# Leaf yellowing



## labskaus (Oct 25, 2014)

This is a Paph. Woessner Komet (Mercatelli x adductum). It always had this leaf issue, sometimes hardly visible, sometimes like this. The only other plant showing this (to a lesser extend) is my Julius, another lowii hybrid. I don't think it is a pest but rather a nutrition issue or even genetic. Any ideas?


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## troy (Oct 25, 2014)

It's an old leaf, paphs loose old growth leaves at the bottom of the fan usually not long after or before growing a new leaf out of the crown, pull off the old leaf the decaying leaf releases ethylene gas it's bad for the other plants especially blooms


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## troy (Oct 25, 2014)

It looks sulphur deficient, sulfur helps with the uptake of nitrogen I would flush with some epsom salts one week the next week use a balanced cal mag thats what I would do


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## NYEric (Oct 26, 2014)

Not genetic.


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## labskaus (Oct 26, 2014)

This effect is not restricted to the oldest leaves, it spreads to all leaves apart from the newest ones, starting from the leaf borders. The plants were almost fine, before this issue started to spread over half a year or so. My NPK fertilizer has Sulphur, and I'm giving Epsom salts frequently. 300 Paphs are fine, two are showing this issue. I've had mites in the past and this looks different. Had my collection treated anyway. Potting mix is orchiata, which looks pretty fresh.


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## Bjorn (Oct 26, 2014)

Plants looks a bit dessicated, how are the roots?


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## troy (Oct 26, 2014)

What exactly do you fertilize with and what kind of water are u using?


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## Stone (Oct 26, 2014)

It is not a nutrition issue because your Paphs are generally healthy. I notice some yellow streaking on some newer leaves? Dare I say virus??


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## troy (Oct 26, 2014)

Virus?


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## troy (Oct 26, 2014)

I have 2 plants that have that, they are improving drastically, I can show a current pic.


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## fibre (Oct 27, 2014)

Hmm, it doesn't look like a bacterial or a fungal infection. 
I don't know any nutrition issue that does look like this. These usually appear in the oldest or youngest leaves first. If it would be a nutrition issue it is closest to the pattern that my lowii album shows. This plant seems to need tons of Fe more than most other Paphs. So it gets some extra Fe directly to the leaves. I guess it has to much Ca in the medium and water and prefers a more acid environment. 

I don't know how virus looks like...


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## labskaus (Oct 27, 2014)

Thanks for the Input, guys!

Bjorn, the plant is sitting in a spot where it dries out quickly, that's correct. I water accordingly. The wrinkling might be due to mechanical stress: the plant sits behind the door and everytime I enter the GH the leaves get bent.

Troy, the plant has seen fertilizing with an NPK(Mg) 8-12-24-(4) at approx. 1/1000 w/v, to something similar to Ricks K-lite with 90% CaN03 (approx 50 ppm N) and 10% of this NPK fert at about 5g/100 l. Mg Sulfate periodically added. I have seen effects after changing to high N at low conc. but not much with this plant.
What have you done to improve your plants?

Mike, I'm going to rule out anything. Virus in Paphs, well, I couldn't find much Information in Terms of Pictures, and nothing looked like this.

What I observe with this (and the Julius which Shows this to a lesser extend) is: once the growth reach maturity, the leafs start to show this yellow colour which spreads from the oldest leaves until most leaves are effected. The yellow Looks different to normal leaf die-back. It is deeper.


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## troy (Oct 27, 2014)

Every week I'll take a picture fir progress so far I only have one, when I got it roth x robinianum all the leaves had yellow on them the oldest leaves were all yellow, first week I fertilized with fish emulsion bone meal and kelp with seabird guano 5-2-1 flushed mid week with arrowhead spring water next fertilizing used epsom salts very dilute next fertilize used a 4-0-0 cal mag with a dash of floralicious plus I fertilize with distilled r.o. water the yellow is just spotting it's going away I think it would be hard to draw a conclusion from what exactly helped because of so many variables but it is going away


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## paworsport (Oct 27, 2014)

Could it be specific to hybrids with pardalopetalum?
I saw 2 weeks ago a bunch of very big paph, roth x ( haybaldianum x philippinense) in flower with 2 or 3 stems in Philippe Lecoufle GH which have exaçtly the same issue, the other paph not.


