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Interesting observation re: CFL lighting

Posted by wordwiz (My Page) on
Fri, Jan 22, 10 at 12:00

About six weeks ago, I transplanted two cucumber seeds, Tasty Jade and Holland Hothouse. These plants are mostly similar to other cucumbers except for being parthenocarpic (they self-pollinate). Jade is rated as 54 DTM, Holland 64. Both prefer trellising to encourage straight cukes.

I used my own mix, pretty much loose dirt from the garden along with some used potting mix and a bit of compost. They are in four-gallon black nursery pots that are filled about 2/3 of the way. No extra fertilizers have been added. The two plants have been placed side-by-side under a 5000K, 105-watt CFL bulb that is on ~16 hours a day.

My intention was to move them to the greenhouse once the vines attained a little length, as the bottom foot or so of the GH is wood and does not allow any sun. I have been somewhat disappointed in their lack of growth - neither plant is much more than six inches tall - after about 42 days. I grew these in a grow cabinet a couple years ago and in six week the vines were five feet long, although I did grow them in a DWC hydro system.

I checked the plants yesterday and was shocked to see both, but especially the Jade has several blooms on it. (Being about ten days longer in DTM, I would not expect the Holland to have as many).

This is what the Jade looks like:

Here is the flower:

I had posted this picture in another thread, but again, it is under the same type of bulb:

The common theme is the very compact growth but lush foliage of the plants, something that is suppose to happen under Blue Lighting. And then throw in the blooms, which is suppose to be largely controlled by Red light. The intensity of the light is not that great, (30,000 Lux for the tom, 13,000 for the cukes), one could even say a little low for the latter. In theory, they should be stretching a bit. Moreover, especially the cukes, have not been watered much. The pots were soaked to excess when first transplanted, but yesterday was the second time I had watered them since. They never wilted or showed signs of being thirsty, and the dirt seemed to be moist, so I saw no reason to give them a drink.

That's all the pertinent info I can think of, but none of it explains the growth pattern, especially the blooms. Those vines ought to be much, much longer. I wonder if the CFL bulb somehow filters out some of the longer (far) red wavelengths yet allows more blue through? But they are rated as 5000K Full Spectrum.

I e-mailed Eiko, who makes the bulbs and asked for some tech info; whether they will replay or not I do not know.

Your thoughts!

Mike


Follow-Up Postings:

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RE: Interesting observation re: CFL lighting

My thoughts are that I will keep watching. It is sure nice to have some one that looks and questions, rather than just repeating the same old wives tales over and over. Could there be lot more to this growth thing than red/blue?


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RE: Interesting observation re: CFL lighting

Regular fluorescent bulbs have practically no far red. Since yours is special "full spectrum" it probably has a substantial amount of far red, but, to be certain, you should ask Eiko for a "spectrum chart." Before the invention of the internet, it was relatively easy to get spectrum charts, as part of the bulb specifications, from any large lighting store.

Although we previously agreed that far red increases stem length in many plants, we never agreed that such lengthening was enough to be of concern in scenarios such as this one. I suspect the Emerson Enhancement Effect is enough to be of concern.


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RE: Interesting observation re: CFL lighting

I called Eiko and they are going to have their QC people send me the data. I also e-mail Paul Fisher, an expert in greenhouse lighting, though I do not know if he will reply - he has in the past.

The guy at Eiko was sorta enthused to hear about the results, as I am sure they would love to be able to market the bulb as a grow light.

The mostly likely explanation is that the bulb has no far red light at all, or very little. But, it has a CRI of 82 - not real high but high enough to suggest it covers most bands of visible light.

I also considered genetics as a possible factor in the cukes, as they are bred for greenhouses which usually have less than ideal lighting. Two things, though: most pictures show them as being long or tall plants, plus the tomato is not a hybrid - it is an heirloom.

There is a third possible explanation, one that many growers do not pay attention to: the combo of light, heat, moisture and fertilizer. Low temps, combined with a bit on the dry soil and lack of fertilizers high in nitrogen tend to produce shorter, compact plants. The temps upstairs, which receive only ambient heat, range from the low-mid 50s overnight to the lower 70s during the day. Several times in the last few weeks, I have worn a jacket up there just so I was not chilly.

Quite frankly, nothing that I have read about, studied or know quite explains what is happening. Maybe it is the Garden Gnomes???!!!

Mike


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RE: Interesting observation re: CFL lighting

Got the spectrum.

