Early K-lite results

[Rick]

She has seen good growth and blooming, but is observing what appears to be premature loss of leaves on back-bulbs. She states that the old leaves turn solid brick red, then pale to yellow, and fall off.

Only the leaves on old bloomed out growths? But no issues with new growth or rates of growth with new growths?

I never considered old leaf senesence (with lots of old backbulbs around) abnormal in Catts, so maybe its just different rather than bad.

But when orchids senesce leaves they do recall more P than any other macronutrient for the next round of growth. So maybe the new fert regime has started a new round of growth and putting the plant in "panic mode" to conserve P since its not in excess like in the good old days.

Another option that just occured to me is that K inhibits Ca and Mg uptake, which also influences P uptake. So if the Ca and Mg are now uninhibited, the increase of Ca/Mg in the tissues could be signalling for an increase in P and stimulating P recycle in the old growths (whether it needs to or not).

 

[gonewild]

If a plant has all the correct nutrients available for all new growth what is the advantage to the plant to continue to send resources to old growths?

Ray this is a perfect opportunity to test if K-lite needs more P. Can you help this grower add P to her k-lite formula? If she does and this "red" leaf drop stops Then perhaps K-lite could be increased in P.

But as Rick suggested first must determine if the dropping of old leaves is a new bad thing or a normal event the grower just never saw in such a pronounced way. If her plants are growing new leaves more vigorously and faster it stands to reason that the plants would also shed old leaves with an equal and opposite force.

 

[dodidoki]

I've been conversing with a K-Lite user who primarily grows cattleyas and a few dendrobiums, down in southwestern Florida. Many are in LECA, others are in bark- or CHC-based media, others are mounted.

She has seen good growth and blooming, but is observing what appears to be premature loss of leaves on back-bulbs. She states that the old leaves turn solid brick red, then pale to yellow, and fall off.

Bill Argo suspects a phosphorus deficiency, and if that's the case, the recommendations here would apply to her.

So my question is "why is she the only one seeing this?"

I think Rick's article is aswer your question. Paphs are slow grower and I think, they can uptake enough K for growing from older growths and rotting litter, too. Catts grow faster so maybe they need a little more K and there are less rotting parts around their roots so if they have not enough they begin to reuptake it from older parts. So I think catts need more K than paphs , maybe 14: 6 N/K ( for paphs optimal 14/3).

 

[gonewild]

I think Rick's article is aswer your question. Paphs are slow grower and I think, they can uptake enough K for growing from older growths and rotting litter, too. Catts grow faster so maybe they need a little more K and there are less rotting parts around their roots so if they have not enough they begin to reuptake it from older parts. So I think catts need more K than paphs , maybe 14: 6 N/K ( for paphs optimal 14/3).

Or simply more of all nutrients?

 

[Ray]

Responding to the last two responses in order:

My cattleyas are not showing any signs of deficiencies. I'm reasonably sure she's not the only other person growing them.

Well, she did a direct replacement of the MSU - same concentration and frequency of application.

 

[dodidoki]

Responding to the last two responses in order:

My cattleyas are not showing any signs of deficiencies. I'm reasonably sure she's not the only other person growing them.

Well, she did a direct replacement of the MSU - same concentration and frequency of application.

She is not the only person. Eg. my cattl. aurea and two rositas are just starting to push up a new growth, each. And all of three catts also push new roots, too. But at the same time oldest leaf begins to turns yellow. I think it is some sign of deficiency, maybe K or P, so I will increase them in fert. water for catts.

 

[terryros]

Rick - I have wanted you to comment on the properties of sphagnum moss and its binding properties. I am in the original K-Lite group but also use pure sphagnum as a medium. My reading says that sphagnum will be active with ion uptake and play a role. I have been using only 30-50 ppm N because of this. What is the differential role of sphagnum with the important electrolytes? I do periodically test effluent EC and pH to make sure the EC stays pretty low (not over 0.4) and the pH is around 5.5 -6.0.


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[Rick]

down in southwestern Florida. Many are in LECA, others are in bark- or CHC-based media, others are mounted.

Indoor, outdoor, GH, Shade house? Humidity control????

The Southeast US got slammed with heat/drought this year.

And leaf drop would be a totally expected response for CAM plants under extra heat/ low humidity conditions. TDS increases also induce drought response in Catts, so if evaporation rates were up and pot TDS went up with it (regardless of fert type) then expect the plant to drop leaves in response.

 

[Rick]

Rick - I have wanted you to comment on the properties of sphagnum moss and its binding properties. I am in the original K-Lite group but also use pure sphagnum as a medium. My reading says that sphagnum will be active with ion uptake and play a role. I have been using only 30-50 ppm N because of this. What is the differential role of sphagnum with the important electrolytes? I do periodically test effluent EC and pH to make sure the EC stays pretty low (not over 0.4) and the pH is around 5.5 -6.0.


