Blue Light is Better for Flowering

[shivaganesha]

Originally Posted by RabidRabbit

True chlorophyll appears green to the human eye because the wavelength of the reflected light is processed as being "green" by most human beings thru the cones/rods in their eyes...thank you for support and clarifying what I said.

Think about it, if red spectrums of light are detrimental to the sacred plant, why is it that the harvest sun (which is quite red in the afternoons and evenings) causes outdoor plants to flower?

Both red and blue irradiance is detrimental to plants (kinda like a cup of coffee, it rehydrates yet dehydrates at the same time, but the rehydration should beat out the dehydration... only with the sun the good points far outweigh the bad), and in fact the green spectrum helps to nullify this irradiance.

Plants only flower beneath more red because this is what the sun mostly puts out and plants have adapted around it. A sun that puts out more blue should result in bigger, better, more potent plants.

[RichardDean]

I posted it before but I will post it again since some people don't seem to know the correlation between the 2 spectrums of blue and red they go hand in hand.

Light Spectrum.
The average color temperature of the sun is 5800 Kelvin throughout the year. What we see on earth has barely measurable spectrum differences between spring and fall.


The sun produces energy in pulses, like a carrier wave. Let us consider the photosynthetically active portion of this pulse, from the lowest frequency--red (675 nm)--to the highest frequency--blue (400 nm). (“nm” means “nanometer”. A lightwave that is one nanometer is one billionth of a meter in length.)


This pulse is like a train, with the blue in front and the red in the rear. The Red light acts like an engine placed at the end of the train, pushing the orange, causing a chain reaction, the whole spectrum working together synergistically. The best light for plant growth is full spectrum, like the sun, with a slight increase in red spectrum due to evolution and the fact that red travels through forest canopy better than blue.


Red light is the most efficient monochromatic spectrum for plant growth. However, all the colors have functions. If a person were especially good at hearing bass sound, that means the other pitches should be emphasized, so that one could hear the whole melody. For light to be efficient for plant growth, it must be full spectrum with close to equal linearity and amplitude through the production of 400-700 nm, with a slight bump in the red.


The blue spectrum has the highest energy and shortest wavelength [see: Light Measurement Handbook (1997), by Alex Ryer, page 8].




Blue is in the front of the light train, acting like a spearhead to penetrate the leaf, carrying the other colors with it. The far blue range includes UV-B, similar to what is found at high altitudes, and increases the prized phenolic compounds. This increases the flavor of peppermint, licorice, pepper, etc.
Conventional wisdom dictates that the growth phase be illuminated by a quartz metal halide (for blue light), the bloom phase by a high pressure sodium (for yellow/
orange light). However, a full spectrum is needed for all phases for a variety of functions. Blue induces growth hormones and rooting, and reduces stem elongation. Red induces flowering hormones, and provides energy for growth of flowers and leaves. Using only quartz halide during growth phase results in slow growth due to less red light. Using only HPS light during flowering stage often causes leaf yellowing, due to lack of growth hormones; and tends to cause stem elongation.


An artificial light which reproduces a red-enhanced full spectrum is the “Ceramic Metal Halide” or “High Pressure Metal Halide”. This has more blue than a metal halide with a conventional quartz arc tube, and more red than an HPS, so it’s spectrum is optimum for all stages. The Ceramic Metal Halide (CMH) features a ceramic arc tube like an HPS, and uses an HPS magnetic ballast. Philips has recently come out with a horizontal version of this bulb, resulting in longer bulb life and 1000 lumens more compared to a vertical cmh bulb operating horizontally. Generally, horizontal works best.


For those limited to magnetic ballasts, CMH is probably the best plant light available. For the Life Light electronic ballast, Life Lights also produces full-spectrum pulse-start metal halide bulbs. These are more efficient than normal halides, with better spectrum. They are designed to accommodate the 100,000 pulse rate of the Life Light electronic ballast. These come in four spectrums:
*6K for rooting and early veg
*4K for general growth/bloom
*3K for late bloom
*10K for finishing (last 2 weeks)
If you can’t afford all four bulbs, the 4K is fine for all stages.


The CMH has a better spectrum and is more efficient electrically than the retro-fit HPS that operates on a MH ballast. The retro-HPS is more expensive, lasts only half as long, and has reduced output, compared to a regular HPS.