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## Erythrone (Oct 27, 2014)

paworsport said:


> Could it be specific to hybrids with pardalopetalum?
> I saw 2 weeks ago a bunch of very big paph, roth x ( haybaldianum x philippinense) in flower with 2 or 3 stems in Philippe Lecoufle GH which have exaçtly the same issue, the other paph not.



I too wonder if it could be genetic


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## labskaus (Oct 28, 2014)

Thanks all for your input, that gives me a few ideas to follow up.

I'll feed additional iron and see what it does. At least the major nutrients should be around in sufficient amounts.

When I suggested "genetic" in my first post, I wondered if the cross of lowii (pardalopetalum) with a Polyantha species might in some cases result in some metabolic pathway not working properly.

I'll take a closer look into chlorosis caused by different nutrient deficiencies (N, Mg, Fe,...).
I'll also take a look at pH ranges for the uptake of these particular nutrients. The plants in question are in relatively fresh Orchiata with 5% Akadama.


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## ditrujillo (Oct 28, 2014)

I'm not sure if this is the correct place to post this, and this is the first time I'm posting pictures, so please let me know if there's anything I can change. 

This is an experiment we set up in a Plant Biology lab that I TA. We wanted to see the effect of nutrient deficiencies on sunflowers plants after ~6 weeks of hydroponic culture. Each row is a different treatment in which one nutrient was excluded from culture. I'll try to add more explanations in a different post. 

Obviously there are huge differences between monocots and dicots, so take these with a grain of salt. Does anyone know of a similar experiment done with orchids? It seemed really easy to set up, the hardest part would be getting 30 genetically identical orchids to sacrifice to science! 















Sent from my iPhone using Tapatalk


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## ditrujillo (Oct 28, 2014)

Wow, uploading from my phone really degraded the image quality. Here is a link to flickr until I can figure out how to insert images into a post:



https://www.flickr.com/photos/[email protected]/sets/72157648603890940/





Sent from my Surface Pro 3 using Tapatalk


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## troy (Oct 28, 2014)

all leaves yellow except 1 when I got it the yellowing is going away, plant is robinianum x roth


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## myxodex (Oct 29, 2014)

Just a thought, ... could it be a genetic sensitivity to too much of some nutrient ? Might be worth trying reduced feeding for a while.


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## naoki (Oct 30, 2014)

ditrujillo said:


> This is an experiment we set up in a Plant Biology lab that I TA. We wanted to see the effect of nutrient deficiencies on sunflowers plants after ~6 weeks of hydroponic culture. Each row is a different treatment in which one nutrient was excluded from culture. I'll try to add more explanations in a different post.
> 
> Obviously there are huge differences between monocots and dicots, so take these with a grain of salt. Does anyone know of a similar experiment done with orchids? It seemed really easy to set up, the hardest part would be getting 30 genetically identical orchids to sacrifice to science!



This is pretty interesting. The common symptoms of deficiency are usually from a few crop plants (e.g. corns). So it is interesting to see how other plants respond. I'm surprised that N deficiency isn't as bad as K deficiency (which seems to be one of the worst with sunflowers). Doing it in orchids would be a bit more challenging (slower growth, and their higher capacity of nutrient recycling). But there are some studies which used Phalaenopsis.

If you don't mind (and if your professor is ok), can you share the protocol of this lab? I think your PM or email is disabled, so I appreciate it if you can email (or PM) me.


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## troy (Oct 30, 2014)

Thank you for sharing yur lab experiment with us diane even though they aren't orchids, the visual description of deficiences are cool, question, are the growth production / systems the same for all plants?


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## PaphMadMan (Oct 30, 2014)

myxodex said:


> Just a thought, ... could it be a genetic sensitivity to too much of some nutrient ? Might be worth trying reduced feeding for a while.



Might be the right track. I was thinking this could be a case of excess of one nutrient (or non-nutrient mineral) inducing deficiency symptoms for another. Symptoms may not be quite typical of a true deficiency. Calcium and magnesium can be mutually antagonistic in this way, or excess potassium or even aluminum might suppress calcium or magnesium, calcium might suppress iron, etc. Since this seems to be lowii (not a calcium lover) hybrids I might look first at reducing calcium without changing anything else and see if the next growths are better. It will take a full growth cycle to know.


