2-4-D Application and Rain ?

Discussion in 'Pesticide & Herbicide Application' started by Stan MI, May 2, 2005.

  1. Stan MI

    Stan MI LawnSite Member
    from MI
    Messages: 103

    How long after application is the product "Rain Safe". Or, how much time should there be before it rains again after I spray to not wash off.


    Is 80oz (2-4-D) to 40gal (Water) to 40,000 square feet, Correct ??

    Thanks in advance for any help.
  2. qps

    qps LawnSite Bronze Member
    from Indy
    Messages: 1,484

    If you applying 1.5 oz a thou you should use 60 oz....how much water depends on the your rate per thousand your spraying (carrier), if your licensed you should know this
  3. Garth

    Garth LawnSite Senior Member
    Messages: 382

    A systemic herbicide, 2,4-D is easily absorbed by foliage and translocated throughout the treated plant, which dies in 7-14 days. Phenoxy acid herbicides like 2,4-D mimic the action of natural plant growth regulators known as auxins, causing treated plants to literally grow themselves to death. In soil, 2,4-D residues usually dissipate within a month, primarily due to microbial degradation.Concentration levels vary for desired effect but are dependent on leaf surface, i.e. the broader the leaf, the more toxin absorbed. Because of this, grass having very little leaf surface shows little to no effect and dandelion, having a broad horizontal leaf structure dies. The longer it stays on the leaf surface, the better the translocation. Although the product dries in a few hours, it is better to leave it on for at least 24 hours before water is applied. If you don't have a license, get someone who does. 2,4D is a restricted material and there are many studies showing increased occurences of lymphoma and other cancers. It can also contaminate water supplies by runoff and should never be used without consulting an Ag commissioner in areas with high water tables.
  4. ArizPestWeed

    ArizPestWeed LawnSite Bronze Member
    Messages: 1,457

    I use 24d @ 1 once per gal and the weeds wilt over night .
    You wrote 7 to 14 days .
    Maybe you are thinking glyfosate , if so , OK
  5. Neal Wolbert

    Neal Wolbert LawnSite Senior Member
    Messages: 407

    Garth, What's your source on 2,4-D and cancer? Take a look at www.pestfacts.org for recent info. I understand there is no science behind the claim. Neal
  6. Grandview

    Grandview LawnSite Gold Member
    from WI
    Messages: 3,251

    2-4D is rainfast within four hours. 80 0z per acres seems high. I have not used it in a couple years. You need to know how much your sprayer is putting out.
  7. Stan MI

    Stan MI LawnSite Member
    from MI
    Messages: 103

    What I was looking for was a simple equation that I could translate easily.

    In other words, if 80 oz per acre is high is 60 correct for 40 gal and 40,000 square feet ?

    I know there are other varibles. My thought was fill the sprayer with the correct mix and cover a specific area. If I have to cross the same path once or several times until the sprayer is empty I have applied what was in the unit.

    Thanks again.
  8. Grandview

    Grandview LawnSite Gold Member
    from WI
    Messages: 3,251

    You need to read the label. How many oz 2-4D per acre does the label say to use? If the label says use 80 oz then use that. The second issue is how much water to mix with it. That depends on how much your sprayer puts out. If your sprayer puts out 40 gals/acre, then mix 80 0z for every 40 gals. You can determine that by filling up your sprayer with water, spray an acre and see how much you use. I only spray 5 gals/acre so I would mix 80 oz/ 5 gals. Every sprayer is different. Speed and pressure also determine output. The math is more complicated than just mixing so many ounces per gallon.
  9. Stan MI

    Stan MI LawnSite Member
    from MI
    Messages: 103

    Thank you for the response.

    As to the label. It is vague at best as to how much to use per acre. That's why I asked here. as to the sprayer out put. I know this is not the most efficient way. In an effort to simplify I am attempting to eliminate speed and pressure from the eqauation.
  10. BCSteel

    BCSteel LawnSite Senior Member
    Messages: 876

    Ok, heres an example *not factual numbers*

    Label says to use 15 oz/10000 sf. to control broad leaf weeds in cool season turf. The math is simple

    15 oz
    ------ = -------
    10000 sf 55000 sf (or what ever area you need to apply it to)

    So the equation goes 15 oz x 55000sf / 10000sf = 82.5 oz. I think its called cross multiply and divide. You can use this formula for any combination of 2 factors as long as you are working in the same unitson the top and the same units on the bottom.

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