Paph. tigrinum chlorosis, help!

[SlipperMatt]

The newest leaf of my tigrinum showns chlorotic shymptons. What kind of nutrient deficiency cause this kind of problem?
I use balanced 20-20-20 in strength of 80ppm N at every watering in vegetative peroid diluted in mix of 1/3 part tap water + 2/3 part RO. Every fourth watering with clear RO. Potting mix is bark mix without any lime component. I do not use currently further Ca and Mg supplementation. Some of my plants has pale green new leaves, mostly the multis + a superbiens. But after the leaf turns mature, the problem disappears.
Any advise or experience?
Photos below:




Please help!
Thanks a lot:
Matyas

 

[gonewild]

Magnesium deficiency most likely.

 

[troy]

Could it be ph induced?

 

[Rick]

With that strength and frequency of a 20/20/20 you certainly won't be short of NPK, but its an uphill battle to get Ca and Mg into a plant with that much K going into it.

I stopped heavy feeding 5 years ago and went to a daily watering / feeding regime with no more than 1ppm K. About a year ago I implemented supplementation with lemon juice to up the citric and malic acid content and really greened pale things up pretty nice.

I presently use 20 drops (about 1ml) of lemon juice per 4L of water and make sure pH doesn't drop below 5.8 s.u.

But I haven't tried citric acid addition for plants with high K content so I don't know if it would work for your plants.

 

[Happypaphy7]

I think it's most likely Mg/Fe deficiency.

For some reason, my henryanum and Doll's Kobold seedlings showed pale green on their newest leaves.
Strange because other henry hybrid seedlings are perfectly fine.

Anyways, I have applied fulvex a few times and things are greening up slowly.

citric acid should help too.
I also read in the old Japanese book that vinegar dilution (I think it said 5ml per gallon or something) also help green things up fast, though I have not tried this myself yet.
If you want to try, be sure to use naturally brewed vinegar and avoid white vinegar.

Good luck!
That's some expensive plant you got there.

 

[Rick]

Could it be ph induced?

Not unlikely that pH could be influential, but need to determine the pH of the pour through and not the pH of whats going into the pot.

Much of the chlorosis I've worked with over the years has been pot specific rather than species specific. And for whatever reason, I've seen radically different pour through pH's on what seemed like identical pot set-ups on my bench.

For the big multifloral species in high growth the pH was drifting up from the optimal of 5.8s.u. Sometimes clearing 7.5 s.u. (especially if you could measure right on a damp root).

Normally a plant would exude citric acid to drop the root pH to around 5.8 so adding enough lemon juice to push the root zone down to around 5.8 seemed to do the trick.

However pH significantly lower than 5.5 is usually not helpful either.

 

[gonewild]

I would try this:

Use this in place of the 20-20-20 for 2 weeks

Calcium nitrate at 80ppm N
Magnesium sulfate at 40ppm Mg
Iron 5ppm

Then after 2 weeks resume using the 20-20-20 alternating with the above.

If you don't see any improvement in a month then the problem is probably not simply Mg or Ca.

If the leaves do respond then you can refine the ratios of nutrients based on what you learned.

 

[abax]

Might dilute use of Miracid help this situation? I know it
works for other types of ornamental plants, however, I
don't know just how acidic it might be under his conditions.
Maybe too much?

 

[SlipperMatt]

Good morning Pals,

Many thanks the advises for all.

