Mixed Pesticides, how long will they last.

Discussion in 'Pesticide & Herbicide Application' started by Shady Brook, Feb 22, 2003.

  1. Shady Brook

    Shady Brook LawnSite Bronze Member
    from Indiana
    Posts: 1,517

    How long can you expect a tank mixed pesticide to last without degrading to the point that is no longer effective? I am sure it likely depends on the particular product, but wondered if there were any generalities for the duration they can be kept before using.

    My concern would be chemicals used for spot treating like Drive, confront, Trimec, things of that nature. I would like to be able to haul multiple sprayers premixed to treat my customers on an as needed basis. Is this a realistic expectaion? I assume Roundup will last quite some time in this condition.

    Thanks guys
    Jay
     
  2. SWD

    SWD LawnSite Senior Member
    Posts: 989

    Typically, it is not a good idea to keep anything other than water in a spray tank for any length of time. Most pesticides are very hard on seals and fittings - and if you have tank mixed - then separation has to be monitored.
    I do not like to keep material in my tanks longer than 24 hrs, but I have gone up to four days in smaller sprayers.
     
  3. xpnd

    xpnd LawnSite Senior Member
    Posts: 378

    It is best to only mix what is needed for immediate use. If the label for the specific product does not state a reduced effectivness over time or use within a certain time period after maiing the finished spray, there shouldn't be a problem.
     
  4. GroundKprs

    GroundKprs LawnSite Bronze Member
    Posts: 1,969

    While I am not up on every reaction with every chemical, in general, pH of your water used will affect chemical degradation. But don't ask me what pH, LOL.

    Some special chems will state on label to use in 1 or 2 days.

    Only thing you can let sit is ester herbicide formulations. Just for laughs once, I let a mixed hand tank sit all winter, and it still worked great in springtime.
     
  5. Shady Brook

    Shady Brook LawnSite Bronze Member
    from Indiana
    Posts: 1,517

    Thanks guys

    So Jim, how long do you let your hand sprayers sit mixed with chemicals? :D

    So if it does not indicate it will go bad in a short time, I should be ok keeping em mixed for a couple weeks or so? I realize maybe the seals will be subject to premature wear.

    I just hate mixing up something for broadleaves, and maybe only using half the tank, and having to do something with the other half. I hope to be able to spot treat lawns at key times while out mowing, rather then setting aside a certain day to make a broadleaf pass on on my lawns.

    Thanks again
    Jay
     
  6. GroundKprs

    GroundKprs LawnSite Bronze Member
    Posts: 1,969

    In time, you will learn to estimate how much you will use in immediate future, and mix amount accordingly. Don't expect to get good control with a mix that has sat for a week. But ½ gal sitting a week, with 2 gal fresh added would be OK generally. Not 2 gal sitting and ½ gal fresh though.

    Make a note, ask me how to keep it potent next time we speak. I don't publish everything, LOL.
     
  7. Shady Brook

    Shady Brook LawnSite Bronze Member
    from Indiana
    Posts: 1,517

    Sounds Great Jim, I appreciate it very much!:)

    Jay
     

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