Culture document

[keithrs]

Why do the other products get the credit? Do you have some new products that other people have not tried before?

I do give others(beneficial bacterias) most of the credit because they have been tested and proven to work! K-lite has not been proven just suspected! Resistance to rot could also be due to lowering N.

That may be the case for beginning growers but a lot of the good reports are coming from experienced folks that already have dealt with these things.

Even experienced growers change and learn new ways. I still think the reduction in N has something to due with reports of lower infection rates.

That one is easy. Plants grow slow and don't give the pleasing result as with a higher N rate. It is not the strength of the fertilizer it is the the balance of nutrients.

Agreed

 

[Rick]

Ok, I follow you fairly well, but there is one thing that puzzles me: If the pH is right (or for that sake wrong) and you disregard any reactions between the compost and the fertiliser mix, when the water hits the plants, how do the carbonate equillibria influence the pH afterwards?

pH is like a black box that measures the sum of H+ in solution.

Certainly in the root zone you can have accumulations of bicarbonate ion (trying to push the pH up) and organic acids (like citric acid) trying to push the pH down, and both can go up in solution proportionately to give the same pH.

The plant will be reacting to the total concentration of bicarbonate ion, but not the net result of the sum of basic and acidic buffering compounds (pH).

I frequently see waters that fluctuate wildly by pH measurement but will have a constant alkalinity value (usually do to the sample not being in equilibrium with the atmosphere). De oxygenated samples in particular have low pH but high alkalinity because the gas balance favors CO2 (and converted to carbonic acid in the system). Let the sample aerate, and pH goes up while bicarbonate/alkalinity stays the same the whole time.

But as before, bacteria and plants need the bicarbonate ion to run many processes (not a generic pH level).

 

[Rick]

To give the accurate dependable results you expect, 500 plants of 25 different species would be needed to test EACH variable.

I agree with all your points except 1 Lance, you can usually hit statistical significance at under 50 replicates.

But still, the "show me crowd" would never be satisfied doing it this way. I've seen plenty of good projects get picked apart to uselessness.

At this point I'm happy with the results in my own GH to give me the confidence to try bigger and better things. I wouldn't have paid $100 for a kovachii seedling until I had seen some of the results of basket and low K growth. The growth of my emersonii after blooming, is making me think of investing in a flask of hangianum seedlings. My results with mastersianum seedlings gave me the confidence to pick up some (hopefull:wink papuanum seedlings.

It seems the point of a hobby is to learn grow experiment. It's depressing to not have stuff grow and bloom. So I'm happier.

 

[Rick]

I don't think it is too much K present in the substrate but rather too much K consumed and stored in the plant tissue. With the correct application of the correct balance of nutrients there should be no reason to repot every year.

True.

With regards to the disease resistance and K/Ca ratio, I didn't make it up or just make a personal observation.

This came from an article by Easterwood in the Fluid Fertilizer Association journal. ( know I posted the link at the time, but it will be referenced in the article).

In challenge tests to (I believe potatoes and beans), the incidence of erwinia and botrytus was reduced or eliminated as tissue Ca went up and K went down. The breaking point was when Ca exceeding K tissue concentration. Challenge tests are pretty extreme since you culture bottles of pathogens and spray them all over the test subject plants trying to force infections. So that seemed pretty convincing.

Since this study was not done with orchids you'll just have to take my word for it that I put 2 and 2 together with my own personal results in my orchid collection.

 

[gonewild]

I agree with all your points except 1 Lance, you can usually hit statistical significance at under 50 replicates.

Yes but when you divide the 50 reps up by all the variables that need to be tested there is not enough to go around. That is what I was referring to.

To be of value to an orchid collector you want to test variables such as:
High light
med light
low light
high humidity
medium humidity
low humidity
high temp
med temp
low temp
(how many variables?)

 

[Rick]

Yes but when you divide the 50 reps up by all the variables that need to be tested there is not enough to go around. That is what I was referring to.