Looks like it has extra violet (~410 nm) added.

Mike


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RE: Interesting observation re: CFL lighting

Looks like it has extra violet (~410 nm) added.

Not to mention some far red at 715 nm and it lacks light between 640 and 700 nm. It wouldn't hurt you to test adding about 30 watts of halogen incandescent.


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RE: Interesting observation re: CFL lighting

I'm still waiting to see if I am doing something wrong! I found an expert at OH St. Univ. whose area is greenhouse veggies under artificial lights. In all this talk about how light and heat affects plants, I don't want to lose track that the goal is to get the most pounds of fruit. The tom still has 47 days before it is suppose to "mature" which I presume means about 30 days before it starts blooming (if one can trust days to maturity claims!).

I will have to move the plant - if it grows more than 3.5 feet I'll run out of room.

Mike


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RE: Interesting observation re: CFL lighting

Is that a Eiko 81180
I see 1000bulbs lists it
I am considering spending the money for a couple of 105 watters.
KennyP


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RE: Interesting observation re: CFL lighting

Yep! I like 1000bulbs. I had a light fail not long after I bought it and they sent me a replacement, free, without me having to send the bad one back.

Mike


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RE: Interesting observation re: CFL lighting

Any knowledge or experience with their 105 watt, Energy miser FC-llB-105? It 8 dollars cheaper.
Kenny


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RE: Interesting observation re: CFL lighting

Kenny,

No, I don't. Made by a different company. But it has fewer lumens and its CRI is lower (meaning it will not have as many different light spectra).

Mike


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RE: Interesting observation re: CFL lighting

I presume means about 30 days before it starts blooming

I have often had ~12" tomato plants in 4" pots bloom within 30 days of germination, using natural light in a greenhouse.


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RE: Interesting observation re: CFL lighting

***I have often had ~12" tomato plants in 4" pots bloom within 30 days of germination, using natural light in a greenhouse. ***
I see that all the time in the green houses where I buy. Assumed it was from them souping them up on drugs and hormones. :-)
Just ordered a couple of those Eiko 105 bulbs. I need more light on the plants.
Kenny


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RE: Interesting observation re: CFL lighting

Early blossoms don't count! I see them all the time also, sometimes on plants in 4" pots. More times than not they drop after transplanting. Rather, I am talking about getting one, two or more blossoms a day for several days.

Kenny, I got about 12 sq. ft. of room per bulb for seedlings last year. They worked fantastic - maybe a bit too good. I started everything based on how things turned out the year before but the combination of better potting mix, quicker germination, improved watering system and the stronger lights resulted in me having 200 plants that were large enough to sell in very early April. Unfortunately, Frost Free is not until the middle of May! I'm hoping I can sit on my hands until the Ides of March, at least for tomatoes and some peppers.

Mike


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RE: Interesting observation re: CFL lighting

struwwelpeter,

Been doing some more research on the use of ICD bulbs and their effect on increasing internode length. A couple of studies tried adding it at different times and what they found was that increased FR light at twilight (lower light, just before dark) could cause up to 30 percent longer length between nodes. When applied at dawn, or without any other lighting, it didn't make much difference.

Mike


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RE: Interesting observation re: CFL lighting

Mike what type of fixture/reflector are you using with the 105 watt CFL? I see they are 12 inches in length. Thanks.

Curt :-)


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RE: Interesting observation re: CFL lighting

Been doing some more research on the use of ICD bulbs and their effect on increasing internode length. A couple of studies tried adding it at different times and what they found was that increased FR light at twilight (lower light, just before dark) could cause up to 30 percent longer length between nodes. When applied at dawn, or without any other lighting, it didn't make much difference.

So, turn off the ICD one hour before turning off the other light.


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RE: Interesting observation re: CFL lighting

* Posted by curt_grow 4 MN (My Page) on
Mon, Feb 1, 10 at 0:01

Mike what type of fixture/reflector are you using with the 105 watt CFL? I see they are 12 inches in length. Thanks.
Curt :-)

Me asking too. Those are big suckers.
KennyP


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RE: Interesting observation re: CFL lighting

Hmmm, gremlins must be back. I thought I had posted this answer!

It's one of those silver parabolic type that often comes with a clip-on fixture. But in the grow chamber and the bench where I raise seedlings, I don't any. Instead, white walls/ceiling or Mylar.

Here's an update pic of the plant, or rather, part of foliage. This is just below the canopy.

