# Light requirements of slippers



## dodidoki (Jan 3, 2014)

I would like you to help collecting all paphs species and their light requirements (1. group: higher (eg. exul), 2. group:moderate (eg. brachys) 3. group: shade ( eg. barbatas, anitum).)
I wrote examples but there are few ones what I have no clear knowladge about. ( eg. chanhii, hangianum, gigantifolium)
I would like to re-arrange my slippers and renew the lighting system in my GH based on this list

Many thanks for help: Istvan


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## TyroneGenade (Jan 3, 2014)

I know someone who was growing Brachies under light at about 200 microEinsteins (which is about about 16 000 Lux of cool white fluorescent light). I guess some species would be happy at 100 microE while others, such as roths, may want much higher values. Full sunlight is about 2000 microE.


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## NYEric (Jan 3, 2014)

dodidoki said:


> ( eg. chanhii, hangianum, gigantifolium)
> I would like to re-arrange my slippers and renew the lighting system in my GH based on this list
> 
> Many thanks for help: Istvan



Really!?


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## dodidoki (Jan 3, 2014)

NYEric said:


> Really!?


Yes. Why?!


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## NYEric (Jan 3, 2014)

Do you have chanhii?


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## SlipperFan (Jan 3, 2014)

Have you looked at slipperorchids.info?


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## Stone (Jan 3, 2014)

Hangianum grows in deep shade with lichen and algae clinging to the leaves. They look like Phalaenopsis with their leaves hanging from the vertical cliffs.


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## dodidoki (Jan 4, 2014)

NYEric said:


> Do you have chanhii?


Yes, got almost rootless, now it seems to be established with new growth and new roots.I keep it in shade.


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## Rick (Jan 4, 2014)

TyroneGenade said:


> I know someone who was growing Brachies under light at about 200 microEinsteins (which is about about 16 000 Lux of cool white fluorescent light). I guess some species would be happy at 100 microE while others, such as roths, may want much higher values. Full sunlight is about 2000 microE.



From what I've seen of in situ pics, niveum and godefroya grow on the same cliffs as exul (in full sun).

Most concolor, thaianum, and bellatulum pics seem more inland and more shaded.

Not sure if generalization of all brachies is warranted even though its only a handfull of species.


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## NYEric (Jan 4, 2014)

dodidoki said:


> Yes, got almost rootless, now it seems to be established with new growth and new roots.I keep it in shade.



Excellent. Hope to see blooms, thanks.


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## TyroneGenade (Jan 4, 2014)

Rick said:


> From what I've seen of in situ pics, niveum and godefroya grow on the same cliffs as exul (in full sun).
> 
> Most concolor, thaianum, and bellatulum pics seem more inland and more shaded.
> 
> Not sure if generalization of all brachies is warranted even though its only a handfull of species.



It might be incorrect to think purely in terms of intensity, but we should also take into account duration. A few hours of full sunlight may be the same, physiologically, as a whole day of shade... The person who advised me of 200 microE was growing thianum and godefroydae. I had no problem growing these on a sunny windowsil in Cape Town with average winter daylight being about 200--300 microE. 

Under the same conditions, the complexes had to go into a more shady spot as they started to bleach. P. insigne on the other hand did its best when it had times of full summer sun. Also, in Cape Town, stonei only flowers when given full sunlight for part of the day (but they also stand the plants in water).

I think, if you want to know what these plant enjoy in nature then you need to get an Apogee light meter and go take measurements in the wild.


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## dodidoki (Jan 4, 2014)

TyroneGenade said:


> A few hours of full sunlight may be the same, physiologically, as a whole day of shade...



I don't think so. I red an article few years ago about that. If you increase light intensity ( with same specral ingredients), photosythesis will increased too, but only up to an optimal light intensity, but if you increase light further, photosynthesis won't be increased, furthermore will be decreased.


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## TyroneGenade (Jan 4, 2014)

Yes and no.

This is a graph I have shown on an Aquarium site:






It is derived from data published by Binzer et al, Limnology and Oceanography, 51:2722-2733, 2006. It refers chiefly to aquarium plants but the basic physiology is the same.

