Root PORN!!!

[papheteer]

All plants are different. So much variability even among plants from the same flask. Maybe you've got an 'easy' sandie. Take good care of it.

 

[Stone]

Nice plants and awesome roots!

Of all of them, my Paph. sanderianum has the best root system

I would love to know EXACTLY D) how you are growing the sandie. mix, pot, heat, feed, light, pH, etc. etc. Please

 

[consettbay2003]

If supplementing K-Lite with ammonium nitrate is a good idea, how much ammonium nitrate should be used if you are currently using 1/4 tsp. K-Lite/gallon of RO water? Would you do this every time you fertilize with K-Lite?

Would supplementing with urea be advisable?

 

[Ozpaph]

Nice plants and awesome roots!

I don't want to take over this thread but I have a question. I have 15 paphs, all but 2 are species. Of all of them, my Paph. sanderianum has the best root system, the roots are growing out the bottom of the pot even. No other paph of mine has roots like that sanderianum. I thought that sanderianum was supposed to be slow and hard to grow, why does it have the best root system?

If you have a sandie growing like that DONT CHANGE ANYTHING and tell us all how you do it, thanks.

 

[paphioboy]

Just to contribute to the 'porn' page My old thread (2011) when I was repotting my multifloras (stoneis etc). They have not been repotted since and are going gangbusters now..

http://www.slippertalk.com/forum/showthread.php?t=23537&highlight=repotting

This is what they look like now..

 

[orcoholic]

Can ammonium sulfate be substituted for ammonium nitrate? Ammonium nitrate does not seem to be readily available. Probably because it is used by terrorists to make explosives.

 

[gonewild]

If supplementing K-Lite with ammonium nitrate is a good idea, how much ammonium nitrate should be used if you are currently using 1/4 tsp. K-Lite/gallon of RO water? Would you do this every time you fertilize with K-Lite?

Would supplementing with urea be advisable?

Why do you feel the need to supplement?
Are you seeing problems with the K-lite you are using?

 

[gonewild]

Can ammonium sulfate be substituted for ammonium nitrate? Ammonium nitrate does not seem to be readily available. Probably because it is used by terrorists to make explosives.

Because Ammonium Sulfate also adds sulfur it is not a direct substitute for Ammonium Nitrate. It depends on what you want to accomplish.

 

[orcoholic]

Thanks Lance.

My only intent is to give more ammoniacal nitrogen. I'll keep the Ms and Ph the same as always, but would like to make the ammoniacal and nitrate nitrogen equal.

 

[naoki]

It's great to learn from anecdotes of experienced growers. I was curious about NO3 vs NH4, so I did a bit of reading. There are quite a lot of research in horticulture about the effect of different types of N sources. Some plant species prefer NO3, and others prefer NH4. Some plants don't care. And these two sources of N have opposing effects on rhizosphere pH environment (due to fairly complex physiology). Some plants have an optimum mix of the 2 source.

The following experiment is not with Paphs, but with Phal hybrid, but there is a pretty dramatic effect.
http://hortsci.ashspublications.org/content/43/2/350.short
I think the main article is not accessible for everyone (contact me if you need it), so here is the summary.

He grew phal hybrid in 100% sphag or in bark-based mix (i.e two different pH). Then used fertilizer with varying proportion of NO3 (0, 25, 50, 75, 100%). There is a fairly linear relationship between aspects of growth and the increasing NO3. With more NO3, the overall leaf size is larger, time to flowering is shorter. Also # of flowers, flower size, inflorescent length, flower stem diamter is larger with more NO3. In other words, most measurements of short-term performance improves with increased percentage of NO3, and 100% NO3 is the best for this experiment. This occured in both acidic sphag moss media or less acidic bark media.

A couple of caveats are that Phals could be quite different from Paphs. However, in a couple other monocots (Colocasia esculanta and Zea mays), they seem to prefer higher proportion of NO3. Also the experiment uses fairly high concentration of fertilizer. With lower concentrations which most of us are using, the source of N may not have such a dramatic effect.

Also there is something called ammonium toxicity, which is not probably an issue with low concentration. I'm not completely sure about this mechanism, but NH4 does inhibit K absorption in some plants.

Probably these are a part of the reasons why MSU (and K-lite) uses NO3 as N source, right?

