Sick leave on Phrag. Eumelia Arias... Advice needed!

[Rick]

Be aware that fluoride can cause this problem. Some species such as cymbids are very susceptible. Perlite contains fluoride. It can be nutralized by mixing a little soil with your first watering. Mains water can also contain fluoride. This may not be your problem?

Fluoride is a real binder to calcium. That's part of the protective aspect of adding it to drinking water, is that it binds to calcium in tooth enamel making insoluble calcium fluoride (rock). I had a big toxicity test (several years ago) to do with fluoride using (soluble) sodium fluoride. Just about as soon as it hit hard water with plenty of calcium in it, it would produce precipitates that clogged up my system!! Even after soaking in dilute acid some of those precipitates remain today like hard scale deposits.:sob:

The mains water may be at a ppm or two of fluoride, and that doesn't seem to be a problem to plants. If there are high levels of a soluble fluoride salt in Perlite, it could easily get neutralized with dolomite.

 

[Stone]

Mr Manrique uses the following in his p/mix: Granite 50%-acid and can have high K, T/fern-very acid pH3-4 and high K, bark-acid and high K. Obviously all but the most acid loving plants would soon suffer without the addition of liming materials of some kind to bring the pH to the neutral territory of the habitat and to balance the K. My point: kovachii does not need extra Calcium. It needs the same amount as Paph. bellatulum, sanderianum or charlsworthii.

 

[Rick]

pH has nothing to do with calcium concentration (that's regulated by hydroxides and carbonates), and I agree that kovachii has no special need of Ca compared to any other plants. But circling back to the K -lite topic, orchids have even less of a need for K than Ca. And we have plenty of evidence that K is antagonistic to Ca and Mg (causing apparent "deficiencies" of divalent cations). In some cases high K may be countered with addition of Ca, making it appear (conversely) that the plants have a higher than normal Ca requirement rather than an inherent intolerance of high K.

No need to start this all over again, but several of us have "cured" our problems with phrag leaf tip burn by dropping K and ensuring normal levels of soluble Ca (even while maintaining fairly high N).

What's to loose by adding less to get better results:wink:

 

[Rick]

Mr Manrique uses the following in his p/mix: Granite 50%-acid and can have high K, T/fern-very acid pH3-4 and high K, bark-acid and high K.

Actually whatever the inherent K is in these plant products, they also have even more inherent Ca, and probably as much Mg as the internal K. As noted from the leaf litter analysis of rain forest plants, plants in general retain more Ca in their tissues than K. K is primarily stored in fruits, tubers, and starchy seeds..corn seed is the prime example.

Most granites is not high in K (even insoluble forms) or low pH. http://en.wikipedia.org/wiki/Granite

The amount of available K in the substrates is negligible compared to the amount added by typical fertilizers.

The natural karst limestone habitats for kovachii are highly deficient in K.

So correct, kovachii has no special Ca requirement, but an intolerance to high K.

 

[Stone]

Actually whatever the inherent K is in these plant products, they also have even more inherent Ca,

Not always, Chc and many fern fibers have very high K and very low Ca concentrations. Pine bark has enough K to make it unnecessery to add more for a year.

Most granites is not high in K (even insoluble forms).

Granite dust is used here in agriculture to supply K.

The amount of available K in the substrates is negligible compared to the amount added by typical fertilizers.

True. If Marique is growing good quality kovachiis with a 15-5-15 formulation and with 300ppm calnitrate and magsuphate ( and I presume he is ) then he has the right K Ca Mg balance.

So correct, kovachii has no special Ca requirement, but an intolerance to high K.

Without Ca and Mg to balance.

 

[Stone]

pH has nothing to do with calcium concentration

Not so! A high ph in soil or p/mix almost always indicates a high calcium carbonate level.

No need to start this all over again, but several of us have "cured" our problems with phrag leaf tip burn by dropping K and ensuring normal levels of soluble Ca (even while maintaining fairly high N).

What's to loose by adding less to get better results:wink:

Ha!!

