Blue light at night the controversy rages

[Tonygreen]

What do you guys think about this?



http://mjgrowers.com/book_what_exper1.htm



"Plants use blue light for certain regulatory processes and also for photosynthesis. Chlorophyll absorbs both blue and red light and uses the light’s energy to power the complex process in which water and atmospheric carbon dioxide are converted to sugar and oxygen gas. Blue light does not affect the regulation of flowering.
When blue light is turned on during the dark period, plants photosynthesize but their flowering isn’t affected. This results in more growth as the plants produce more sugars. Before LED lights it was difficult to create a pure blue light. Instead, most of the time other spectrums were filtered out, which can be an inconvenient process. Try using between 20 and 40 watts of mixed blue light per 1000 watts of regular light. I have done only initial experimentation with this so test this in a limited way first. I suspect that the additional light is an efficient way of increasing total yield."



Does he mean running blue lights all during the dark period? He goes on to say orange light may be similar. Very interesting.

 

[Oregonism]

Is it bad that he doesn't pin down a specific blue? He seems fairly ambiguous, its a good sized spectrum. The led people these days are dialing in the specific blues.

But it does make sense on some levels, others remain a little mysterious. Photosynthesis at night?

I am interested to see how the plant is able to either bypass? or regulate both oxygen release at night and photosynthesis.

If plants can "talk" by clicking their roots, this is easily imaginable.

 

[TLoft13]

Interesting shit. Sadly I am not able to do side by sides.

 

[razor ridge]

I call BS, I left a UV-B bulb on unknowingly in my flower container and it caused re-veg

 

[Crusader Rabbit]

Yeah, he is talking about using blue light only for your "dark" period to increase photosynthesis time without screwing up flowering. The idea of using blue to supplement your white light is a separate concept for during the "daylight" period.

Flowering is induced by the lack of certain wavelengths within the red spectrum. These red wavelengths of light cause the destruction of flowering hormones, which need to build up to certain levels in the plant bring about flowering. Eliminating these red wavelengths for periods of ten to twelve consecutive hours allows these hormones to accumulate in plant tissues and induce flowering. The presence of blue wavelengths shouldn't affect the flowering response.

Oxygen release is a by-product of photosynthesis. Photosynthesis produces sugars. During the process of cellular respiration, sugars are broken down to generate energy for plant growth. A by-product of cellular respiration is the release of carbon dioxide. In plants, both of these processes take place simultaneously during daylight hours. It should be the same under pure blue light. In fact, using blue light to maintain photosynthesis during the "dark" period should increase the carbon dioxide available for plant growth during "lights off".

edit; Whoa, I really got this wrong in a big way. Sorry Oregonism. Maintaining photosynthesis during "dark" will not increase the carbon dioxide levels. It will reduce carbon dioxide levels since the plants under night blue will be consuming carbon dioxide to get the carbons for making carbohydrates (sugar).

 

[Tonygreen]

Anyone with an LED willing to test the water and risk a girl in the name of science?

Any ideas about what wavelength of blue would be an option to try?

 

[SeaMaiden]

I'm curious about what 'blue' lights the author is using as well. I'm thinking actinics, which produce a very narrow spectrum field that ranges from 420nm-430nm.

Crusader, I understand phytochromes and their manipulation a little differently, I'm going to have to go back and revisit that information, as I've been 'viewing' the red wavelengths as 'switches' that can turn flowering either on or off, depending on when the plant is exposed.

 

[Oregonism]

Yeah, he is talking about using blue light only for your "dark" period to increase photosynthesis time without screwing up flowering. The idea of using blue to supplement your white light is a separate concept for during the "daylight" period.

Flowering is induced by the lack of certain wavelengths within the red spectrum. These red wavelengths of light cause the destruction of flowering hormones, which need to build up to certain levels in the plant bring about flowering. Eliminating these red wavelengths for periods of ten to twelve consecutive hours allows these hormones to accumulate in plant tissues and induce flowering. The presence of blue wavelengths shouldn't affect the flowering response.