To be of value to an orchid collector you want to test variables such as:
High light
med light
low light
high humidity
medium humidity
low humidity
high temp
med temp
low temp
(how many variables?)

Yup where's me out just thinking about it. Sounds like a job for Monsanto

 

[gonewild]

I do give others(beneficial bacterias) most of the credit because they have been tested and proven to work! K-lite has not been proven just suspected! Resistance to rot could also be due to lowering N.

Even experienced growers change and learn new ways. I still think the reduction in N has something to due with reports of lower infection rates.

Agreed

Lowering the N level will help to reduce the disease but at the cost of plant growth. It reduces the susceptibility to disease by hardening the pant tissues and reducing the amount of soft new tissue.

The idea of K-lite is to provide high enough N to grow rapid and balance out the K lower which IS BEING proven to reduce disease outbreaks.

I agree K-lite has not been proven long term but it has proven to be correct in the "medium" term. Your idea that lowering the N will get better results is not the correct approach. No offense to your concept I just know it is not correct and will result in less plant growth and smaller and fewer blooms.

At one point in time a lot of orchids were grown with low N....because there was no option, no premixed 1 pound bags of balanced fertilizer available. When complete fertilizer mixes started becoming available growers saw huge improvements in their plants mainly due to the higher N levels. It worked so well no one really thought to challenge the K levels until now. So you are correct even experienced growers change and learn new ways, but they don't normally go backwards.

 

[katzenhai2]

I don't think it is too much K present in the substrate but rather too much K consumed and stored in the plant tissue.

This could be measured as the MSU measured the plant tissue of orchids in the wild. Maybe someone should measure an orchid in culture and see if there is a difference.

Yes but when you divide the 50 reps up by all the variables that need to be tested there is not enough to go around. That is what I was referring to.

There is no need to test all variables. If paphs grow better ie. with high humidity than others should do the same and not expecting a fertilizer which will solve their problems on a windowsill. Thats ridiculous IMO. So testing fertilizers in a standarized condition which anyone can adapt to should be fine.

 

[gonewild]

This could be measured as the MSU measured the plant tissue of orchids in the wild. Maybe someone should measure an orchid in culture and see if there is a difference.

The object is not to mimic Nature but rather develop methods that improve on Nature under artificial conditions. The mineral content of wild growing leaves doesn't necessarily mean that is what is best under artificial conditions. Too many variables to rely on tissue analysis...is it the same consistently in all seasons and climates and light exposures? Doubtful.

There is no need to test all variables. If paphs grow better ie. with high humidity than others should do the same and not expecting a fertilizer which will solve their problems on a windowsill. Thats ridiculous IMO. So testing fertilizers in a standarized condition which anyone can adapt to should be fine.

That depends on what results you want to end with. I am making the assumption that the desired result of the ST K-lite trials is to have a formula that is known to work well under a wide range of artificial conditions benefiting the hobby grower.

Of course with 500 plants you could get results and prove one set of conditions. That is what MSU did, they developed a formula that grew orchid plants rapidly to bloom. Their concern was to finish a crop and get it off the benches so another can be produced. They did not consider the long term health of the plants, it does not matter for commercial production. What mattered was planting a Phalaenopsis seedling and selling it in bloom in less than 2 years.

I'm not saying that controlled trials are not worthwhile (I've done plenty) I'm just saying that to the members of the orchid growing community this informal ST trial has more practical value.

 

[keithrs]

Lowering the N level will help to reduce the disease but at the cost of plant growth. It reduces the susceptibility to disease by hardening the pant tissues and reducing the amount of soft new tissue.

The idea of K-lite is to provide high enough N to grow rapid and balance out the K lower which IS BEING proven to reduce disease outbreaks.

I agree K-lite has not been proven long term but it has proven to be correct in the "medium" term. Your idea that lowering the N will get better results is not the correct approach. No offense to your concept I just know it is not correct and will result in less plant growth and smaller and fewer blooms.

