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Phalaenopsis growth is determined by temperature. There are variations and exceptions between species but as a general rule...

At temperatures above 28c degrees the plants are in a vegetative state and grow leaves and do no flower.
Below 28c degrees the plants switch to a reproductive state and leaf growth slows down or stops and flowering is induced.
 
Phalaenopsis growth is determined by temperature. There are variations and exceptions between species but as a general rule...

At temperatures above 28c degrees the plants are in a vegetative state and grow leaves and do no flower.
Below 28c degrees the plants switch to a reproductive state and leaf growth slows down or stops and flowering is induced.
Aha... *coughs* Well, then that solved it I guess. Yeah, my Phals need some warmth quite obviously.
 
Phalaenopsis growth is determined by temperature. There are variations and exceptions between species but as a general rule...

At temperatures above 28c degrees the plants are in a vegetative state and grow leaves and do no flower.
Below 28c degrees the plants switch to a reproductive state and leaf growth slows down or stops and flowering is induced.


From the duration of daylight as well.
 
Mike, I've got to wonder if this is a "chicken or egg" thing that you've chosen to interpret one way.

Phalaenopsis, if kept very warm, are pretty fast growers in the orchid world. Growth requires nutrition. If they are in a fast growth mode, they will take advantage of the nutrition supply. Keep them cooler so they are not growing so fast, and I doubt that applying more fertilizer will accelerate their growth.

I have several phals in my greenhouse, getting the same 25 ppm N that everything else does, and over the summer, they pretty much all doubled in size.


Ray Barkalow
firstrays.com

My point is (if it is a point) that in this case at least, increasing fert concentration lead to ingreased growth. (which is what I want) I started with an total EC of about 0.4 dS/m. Growth was ok and the plants grew steadily. Now thay are getting double that (around 0.8 to o.9). But I think I could go up to 1.00 dS/m or even higher (about 1 gram of fert per litre as in many of the trials) without problems and possibly even greater results.
One thing Iv'e noticed with more feed too is leaf width has definately increased. (another desirable quality in my eyes)
According to one of the Wang trials, leaf width was attributed to increasing potassium.
Of course temps have to be high with this feeding rate. (min of 18 to 20C and up to 30C during the day. Hours of light is probably important too) and plenty of air and humidity.
I plan on reducing the rate drastically over the next winter to maybe 0.4 again.
 
Maybe high feed rates age Phalaes at a faster rate than otherwise.

There is no evidence that I know of the shows that and thinking about it it doesn't make sense to me. If it's growing well, it's growing well.

A plant can only grow in speed and size according to it's genetic potential. And to do that it must have everything at it's optimum level. ( and I'm not propsing we know what they are in most cases) Just because it does not see these quantaties of nutrients and water in the habitat, does not necessarily mean it does not have the genetic potential for accumilating much higher nutrient imput and do better for it.

Consider this example: Isabellia violacea grows in Brazil and generally produces 1 flower in the habitat. But in cultivation it almost always produces 3 or even 4 flowers. So the genetic potential of the plant for ''bettter'' conditions is there waiting for a change in circumstaces to manifest themselves.

I believe (some) plants are very elastic in what they can cope with or exploit.
Sometimes we can actually go by what the plant actually does rather than what we expect it to do.
 
Don't forget that plants (not just phaleas) are 99% water and carbon. Every new inch of leaf and root you see is 99% water and carbon. So growth is primarily limited by the amount of water and CO2 a plant gets way before worrying about the NPK.....

So the more you water the faster they grow. The higher the humidity the less water lost between watering events, and more CO2 brought into the plant. Dipping in a bucket of water 3 times a day is better than spraying down 1 time per day, or adding an ice cube once a week.


With regard to the inorganic chemistry issues, ammonia is an effective blocker of all the other cations. In a relatively high ammonia feed you may need a ton of K to break through the ammonia antagonism. Wang's conditions includes a lot of ammonia, and ultimately a lot of pesticides and fungicides since the plants are low in Ca and extra susceptible to disease. But you can certainly get them to market faster!!!
 