Sent from my iPad using Tapatalk HD

I think CHC will ulimately hold up more ions than moss, but I believe it can get saturated pretty fast. I think your strategy to watch/control EC and not use more than 30-50 ppm is sound. You can probably use 100ppm, but will probably find that EC goes up faster, and need to flush more frequently to keep it down.

 

[gonewild]

Responding to the last two responses in order:

My cattleyas are not showing any signs of deficiencies. I'm reasonably sure she's not the only other person growing them.

Well, she did a direct replacement of the MSU - same concentration and frequency of application.

Your plants are in a controlled greenhouse environment with little fluctuations.
Is that correct?

I have the impression hers are growing outdoors in a garden environment?

If this is the case and your plants are not showing the same red leaf then the environment is probably the direction. It is probably a mistake to assume one fertilizer formula will work perfectly in two such different environments.

 

[gonewild]

So my question is "why is she the only one seeing this?"

Don't try to solve a problem until you are sure it is a problem.

How much is she actually seeing?
Is this happening on most plants or only one or two?
On all genera or only Catts?
Is this ongoing or seasonal?

Since she is the only one reporting this then to consider it you need to know if there is actually a widespread condition or is this something that she just noticed on a few plants and it has her worried.

She says the leaves fall prematurely.... and what is premature in reality?
If the new growth is vigorous and blooms are correct then the plant has no need for the old foliage. Perhaps what she is seeing is actually normal growth rather than plants hanging on to old leaves trying to rake in enough minerals to produce new growth.

It is not uncommon for leaves to turn pretty colors before they fall.

 

[keithrs]

Is this the same person that was discussed in an earlier thread or a new person?

 

[gonewild]

Is this the same person that was discussed in an earlier thread or a new person?

Or same person with a new current report?

 

[Stone]

I think CHC will ulimately hold up more ions than moss, but I believe it can get saturated pretty fast. I think your strategy to watch/control EC and not use more than 30-50 ppm is sound. You can probably use 100ppm, but will probably find that EC goes up faster, and need to flush more frequently to keep it down.

Here's an interesting thread ( page 1) (and links) on cec of coco on ''another forum''
https://www.icmag.com/ic/showthread.php?t=142846

 

[Rick]

Here's an interesting thread ( page 1) (and links) on cec of coco on ''another forum''
https://www.icmag.com/ic/showthread.php?t=142846

I'll try to link some other articles on coco coir. I have the PDF downloads, but I can't figure out how to upload those directly. They are some of the information that ANTEC used with regards to the problems with chc holding K/Na and needing calcium/magnesium to knock it out of matrix.

http://www.agrococo.com/Bethke/NUTRIENT_ANALYSIS_OF_AGROCOIR.pdf

This one is real upbeat on the high amount of K in the matrix.

http://www.usu.edu/cpl/PDF/CoconutCoirPaper.pdf
But when you check out this one, the K retentive aspects of chc will scare the crap out of you.

Sphagnum moss and sphagnum peat are comparisons in both articles.

 

[rcb]

I've been conversing with a K-Lite user who primarily grows cattleyas and a few dendrobiums, down in southwestern Florida. Many are in LECA, others are in bark- or CHC-based media, others are mounted.

She has seen good growth and blooming, but is observing what appears to be premature loss of leaves on back-bulbs. She states that the old leaves turn solid brick red, then pale to yellow, and fall off.

Bill Argo suspects a phosphorus deficiency, and if that's the case, the recommendations here would apply to her.

So my question is "why is she the only one seeing this?"

Hi Everybody, I'm the person Ray is referring to here, and I really appreciate the comments that have been given. To answer some of the questions, I thought it might be easier if I joined and answered them myself instead of going through Ray.

First, I don't use bark at all. The majority of my plants are in inorganic media, with about 10 still in CHC, they just haven't been repotted since I switched.

These are the trends I've noticed - although there are a few exceptions to the trends.

This only is affecting the sympodials. I don't have many monopodials, but I'm not seeing any issues with them.

The leaf drop for the most part starts happening when the plant comes into flower. There are one or two exceptions where a plant that has flowered hasn't dropped it's older leaves, and I have one plant that is dropping older leaves that hasn't bloomed. But for numbers, I'm seeing this so far on about 50 - 60 plants.

I don't really see any issues on my mounted plants, with one exception - although the majority of my mounted plants are deciduous Dendrobiums.

 

[rcb]

CNYCharles - I dont use bark at all in my pots.

Rick - "Only the leaves on old bloomed out growths? But no issues with new growth or rates of growth with new growths?" Mostly. The new growth and rate of new growth are ok. I have seen new growths stronger since I switched to K-lite.

