Black Dragon, Red Dragon, Marble Dragon

[jgturpin]

I have an improved potted terrarium (Wilder, Mike (2001) Refining the terrarium: alternative techniques for the indoor gardener. Carniv. Pl. Newslett. 30(1):21-25 ) with a Sunleaves Pioneer II Jr. T5 Fluorescent Fixture(http://www.sunleaves.com/detail.asp?sku=SPJ102) for lighting on a 14 hour timer.

I use RO/DI water from a watergeneral.com unit, tested at 000ppm TDS. Temps run from the low 70’s at night to the mid 80’s in the day.

Plants are watered about once a week, and are misted lightly about once a day and feed with a diluted Epiphyte's Delight about once every four weeks.

Does anyone else notice a few red freckles with alot of light on there Neps? How can you tell if it is rust spots or just sun freckles? My pitchers are coming up really nice and all the plants are growing well. Some of the leaves are getting pretty (tan?) or reddish is that just because of a lot of light or is this a problem?

[trimen1000]

The best way to tell the difference is in context. If you just put them under a whole lot more light and they get red spots all over it's probably sun burn. If they've been under the sun for a year and suddenly they get red spots then it's probably rust.

A little note. If your conditions in the terrarium are really good (as I would guess they are) those guys will outgrow your terrarium very very quickly. My experience with these have told me that these guys get big quick.

On a side topic, do we know what all the parents for these hybrids are?

[jgturpin]

I know that they are Geoff Mansel's Nepenthes cultivars, from
www.exoticaplants.com.au/

I got some Physan 20 fungicide, virucide, algaecide and disinfectant, mixed 2 tsp with 1 Gal RO Water and treated just to be on the safe side.

According to there tips page with enough RH and light the leaves will get a "tinge of red/burgundy to the leaves". So I must be doing something right.

Thanks for the warning, the marble pitcher on the right is new and is already 6.5 Inches! I think I will be getting a larger tank by the end of the summer. ;D

[brokken]

Haven't had much experience with Nepenthes, but I doubt that they'd be getting sunburnt. The pitchers on the red dragon should be deeply red. I'll try to take pics of my red dragon and show you how my pitchers look in full sun.

Very nice setup by the way. Très Chic!

[trimen1000]

It really depends on previous conditions and how intense the light is. In this case the plants are pretty close to the light and the light seems to be pretty bright, so it's very possible that they would get sunburn.

[endodoc]

trimen1000
I have a little experience with these hybrids (Black/Red/Marble Dragon) and see similar red spots, I do not think these are 'rust'; i think the result of high light, not necessarily sunburn; i have some neps that have very rusty/red leaves when first placed in a high light area, they seem to adjust quickly; my orchids have had sunburn and turn leathery, when they have a fungus they seem to turn slimy, other growers have any thoughts??
regards
ed
very nice setup, congrats!!

[endodoc]

trimen1000
sorry the above post was meant to reply to jgturpin
regards
ed

[Michael Catalani]

Under intense light, many species of Neps will have their new leaves develop a tannish to caramel coloration. They will eventually turn more of a green color, but this initial coloration is an indicator that the plant is receiving plenty of light.

Under artificial lighting, you must watch carefully for this coloration. The intensity of light quadruples as the distance to the light source is cut in half. In your setup, the lights are already very close to the plants, so a newly emerging leaf can easily see light insensities that fluctuate 5x-10x higher as the leaf grows upwards.

Some Neps can take buttloads of light, whereas others simply hate it. Anytime I see the tannish color on the new leaves, I know the plants are receiving plenty of light. But I also know that if I am growing them under artificial light and see this coloration that I have to monitor them closely, because they could easily grow and close enough distance between themselves and the lights to cause the light intensity level to rise to a level that is much too high.

In natural light, the distance from the sun to the Earth keeps a nep from seeing the intensity level change by simply growing taller. But they can see a major difference of light intensities when artificial lighting is used, and the closer the lights are located to the plants, the higher the differences can be by the plant simply growing a little taller.

[neps]

Under artificial lighting, you must watch carefully for this coloration. The intensity of light quadruples as the distance to the light source is cut in half. In your setup, the lights are already very close to the plants, so a newly emerging leaf can easily see light insensities that fluctuate 5x-10x higher as the leaf grows upwards.

It is true that intensity of a point source diminishes as the inverse
square of the distance from that source. However, this is not
true for a distributed source, such as a fluorescent tube. In
fact, for such a source the variation of intensity as a function of the
distance is roughly the reciprocal of the distance, not the
reciprocal of the square of the distance.

So, yes, plants will see some degree of variation in incident light
intensity according to their distance from an extended source,
but it will likely not be as great as indicated.

Not trying to be pedantic here, just trying to be helpful....

[Michael Catalani]

neps said:

Under artificial lighting, you must watch carefully for this coloration. The intensity of light quadruples as the distance to the light source is cut in half. In your setup, the lights are already very close to the plants, so a newly emerging leaf can easily see light insensities that fluctuate 5x-10x higher as the leaf grows upwards.