 

[Bjorn]

Yes, in this paper, phalaenopsis preferred NO3. In the paper below,
http://aob.oxfordjournals.org/content/111/6/1181.abstract
the preference of Cymbidium goeringii was shifted from NO3 to NH4 by the presence of mycorrhizal fungii.
Could it be that the yellowing I have observed with NO3-only nutrition was due to the presence of mycorrhizaes?
Substituting NO3 with urea (though total N at a lower concentration due to lower ppm) made my plants look much healtier, i.e. greener.
Previously(100%NO3): N was at approx 35ppm, now with urea it is (37% from NO3+ 63% Urea-N) at N=16ppm.
The latter gives greener leaves. and growth is adequate (which means as good as before)
Of course, all irrigation water has nutrients added.
B

 

[emydura]

It's great to learn from anecdotes of experienced growers. I was curious about NO3 vs NH4, so I did a bit of reading. There are quite a lot of research in horticulture about the effect of different types of N sources. Some plant species prefer NO3, and others prefer NH4. Some plants don't care. And these two sources of N have opposing effects on rhizosphere pH environment (due to fairly complex physiology). Some plants have an optimum mix of the 2 source.

The following experiment is not with Paphs, but with Phal hybrid, but there is a pretty dramatic effect.
http://hortsci.ashspublications.org/content/43/2/350.short
I think the main article is not accessible for everyone (contact me if you need it), so here is the summary.

He grew phal hybrid in 100% sphag or in bark-based mix (i.e two different pH). Then used fertilizer with varying proportion of NO3 (0, 25, 50, 75, 100%). There is a fairly linear relationship between aspects of growth and the increasing NO3. With more NO3, the overall leaf size is larger, time to flowering is shorter. Also # of flowers, flower size, inflorescent length, flower stem diamter is larger with more NO3. In other words, most measurements of short-term performance improves with increased percentage of NO3, and 100% NO3 is the best for this experiment. This occured in both acidic sphag moss media or less acidic bark media.

A couple of caveats are that Phals could be quite different from Paphs. However, in a couple other monocots (Colocasia esculanta and Zea mays), they seem to prefer higher proportion of NO3. Also the experiment uses fairly high concentration of fertilizer. With lower concentrations which most of us are using, the source of N may not have such a dramatic effect.

Also there is something called ammonium toxicity, which is not probably an issue with low concentration. I'm not completely sure about this mechanism, but NH4 does inhibit K absorption in some plants.

Probably these are a part of the reasons why MSU (and K-lite) uses NO3 as N source, right?

Correct me if I'm wrong, but most people on this forum (Xavier for one) are recommending NH4 but this paper saw better growth when using NO3, although for Phals rather than Paphs.

Does most people think NH4 is the go for Paphs, and if so, why are MSU and Klite using NO3?

 

[orcoholic]

Does most people think NH4 is the go for Paphs, and if so, why are MSU and Klite using NO3?

I think NH4 is a lot more expensive. Also, Klite was developed by producers of MSU with Ray's input.

 

[Ray]

I switched to K-lite in Oct. 2011. So I used it for almost 6 months. As i have said. It's the combination of crushed oyster shells and nitrate that caused the N deficiency.

I am way behind on reading this thread, but I do have an issue with that statement, as the first batch of K-Lite was manufactured in December of 2011, and the first jars shipped did not reach the users before January of 2012.

Maybe I missed it, but how does a nitrate nitrogen source plus oyster shell lead to a nitrogen deficiency?

 

[papheteer]

Typo ray. It's October 2012. Used it till march of 2013 when noticed plants getting very pale.

 

[papheteer]

I am way behind on reading this thread, but I do have an issue with that statement, as the first batch of K-Lite was manufactured in December of 2011, and the first jars shipped did not reach the users before January of 2012.

Maybe I missed it, but how does a nitrate nitrogen source plus oyster shell lead to a nitrogen deficiency?

That's what RIck said in a lot of his posts. Nitrate is harder to absorb in more alkaline situations.

 

[papheteer]

I am way behind on reading this thread, but I do have an issue with that statement, as the first batch of K-Lite was manufactured in December of 2011, and the first jars shipped did not reach the users before January of 2012.

Maybe I missed it, but how does a nitrate nitrogen source plus oyster shell lead to a nitrogen deficiency?

Join Date: Jun 2006
Location: Leiper's Fork, TN
Posts: 10,209

Quote:
Originally Posted by papheteer
I have been using k-lite at 1/10 -1/8 tsp per gallon of water. I also supplemented with crushed oyster shells. The one that i got was very powdery. I did notice that after putting it all the root tips stopped growing. I dunno if its coz of that.
If you are using K lite (especially at a weak rate like 1/10 tsp per gal) and add high carbonate potting amendments (like oyster shell) then you are setting yourself up for nitrogen deficiencies.

