Will green light kill your plants?

Discussion in 'Plants: Science and Cultivation' started by photopro, Sep 29, 2006.

  1. photopro

    photopro Well-Known Member

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    I was indirectly asked this question via a search engine earlier this week. The person who was wondering typed that question into Google and asked "Will green light kill your plants?" I've never heard anyone ask that question before and was wondering if there is some sort of discussion going on somewhere to that end? I've done my own research and recently posted a response on my plant website but would enjoy hearing any other opinions or comments. Especially if this question is on some plant forum.

    Thanks!

    I'm adding this amendment: Some have emailed me asking how I was "indrectly" asked a question via a search engine. You likely don't know it but everytime you type a search into any search engine there are companies who log what you ask or search for. When a search leads you to a specific website the owner of that site can have the ability to see what question you asked, but not who asked it. The information is used to improve the content of the site.
     
    Last edited: Oct 5, 2006
  2. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    It may not kill them, depending on the relative amount of other accessory pigments, but it will certainly make them suffer, since chlorophyll a absorbs very little light in the green part of the spectrum: see The Spectrum and Photosynthesis. This is a general rule of thumb, with a number of exceptions.
     
  3. photopro

    photopro Well-Known Member

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    Thanks Daniel. As a photographer (retired) I am aware that green is one of the three primary light colors that create what we see as "white" light. Plants, at least shade lovers, seem to thrive in lower light because it is actually bluer (less red). But since green is a primary component of "white" light it would appear plants actually get green light even if they don't use green light, just not total green light. But your point is well founded and I will research it further. Thanks again.
     
    Last edited: Oct 5, 2006
  4. photopro

    photopro Well-Known Member

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    Daniel,

    I included your comments and a quote from the site you gave on my website discussion of this subject. If you'd care to proof what I said I'd appreciate your comments. And I certainly appreciate your response thus far. You can find a link to my post at the top of my website homepage. Thanks again!
     
  5. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    Looks mostly fine to me - though I'm not certain about saying that white light is made up of three different colours. If you take white light and pass it through a prism, you break light up into the whole visible spectrum, not just the three colours.

    Then again, I'm a decade away from the last university physics course I had to take, so I'm not well-qualified to answer.
     
  6. photopro

    photopro Well-Known Member

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    Thanks again Daniel. That is the way it was taught "way back when" when I studied this in school. I checked and found a site to explain and support that which I'm now posting. http://acept.asu.edu/PiN/rdg/color/composition.shtml I also had it demonstrated once you could take those three colors of light and produce white light.
     
    Last edited: Oct 5, 2006
  7. pierrot

    pierrot Active Member 10 Years

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    Photo pro
    if you blast just green light at the plant it most probably will not have an immediate effect but the plant needs red and blue light to power photosynthesis. As you may already know plants look green as they reflect green light back at us.

    http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect10.htm

    In order to cause photosynthesis to happen the plant absorbs blue and red lights to excite the elctrons in a cascade effect. This caused the energy bursts needed to form the end products of photosynthesis.

    It will most probably be detrimental to plants if it is only green light you are using.
     
    Last edited: Oct 4, 2006
  8. photopro

    photopro Well-Known Member

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    Thanks. I believe you'll find all that explained on my website explanation.
     
  9. Wslyder

    Wslyder Member

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    NASA came out with a report on different colored light and its effect on plants in other solar systems which is where this thread may have started. Here's the link below which also links to other sources of information. My inquirey that brought me here was what would happen if plants only received green light? Would they then reflect a different color other than green? Say red or blue? Just yet another sidetrack in my curious mind.
    http://news.yahoo.com/s/nm/20070411/sc_nm/plants_planets_dc
     
  10. bioramani

    bioramani Member

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    In another context a statement was made that reading in a dim light will harm the eyes. To which the response was: Hearing a whisper will damage the ears?

    The point is that green light is like darkness to green leaved plants since they cannot use that wavelength. This only means that photosynthesis will be slowed. There cannot be any harm. If you hold a large green filter between the plant and sunlight the plant will get the green light that is anyway part of the sunlight, which was not harming it earlier.

    Daniel Mosquin is right.

    bioramani
     
  11. photopro

    photopro Well-Known Member

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    I'm at a loss to understand your point. I quoted in my on-line piece information from Daniel. As I recall, he and I exchanged several emails over this question. I also quoted other references from scientific sources attempting to explain why the green portion of the spectrum is of little use to most plants. I suspect the person who originally asked the question was hoping to do something ornamental with their plants.

    The whole point is not that the green light will actually kill your plants as I was originally asked, it is that green light is of little use to your plants. As a result, they may eventually die. I tried to explain this. So again, I'm at a loss to understand what point you are attempting to make or prove.

    Look up achromatic color in any physics book for a better explanation of how the total spectrum is combined to make "white" light. Sometimes people have trouble understanding the composition of light since it is not easily seen. Unless, of course, you use a prism.

    http://www.chemistrydaily.com/chemistry/White

    http://micro.magnet.fsu.edu/primer/java/aberrations/chromatic/index.html

    http://en.wikipedia.org/wiki/White
     
    Last edited: Apr 19, 2007
  12. DamienO'Connor

    DamienO'Connor Active Member

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    So why is it that same plants, like maples, turn an orangey-red colour during the year (Autumn is it? I'm from Australia sorry.).
     
  13. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    That's when the plant removes the chlorophyll from the leaves before they die in the winter. Chlorophyll contains a lot of important nutrients etc., and the tree doesn't want to lose them when the leaves die and drop off, so it withdraws the nutrients down to the roots. The yellow, orange, red is the background colour of the leaf after the green chlorophyll has been removed.
     
  14. GreenLarry

    GreenLarry Active Member 10 Years

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    I think I'm right in saying that the colours we see in autumn are the leaves true colours which for most of the year are masked by the chlorophyll. As for light composition,if you take a look at photographic film you will see it is made of just 3 layers,magenta,cyan and yellow. These colours have their counterparts in the colour wheel,green red and blue which come out when the negative is printed(opposite of yellow is blue etc) and from these 3 primary colours we get white if mixed in equal amounts.
     
  15. photopro

    photopro Well-Known Member

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    You are correct with the exception film producer Fuji added a fourth layer well over 10 years ago to many of their films. I used to do some work for Fuji and was privileged to be asked to test the new films when they came out. Dr. Kenji Yoko of Fuji in New York sent down a large box of the new films which are capable of working under mixed light conditions. Many people notice when you take photos under either tungsten or fluorescent light the photos have a rather bad color outcome. Fluorescent light makes film look an ugly green and tungsten tends to make everything very red. If you read my total article on the internet on this subject you'll note I explained about color temperature to which this is directly related. The Fuji films, with the 4th layer, are able to compensate for this. That new technology gave Kodak quite a fit for a while since professional photographers loved the new film.

    It just dawned on me I never actually gave a direct link to the page on my website that explains all of this. So here is the page:

    http://www.exoticrainforest.com/Will green light kill.html
     
    Last edited: Sep 21, 2007

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