Oxygen release is a by-product of photosynthesis. Photosynthesis produces sugars. During the process of cellular respiration, sugars are broken down to generate energy for plant growth. A by-product of cellular respiration is the release of carbon dioxide. In plants, both of these processes take place simultaneously during daylight hours. It should be the same under pure blue light. In fact, using blue light to maintain photosynthesis during the "dark" period should increase the carbon dioxide available for plant growth during "lights off".

I apologize but I meant Oxygen respiration during "night" periods, not release.
But.....you might have answered that, as "blue" is not inhibiting the circadian rhythm at night it seems, which is no different than 24 hour veg in some regards.

 

[Tonygreen]

If this works and you ran a side by side I imagine the difference would be dramatic?

 

[blueberrydrumz]

yo guys,


check out http://boards.cannabis.com/grow-log/165934-first-attempt-24-hour-martian-method.html
also google martian nights or martian methodthere enough infos already on this</p>

 

[Tonygreen]

Now those are done using red at night. The blue light would activate chloropyll B. While the red light would activate chlorophyll a. From looking at the chart it appears more chlorophyll b is used by blue light than chlorophyll a is by red at certain wavelengths.

I see some people had issues with reveg usin the reds, the blue would avoid this it seems?

 

[ozman]

Count me in,I got my chair and my pipe,its gonna be a long ride.........
I never thought of this,but if it works out it would be something to consider.This would be a boon to us cabinet growers.

 

[medmaker420]

This has been on my to do list for 2013 actually. I have pure blue led grow lights but not sure when that test will go down.

I wanted to have it so the red panels were on 12 on and then blue for 12 hours and see first if flowering induces and then the affects overall.

As far as orange lighting, that too has some research that needs to be done among many others obviously. Unlike hps lighting, the end user ( the grower ) can actually do diy style testing to see what works best for them and their environment which totally rocks in my book.

I know there are a few led sites that offer blue leds as well so there has to be others out there with all blue panels for their veg who might want to do a test.

Another one I wanted to test was an all blue flower cycle where the lights on were blue and the lights off was actually OFF and to see what the all blue does for inducing flower if anything and how the plants grow during the light off period from whatever it got from the blue lights on portion.

I wonder if anyone online has done these tests outside of herb but then again I think actually testing with our plant is the only way any of us growers would use the results and know it can and will be possible to duplicate for others growing herb as well.

 

[trichrider]

Summary

Cryptochromes are photoreceptors that regulate entrainment by light of the circadian clock in plants and animals. They also act as integral parts of the central circadian oscillator in animal brains and as receptors controlling photomorphogenesis in response to blue or ultraviolet (UV-A) light in plants. Cryptochromes are probably the evolutionary descendents of DNA photolyases, which are light-activated DNA-repair enzymes, and are classified into three groups - plant cryptochromes, animal cryptochromes, and CRY-DASH proteins. Cryptochromes and photolyases have similar three-dimensional structures, characterized by an α/β domain and a helical domain. The structure also includes a chromophore, flavin adenine dinucleotide (FAD). The FAD-access cavity of the helical domain is the catalytic site of photolyases, and it is predicted also to be important in the mechanism of cryptochromes.
http://genomebiology.com/2005/6/5/220

these are present in every cell and tell the cells whether or not to repair themselves. i'm doubting the ability to fool these cryptochromes with any light.

 

[Thule]

I thought it was green light that the plants can't use and blue spectrum equals daylight. I'm actually using a blue energy saving lamp for flowering right now, so I find all this hard to swallow. Do blue leds really differ that much from light bulbs with a 6400k spectrum?

 

[Phillthy]

we need wavelength info.

 

[Tonygreen]

What kind of bulb is it? Pure blue? The thing is with an LED you can get a very narrow and specific segment of the light. A 6500 bulb is probably not pure blue it has other areas of the spectrum. Unless your light is pure blue!

 

[Cannabispassion]

i'd like to see it in action.
sounds a bit impossible though.

 

[Tonygreen]

A worthy experiment that should yield very direct results, either way.

 

[Thule]

What kind of bulb is it? Pure blue? The thing is with an LED you can get a very narrow and specific segment of the light. A 6500 bulb is probably not pure blue it has other areas of the spectrum. Unless your light is pure blue!

It's one of those cold light esl:s, seems like it's way different then.