That explains why my Phals don't grow anything but roots... I need to up the fertilizer then. Thanks! :D

Absolutely no reason to increase feed rate, need to increase watering.



Mike can you post some pics showing the roots better? Ever since changing my feed to facilitate better Ca uptake, the roots will just about cover the entire mount in about a year.
 
Absolutely no reason to increase feed rate, need to increase watering.
I figured out (or rather NYEric did) that it's not the feed rate that's the major issue, but the temperatures. The average temperature in my apartment is too low for Phals, and if it's something I don't need to increase it's watering. I'm a chronic overwaterer already.
 
Don't forget that plants (not just phaleas) are 99% water and carbon. Every new inch of leaf and root you see is 99% water and carbon. So growth is primarily limited by the amount of water and CO2 a plant gets way before worrying about the NPK.....

Yes but they get 99 times more water than nutrients anyway. Water and CO2are not really my concern. They always get about the same amount ie; whenever they are dry. Varying the NPK in that water does vary the results though.

So the more you water the faster they grow.

Assuming they get as much water as they could possibly use, the limiting factor then becomes N etc.


With regard to the inorganic chemistry issues, ammonia is an effective blocker of all the other cations. In a relatively high ammonia feed you may need a ton of K to break through the ammonia antagonism.

That's possible but what constitutes reletively high ammonium? I'm giving mine 25% and the rest nitrates. I have no idea how much K you need to overide the NH4 but it is way higher in this mix. As you say NH4 does also affect uptake of Ca and Mg but I see no issues in the plant at the moment,
Root growth is good and no old leaf senescence or yellowing yet which is the first sign of low Mg or low K or N. So it seems to be pretty well balanced visually.

Wang's conditions includes a lot of ammonia, and ultimately a lot of pesticides and fungicides since the plants are low in Ca and extra susceptible to disease.

If you are worried about low Ca in the plant you can simply feed plain Cal nitrate a couple of times at the end of the growing season. But I doubt that would be necessary.
 
Absolutely no reason to increase feed rate, need to increase watering.



Mike can you post some pics showing the roots better? Ever since changing my feed to facilitate better Ca uptake, the roots will just about cover the entire mount in about a year.

Next time I'm in there with the camera. I certainly don't get roots like that. But we also have to compare species with species.
If you can achieve that kind of root growth with the nitrate only and low K (which makes sense), it would be an interesting experiment to see just how much explosive growth you would get by maxing out the feed for a while!:evil: (in the summer of course)
If fact that could be a new way of growing???? A root promoting cycle (which may take a year) followed by a leaf and flower cycle then back to the roots..... Interesting!
 
Next time I'm in there with the camera. I certainly don't get roots like that. But we also have to compare species with species.
If you can achieve that kind of root growth with the nitrate only and low K (which makes sense), it would be an interesting experiment to see just how much explosive growth you would get by maxing out the feed for a while!:evil: (in the summer of course)
If fact that could be a new way of growing???? A root promoting cycle (which may take a year) followed by a leaf and flower cycle then back to the roots..... Interesting!

Not sure if we have matching species, but extensive root growth isn't limited to this pallens. How about a stuartiana, belina, bastiani, mariae, deliciosa, or parrishii?

I've had this plant since 2006 (?) so I've seen it grow under the old "weekly weekly MSU" program vs the "lowK starvation" plan with night and day difference so I'm not really interested in going back to the heavier feeding days.
 
If you are worried about low Ca in the plant you can simply feed plain Cal nitrate a couple of times at the end of the growing season. But I doubt that would be necessary.

That's a potential strategy, but I doubt you'd get much Ca into a plant (quickly) with all that K stored up in the tissues.

Switching from MSU to K lite showed some good responses over a couple months, but cleaning up the pallens to what it is now took a year.

Also would probably have to start from scratch with a compot of seedlings. Over the years I've had a lot of force fed rescue phals dumped on me that died of rots in the first month of trying to wean them off of their old regimes.
 
Just thinking going from MSU to the work around and finally K lite basically just changed the % calcium and magnesium nitrate salts from about 40% to 90% anyway.

