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UV Light Weeder

Discussion in 'Organic Lawn Care' started by OrganicBob, Jul 29, 2005.

  1. OrganicBob

    OrganicBob LawnSite Member
    Messages: 73

    I've been speaking to a guy in Denmark for a month or so about a product that he has a patent for. It is a weeder that uses thermal radiation for weed control. At first I was skeptical. I knew from agriculture that flamers and steamers have been used with good success for erradicating weeds in crops, but their lawn applications seemed limited by safety, lisencing to carry/store propane, and affordable small scale units. As I looked more deeply, I could see the benefit of using ultraviolet light as a solution.

    Has anyone out there heard of this technology?
    What are your thoughts?

    :cool2:
     
  2. BRANDMEL

    BRANDMEL LawnSite Member
    Messages: 58

    I've used the heat weeder before, with a small propane tank that attaches to the handle. I don't know if it's the same thing you described? It works good if you have 24 hours to spend on a lawn for weed control. It's a fun tool for a retired homeowner :sleeping:
     
  3. OrganicBob

    OrganicBob LawnSite Member
    Messages: 73

    I think that the unit that you're referring to is a radient heat weeder that uses a propane to heat a heating element like steel or ceramic. This model uses UV radiation. The UV light is absorbed by the outermost layer of the weed very efficiently causing the cells in the leaf to burst. Basically working on the same principal as a heat weeder or a flame weeder, but more efficient, safe, and a lot faster.

    :alien: Thanks for your post.



    *at least that's what it is supposed to do. Whenever I get the model, I'll post on how it works and whether it is at all a good alternative for pesticides.


    :drinkup: :drinkup: :drinkup: :drinkup: :drinkup: :drinkup: :drinkup:
     
  4. sgbotsford

    sgbotsford LawnSite Member
    Messages: 123

    I can see the advantage of a thermal weeder for anyone working organically. Properly shrouded it would make a great edging tool.

    A UV tool would be cool too, but you would need to be leashed to a power source. Don't think this will work with a battery.
     
  5. phasthound

    phasthound LawnSite Fanatic
    Messages: 5,054

    You're referring to a post that is 12 years old. If it was effective, there would be more knowledge about it by now.
    Propane flame weeders do work well in the right circumstances.
     
    hort101 likes this.
  6. sgbotsford

    sgbotsford LawnSite Member
    Messages: 123

    I keep forgetting to look at the dates. However now there are high power (5 watt) UV LED's out there. May be time to revisit the idea.
     
  7. GrassManKzoo

    GrassManKzoo LawnSite Silver Member
    Male, from Kalamazoo, MI
    Messages: 2,997

    Maybe a 10watt laser pointer
     
  8. sgbotsford

    sgbotsford LawnSite Member
    Messages: 123

    Did some more reading. Would take a hell of a UV lamp. Sunlight is about 1000 watts/square meter. (w/m2) About 7% of that is UV. Damage is cumulative -- at least for short periods of time (days) damage = power * time.

    To have an effect on the scale of a lawnmower you would need to apply power at several thousand watts/m2.

    Once you get this sort of level, you are being unsubtle. Back to some form of thermal cooking the plant.

    Plants are 4 orders of magnitude more resistant to UV than are even UV resistant bacteria. So it would take 10,000 times the dose that are in UV water purifiers.

    So, forget UV weed killers.

    ***
     
    rlitman and hort101 like this.
  9. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,562

    Actually sunlight works fine for weeds--just cover them with black plastic and let the sun heat 'em up. Bubble wrap pool cover helps keep it warm.

    Or use a big magnifying glass or Fresnel lens--when smoke starts to rise--that is hot enough. Concentrate on the growing point and crown of the plant.
     
  10. phasthound

    phasthound LawnSite Fanatic
    Messages: 5,054

    [QUOTE="RigglePLC,
    Or use a big magnifying glass or Fresnel lens--when smoke starts to rise--that is hot enough. Concentrate on the growing point and crown of the plant.[/QUOTE]
    You have a lot of time on your hands my friend. :)
     

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