A brother-in-arms on another site has just posted some excellent GREEN nm info.Now, if I only understood what it means...
Active chlorophyll blocks penetration of blue and red to the inner chloroplasts, green makes it all the way to the middle.
This is a higher light intensity phenomenon, lower light levels do not activate the blockage. Although green has 1/15 the absorption rate of red, leaf reflectance gives each green photon 5 strikes before exiting the canopy. At 80% DLI levels green exceeds the energy absorption of blue.
HGL grow lights are 15% green, 10% blue, one of the parameters used for choosing the brand. I spent a year with a test room running spectrum and intensities past budding plants, overwhelming information load. I had to pick and choose, hopefully I chose correctly, this grow is the test.
Also learned more about green light in the real world of the grow room. This is third visit with green, getting stuck on an idea is sometimes a perk.
A review of lab work (not mine) on green light, only enough numbers for ratio's.
Red blood cells and chloroplasts, chlorophyl came first and hemoglobin copied the molecule atom for atom except the magnesium center, hemoglobin uses iron and transports oxygen, chlorophyl uses magnesium and transports hydrogen.
This is brought up for the color change blood goes through, veins are blue but bleeding is red, color change from blue to red when active. Not sure what color inactive chlorophyl is but activated it turns green. The inside of the leaf is bright green, no red or blue gets through the cloroplasts once they are fully active. The effect begins about 50% of DLI, Daily Light Integral, the maximum light a perfectly environed leaf can use.
That is the research condensed to basic. Test room did not bear this out, adding green at 800 umol eventually bleached the leaves but did not appreciably increase growth.
When the current LED's were put in the 15% green was a factor, spacing ended up at 750 umol as more did not increase growth. Green was added to the tune of 250 umol extra and yellow leaves came right back again. Green removed. Twice failed.
Research on a long day plant needing very intense light led to the tight beam Magnum's putting 1350 umol on the plant when the beams crossed. Surprise surprise surprise, a stray MJ plant adjusted and began growing.
300 watts per square foot, all previous tests stopped at 130 as the benefits quit there. 110 grew the same as 130 so no reason to go further.
Green was added to the 1350 umol, bringing it to 1577, more than the leaves could take. NO yellow, this time the green helped. Wattage grew to 380 watts per square foot and can only cool six square feet.
But the green breakpoint happens at 90% DLI when the red/blue blockage is almost total, in nature this happens midday if the sky is clear. Not overly practical inside a house.