Photosynthesis is limited by the photon flux (measured in microE/m2/s), water and CO2 supply. The curve above grows less and less sensitive to photon flux because the plant has only so many chloroplasts with only so much chlorophyll (CO2 and water are kept constant in the experiments). Eventually the chlorophyll is saturated with light, and then the ADP and NADP are all used up to make ATP and NADPH (which will be used to build sugars by the plant). So yes, eventually increasing the light has no effect, but this is not the case if CO2 and water are limiting.

CO2 enters via stroma on the leaves. Water leaves the plant via stroma on the leaves. If the plant can't take up enough water via its roots to replenish loss through the leaves it will close the stroma and the sugar-synthesizing aspects of photosynthesis will grind to a halt and eventually the chlorophyll will become saturated with light and without enough ADP and NADP it will start producing free radicals and the leaves will burn.

My observation with Disa etc... is that they are always south east facing (so they get the bright morning sun but avoid much of the midday sun and heat). My guess is that Paphs are much the same. They will orientate to get the most sun with the least heat. The more heat, the more water evaporates from the plant tissues. For a few hours of high intensity sun in the morning the plant can generate enough ATP and NADPH to supply all its needs. By midday the bright sun is gone and the plant avoid being roasted by the free radicals produced by the chlorophyll by too much light.

To survive and grow, the plant needs to produce enough sugars from photosynthesis. If it can do this from a few hours of bright sun then that is great for the plant. If it can do it from a whole day of low light then that is great too. The absolute intensity isn't as important as the volume of light needed to meet the plant's metabolic demands.

I find Brachy leaves very interesting. Ever had a good look at them? There is he mottling on the surface and then what looks like a clear layer of tissue and then green tissue underneath. Maybe the plants have their own shade-system to ensure that all their chlorophyll isn't saturated at once? Its very different to the mottling of Barbatum types.

So, the important point here is this: if you can maintain high humidity and adequate water supply, then many of the plant could possibly stand high light all day long; but if you can't, then high light will cook the plants.

Before you redesign your setup, take some plant and place them in different lighting conditions and see how they respond. Back in South Africa you could grow pretty much any Paph under 50--80% shade cloth. This would be about 400--1000 microE of 2000 microE full-summer-sun. To get multies to bloom more light was needed together with more humidity.


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## dodidoki (Jan 4, 2014)

Charles fma. sandowee expused to full sunlight


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## naoki (Jan 4, 2014)

Nice summary by Tyrone. Another factor is the problem of photorespiration, which is a significant problem for C3 plants. Strong light + low water and/or low air humidity causes the loss of assimilated carbon because they can't get rid of the oxygen (when rubisco binds to O2, the plants lose assimilated carbon).

The saturation curve is also influenced by light spectra (e.g. addition of green light to red+blue can increase the photosynthetic rate near the saturation point).

The other factor is photoinhibition (how different intensity/spectra influence the break-down/renewal of photosystems), which is important for the optimal light intensity.

It depends on how you define the "optimal" light intensity, but frequently what plants are experiencing in the nature may not be the optimal (from physiological point of view). Biological competition is important in the nature (unlike under cultivate), so plants have to compromise, and they might need to "tolerate" in one or a few dimension of the abiotic factors.

Looking at photos do help to understand the range of tolerance, though. However, I'm not completely convinced that the photos accurately represent their habitat. I frequently take photos of wildflowers along well-lit trail/road side even though majority of the population is in the dark wood.


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## Rick (Jan 5, 2014)

naoki said:


> Another factor is the problem of photorespiration, which is a significant problem for C3 plants. Strong light + low water and/or low air humidity causes the loss of assimilated carbon because they can't get rid of the oxygen (when rubisco binds to O2, the plants lose assimilated carbon).



I'm glad you brought up the connection between light and water availability (and should probably add temp) in connection with C3 plant needs.

Although it seems like a lot of orchids are CAM plants, there have not been any paphs to be determined to be CAM (and therefor able to work in water/humidity restricted conditions).