The plant is about 14" tall now, 36 days after transplanting. You can see how close the leaves and stems are - quite unusual for a CFL-grown plant.

Mike


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RE: CFL lighting

>> So, turn off the ICD one hour before turning off the other light. <<

strew,

Why add one to begin with? This is an experiment to see how the plant produces under a CFL light. If it was suffering I wouldn't hesitate to alter something or several somethings.

No, I am not a botanist but it appears the plant is doing a great job converting light and what heat it receives into foliage which should allow it to produce more offspring - in this case fruits that contain seeds. According to my high school science teacher, that is why plants live - not to look good in a garden or even to provide food to mankind or fertilizer to plants around it - that's a side benefit.

It is certainly your prerogative to posit that stems contribute a lot to photosynthesis, more than leaves do, and I will be glad to review any reliable research articles that support this. And I will admit that there is a chance that in time, the foliage will be so dense that the leaves are starving for more illuminance, more than the CFL can provide. But that would be true for a taller plant, with or without a dense foliage.

Also to note in passing - the study said the ICD bulbs did not significantly impact stem elongation when applied during dawn or without other lighting. It did not say anything that turning it off an hour before twilight would not have an adverse effect.

We can continue to but reality is that if ICD added enough value to pay for their use, greenhouse growers would be incorporating them.

Mike


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RE: Interesting observation re: CFL lighting

It is certainly your prerogative to posit that stems contribute a lot to photosynthesis

No, it is not my prerogative to lie.

We can continue to but reality is that if ICD added enough value to pay for their use, greenhouse growers would be incorporating them.

I already explained that supplemental FR is useless in a greenhouse because daylight has a surplus of FR. Your CFL is not in a greenhouse so why are you acting as though it is? Furthermore, I said that incandescent is not an economical source of FR. I said that incandescent provides an easy way to test the value of supplemental FR and, if that test is positive, one should try Philips White Son HPS as an economical FR source. To be redundantly clear, I am NOT talking about inside a greenhouse.

You continue to misinterpret my recommendations to experiment as recommendations to practice.


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RE: RE: Interesting observation re: CFL lighting

Incidentally, it is economical to control internode length of ornamentals with chemical growth regulators such as Arest, Bonzi, or Sumagic. I often use Bonzi to keep zinnia seedlings short. Bonzi works on tomato plants but it is against the law to use it on food crops .

You can also shorten tomato plants by roughly brushing the tops with a folded up newspaper every day.


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RE: Interesting observation re: CFL lighting

struw,

Keep looking at the trunk of a tree and ignoring the forest.

First, a GH located at 39 degrees North Latitude is going to require supplemental lighting form the middle of December to the middle of February, at the least. On most days, that will be the major source of non-thermal energy. No different than my experiment, which I think I have explained - of growing a plant upstairs where it gets no sunlight. Yet you persist in suggesting I add ICD lighting.

If you are not talking about a GH in southern OH in the middle of winter, what are you talking about and why are you insisting I should do this or that?

I'll type this real slow, in the hopes that you can comprehend what I am doing:

I start plants then stick them under different lights to see how they produce under those lights. I do not, in the middle of an experiment, add another spectrum unless that is the goal of the test. Furthermore, my goal is to grow plants that produce the most salable product, and GH growers seem to have the process down pat. No where, in any literature besides the ones you cited, does anyone suggest that adding FR light, in a GH or growing pot in a darkroom, will increase production. Plant height, yes, production - no.

As far as using growth hormones to control internode length, it seems clear that not trying to cause it in the first place and then, worse, using chemicals to try to counteract it, is not a path I want to walk. But happy trails to you!

Mike


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RE: Interesting observation re: CFL lighting


struw,
Keep looking at the trunk of a tree and ignoring the forest.

First, a GH located at 39 degrees North Latitude is going to require supplemental lighting form the middle of December to the middle of February, at the least. On most days, that will be the major source of non-thermal energy. No different than my experiment, which I think I have explained - of growing a plant upstairs where it gets no sunlight. Yet you persist in suggesting I add ICD lighting.

If you are not talking about a GH in southern OH in the middle of winter, what are you talking about and why are you insisting I should do this or that?

I'll type this real slow, in the hopes that you can comprehend what I am doing:

I start plants then stick them under different lights to see how they produce under those lights. I do not, in the middle of an experiment, add another spectrum unless that is the goal of the test. Furthermore, my goal is to grow plants that produce the most salable product, and GH growers seem to have the process down pat. No where, in any literature besides the ones you cited, does anyone suggest that adding FR light, in a GH or growing pot in a darkroom, will increase production. Plant height, yes, production - no.