[Gatson]

^^^^^^^^^^^



To the OP...why in the world would you try and discount decades of research because you read one article that looks pretty? As someone said before...do an experiment and prove yourself wrong. There are grow journals on this very site and all around the internet with side by side comparisons. It has been shown time and again that a CMH bulb is the best bulb to use in any phase...if you can't do that, stick to the conventional, proven way of doing things. Look a few up, then apologize to everyone here at GC.

[shivaganesha]

Originally Posted by RichardDean

Red light is the most efficient monochromatic spectrum for plant growth.

Who says so? Could you point me in the direction of any scientific research on any plant where tests have proved red light to be better for plant growth?

Blue is in the front of the light train, acting like a spearhead to penetrate the leaf, carrying the other colors with it. The far blue range includes UV-B, similar to what is found at high altitudes, and increases the prized phenolic compounds. This increases the flavor of peppermint, licorice, pepper, etc.

Well said, I agree completely that blue light is excellent for the terpenes... even in cannabis and will enhance flavour and aroma.

Conventional wisdom dictates that the growth phase be illuminated by a quartz metal halide (for blue light), the bloom phase by a high pressure sodium (for yellow/
orange light). However, a full spectrum is needed for all phases for a variety of functions. Blue induces growth hormones and rooting, and reduces stem elongation.

Again I agree with everything here except the rooting. Cannabis works hard (using a hormone called cytokinin) to keep its roots to a minimum. The only reason plants have a root system at all is to better take nutrients. I am yet to find a study on the causes of a plants rooting... maybe you could point me in the right direction?

Red induces flowering hormones, and provides energy for growth of flowers and leaves.

Of course red is used too for energy... but i am also yet to read a study that says red light induces flowering. In fact everything I have read suggests that blue is the best for this event. The red light, being the weakest, seems to be a waste of time.

Also by your reasoning on red light, in an absence of red light and an abundance of blue light cannabis would either not flower or flower slower. Is this the case?

[curtropolis420]

the color spec doesn't have anything to do with flowering beggining you just need a dark period of 10 or more hours..... i would agree that blue light is best for flowering on another note though because it is harsher in uvb rays and therefore produces more trichomes=danker nugs bitchesssss metal haldie and hydroponics if you want some super sticky icky and hps and soil if you wanna make some money i thought everyone knew that shit

[shivaganesha]

I'd like to take the time to direct you all to this link... http://www.plantphysiol.org/cgi/cont...ract/137/1/199

Here's a snippet of what you can expect to read when you get there...

Manipulation of the Blue Light Photoreceptor Cryptochrome 2 in Tomato Affects Vegetative Development, Flowering Time, and Fruit Antioxidant Content

This is the only test of its kind, and only done on one species of plant.

[GluTrog]

I figure mimicing nature is probably best. Plants have had a long time to evolve so I'm sure they have adapted. Wish I could articulate better but I'm stoned and can't get what I'm thinking out.

[shivaganesha]

Ever wondered why you feel better in the summer? It's not just the readily available heat, but also the light. UVB in particular. Even though there are still plenty of red photons and they still far outweigh the blue, there are more blue photons. So we have more good light hitting us. The same thing works for plants... cannabis would fare better if it didn't have a 'Fall' season to finish off in. Which implies that blue photons, being a richer source of light are more prized by the plant.

However, there does appear to be a downside in the enhancement of the blue spectrum. If we go by the experiment in the above link, a plant with excess cryptochromes or a plant grown in an abundance of blue light will delay flowering time.

But what do we take this to mean exactly? Well after clicking to read the full article on the effects on flowering time, I discovered that they took it from the seedling stage to the signs of the first flower. We all know flowering itself is genetic, right?

Yet I know this to be untrue of cannabis (the maturation part). I have seen plants vegetated in a pure UV (a and B) environment and the plants showed sex in 4 weeks.

To be sure, tests would need to be done on cannabis... anyone got a lab?

[Edge69]

I can tell you that from my most recent project that a single shiva was grown under blue cfl for approximate 8 months. (No red spectrum lights were used at all, also no natural sunlight).

After about the 3-4 mo period, she began to flower by herself, without any light schedule changes.

The only reason she died is because the power went out for four consecutive days hence no light at all, just pure darkness .

I believe that she could have survived a lot longer given more light.