If we were talking Cattleya that could be a whole different matter.


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## Migrant13 (Jan 5, 2014)

This is all very informative and thanks for sharing such detailed info. Though I have to admit I had to do a lot of googling of certain terms (e.g., CAM, rubisco). The bottom line to me is that orchid growing is not an exact science and most of these buggers are quite adaptable...within limits.


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## TyroneGenade (Jan 5, 2014)

Paph insigne and parishii are C3 plants, see: http://aob.oxfordjournals.org/content/54/4/583.full.pdf .
A phylogenetic analysis suggests all the Cypripedioideae are C3 (while Catts seem to be mostly CAM): http://www.plantphysiol.org/content/149/4/1838.full

Homeostatic set-point tend to have broad optimum ranges rather than exact points, further more, homeostasis is balancing act of competing needs. Being able to function of a range of conditions throughout the day may be essential for the allocation of resources away from, for instance, light harvesting, to some other function. It may be wiser to try meet the lower range of the optimum than the higher simply as this would allow for more flexibility with regards to the plant meeting its other needs. If you keep the engine revving at 5000 rpm you are going to damage the engine. If you keep the plants photosynthesizing at 1000 microE you are going to damage the leaves.

So, because I'm something of an empiricist, if you have a wild location of Paphs near you, spend a day tracking the light intensities that the plants endure. (There are handy gadget that can actually measure photosynthesis i the field but that is perhaps too much to ask...)


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## paphioboy (Jan 6, 2014)

Couple of threads I posted previously showing several barbata and Thai species in situ.. You can roughly gauge how much sunlight is reaching the paphs from the photos.. 

http://www.slippertalk.com/forum/sho...highlight=situ
http://www.slippertalk.com/forum/sho...highlight=situ


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## paphioboy (Jan 6, 2014)

Not all brachys grow in direct sun... Here some examples of niveum and angthong growing in situ (photos are not taken by me, credits to the respective photographers):

Angthong:









Niveum grows on rocky surfaces but usually partially shaded by small shrubs:





Some of the barbata like tonsum can grow very shady:


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## paphioboy (Jan 6, 2014)

Some barbata like volonteanum are known for inhabiting very shady areas..







Rothschildianum does not always grow in bright light. Different populations take different amounts, such as these plants growing in leaf litter:


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## paphioboy (Jan 6, 2014)

More pics of volonteanum in habitat:









Stonei when kept shadier grows large shiny leaves:





In brighter light but still partially shaded:


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## paphioboy (Jan 6, 2014)

Personally I grow my stonei quite bright. They receive several hours of direct sun on the leaves daily, but are growing well and clumping (pot diameter is 15cm/6 inches for size reference):


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## Secundino (Jan 6, 2014)

I wouldn't call the first pictures like 'very shady' - it seems to me that the light question is very subjective. As most of us do not own light-meters (lux or energy) and grow in very different regions (50% shade cloth - 50% of what sun/light-quality!?) it seems to me that this can be endless. I do give more shade in direct relation to rising temperatures and when the fans are on, I give more light. In practise its more a balance between light AND temperature AND ventilation than the absolute value of one of theses parameters.


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## Dido (Jan 6, 2014)

this pic are great thanks for sharing


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## paphioboy (Jan 6, 2014)

I judge by leaf colour. That is the easiest. Paphs are happiest and grow fastest when light provided matches their requirement. Usually the leaves show good contrast for mottled leaves and are nice and shiny like the in situ stonei posted above. I personally am not a fan of bleached-out looking plants grown under high light, although that may encourage earlier blooming and give better colours. I think the excessive light could be a factor in these precocious plants dying after flowering on small growths.


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## TyroneGenade (Jan 6, 2014)

Hmm... a lot to ponder. Perhaps the way to experiment is to use successive layers of 50% shade cloth (as well as shifting plants around under it) and find out when the plants look their best, as you describe Paphioboy?

I assume where you are in Penang, there is very high humidity? Those of us growing under lower humidity conditions might need to rethink the amount of light/heat due to excessive water loss?