At one point in time a lot of orchids were grown with low N....because there was no option, no premixed 1 pound bags of balanced fertilizer available. When complete fertilizer mixes started becoming available growers saw huge improvements in their plants mainly due to the higher N levels. It worked so well no one really thought to challenge the K levels until now. So you are correct even experienced growers change and learn new ways, but they don't normally go backwards.

Why are lots of grower reducing there N and still seeing same or better growth and equally important, same or better flowering? What I'm more interested in is root growth. Rick has documented that he only uses about 50 ppm N a week and he may be even be reducing that. I use 30 ppm N every water which is about 175-200 ppm N in a week while in growth and I feel it's still to much. I feel 75-100 ppm N a week will do just fine.

 

[gonewild]

Why are lots of grower reducing there N and still seeing same or better growth and equally important, same or better flowering?

Do they really know how much they were actually using to start with?
If have the amount of N that MSU recommends is better then why did they advise to use more?

It makes no sense to think a large amount of growers are suddenly cutting their N below recommended levels and then seeing better results.......UNLESS it is because at the same time they are also lowering the K to acceptable levels. And then if the raise the N back up they will have even better growth.....and then you have K-lite.

What I'm more interested in is root growth. Rick has documented that he only uses about 50 ppm N a week and he may be even be reducing that. I use 30 ppm N every water which is about 175-200 ppm N in a week while in growth and I feel it's still to much. I feel 75-100 ppm N a week will do just fine.

But Rick is also reducing K. The point is that by reducing K you can use lower rates of N. But if you reduce N and keep K at a high % then you will slow growth as proven by history and MSU trials.

 

[keithrs]

Do they really know how much they were actually using to start with?
If have the amount of N that MSU recommends is better then why did they advise to use more?

It makes no sense to think a large amount of growers are suddenly cutting their N below recommended levels and then seeing better results.......UNLESS it is because at the same time they are also lowering the K to acceptable levels. And then if the raise the N back up they will have even better growth.....and then you have K-lite.



But Rick is also reducing K. The point is that by reducing K you can use lower rates of N. But if you reduce N and keep K at a high % then you will slow growth as proven by history and MSU trials.

As Ray has pointed out several times... 125 ppm N was a random dosage that just seemed to work so that's what they recommend. Ray has also pointed out that he no longer recommends that dosage from my understanding.

Your right... It does make no sense that large amounts of growers will suddenly lower there fertilizer rate... But I do see it happing and becoming a tread only for the reason that the growers(when I say growers I mean hobbyists)that have lowered there dosage of fertilizer have seen the same growth or better growth... Its a waste to use much more than 50 ppm N during a single watering no matter the make up of the fertilizer. Orchids just can't uptake that much fertilizer in the short periods that most fertilize in.

 

[gonewild]

As Ray has pointed out several times... 125 ppm N was a random dosage that just seemed to work so that's what they recommend. Ray has also pointed out that he no longer recommends that dosage from my understanding.

125 ppm N is not just a random dosage. When MSU is mixed at a total strength that is the known proper strength traditionally used as fertilizer on greenhouse crops the result is about 125 ppm of N. Additionally the MSU trials supported that rate.
Originally the strength was determined by stair stepping the dosage gradually upwards and monitoring plant growth. When it became obvious that too much fertilizer was being applied the dosage was reduced back to the level that had given the best results. In the case at that time the best result was the fastest growth.

Your right... It does make no sense that large amounts of growers will suddenly lower there fertilizer rate... But I do see it happing and becoming a tread only for the reason that the growers(when I say growers I mean hobbyists)that have lowered there dosage of fertilizer have seen the same growth or better growth...

Maybe we have a different perception of what good growth is?

I don't know what large amounts of growers are doing but if they think suddenly they are getting better growth by using half the nutrients as before something has changed. perhaps the fertilizer brands they are using are not mixing the fertilizers the same. If they are using fertilizer that is based on UREA then they may be better off with less fertilizer.
So far here on ST I don't read a large amount of posts saying that cutting fertilizer rates in half are giving better results...except those that are using K-lite.