I'm not out to prove your low K theory wrongoke: and no there's nothing wrong with reducing K. I totally to agree with the problems it can cause, and I'm continuing to try to monitor K levels.
BUT!!, There is no getting away from the FACT that millions of orchids consisting of thousands of species are being grown to superb standards all over the world using all kinds of fertilizer combinations and concenrations including many with high K. ( just ask any award winner what he's feeding ) A lot of people don't have a clue what's in their feed! SO,--- is it possible that the high K problem is in many cases being balanced with the apropriate amounts of Ca and Mg whatever they happen to be and probably without the grower even realizing it?
Consider my Cattleyas, for many years I had been growing them without even considering Ca and Mg. and feeding with standard osmocote with very high K but without added Calcium or Mag. and I had no problems. My water was very hard. When I switched to rain water I noticed problems of reduced and unhealthy looking growth. Now when I pot up I use osmocote formulated for citrus with high Mg and top dress with Gypsum. They have NEVER grown better. The formulation is 16.6-2-6.6+2.2mg. AND I use bark/chc mix. Plenty of K and no problems!
I think it's all in the balance.
Not trying to start a new thread and no need to reply
Mike

 

[Rick]

Not always, Chc and many fern fibers have very high K and very low Ca concentrations. Pine bark has enough K to make it unnecessery to add more for a year.

So have you even checked to see how much Ca and Mg it has in it?



Granite dust is used here in agriculture to supply K. As noted some forms will have a bit more K than others, and dust is way more soluble than pea gravel. But some folks also use high alkaline silicate granite pebbles to raise pH. What kind of "granite" gravel is Manrique advocating?



True. If Marique is growing good quality kovachiis with a 15-5-15 formulation and with 300ppm calnitrate and magsuphate ( and I presume he is ) then he has the right K Ca Mg balance.





Without Ca and Mg to balance. Well he's plowing way more Ca/Mg into his plants than K so unless he experiments with a system devoid of Ca we won't know

My kovachii is doing just fine in a moss/basket system using limestone gravel, aragonite sand, silica sand, K lite fert (<50ppm N) with 10:1 RO:well water for primary irrigation water. Plenty of new leaves (no burn), roots, it just started a second growth at only 12" leaf span.

 

[Kavanaru]

Wow! Thanks a lot for the tips and the informative discussion... I have been following the K-Lite thread, and had decided to start a test with some friends on our Catasetinae, as we had some issues we have not managed to solve (the good about Catasetinae, is that if it will have a negative impact, you will see results in one growing cycle)... Did not plan to apply to me other p lants, as they are all performing very well, and wanted to see more results coming from you... Maybe I will use I it for my Phrags as well...

Some more detailed information regarding the conditions of my plant in this thread, which is missing:

Aware of the information that Pk needs "extra" calcium, I do add two tsp of dolomite sand to the pot of bot Pk hybrids I have (also to fischeri). Fluoride in the well water is below 1.5 ppm. I use well water, which is pretty soft here, and fertilize with Rain Mix for soft water (Dutch brand, developed according to MSU standards, and pretty similar to it - funnily, when using MSU and RO I started seeing deficiency symptoms in many of my plants, which disappeared after changing to Rain Mix). Perlite, is less than 25% of the substrate... Maybe I should reduce it as well...
what confuses me the most, is that of the two Pk hybrids, only one developed the symptoms shown in the pics above... Actually, this is the only plant in my collection with those symptoms...

As mentioned, I will repot the Phrags today, and check the roots and compared the quality of the substrate in all 5 Phrags...

 

[Rick]

Another compounding factor with K is how different potting compounds selectily retain K rather than Ca/Mg as a Cation Exchange property.

Some things like CHC really likes to suck up K and release divalents. So unless you repot frequently the potting mix can be saturated with K, increasing the effective K dose well beyond the amount pulled by the plant during fertilizing.

Root mass, ratio of root mass to pot volume, feeding rate, growth trajectory on plants all increases the variable nature of the symptoms, not to mention the genetic composition of the individual plant.

Since fertilizers were basically developed for corn and corn is a totally domesticated plant, then you can't tell how many generations of selective presure will it take to get different orchids to "adapt" to a high k regulated environment. Complex phal and catts hybrids may be totally domesticated at this point.