K lite nitrogen is nitrate based which is most efficiently used by plants in low alkalinity (low carbonate/bicarbonate) systems. As you increase the root zone alkalinity plants would like to see more ammonia (as from urea).

What is the alkalinity of your irrigation water? Are you using RO or rain water? If you use tap water, that could already supply enough bicarbonate to require ammonia/urea before the addition of calcareous pot amendments.

 

[naoki]

Thanks, Bjorn for the paper. It's interesting. N15 labeled NO3 and NH4 were separately supplied in that experiment, and with mycorrhizae, NH4 uptake increased while NO3 intake didn't increase so much. So mycorrhizae seems to mainly take up NH4 while root by itself is still taking up NO3 more. But it's unlikely that your pot-grown paphs had mycorrhize association, isn't it?

I don't have any explanation to what you observed. But the phal paper is using the size as the perfomance metrics, and it would be interesting if they had detected effects on leaf color (yellow leaf may not necessarily leads to less growth).

David, maybe, Paphs could have quite different preference from Phals. So generalization from Phal experiment could be problematic (and some people here have good experience with NH4). Based on soil-based plant knowledge, there are some advantages of NO3 over NH4. NH4 acidifies media. NH4 reduces the absorption of other cations such as K, Ca and Mg while NO3 has synergistic effect on their absorption (i.e. absorption of NO3 will help absorbing other cations).

With pH vs N absorption, different plants seem to respond differently. Rick knows about this topic better, so hopefully he will correct me if I'm wrong. In general, NH4 absorption is influenced by soil pH in most plants (low pH = low NH4 absorption). NO3 seems to show the opposite pattern in some plants. In other plants, NO3 absorption seems to be unaffected by pH: http://link.springer.com/article/10.1023/A:1004740204876

The Phal experiment doesn't seem to have a strong support that Phals do better with NH4 in less acidic media (although the pattern is somewhat consistent with this idea). It was a bit of surprise to me.

Again, the pattern could be species specific, so generalization to Paphs may be difficult without an experiment.

As a side note, I found following site (someone's lecture), which goes through basics of roots:
http://ww2.odu.edu/~jrule/Biol695/pdf/3.pdf

 

[Stone]

I read that plants from acid habitats have been found to have less nitrate reductase activity and respond better to NH4. Blueberies are an example which grow in very acid conditions (possibly pH 4?) and have almost no reductase and therefore NEED NH4. Most orchids also come from acid habitats. (one sample taken from water running over Odontoglossum roots in Ecuador read pH4) So I think it is resonable to assume that these types of orchids may prefer NH4. With paphs comming from limestone areas where the acidity is modified (a little), perhaps a 50/50 combination of H03 and NH4 is called for? In fact without specific data for specific species, wouldn't it be wize to go 50/50 or something similar? That's what I'm doing at the moment but I'm trying to give half of my total N as amino acids as well.

 

[Bjorn]

Thanks, Bjorn for the paper. It's interesting. N15 labeled NO3 and NH4 were separately supplied in that experiment, and with mycorrhizae, NH4 uptake increased while NO3 intake didn't increase so much. So mycorrhizae seems to mainly take up NH4 while root by itself is still taking up NO3 more. But it's unlikely that your pot-grown paphs had mycorrhize association, isn't it?

Never say never, it has been some time since my last posts on composts, so I do understand your assumptions. I do not know whether I have mycorrhizae in my pots, but I do know that I have other fugii, some of them producing mushrooms. So definitely life down there. Algae and moss and lichen thrive as well. Within reason, I have always attempted to grow in a way that is not too far from nature, that means with moss, ferns etc. I do remove the ferns, but they come and then I remove them when they start to annoy. Mushrooms pop up and I leave them, I have never seen a problem associated with that. To make moss etc. thrive, fertiliser additions have to be kept low, and use of algicides etc. is forbidden. By growing this way, I will never get a collection suited for glossy magazines, but entering my collection gives associations to the jungle. Its a mess, yes, but generally a healthy mess.
I must confess that I do envy those of you that are able to grow in a tidy and clean manner, without moss coming on the substrate and so on. And that is how it looks for me as well when I deflask or pot my flasklings. After a while though, everything full of all these (untidy) life forms. But they are a part of it and I firmly believe that since the orchids have persisted in nature for millions of years, having conditions close to nature cannot be anything but good.