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## eggshells (Jan 6, 2014)

My roth, stonei, lowii and philippinense flowered under 400-500 foot candles. All single growths and grew second growths and starters before they flower. 2 flourescent light bulbs with a distance of 18 inches from the apex of the leaves. The lights are on for 8 hours a day.


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## TyroneGenade (Jan 6, 2014)

500 ftc is about 5382 Lux. You can get Lux meter apps for cell phones so this is easy to work out. Interestingly, this is only about 67 microE of light. To grow "high light" aquarium plants only about 40 microE/m2/s of light is needed and this falls in the zone of maximum responsiveness of plants to light with respect to photosynthetic flux (see the orange line in the graph I posted).

BUT, if you are using grow-lamps, then your 500 ftc may be producing a lot more Photosynthetically active radiation. Gro-Lux tubes are 2.7x duller than cool whites (to which most fluorescent light sensors are calibrated), so you could have the equivalent of about 187 microE/m2/s over you plants. 

Thanks for sharing your experiences and data.


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## eggshells (Jan 6, 2014)

Thanks Tyrone, I am using the hydrofarm light meter. I will post later again.


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## dodidoki (Jan 6, 2014)

Tyrone, can you estimate equivalent dose of 2/3 B/R led grow lamp, 5X3W ( measured 1000 lux from 40 cm), compared with sunlight???


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## consettbay2003 (Jan 6, 2014)

*Eggsjells*

What is the length of your tubes and are they T5HO?


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## NYEric (Jan 6, 2014)

Lighting nerds! oke:


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## eggshells (Jan 6, 2014)

consettbay2003 said:


> What is the length of your tubes and are they T5HO?



2 x 48 inches T5HO tubes 6500k for multiflorals (and long inflorescence species). I have some 24 inches ones and I use them for the medium to small species. One tube per shelf.


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## papheteer (Jan 6, 2014)

I am not really sure myself if I'm giving my plants good light but I tend to shoot for nice green foliage. I like to see very contrasting mottling in my parvis. Some of my plants are under 2 54watt T5HOs about 12" away from the leaves and most of them got bleached.


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## TyroneGenade (Jan 6, 2014)

dodidoki said:


> Tyrone, can you estimate equivalent dose of 2/3 B/R led grow lamp, 5X3W ( measured 1000 lux from 40 cm), compared with sunlight???



No, LEDs are tricky. You need to know the spectrum of the LED and the bias current. There is a lot of data on LEDs at http://www.apsa.co.za/board/index.php?topic=4454.0. I don't even begin to speculate... What we are finding for the aquariums is that a daylight LED gives just as good growth as weird combinations.

Cool whites and Daylight have almost the same Lux output but the latter have a slightly higher PAR rating so the lower microE estimate is probably closer to the truth.


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## consettbay2003 (Jan 6, 2014)

*Paphateer*

I have been using HO T5 for several years and I use 24" for most of my plants.


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## papheteer (Jan 6, 2014)

consettbay2003 said:


> I have been using HO T5 for several years and I use 24" for most of my plants.



What type of bulbs do you use? How many/set-up? How far from the plants? And what size is the shelf? Thanks!


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## consettbay2003 (Jan 6, 2014)

*papheteer*

My fixutres are 4 tube 54 watt (5600K). Distance to tips of multifloral leaves
is 20 inches.
I have 9 of these fixtures in my grow room. 




papheteer said:


> What type of bulbs do you use? How many/set-up? How far from the plants? And what size is the shelf? Thanks!


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## consettbay2003 (Jan 6, 2014)

*paphateer*

For multiflorals one fixture covers an area of approximately 2' x 4'.


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## naoki (Jan 6, 2014)

Very nice photos, Paphioboy! It is difficult to judge the intensity from most photos. There are only 2 photos with EXIF intact, and the first P. volonteanum seems to be pretty dim around 125-200fc, and roths are even dimmer, 60-100fc. The date/time stamp was modified, so I don't know if these photos were taken what time of the day.