I forgot to mention that the pH of my irrigation water is corrected with crystallic citric acid before watering.
I bought the citric acid in the pharmacy.
As i mentioned, my content of the irrigation water is 1/3part chilled tapwater beside of RO for increasing the buffer capacity.
The exact parameters of my irrigation water are:
10ltrs RO warer + 5ltrs chilled tap water + 0,4gr/1ltr 20/20/20 (summa 6gr) + summa 1,4gr citric acid.
The pH is between 5,9 and 6,0,
EC is 400uS/cm.
The outgoing water is generally 6,5-6,6 after 10 minutes soaking of pots.
Unfortunately i don't know the exact salt content of our tapwater. What i know about clear tap water is:
pH: 7,8
EC: 500uS/cm.
Cultivate infos:
RH: 50-60%
Temp: 23-26C degrees
Light: 2 x 6500K full spectrum 120cm t8 sylvania activa fluorescent tubes in a fixture in height of 30-40cm above the foliage in center of my 60cm x 120cm growing area @ 12 hours daily the whole of the year.
I bought yesterday calcium nitrate (Yaraliva Calcinit) in a Garden store, and magnesium sulfate (epsom salt, magnesii sulfas heptahydricus) in the pharmacy.
I'm going to try supplement of both with the suggested quantities of yours, and we will see.
Both of them should use through the roots, or may i use the epsom salt as foliar spray?
Unfortunately i don't know the exact parameters of the 20/20/20 because I bought it from Mr. Franz Glanz, but i think it contains micronutrients too as any other manufacturers similar product.



Update afer a month will come.
Thanks again guys:
Matyas

 

[gonewild]

I'm going to try supplement of both with the suggested quantities of yours, and we will see.
Both of them should use through the roots, or may i use the epsom salt as foliar spray?

Foliar spray may be effective (there will likely be those that say different).
For this method of correcting the deficiency it will be best to apply all the new nutrients to the roots.
BUT I always wet the leaves when I fertilize so in effect all of my fertilizing to the roots is also foliar feeding.

 

[Wendy]

Off topic, but I LOVE your growing setup!

 

[Rick]

Good morning Pals,

Many thanks the advises for all.

I forgot to mention that the pH of my irrigation water is corrected with crystallic citric acid before watering.
I bought the citric acid in the pharmacy.
As i mentioned, my content of the irrigation water is 1/3part chilled tapwater beside of RO for increasing the buffer capacity.
The exact parameters of my irrigation water are:
10ltrs RO warer + 5ltrs chilled tap water + 0,4gr/1ltr 20/20/20 (summa 6gr) + summa 1,4gr citric acid.
The pH is between 5,9 and 6,0,
EC is 400uS/cm.
The outgoing water is generally 6,5-6,6 after 10 minutes soaking of pots.
Unfortunately i don't know the exact salt content of our tapwater. What i know about clear tap water is:
pH: 7,8
EC: 500uS/cm.
Cultivate infos:
RH: 50-60%
Temp: 23-26C degrees
Light: 2 x 6500K full spectrum 120cm t8 sylvania activa fluorescent tubes in a fixture in height of 30-40cm above the foliage in center of my 60cm x 120cm growing area @ 12 hours daily the whole of the year.
I bought yesterday calcium nitrate (Yaraliva Calcinit) in a Garden store, and magnesium sulfate (epsom salt, magnesii sulfas heptahydricus) in the pharmacy.
I'm going to try supplement of both with the suggested quantities of yours, and we will see.
Both of them should use through the roots, or may i use the epsom salt as foliar spray?
Unfortunately i don't know the exact parameters of the 20/20/20 because I bought it from Mr. Franz Glanz, but i think it contains micronutrients too as any other manufacturers similar product.

Given that you are essentially throwing the kitchen sink at your plants I would suggest any "deficiencies" are actually cation antagonism effects (i.e. excess ammonia and potassium excluding Ca Mg and trace metals). Note that not all Nitrogen is equal so see if you can determine what the % of ammonia to nitrate is in your 20/20/20.

There should be plenty of potassium in your tap water without the need to supplement it (actually there is plenty of Calcium and Magnesium in most tap waters without the need to supplement too). So switching to calcium nitrate with a dash of epsom salt in tap water with citric acid should alleviate ammonia and potassium antagonism if that's whats going on.

As I mentioned earlier I haven't dosed my orchids at more than 1ppm of potassium for years now with nothing but positive effects.

 

[Ray]

Angela, as others have ignored your proposal, I will throw out that Mir-Acid, if I recall correctly, contains a fair amount of urea, which is better absorbed through the foliar route than are nitrates and ammoniums, so that'll green things up in the case of nitrogen deficiency, which doesn't sound like the case here.

