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Photosynthesis

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Photosynthesis

Homesteader 47 Replies 11,520 Views
Page 1 of 3 · Replies 1–20 of 48
#5
The color of the sun
Slide3
 
#8
Some have been successful at speeding up flower time by giving 15 minutes of red flash only at the end of the light periods each night. I have about 20watts of 730nm on a seperate channel and look forward to trying it out but I think I am going to only run it during the last few weeks of flower instead of the whole cycle and see if anything positive comes from it.

The Red Drop and The Emerson Effect
http://www.life.illinois.edu/govindjee/photosynBook/Chapter13.pdf

 
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#9
thank you for positing this.. ill be trying to learn.. most of it is over my head but the more i learn the more shit makes sense. :)

so ill just keep trying till my it sinks into my dumb ass.

chris.
 
#10
The Crash Course series in the first post is a great starting point!
 
#11
Took this from the google machine a while back but the link I had is no longer available...


  • 439 nm is the blue absorption peak of chlorophyll a.
  • 450-460 nm is the royal blue that is absorbed by one of the peaks in beta-carotene. It is a readily available LED wavelength commonly used to excite the remote-phosphor in white LED lamps.
  • 469 nm is the blue absorption peak of chlorophyll b.
  • 430-470 nm is a range that is important for the absorption of chlorophyll a and b, which is key for vegetative growth.
  • 480-485 nm is the second absorption peak of beta-carotene.
  • 525 nm (green light) is a phototropic activator that researchers are still trying to find the chromophore of. Green light isnā€™t important for photosynthesis, but it is apparent that plants are gaining direction and environmental signals from it, and that it affects internodal spacing. This is also the wavelength of GaN or InGaN green LEDs commonly used in RGB and tunable applications.
  • 590 nm is key for carotenoid absorption. Carotenoids are starch-storing, structural and nutritional compounds.
  • 590 nm is additionally the phycoerythrin absorption wavelength. Phycoerythrin is a red protein-pigment complex from the light-harvesting phycobiliprotein family, present in red algae and cryptophytes, and is an accessory pigment to the main chlorophyll pigments responsible for photosynthesis.
  • 625 nm is the phycocyanin absorption peak. Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein family, along with allophycocyanin and phycoerythrin. It is also an accessory pigment to chlorophyll.
  • 642-645 nm is the peak absorption point of chlorophyll b.
  • 660 nm is often called the super-red LED wavelength and is important for flowering.
  • 666-667 nm is the peak red absorption point for chlorophyll a.
  • 700 nm light is to be avoided. It confuses the phytochrome recycling systems in green plants. Phytochromes are photoreceptors that are sensitive to light in the red and far-red region of the visible spectrum.
  • 730 nm, often referred to as far-red, is important for phytochrome recycling. It is needed for all kinds of morphogenic (shape-forming) processes. A few minutes of 730 nm light treatment after the full light cycle is over will revert the phytochrome chromophore from activated to inactive. This resets the chemistry for another lights-on cycle and may be useful in shortening the classic dark side of the photoperiod. This color is important to plants but is not considered in PPF as it is outside of the 400-700nm PPF range.
 
#13
Ive thought of this a few times, green light is reflected by the same color green on the leaves so if you had an led that changed between every wavelength of green then the plant should absorb more of the green wavelength?
 
#14
DrMcSkunkins said:
Ive thought of this a few times, green light is reflected by the same color green on the leaves so if you had an led that changed between every wavelength of green then the plant should absorb more of the green wavelength?
Click to expand...

Most LEDs have a range of about 20nm + or - but I would assume that various strains/crop use green light differently. Interesting stuff
 
#18
I love the fact that science can name a process and all its intermediate processes but in such a way as to make it
almost unintelligible - View the Ted talk by Drew Berry who does amazing animations and admitted that he could make sense of the gibberish until he turned into pictures .https://www.ted.com/talks/drew_berry_animations_of_unseeable_biology
By the time you truly understand no only the process but all the meanings of all the names give to each step I think you might well be dead !
Good thread though, best to watch before you inhale !
 
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