Its a waste to use much more than 50 ppm N during a single watering no matter the make up of the fertilizer. Orchids just can't uptake that much fertilizer in the short periods that most fertilize in.

That just is not true. I have done those trials personally years ago and orchids grow faster with 125ppm N compared to 50ppm. Now it may be true if your environmental conditions are not at the ideal levels for maximum growth. If you are comparing growing orchids outdoors on your patio to growing in an environmentally controlled greenhouse then you would be correct, conditions that promote slow growth only require small amounts of nutrients.

in the short periods that most fertilize in.

I'm not sure what you mean?
Fertilizer should be applied with every watering and as a result the moisture in the media always has nutrients available.

 

[Rick]

The first several months of Low K I was still feeding N between 75 to 100ppm with K dropped down to around 20 ppm. And already seeing noticeable differences. Klite didn't come in til 9 or more months, and I started out at roughly 80 ppm N initially (at least for the spring summer months after it came out around December). I don't think I cut back to 30-50 ppm N until somewhere late summer (need to check when I started checking pot conductivity), and results were well under way by then.

Typically people cut back in winter by either cutting concentration, frequency, or both. Some don't feed at all for the entire winter season. During warmer months I'm pretty religious about weekly feeding. During winter if its snowy, cold and gray, it doesn't hurt my feelings to skip a week or two. This year I'm doing something a little different. I might make up a batch of Klite to feed at 50 or so ppm on Sunday. If the weather is crappy and cold, I might just water with maybe 5ppm N from the concentrate. I'm typically watering at least the mounted stuff daily, and give them daily shots at 5ppm(??) to use up the Sunday concentrate over the coarse of the week.

 

[gonewild]

I forget you have winter. In our growing conditions here in California everyday is pretty much the same as the last. In a greenhouse it is Spring everyday. Maybe not watering on one of the 20 days per year it rains but on the other days watering is no problem.

Yesterday I saw the first wildflowers of the year. It even rained last week!

In my indoor artificial light growing area I watered everyday because the environment was constant and not affected by the outside climate.

That just goes to illustrate all the variables that would need to be addressed in a controlled trial.

So are you cutting back the N because it is winter or because you think 30ppm is enough year round?

 

[Stone]

Here's a study of Catt, cym and phal hybrids that (from what I see with a quick look) basically found that at 50, 100 and 200ppm K had little effect on growth and didn't really inhibit Ca or Mg uptake any more than N did. But it can get very complicated with all the interelationships between the N, K, Ca and Mg and whether NH4 is used.
http://www.firetailorchids.com.au/_pdfs/poole_and_seeley.pdf

 

[Rick]

I forget you have winter. In our growing conditions here in California everyday is pretty much the same as the last. In a greenhouse it is Spring everyday. Maybe not watering on one of the 20 days per year it rains but on the other days watering is no problem.

Yesterday I saw the first wildflowers of the year. It even rained last week!

In my indoor artificial light growing area I watered everyday because the environment was constant and not affected by the outside climate.

That just goes to illustrate all the variables that would need to be addressed in a controlled trial.

So are you cutting back the N because it is winter or because you think 30ppm is enough year round?

I started in September (this year) just because pot TDS levels were high so I was planning on just cutting back on feeding until pot TDS levels stayed down. But then I got a flush of root growth in the process, and then fall/winter ensued. So I really am playing wait and watch with what comes up as spring kicks in. My habits would be to pick back up to at least 75, but the eco data doesn't indicate that's necessary.

I hate to make things more complex than I need, but maybe I'll keep the seedlings and little things at less than 50, but the big specimen plants back up to 80-100?

 

[Rick]

and didn't really inhibit Ca or Mg uptake any more than.
http://www.firetailorchids.com.au/_pdfs/poole_and_seeley.pdf

Ya I saw this article when I was looking at things in the past.