Gonewild - "Can you help this grower add P to her k-lite formula? If she does and this "red" leaf drop stops Then perhaps K-lite could be increased in P." I started something to try this, and Ray has passed along suggestions for adding more P.

Rick- "Indoor, outdoor, GH, Shade house? Humidity control????

The Southeast US got slammed with heat/drought this year.

And leaf drop would be a totally expected response for CAM plants under extra heat/ low humidity conditions. TDS increases also induce drought response in Catts, so if evaporation rates were up and pot TDS went up with it (regardless of fert type) then expect the plant to drop leaves in response."

I actually live in coastal NW Florida, we have not been under a drought at all. As for humidity levels, we average 70 - 80% year round, and this is inside. We do occasionally get a dry spell and drop to about 50 - 60% humidity. But I do nothing to control it as the plants spend the majority of the time outside. Temps have been normal for the most part this past year.

Gonewild - "I have the impression hers are growing outdoors in a garden environment?" Yes mostly. All my orchids spent about mid-March through November outside. But maybe 30% of them do come inside and are put under light during the winter time. These are ones that I dont think will take the outside temps during winter.

Again thank you everyone!

 

[rcb]

Gonewild - "How much is she actually seeing?
Is this happening on most plants or only one or two?
On all genera or only Catts?
Is this ongoing or seasonal?"

This is happening on most plants that have bloomed since last fall. Many of my plants are mid to late spring bloomers, and a few are summer bloomers, and I haven't seen anything suspicious on the plants that haven't bloomed. Total number of plants this has happenend to, 50 - 60.

I don't think I see a correlation or not between my different genera. I grow Catt Alliance (100 or so plants), Dendrobiums (150 or so plants), Catasteums and Bulbophyllums (50 plants) and a mix of odds and ends. I don't see any problems with the Catasetums, which are potted in spag, but I wouldn't, would I Dendrobiums, if they are mounted, not really seeing a problem, if they are potted definitely yes. I have a BALD Dendrobium convolutum that won't stop blooming. Bulbos, yes if they have bloomed over the winter. But many of mine are summer bloomers.

As for ongoing or seasonal - seasonal if you consider blooming a season. When the plants stops blooming, any leaves that haven't started the change do not.

Gonewild - "She says the leaves fall prematurely.... and what is premature in reality?
If the new growth is vigorous and blooms are correct then the plant has no need for the old foliage. Perhaps what she is seeing is actually normal growth rather than plants hanging on to old leaves trying to rake in enough minerals to produce new growth."

Good points. Some of the plants this is happening to, I have had for over 10 years, and yes I know old leaves drop and I know their growth habits. But leaves that are two to three years old have never done this before for me. My plants, especially if they are blooming overexceptionally well (which many are) are going bald. I don't think that is normal. When I first noticed this happening, I did spend some time telling myself I was seeing things. I'm not a worrier when it comes to growing orchids. But once the wintertime bloomers started blooming, and there were enough that were doing this, I had to approach Ray and try and figure out what is going on.

It is possible this is not related to K-lite. And yes it's possible I'm imagining things. But I don't think so, there are too many all at the same time.

Thank you everyone for their thoughts and suggestions. I hope what I have written here has given you enough additional information.

 

[DavidCampen]

Gonewild - "Can you help this grower add P to her k-lite formula? If she does and this "red" leaf drop stops Then perhaps K-lite could be increased in P." I started something to try this, and Ray has passed along suggestions for adding more P.

Add some more K too and then you will have a properly formulated fertilizer.

Good points. Some of the plants this is happening to, I have had for over 10 years, and yes I know old leaves drop and I know their growth habits. But leaves that are two to three years old have never done this before for me. My plants, especially if they are blooming overexceptionally well (which many are) are going bald. I don't think that is normal. When I first noticed this happening, I did spend some time telling myself I was seeing things. I'm not a worrier when it comes to growing orchids. But once the wintertime bloomers started blooming, and there were enough that were doing this, I had to approach Ray and try and figure out what is going on.

It seems that your plants are starved for one or more nutrients, probably both potassium and phosphorus, and are cannabalizing the older leaves to obtain the materials necessary for new growth.

 

[DavidCampen]

...
http://www.usu.edu/cpl/PDF/CoconutCoirPaper.pdf
But when you check out this one, the K retentive aspects of chc will scare the crap out of you.

Sphagnum moss and sphagnum peat are comparisons in both articles.

A good argument for not using coir but this article does not provide much _if any_ confirmatory evidence for your potassium toxicity thesis, neither do the Antec articles.

The summary from the article referenced above:
"These studies show that coconut coir should be used with great caution ... The addition of calcium sulfate to the media did not have a consistently beneficial effect ... We are continuing these studies to determine the causes of poor plant growth in coir."