Those are really good questions and as far as anyone knows, we just go by what the diagrams say and also by trial and error. Far red is used in Pr-Pfr conversions, google it and it might make more sense. It's also useful in the Emerson effect for photosynthesis. 660nm seems to be the main driver of photosynthesis, I guess it does the most work. Regular red is for chlorophyll B process. Again, google it because the terminology more advanced than I can handle. To me, red is red, you would think anyway. TBH why do plants gotta be so picky? I mean, why can't they just tolerate acid rain instead of 6.8. What's with the decimal? It's just the way they work?
I found out today that my medium is really acidic. Not sure why I didn't check it to begin with when I sprouted $500 worth of seeds? But I found it out so it may have a lot to do with why I'm having a delay in growth and overall happiness. I watered with ph 7.5 to try and balance it back out then stuck the seedlings back under some florescent lighting to be safe. I figure it's better to introduce them slowly to 1300w anyway right?
Great post..it helped me understand somethings I wasn't aware about but now I have found something else after googling Pr-Pfr...dooohhhhh
I found this very interesting...Check out link and look at table 1. It seems to indicate that red and far red for seed germination is dependent on the order of red and far red and which one is last. Also this tidbit "
D. Efficiency of photoconversion
Phytochrome acts like a weird light switch that only turns off/on a portion of the lights. In other words, red light treatment of Pr results in about 85% Pfr + 15% Pr; far red light treatment of Pfr results in 97% Pr + 3% Pfr. Thus, at photo-equilibrium not all the phytochrome is interconverted. The reason for this is because the absorption spectra for the two pigments overlap and they are essentially competing reactions."
Study was done on lettuce and I'm aware it would be different for other plants but it does show there is some rhyme and reason to use far red in addition to red . I'm sure this would apply for every plant at different stages of growth for their own individual needs.
Has anyone tried anything like this with weed ? I don't think so because I never see far red mention much .
See Table 1
http://employees.csbsju.edu/ssaupe/biol327/Lecture/phytochrome.htm
I don't know..I just think nature knows more than us arrogant humans and I believe all of the spectrum should be used.
Sure plants use more of some colors in the spectrum than other's but that doesn't mean the other's are less important because less is eaten by the plant.
Tonsils were thought to be usless and 100% left over gills but now data shows they do play a part in our immune system.
It was also believed that life couldn't exist in the deep ocean (until a few years ago) where light didn't exist but that's also not true.
Humans and science is a beautiful thing but we don't even know why most plants are green for crying out loud.
I wonder if there are studies done on plants (veggies + Fruit) that were only given the blue/red spectrum to see if there were the same amount of nutrients or less or more as a veggie/fruit that was given the entire spectrum..Hmmm now I have to research this.
Sorry for rambling..one of my problems is I tend to complictae things too much and have a need to know the why. So When scientists don't have the answer I'll go with nature everytime. Nature has a reason for what it does and knows way better than us humans ever will.
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"Why green and not black?
Black plants can absorb more radiation, and yet most plants are green
It still is unclear exactly why plants have mostly evolved to be green. Green plants reflect mostly green and near-green light to viewers rather than absorbing it. Other parts of the system of
photosynthesis still allow green plants to use the green light spectrum (e.g., through a light-trapping
leaf structure,
carotenoids, etc.). Green plants do not use a large part of the visible spectrum as efficiently as possible. A black plant can absorb more radiation, and this could be very useful, if extra heat produced is effectively disposed of (e.g., some plants must close their openings, called
stomata, on hot days to avoid losing too much water, which leaves only conduction, convection, and radiative heat-loss as solutions).
The question becomes why the only light-absorbing molecule used for power in plants is green and not simply black.
The biologist John Berman has offered the opinion that evolution is
not an engineering process, and so it is often subject to various limitations that an
engineer or other designer is not. Even
if black leaves were better, evolution's limitations can prevent species from climbing to the absolute highest peak on the
fitness landscape. Berman wrote that achieving pigments that work better than chlorophyll could be very difficult. In fact, all higher plants (
embryophytes) are thought to have evolved from a common ancestor that is a sort of
green alga – with the idea being that chlorophyll has evolved only once.
Shil DasSarma, a microbial geneticist at the
University of Maryland, has pointed out that species of
archaea do use another light-absorbing molecule,
retinal, to extract power from the green spectrum. He described the view of some scientists that such green-light-absorbing archae once dominated the earth environment. This could have left open a "niche" for green organisms that would absorb the other wavelengths of sunlight. This is just a possibility, and Berman wrote that scientists are still not convinced of any one explanation.
Astronomer and mathematician
Fred Hoyle conjectured that chlorophyll was likely to be an interstellar molecule, pointing out the similarities of its light absorbing properties to interstellar dust.[SUP]
https://en.wikipedia.org/wiki/Chlorophyll
[/SUP]