Actually if you look at table 3 it shows that as K goes up, Ca an Mg go down (and significantly) all those little ABC's off to the side denote which items in that column are statistically significant.

In table 3 they only show the lowest K at 100 ppm (for Phales) 50ppm for the other genera, so we are dealing pretty much with the old MSU data that looked at orchids already exposed to high K.

Note that the K is always higher than Ca/Mg This ain't like it is in the jungle, where K is lower than 5ppm and Ca higher than K

 

[keithrs]

125 ppm N is not just a random dosage. When MSU is mixed at a total strength that is the known proper strength traditionally used as fertilizer on greenhouse crops the result is about 125 ppm of N. Additionally the MSU trials supported that rate.
Originally the strength was determined by stair stepping the dosage gradually upwards and monitoring plant growth. When it became obvious that too much fertilizer was being applied the dosage was reduced back to the level that had given the best results. In the case at that time the best result was the fastest growth.

Thank you for clarifying!

Maybe we have a different perception of what good growth is?

It may be so... I don't look for super fast growth as it is more prone to infections.

That just is not true. I have done those trials personally years ago and orchids grow faster with 125ppm N compared to 50ppm. Now it may be true if your environmental conditions are not at the ideal levels for maximum growth. If you are comparing growing orchids outdoors on your patio to growing in an environmentally controlled greenhouse then you would be correct, conditions that promote slow growth only require small amounts of nutrients.

I dont doubt your findings as my plants grow faster on 125ppm N but does that make them 'better'? They grow faster but how long do they live? I compare that to someone eating a fatting diet for there whole life and another eating a limited controlled diet that supports there activity levels. Sure some may be active enough to support that fatty diet and show little effects other than being alittle 'over weight' and then suddenly die from there health problems or show the effects of there diet and die a slow death.... While the one on a healthy diet that supported normal growth lived a longer healthier life.

I also ask you, How many of us have ideal conditions? If we did we could all do a trial on K-Lite and prove that works or not.oke:

Personally, I like the results of K-lite and buy the proof mother nature provides. I'm not sold on the fact that it drastically reduces infections.(I have an epiphyllum that was feed K-lite and is full of an infection as we speak) Just like I'm not sold on aspirin as a cure to infection.

As you said earlier...Its easier to correct an deficiency than an over feed plant.

I'm not sure what you mean?

Most people just give there plants a quick spray of fertilizer. Some may come back for a second dose. I suggest to water like mother nature does and water for longer periods with less fertilizer as a mist or small drops. Not a drench that flows water so fast that your plant barely has time to absorb the water.

Fertilizer should be applied with every watering and as a result the moisture in the media always has nutrients available.

I do agree with applying fertilizer at every watering and that nutrients may be available in the pot but if the roots can't uptake because the media has absorbed the moisture with nutrient.... Or if you flush more then fertilize to control the EC in the pots... How about plants on mounts? What use does excess fertilizer in the pot really have? How much fertilizer is really available to the plant vs how much are you really hurting the plant with excess salts? As you know...Medias have different properties that may or may not allow the root zone to stay moist to the point the roots can absorb the nutrients.

 

[Rick]

didn't really inhibit Ca or Mg uptake
http://www.firetailorchids.com.au/_pdfs/poole_and_seeley.pdf

I think what is really telling (unless its a typo) is that Ca was available at constantly 200ppm (!!!) while the K is added at 50 -300 ppm. And the K was still ending up in the plants at higher concentrations than the Ca or Mg! And suppressing with increasing K dose. Isn't this in total support of the theory that if K is present in large quantities, the plants will pick it up preferentially to Ca? Shoot I wish I had looked at this article closer when I did, it really helps make the low K point!

They only ran this test for 1 growing season too it seems, and with easy plants.

What would the results be like if (like the rest of us RO users with MSU) are seeing with 100ppm K and only 50ppm Ca?