The concept of "success" is relative. When I reduced K I was focused on the problem plants, but I was surprised as to the number of plants in my collection that I considered as already doing good, are better than ever.

 

[Brabantia]

Receives not more than 120 ppm nitrogen every second watering and is always sitting on a 1 inch deep reservoir of water... Same as the other Phrags...

120 ppm Nitrogen is to hight! I use AKERN Rain Mix at 65 ppm Nitrogen one time per week this is enough. I flush the substrate with rain water one time per month. If you hold the pots in water make some holes (6 mm diam.) at 3 cm from the bottom of the pot that will allow air to renter in the substrate what is not possible if you maintain the bottom of the pot in a level of water.

 

[Kavanaru]

120 ppm Nitrogen is to hight! I use AKERN Rain Mix at 65 ppm Nitrogen one time per week this is enough. I flush the substrate with rain water one time per month. If you hold the pots in water make some holes (6 mm diam.) at 3 cm from the bottom of the pot that will allow air to renter in the substrate what is not possible if you maintain the bottom of the pot in a level of water.

120 ppm is what I have used for more than 6 years without major problems... As for the pot, that's how they are constructed... 3 cm reservoir and holes at that level... The pot is filled to the top at each watering and the water flushes away, leaving only the reservoir...

 

[Kavanaru]

By the way, I repotted the plant yesterday... Substrate was in good shape (1 year old) roots in the center were dead, but there were plenty of good roots (with active tips) on the sides...

 

[John M]

What exactly is pea gravel?

Interesting the experience with the aspirin... I know of some studies related to ASA in the jungle c plants are attacked by insects... How often do you that?

Pea gravel is simply small, rounded gravel, about the size of a large green pea. You can buy it in bulk from landscaping companies.

If you google and look around on the Internet, you will find plenty of published studies that show the benefits of ASA in helping plants to fight off disease. I was skeptical at first; but, I've become convinced now that I've seen the results of using it. I only spray plants that have a problem. I try to grow my plants in an environment and with nutrition that does not encourage Erwinia; but, I do see it in some plants, from time to time. Usually, once a plant gets an Erwinia infection, it is very difficult to stop the infection, even if all the affected tissue is removed. However, I've found that if I remove the affected tissue and then thoroughly spray the entire plant with the ASA solution, the Erwinia does not come back. I've only been using it for a few months; but, I'm very pleased with the results so far.

 

[Kavanaru]

Thanks a lot for sharing the experience with ASA!

PS.- I have checked for pea gravel in Wikipedia, as it made curious...

 

[Brabantia]

@John: what is the ASA concentration you use to drench your plant?

 

[John M]

I disolve 1 regular strength (325mg), tablet in 1 litre of water. I've seen it published that even as little 1 extra strength (500mg), tablet in 2 US gallons (~ 8 litres) works. I haven't used it at that low concentration. I'm happy with the results I'm seeing now and it's not as if I can't afford to use a whole tablet in just 1 litre of spray solution.

 

[SlipperFan]

Even the 1 tablet per litre of water seems dilute!

 

[Ruth]

How often do you spray with the asprin water?

 

[Kavanaru]

Even the 1 tablet per litre of water seems dilute!

According to the articles I have read, the ASA itself does work against the infection, but induces the plant to activate a defense metabolism producing metabolites that work against the infection. Only very low concentrations of ASA are needed for this.... One of the cases they studied was on trees in the jungle, which (when attacked by caterpillars) produced those defense mechanisms, including as well the production of ASA and some volatiles. The presence of ASA in the ground (due to fallen leaves) and/or the volatiles in the air, were sufficient to induce the activation of the defense mechanism in all trees around the infected one...

 

[SlipperFan]

According to the articles I have read, the ASA itself does work against the infection, but induces the plant to activate a defense metabolism producing metabolites that work against the infection. Only very low concentrations of ASA are needed for this.... One of the cases they studied was on trees in the jungle, which (when attacked by caterpillars) produced those defense mechanisms, including as well the production of ASA and some volatiles. The presence of ASA in the ground (due to fallen leaves) and/or the volatiles in the air, were sufficient to induce the activation of the defense mechanism in all trees around the infected one...

Interesting -- thanks for the info. Sound a bit like homeopathy.