For those who are not 'current' on led lighting, much of which is flat out wrong, especially the importance of GREEN...
This from StarDustSailor on another thread
Q: How do we utilize green light in an indoor growing environment? Would more green in a spectrum allow a plant to utilize red/blue more efficiently to increase amount of photosynthesis taking place (raising the photosynthetic "cap", so to speak...)?
A: -Well ...That actually is way long talk ...
In summary ....
In low overall light powers ...( small grow spaces & small powered lights ) ...
At this situation ,plants ,"concentrate " on absorbing mainly red and blue wls ......
If much of green light is introduced in low overall light powers ,then it will slow down photosynthesis ,
induce severe shade avoidance syndrome effects (internodal stretching/elongation )
and generally impact plant growth in a negative way .....
So ,indeed ,in low light conditions R/B combos can work almost as fine (IF NOT BETTER !) as white light would ..
(.... very good,indeed, for seedlings ,bedding greens ,leafy small plants, etc ....)
Now...If overall light power increases ......
Things change now ......
Green wls have to be introduced ,at a certain power level.
-Green light will slow down PS systems ,protecting them ,in fact,from photo-inhibition,light saturation ,photo-respiration, etc ....
PS slows down ,but can continue it's activity for prolonged period of time ,under strong light ....
Either full power for a 100 meters sprint or ....at 40% of power for 10.000 meters jog .....
I think you get where this leads ...
Balance between i.e flowering hours (12 ) and overall light power ...
Way strong red & blue light ,will saturate the photosystems in i.e 4 hours under illumination ....
Rest 8 hours of 12 ,plant is protecting itself from light .....Mainly .....
-Plants have "developed " while evolving under the sunlight ,the "green window policy " ,
so for older leaves deeper in canopy to keep photosynthesizing ...(strong light=bigger plants=>deeper canopy )
(thus the lower-older leaves are darker-almost black ,sometimes -,
than newer ,top leaf tissue ..they absorb all the light they can get ! Reflecting only a little back ...)
-At higher light power (white light ), green photons are also absorbed just fine as the rest of photons and actually have quite big RQE ....
So in fewer words ....
The more overall power? The more the green part inside the white light ...
(that's how HPS work,actually .....)
https://www.rollitup.org/led-other-lighting/613358-new-experimental-advanced-diy-designs-14.html