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## Brabantia (Nov 1, 2014)

naoki said:


> This is pretty interesting. The common symptoms of deficiency are usually from a few crop plants (e.g. corns). So it is interesting to see how other plants respond. I'm surprised that N deficiency isn't as bad as K deficiency (which seems to be one of the worst with sunflowers). Doing it in orchids would be a bit more challenging (slower growth, and their higher capacity of nutrient recycling). But there are some studies which used Phalaenopsis.
> 
> If you don't mind (and if your professor is ok), can you share the protocol of this lab? I think your PM or email is disabled, so I appreciate it if you can email (or PM) me.


It is an other publication about the effect of K deficient on Guzmania.
Ref: HortScience 43(1): 146-148 2008 Chao-Yi and Der-Ming Yeh.


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## Happypaphy7 (Jan 5, 2015)

I vote for nutrient deficiency or virus.


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## abax (Jan 6, 2015)

It looks to me to be an iron deficiency and I've had quite a bit of experience
with this problem with annuals. The streaky appearance of the yellowing
catches my attention. A once a month or so fertilizing with Miracid helped
and/or entirely corrected the problem.


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## gonewild (Jan 6, 2015)

labskaus said:


> Troy, the plant has seen fertilizing with an NPK(Mg) 8-12-24-(4) at approx. 1/1000 w/v, to something similar to Ricks K-lite with 90% CaN03 (approx 50 ppm N) and 10% of this NPK fert at about 5g/100 l. Mg Sulfate periodically added. I have seen effects after changing to high N at low conc. but not much with this plant.



Your fertilizer is not similar to Ricks K-lite. Your potassium (K) level is at a ratio of three times more than nitrogen. Your fertilizer is K-heavy!

What you are seeing is the decline or "sudden collapse" of a plant that won't tolerate high levels of potassium. The symptoms look like disease but there is no environmental reason for the plant to have a disease and the disease does not quickly kill the plant. That's because it is not an infection and it is not a nutrient deficiency, it is most likely a nutrient toxic reaction caused by excess potassium.

When you change to high N you are effectively lowering the potassium ratio, that's why you see effects. Lower the K ratio to zero on this plant and see what happens.


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## Happypaphy7 (Jan 6, 2015)

Fusarium wilt and other diseases will turn an entire plant into a mushy mess overnight. Not saying this is it, but just read that your comment saying disease do not kill plants quickly.
Plus, disease organisms are usually everywhere. It's when the plants get weak or balance in growing environment breaks that diseases break out or plants become more susceptible to diseases.

A good question is if this is nutrient deficiency or overdose reaction, why only this plant but not many others around it?
I assume they are all treated the same way?


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## gonewild (Jan 6, 2015)

Happypaphy7 said:


> Fusarium wilt and other diseases will turn an entire plant into a mushy mess overnight. Not saying this is it, but just read that your comment saying disease do not kill plants quickly.



Sorry, I think you misunderstood what I said (or meant to say).
My point was that the diseases usually kill the plant quickly and since this problem is just lingering I suggest that it is not a disease but instead related to a nutrient excess.



> Plus, disease organisms are usually everywhere. It's when the plants get weak or balance in growing environment breaks that diseases break out or plants become more susceptible to diseases.



Exactly my point.



> A good question is if this is nutrient deficiency or overdose reaction, why only this plant but not many others around it?
> I assume they are all treated the same way?



Genetics is likely the answer to why some plants tolerate nutrient excess and some don't. Why can one person tolerate more sun than another...genetics. 
Other reasons could be environmental related to the condition of media or type of media.


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## Happypaphy7 (Jan 7, 2015)

Oops! sorry. 

Genetics maybe.
I like all green complex paph with no white halo on the dorsal.
Every single of those I buy or I see at shops has this dark (nearly black) mark along the veins with some rust-like stuff on the surface.
These marks will get worse and worse with time. very frustrating.
Anyways, back to the main post, so maybe it's genetics or virus?
Who knows? lol


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