As far as using growth hormones to control internode length, it seems clear that not trying to cause it in the first place and then, worse, using chemicals to try to counteract it, is not a path I want to walk. But happy trails to you!

Mike

Too verbose. To paraphrase that more succinctly for you, "I'll never try it".


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RE:RE: Interesting observation re: CFL lighting

The plant is about 14" tall now, 36 days after transplanting. You can see how close the leaves and stems are - quite unusual for a CFL-grown plant.

How can I see that is unusual when

1. I can't compare with the same variety of tomato grown under a different 105 watt CFL?

2. I don't know the name of your tomato variety so I can't reproduce your experiment? For all I know, that is a "bush" or determinate tomato. I only know is that it is an heirloom which is irrelevant information.


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RE: Interesting observation re: CFL lighting

It's a Delicious, an indeterminate heirloom from Victory seeds. I say it's unusual because I have grown other tomatoes under CFL bulbs before and they were never this thick with foliage and such tight nodes. I've never had it grow like this in the garden, either, and I had about six plants last year.

Mike


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RE: Interesting observation re: CFL lighting

>> To paraphrase that more succinctly for you, "I'll never try it". <<

Strew,

I wouldn't go quite that far. It's more like "when pigs fly."

Show me studies from multiple tests from various recognized research institutes where tomato plants produced more pounds of fruit (incorporating ICD lighting) using the same amount of energy, growing under only artificial lighting and I'll be happy to reconsider.

Mike


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RE: Interesting observation re: CFL lighting

It's a Delicious, an indeterminate heirloom from Victory seeds. I say it's unusual because I have grown other tomatoes under CFL bulbs before and they were never this thick with foliage and such tight nodes. I've never had it grow like this in the garden, either, and I had about six plants last year.

I have grown Delicious and agree that is not normal. But, one plant might be a natural cross or the seeds may have been mislabled. I am eager to see your first ripe tomato.

Show me studies from multiple tests from various recognized research institutes where tomato plants produced more pounds of fruit (incorporating ICD lighting) using the same amount of energy, growing under only artificial lighting and I'll be happy to reconsider.

Show me studies ... under only CFL than under only HID. And, yet, you probably spent about $25 to experiment with a 105 watt CFL. I would have spent about $8 for seven 26 watt CFL bulbs and one ~25 watt halogen bulb. Then I would have simultaneously grown one plant under just four CFL and another under three CFL plus one halogen.


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RE: Interesting observation re: CFL lighting

Struw,

Actually, I bought five of these bulbs in the December, 2008 to use for lighting for my seedlings. At one time last year, I had just over 1,000 tomato, pepper, basil and flower seedlings in nursery trays. I never really thought about using them to grow mature plants as they do not have enough illuminance, at least I do not think they do.

This experiment is an accident. I had ordered a 400 watt HPS system and had planned on growing the plant under it. But I had already transplanted it and needed to move it from where it was (under a 150 HPS) so I could install the new system there. I could not hang the other HPS anyplace but had this CFL in a socket so decided to try it. Stuck it in a socket with a reflector and place it just over the plant.

It took about a week longer than anticipated to get the light and set it up to work. Over that time I started noticing how the plant was getting so bushy but not tall. So I decided to let it go for a while. It's a 77 Days to Maturity plant and has been transplanted for 40 days. So I should have close to a month before I start seeing blooms of any significant number.

I'm still presuming I will need to add more lighting to this plant once it gets taller, that is, if it develops blooms more than 6-8 inches lower than the canopy.

It won't be an equal test because of the difference in temps (cooler temps do help restrict vertical growing) but I may try another grow this summer using the 400 watt system with a couple of these bulbs.

Mike


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RE: Interesting observation re: CFL lighting

Have you tried Supercropping?


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RE: Interesting observation re: CFL lighting

No. Can't bring myself to twist my plants like that!

Mike


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RE: Interesting observation re: CFL lighting

I ended the experiment of trying to grow a mature plant under the light. While the foliage has remained lush and the internode length minute, the plant has basically stopped growing, adding only an inch over more than a week.

Mike


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RE: Interesting observation re: CFL lighting

That would have been a good time to try supplemental incandescent.


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RE: Interesting observation re: CFL lighting

I wanted to try the LEDs. If it works, I may try the 120 watt I read about.

Mike


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