Green light

[clever]

Does anyone know the effects of a green light in the dark period. in the past few weeks I was careless and forgot to turn the green light off for a few hours durring the night. I woke up this morning and it was on again. will this effect the flowering?

 

[Electricthom]

I saw a show a few months ago with Pro growers and they would use the green flo bulbs to work on the plants during the dark cycle. I would assume that means it is OK and the green wont stress the plants. Many around here with more knowledge in case I am wrong. It was in the show about Harborside Health Center if I remember correctly now that I looked down and saw their banner add below.

 

[clever]

I'm using a green cfl if that matters

 

[Dank Gorilla]

I think you're fine. Just don't make it a habit.

 

[Icemud]

I would be careful with the amount of green light your using and keep it limited to only when absolutely needed. Its best to just not disturb your plants in their dark cycle period. Even though the cannabis community widely accepts the knowledge that green light is harmless it may not be entirely true. I wouldn't chance it and would just work on my plants when the light is on.


This was copied from a blog from a Professor of Biology

Chlorophyll absorption spectra indicate a very low absorption of green
compared to red or blue wavelengths. However, the photosynthesis action
spectrum of an intact leaf indicates the rate of photosynthesis is roughly
60% as much with green light as with red and it may actually be higher
than with blue (see Salisbury & Ross, Plant Physiology, 3rd, p. 185) Thus,
leaves can use green light fairly effectively in photosynthesis. Some of
the absorption may be due to accessory pigments. Chlorophyll in an intact
leaf can also absorb green light much more effectively than the
chlorophyll absorption spectrum (chlorophyll extract in a
spectrophotometer) indicates. One reason is that although green light is
absorbed with low efficiency, it has many chances to be absorbed because
it is repeatedly reflected from cell to cell by the complex leaf geometry
so it has many chances to be absorbed. Such geometry effects do not occur
with chlorophyll extract in a spectrophotometer tube. This provides an
excellent illustration of how in vitro can differ markedly from in vivo.
Unfortunately, biology textbooks usually just publish the in vitro
chlorophyll absorption spectrum rather than the in vivo photosynthesis
action spectrum.

Thus, the common idea that leaves are green because they reflect ALL green
light is incorrect. Most leaves reflect relatively more green light
relative to red/blue wavelengths and appear green to our eyes. An
exception is the blue Colorado spruce (Picea pungens 'Glauca') with bluish
needles. The sensitivity of our eyes might have something to do with it
too because our eyes are most sensitive to 550 nm wavelengths and much less
sensitive to red or blue wavelengths.

And this from The NIH.gov website at the national library of medicine.

Light quality and quantity affect plant adaptation to changing light conditions. Certain wavelengths in the visible and near-visible spectrum are known to have discrete effects on plant growth and development, and the effects of red, far-red, blue, and ultraviolet light have been well described. In this report, an effect of green light on Arabidopsis (Arabidopsis thaliana) rosette architecture is demonstrated using a narrow-bandwidth light-emitting diode-based lighting system. When green light was added to a background of constant red and blue light, plants exhibited elongation of petioles and upward leaf reorientation, symptoms consistent with those observed in a shaded light environment. The same green light-induced phenotypes were also observed in phytochrome (phy) and cryptochrome (cry) mutant backgrounds. To explore the molecular mechanism underlying the green light-induced response, the accumulation of shade-induced transcripts was measured in response to enriched green light environments. Transcripts that have been demonstrated to increase in abundance under far-red-induced shade avoidance conditions either decrease or exhibit no change when green light is added. However, normal far-red light-associated transcript accumulation patterns are observed in cryptochrome mutants grown with supplemental green light, indicating that the green-absorbing form of cryptochrome is the photoreceptor active in limiting the green light induction of shade-associated transcripts. These results indicate that shade symptoms can be induced by the addition of green light and that cryptochrome receptors and an unknown light sensor participate in acclimation to the enriched green environment.

 

[clever]

thanks, very informative information, pretty much says it all.

 

[Stoneybud]

I have to agree with Icemud.

Although it is believed that green light is harmless to use during the night/dark cycle,
I wouldn't recommend doing it at all.

Anything that your garden/grow room needs can and should only be done during its
lights on hours.

You have invested your time and hard work to bring your girls this far, just let them be
when the lights are off.


~Stoney~

 

[rodzilla420]

I left a grenn cfl on for 3 Days and was rewarded with aman hermi. Germinated my entire room 7 weeks into flowering. Needless to say I got rid of the green light bulb...