Roth
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Over the course of a study sponsored by Pacific Wide/Besgrow, and carried out at Lincoln University, the following points appeared on a Phalaenopsis Sogo Yukidian 'Clone' mericlone population used for the test:
* The media and root concentration were not related. Instead, the potassium contents of the roots was related to the media type used, but not the ionic concentration of potassium.
* The foliar concentration of potassium was not related to the root concentration or the potting mix concentration. As an extract of the whole analysis:
Coir : foliar concentration 56000ppm root concentration 23600ppm, media concentration 2073ppm
Orchiata : foliar concentration 35600ppm, root concentration 8688ppm, media concentration 875ppm
New Zealand sphagnum moss foliar concentration 44000ppm, root concentration 18600ppm, media concentration 1914ppm
Us fir bark : foliar concentration 41600ppm, root concentration 10370ppm, media concentration 1100ppm
The US fir bark had the poorest leaf color of the various potting mixes tested ( here are only 4 as samples, but the total study encompassed 8 different potting mixes), with a low potassium value. There is no correlation between plant growth, quality and potassium content of the potting mix apparently...
As for the plant quality, weight, size, and leaf color have been assessed. It appears that the plant quality and strength was not related to the potassium concentration at all.
There are many more data from that study, being currently processed. However, it appears that we cannot find any intoxication by potassium, and there was no correlation between plant health and potassium. Other intermediate measurements are not included here, but plants are not intoxicated by potassium. The calcium and magnesium levels were not correlated to the potassium content either...
More will be published in the coming months out of the whole study.
We could say that maybe some other genera and species would respond well to the low K concept, but I do not use it, and many people neither. However, I use ammonium and urea in the feeding program, which always gives superior results, regardless of the potting mix used...
The low potassium could work well in the case of an all nitrate fertilizer only, because the nitrate force an ion. However, with the use of the monovalent cation ammonium, I have the feeling that the results would be the same, but superior.
* The media and root concentration were not related. Instead, the potassium contents of the roots was related to the media type used, but not the ionic concentration of potassium.
* The foliar concentration of potassium was not related to the root concentration or the potting mix concentration. As an extract of the whole analysis:
Coir : foliar concentration 56000ppm root concentration 23600ppm, media concentration 2073ppm
Orchiata : foliar concentration 35600ppm, root concentration 8688ppm, media concentration 875ppm
New Zealand sphagnum moss foliar concentration 44000ppm, root concentration 18600ppm, media concentration 1914ppm
Us fir bark : foliar concentration 41600ppm, root concentration 10370ppm, media concentration 1100ppm
The US fir bark had the poorest leaf color of the various potting mixes tested ( here are only 4 as samples, but the total study encompassed 8 different potting mixes), with a low potassium value. There is no correlation between plant growth, quality and potassium content of the potting mix apparently...
As for the plant quality, weight, size, and leaf color have been assessed. It appears that the plant quality and strength was not related to the potassium concentration at all.
There are many more data from that study, being currently processed. However, it appears that we cannot find any intoxication by potassium, and there was no correlation between plant health and potassium. Other intermediate measurements are not included here, but plants are not intoxicated by potassium. The calcium and magnesium levels were not correlated to the potassium content either...
More will be published in the coming months out of the whole study.
We could say that maybe some other genera and species would respond well to the low K concept, but I do not use it, and many people neither. However, I use ammonium and urea in the feeding program, which always gives superior results, regardless of the potting mix used...
The low potassium could work well in the case of an all nitrate fertilizer only, because the nitrate force an ion. However, with the use of the monovalent cation ammonium, I have the feeling that the results would be the same, but superior.