It is true that intensity of a point source diminishes as the inverse
square of the distance from that source. However, this is not
true for a distributed source, such as a fluorescent tube. In
fact, for such a source the variation of intensity as a function of the
distance is roughly the reciprocal of the distance, not the
reciprocal of the square of the distance.

So, yes, plants will see some degree of variation in incident light
intensity according to their distance from an extended source,
but it will likely not be as great as indicated.

Not trying to be pedantic here, just trying to be helpful....

Actually, you bring up a good point, and one that I hadnt really received a good answer to. I've read some posts before about how flourescent lighting doesnt follow the inverse square law. Unfortunately, these well thought out arguements didnt have any scientific backing to them, nor point to any references about the subject. So i didnt know if they were simply blowing smoke up my butt or not. They were good arguements, although some were shot down in flames by good rebuttals.

Just last night I was finally reading "Plants From Test Tubes" by Lydian Kyte. (I had been wanting to read this book for more than 10 years, finally got around to it.) Anywho, there was a section on lighting. Although she didnt mention the inverse square law per se, an example she gave eluded to it. She gave an example of where a 48" shelf had two flourescent tubes separated by 20", and that the lights weres 10" above the shelf. She then talks about how the lighting will not be uniform, and that cultures directly under the tubes would have light intensities about 3x that of the cultures on the edge of the shelf.

So I calculated that if the cultures under the lights were 10" away, and the cultures on the edge of the shelves were 14" away from the cultures under the lights, then the cultures on the edge of the shelves would be 17.2 inches away from the lights. So the distance to the light source for the cultures under the lights would be 1.72 times closer than the ones on the edge of the shelf. If we use the inverse square law, we get 2.96 times more intensity for the cultures directly under the lights than the cultures on the edge of the shelf, which was the difference in intensity Lydian alluded to in her example. So I thought that flourescent lights do follow the inverse square law after all.

Now you are telling me otherwise again.

[Dave Evans]

Hello Michael,

Well, that "law" is for the single point light source, like the sun, whereas the tube is more of a two dimensional light source, but if you got far enought away from, it would become more like a single point... Does that help? Physics isn't my area...

michaelcatalani said:

So I thought that flourescent lights do follow the inverse square law after all.

Now you are telling me otherwise again.

[neps]

Well, that "law" is for the single point light source, like the sun, whereas the tube is more of a two dimensional light source, but if you got far enought away from, it would become more like a single point... Does that help? Physics isn't my area...

That's correct, Dave! Physics is my area, and I can tell you that
the distribution of the light source over a region which is macroscopic
in relation to the distance to the receiver (the plant, in this case)
is the fundamental reason why an inverse square law does not
apply. But, as you pointed out, on a scale where the distance to
the light source is much larger than its dimensions, then its
intensity does fall off according to an inverse square relationship.

[jgturpin]

Wow, I didn't know that the subject of lighting was so complex. There is alot of good info here. I think that I am moving into a larger tank this weekend ( 30L X 12W X 18H ), because I am adding a new pitcher and I want some more space for the other three to grow out a littler more. I can adjust the supports on the diffuser grid to be taller or shorter if I need to and use a little trial and error to see what the best distance is from the light. I think that I agree that they might be bit close, so I might move them down about 2 inches to start with and see how they react.

[glider14]

On a side topic, do we know what all the parents for these hybrids are?

'Red Dragon' -->thorelli x truncata
'Marbled Dragon' -->truncata x maxima
'Black Dragon' -->truncata x izumiae(spelling?)

i think that is what most people agree on. i dont know if the order is correct(maxima x truncata or tuncata x maxima?).
Alex

[trimen1000]

Thank you glider 14.

Do we know anything about Sabre?

On the light source matter:

I'm not a physicist, but this is what I believe is true.

Intensity is looked at as power per unit area.

Now
P = I A
I = P / A

Now let's say for the sake of simplicity that the thing is a meter long. Lets also say that the light is traveling outwards in semi-circles creating a volume that looks like half a cylinder who's surface area excluding the ends is [pi] r h (2 [pi] r is the circumfrence of a circle, then multiply that by the h to get the surface of a cylinder excluding the circle ends, then divide it by 2 to get half the cylinder excluding the semi-circle ends and the flat surface). Thirdly, lets say that the source is a line(a line source?).

Then the equation looks like this.

I = P / [pi] r

Now it can be clearly seen that the relationship is an inverse relationship. Now it is clear, if you make the distance half the original you double the intensity. If you make the distance 1/10 the original you make the intensity 10 times as great.

This is approximate, obviously the light lost to the sides must be considered. If there is reflective paneling this will change it dramatically. Also if there is reflective backing to the inside of the light holder that will also complicate the matter. All this will make for a much more complex problem then I think anyone wants to deal with.