Hose Gun vs. Low Volume Tips (Kill question)

Discussion in 'Pesticide & Herbicide Application' started by Turfdoctor1, Mar 25, 2010.

  1. Turfdoctor1

    Turfdoctor1 LawnSite Senior Member
    Messages: 707

    The last 2 seasons I have had very poor results trying to kill fescue clumps with glyphosate in February-March while Bermuda is dormant. Last year I thought it may have been a surfactant issue. But, again this year poor results.

    Do you think this could just be a factor of the high volume with the spray hose versus using a boom type sprayer with low volume nozzles? There was one property that I used both types of equipment, and the kill seems much better with the low volume vs the hose. But, maybe it is just quicker. Anyone else had similar problems in the past?

  2. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    Same issues here with my Teejet 25660 lawn gun. Nothing beats getting the product to disperse out more evenly and smaller drops. My larger droplet tips are only good for pre emerge's. Even if I perform the swirling pattern or rapid sweep pattern, the results are still nil. Out comes the backpack and hit those spots with gly, trimec, or something equivalent on a flat fan nozzle.
  3. lilmarvin4064

    lilmarvin4064 LawnSite Senior Member
    Messages: 757

    I'm kinda opposite you, trying to grow fescue and kill bermuda, but... I've always had the best luck killing grassy weeds with fan tips, and broadleaves w/ spray guns(speed). I like teejet TP6506 with backpacks or maybe TP8006. 1 gal/1000. Greendoctor probably could give you some good advice.
  4. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 9,694

    One parameter never works for me. That is any combination of very large droplets, at low pressure, and at high travel speed. Therefore, all herbicides applied to turf goes through an AI fan nozzle operated at 25-40 PSI, 5 MPH or less travel speed and 20+ gallons per acre. Glyphosate can be really poor when not applied in a specific way. There is no dormant turf, but when I am asked to wipe out an existing grass area ahead of the landscaper, it gets done with an AI tip operated to apply 20-40 gallons per acre and 40 PSI. Can't kill what does not get hit and stay hit. If a spray rolls back off a weed while you are spraying, something's wrong. Those sprinkler head nozzles on lawn guns are only good for one thing in my book. They are good for applying concentrated liquid fertilizers because the large low pressure droplets roll off the grass, minimizing what can stick and burn. Go out and apply a lb of 46-0-0 in 2 gallons both ways to grass in midsummer: with a fan tip and with a sprinkler head nozzle. See which one burns more. lilmarvin, for me, 06 tips put down close to 1.5 gallons per 1000 unless I am running. I do not run when treating a lawn. Also, unless it is an AI nozzle, there is way too much drift. Regular flat fans either mist at 40 PSI or dribble out a less than full pattern if operated at under 40 PSI. I am able to cover over 24 inches with an AI110 nozzle held about 18 inches above the grass with little drift at 40 PSI. The spraying pressure is known to me because of the secondary regulator and gauge that goes between the hose and hand piece.

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