cation that effectively blocks K into plants. Nitrate (an anion) does not do this, so as Mike pointed out that Roth's (Xavier's) nitrogen source is ammonium dependent, the difference in leaf tissue NPKCaMg of his cultivated paphs is most likely different than the UH plants (or MSU plants) due to the use of ammonium /urea rather than some unknown natural self K/Ca regulating feature of the plants.

 

[gonewild]

Keep in mind that the K ranges are inverse to Ca and Mg when you look at individual plant data (i.e the higher the K the lower the Ca/Mg).

So supplying more Ca doesn't put it into the plant if the K is high. (Remember the Cornell data??).

I was avoiding suggesting lowering K.

Another point of note is the effect of ammonium as opposed to nitrate. Once again there are references in the Cornell work and others that ammonium (which is a potent cation) is antagonistic to K, Ca, Mg. It seems to be the only cation that effectively blocks K into plants. Nitrate (an anion) does not do this, so as Mike pointed out that Roth's (Xavier's) nitrogen source is ammonium dependent, the difference in leaf tissue NPKCaMg of his cultivated paphs is most likely different than the UH plants (or MSU plants) due to the use of ammonium /urea rather than some unknown natural self K/Ca regulating feature of the plants.

That explains to me why I have never liked the results of UREA based fertilizers and why I keep the Ammonia lower than the Nitrate. Doing so will allow using less K which results in higher Ca/Mg. You get more for less.

 

[ALToronto]

This may also explain why my living walls do so well. I use ammonia based 25-10-10 with no additional Ca or Mg. The walls provide plenty of Ca, I add a pinch of Epsom salts every time I water, and the ammonia prevents the plants from overdosing on anything other than N. About 10-15 ppm N every day seems to do the trick. The only plants that do less well are the ones in drier areas, and that's an easy fix if I bothered to do it.

 

[gonewild]

This may also explain why my living walls do so well. I use ammonia based 25-10-10 with no additional Ca or Mg. The walls provide plenty of Ca, I add a pinch of Epsom salts every time I water, and the ammonia prevents the plants from overdosing on anything other than N. About 10-15 ppm N every day seems to do the trick. The only plants that do less well are the ones in drier areas, and that's an easy fix if I bothered to do it.

That makes sense.

 

[Rick]

Rick, what about the sodium and chloride in particular? I have seen similar in leaf analyses, and still, no fertliser contain chloride and sodium, at least not sodium, the chloride is normally there from other ingredients
This discepancy is normally explained with 'its there anyhow' and that is right, but when chloride gets one of the major as in this case......just my twocents

Check this out Bjorn
http://www.spectrumanalytic.com/support/library/ff/Cl_Basics.htm

Basically infers antagonism amongst anions (Nitrate, Phosphate, Chloride, Sulfate)

And note the picture of the chloride deficient plant.

This could go back to the potential for sclerosis when calcium nitrate is used in RO as the sole source of N, and Ca, and a better reason why epsom salts (magnesium SULFATE) greens things up in the presence of excess nitrate.