Ray's calculater (http://www.firstrays.com/measurelight.htm) seems to be pretty close to my high-end incident light meter (when I use white paper + D300). Since the photos are not using white paper, I added about 1.5 stops to EXIF data.



eggshells said:


> My roth, stonei, lowii and philippinense flowered under 400-500 foot candles. All single growths and grew second growths and starters before they flower. 2 flourescent light bulbs with a distance of 18 inches from the apex of the leaves. The lights are on for 8 hours a day.



That is amazingly small amount of light (even for constant light source). Your setup looks like some light is coming from the window. Do you think that they are getting fair amount of natural light or is the artificial light main source? I'm giving 2-4 times more per day (even for Sigmatopetalum)...



TyroneGenade said:


> Paph insigne and parishii are C3 plants, see: http://aob.oxfordjournals.org/content/54/4/583.full.pdf .
> A phylogenetic analysis suggests all the Cypripedioideae are C3 (while Catts seem to be mostly CAM): http://www.plantphysiol.org/content/149/4/1838.full
> 
> So, because I'm something of an empiricist, if you have a wild location of Paphs near you, spend a day tracking the light intensities that the plants endure. (There are handy gadget that can actually measure photosynthesis i the field but that is perhaps too much to ask...)



Thanks for the citation, the 2nd one is very interesting. It is amazing how CAM can evolve repeatedly, which tells us how important the interaction between light, water, humidity, and temp. I think there is another paper which checked Brachy (their appearance is closer to CAM), and concluded that they are not CAM, neither.

Yes, field measurement would be great. Portable IRGA (like Li-Cor 6400) is quite expensive (ours are like $20k), though. But I agree that it would be nice if someone can measure PAR or even just lux/fc with a data logger (pretty cheap). I did quick literature search for some field measurements of Paphs, but I haven't found one yet.

For rough estimation of PAR (convert fc to micro mole/m^2/s), here is a couple conversion factors: http://www.apogeeinstruments.com/conversion-ppf-to-foot-candles/
The site says it is PPF, but I think that if you use fc, you get PPFD (photosynthetic photon flux density). micromole = micro E.


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## naoki (Jan 6, 2014)

TyroneGenade said:


> No, LEDs are tricky. You need to know the spectrum of the LED and the bias current. There is a lot of data on LEDs at http://www.apsa.co.za/board/index.php?topic=4454.0. I don't even begin to speculate... What we are finding for the aquariums is that a daylight LED gives just as good growth as weird combinations.
> 
> Cool whites and Daylight have almost the same Lux output but the latter have a slightly higher PAR rating so the lower microE estimate is probably closer to the truth.



I also used to think R+B is better than white LEDs, but it seems that the technology of white LEDs are progressing faster than single color LEDs. So I agree with Tyrone, photosynthesis per consumed electricity of white LEDs seems to be pretty good now. Check Table 1 PPF efficiency column of http://cpl.usu.edu/files/publications/factsheet/pub__4964212.pdf

Additionally, Fig 8A (not the photos) and 7 is pretty interesting:
http://cpl.usu.edu/files/publications/poster/pub__2576523.pdf
In addition to PPF, the spectra influence the shape/size of leaves and photosynthetic efficiency.


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## eggshells (Jan 6, 2014)

naoki said:


> That is amazingly small amount of light (even for constant light source). Your setup looks like some light is coming from the window. Do you think that they are getting fair amount of natural light or is the artificial light main source? I'm giving 2-4 times more per day (even for Sigmatopetalum)...



Nope because my multifloral bench is not even close to a window. Besides all blinds are close all the time and its even bad because I got frost on it every winter. (seals are not very good anymore)

Anyways, I have a photo that you guys might find interesting. Too many to post but this one should summarize it. 

I got this philippinense from Ching Hua. Supposed to be the long petalled type. Anyways it has long skinny leaves when I got it. The first picture shows the widest leaves and one of the newest (at that time) it measured 4cm. 

Now the second picture shows the new top leaves. They are not as long but its wider. 6-7 cm now. 68cm total leaf span. 

















So yeah I think its safe to say they got wider.


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## paphioboy (Jan 7, 2014)

Those are pretty dark leaves for a phili..


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