I just never looked back the following summer to switching back to a higher percentage of potassium nitrate. Growth never slowed down to indicate any shortages. In fact I just kept cutting back on concentration and increasing frequency to get better results each year.
 
Yes but they get 99 times more water than nutrients anyway. Water and CO2are not really my concern. They always get about the same amount ie; whenever they are dry. Varying the NPK in that water does vary the results though.

Assuming they get as much water as they could possibly use, the limiting factor then becomes N etc.

Actually you missed my point that most of us limit growth not by shortages of inorganic nutrients by by limiting water. Your explosive growth is most likely due to watering 3 times a day as opposed to a grower with a potted phal giving an ice cube a week who is afraid to rot the roots off.

Plants must transpire a lot of water to fix carbon. And 97 percent of water goes in and out of plants with only 3% going to metabolism. And according to the plant physiology books, it takes about 800 to 1200 moles of water to fix 1mole of CO2 (and 1 mole of cellulose needs 6 moles of CO2). The solid structures of plants are mostly cellulose, which actually has no NPK incorporated into it (cellulose is C6 H10 O5) repeated over and over into huge polymeric structures.

A gram of new plant is 1% inorganics or 10mg of inorganic nutrients.

But conservative water use in plants indicates it will take about 200 ml of water to grow that 1 gram of tissue that contains 10mg of fert. So at .8dS/M that's a TDS of ~550 mg/L. 200 ml of fert at that concentration holds 110 mg of NPK..... or about 10 times what the plant needs to make a gram of fresh growth.

So now it just goes back to what the plant does to handle the excess fert. But you are definitely not N limiting.
 
Actually you missed my point that most of us limit growth not by shortages of inorganic nutrients by by limiting water. Your explosive growth is most likely due to watering 3 times a day as opposed to a grower with a potted phal giving an ice cube a week who is afraid to rot the roots off.

Well actually no. The increased growth rate was due to more nutrients entering the plant. The water it recieved in the first year was exactly the same as it gets now. It was very easy to identify the increased growth rate. Believe me this plant was never short of water for more than 1 or 2 hours. Probably much less than if it were in the habitat. Water is and never was a limiting factor in this case.

Plants must transpire a lot of water to fix carbon. And 97 percent of water goes in and out of plants with only 3% going to metabolism. And according to the plant physiology books, it takes about 800 to 1200 moles of water to fix 1mole of CO2 (and 1 mole of cellulose needs 6 moles of CO2). The solid structures of plants are mostly cellulose, which actually has no NPK incorporated into it (cellulose is C6 H10 O5) repeated over and over into huge polymeric structures.

You are over-thinking it.




But conservative water use in plants indicates it will take about 200 ml of water to grow that 1 gram of tissue that contains 10mg of fert. So at .8dS/M that's a TDS of ~550 mg/L. 200 ml of fert at that concentration holds 110 mg of NPK..... or about 10 times what the plant needs to make a gram of fresh growth.

That is not the way to look at it. If you tried to supply exactly what the plant ''needs'' you end up starving it. The way to feed (assuming everything else is right), is to increase the EC up to just before the point where any higher increase begins to reduce growth. (over the hill in the graph) Anything before that point is good not bad. That's the was trials are carried out and that's really the only way. This can only be done with close observation of the plants' response to treatment. Trying to work it out mathematically will lead to confusion and probably substandard results.
 
That is not the way to look at it. If you tried to supply exactly what the plant ''needs'' you end up starving it. The way to feed (assuming everything else is right), is to increase the EC up to just before the point where any higher increase begins to reduce growth. (over the hill in the graph) Anything before that point is good not bad. That's the was trials are carried out and that's really the only way. This can only be done with close observation of the plants' response to treatment. Trying to work it out mathematically will lead to confusion and probably substandard results.

The sufficiency standards are very broad and flat between "deficiency" and "excess". There's a huge span of minimal need and over the top for the sufficiency standard curves I've reviewed, and I have yet to see a trial for species orchids.

Also I have yet to see a sufficiency curve for parameters outside of a single growth or crop production cycle.

Since I'm feeding at less than 1/50th your rate N and 1/200th your rate of K, how are my plants even surviving (let alone thriving).
 

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