 

[abax]

Thank you sir. I just tossed that out there because it works
on other ornamental plants in pots, not necessarily orchids
though. Probably I should have been ignored.

 

[SlipperFan]

Beautiful set-up!

 

[Stone]

The newest leaf of my tigrinum showns chlorotic shymptons. What kind of nutrient deficiency cause this kind of problem?

I have seen this exact same problem now and then including with tigrinum and roth. Overall paleness with some deeper green mottling on the newer leaves. I believe it is a nutritional problem but not because of the fertilizer. Either not enough roots with active tips or some kind of imbalance in the rhizosphere caused by either the plant itself or the medium or even the microbe population? Quite possibly it is the various carbonates causing the problem. It does eventually correct itself without any change to the fertilizer at all. I would possibly acidify your water and your feed solution to 5.5. There is no need to change your fertilizer.

 

[phraggy]

If you are using calcium nitrate and magnesium mix them seperately before adding together.

Ed

 

[troy]

Thanks angela, I'm gonna pick a plant and expirement with urea to see how it works out, could be positive....???

 

[myxodex]

Is your tap water hard ? (does your kettle get limescale build up?). If so it looks to me that you could simply reduce the proportion of tap water in your mix.

If you can get a tap water analysis from your water supplier (should be free of charge), it would help you correct any imbalance that might be occurring. If your water is hard, then knowing the Ca/Mg ratio is helpful. Not all hard water supplies have good Mg levels, and excess Ca can reduce Mg uptake. I wouldn't start supplementing without having more information about what you are already putting into the system as you are already feeding at a moderate rate.

It does look as if this problem is specific to your tigrinum, your other plants look OK. I believe it comes from a region of old volcanic soils rather than limestone (unlike many of it's close relatives), which might mean higher micronutrient concentrations and less alkalinity (maybe someone here who knows this species can help here). Maybe it would prefer to have a pH nearer to 5.6 to 6.0 rather than 6.5 to 6.6, particularly in the presence of the high phosphate levels in your fertiliser (phosphate can cause micronutrient deficiencies at higher pHs).

If you don't wish to change anything for the unaffected plants you could make up a batch of your mix, feed all the other plants except the tigrinum, dilute the mix with an equal volume of RO water, optionally add a bit of ammonium sulphate (to reduce the pot pH a bit), and magnesium sulphate and feed your tigrinum with this. Kelp/seaweed extract would help with micronutrients if this is the problem.

I wouldn't add anything without diluting your feed mix first.

 

[SlipperKing]

Is your tap water hard ? (does your kettle get limescale build up?). If so it looks to me that you could simply reduce the proportion of tap water in your mix.

If you can get a tap water analysis from your water supplier (should be free of charge), it would help you correct any imbalance that might be occurring. If your water is hard, then knowing the Ca/Mg ratio is helpful. Not all hard water supplies have good Mg levels, and excess Ca can reduce Mg uptake. I wouldn't start supplementing without having more information about what you are already putting into the system as you are already feeding at a moderate rate.

It does look as if this problem is specific to your tigrinum, your other plants look OK. I believe it comes from a region of old volcanic soils rather than limestone (unlike many of it's close relatives), which might mean higher micronutrient concentrations and less alkalinity (maybe someone here who knows this species can help here). Maybe it would prefer to have a pH nearer to 5.6 to 6.0 rather than 6.5 to 6.6, particularly in the presence of the high phosphate levels in your fertiliser (phosphate can cause micronutrient deficiencies at higher pHs).

If you don't wish to change anything for the unaffected plants you could make up a batch of your mix, feed all the other plants except the tigrinum, dilute the mix with an equal volume of RO water, optionally add a bit of ammonium sulphate (to reduce the pot pH a bit), and magnesium sulphate and feed your tigrinum with this. Kelp/seaweed extract would help with micronutrients if this is the problem.

I wouldn't add anything without diluting your feed mix first.

tigrinum is typically a tree dweller not a rock dweller so the soil content in the area probably has very little or nothing to with the species.