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Volume question

Discussion in 'Pesticide & Herbicide Application' started by Loosa, Oct 14, 2005.

  1. Loosa

    Loosa LawnSite Member
    Posts: 4

    I have been struggling all year with good control on the weeds. The question I have is, is the volume to chemical rate correct. EG

    I use a 200gal tank

    Its calibrated spraying 3 gallons/1000sqft.

    Trimec as an example. Top end rate 1.5oz

    My formula would be 200g/3gall per 1k = 66k of coverage multiplying that by the product rate of 1.5oz gives me 100oz of product for the tank mix. Correct right?

    My weeds look terrible, and this is the top end. Am I missing something?:dizzy:
  2. Dallas Turf

    Dallas Turf LawnSite Member
    Posts: 246

    Are you using sticker or surfactant?

    Are you adding any Nitrogen (urea, uan, or ams)? They will sometimes help with uptake.

    What is your ph? If too high it can break down your product within an hour.

    Per the label what is the recommended carrier (water) volume per msf?

    3 gallons per thousand may be a little high and be causing your problem by washing most of your product off before it is absorbed since it needs foliar contact.
  3. Ric

    Ric LawnSite Fanatic
    Posts: 11,956


    Ditto your post. I use 1 gallon per thousand on most Herbicides. Unfortunate insecticides require more volume of carrier.
  4. Grandview

    Grandview LawnSite Gold Member
    from WI
    Posts: 3,251

    120 gals per acre seems real high. I like 5 gals per acre. l
  5. GrazerZ

    GrazerZ LawnSite Senior Member
    Posts: 671

    Your rates should give you good control. I use to use a 3 gallon nozzle when I started out also. Personally I think its a good idea, safer when you are learning. I would also recommend that you use a sticker for applications. Other things that can affect your kill are, temps over 80 degrees, rain soon after, ph of water . I'm guessing that its the surfactant though.
  6. Kent Lawns

    Kent Lawns LawnSite Senior Member
    from Midwest
    Posts: 870

    You're walking too fast and only putting down 1.5 - 2 gal/M thus cutting your ai in half.

    My suspicion in that the calibration is not verified.
  7. tngreen

    tngreen LawnSite Member
    Posts: 12

    Loosa, I dont think your 3gal rate is the problem, back at the begining of time 4gal rate was the standard. All the old chemlawn tankers used to carry 1200 to 1600gals of material and spray at 4gals. We killed weeds like crazy, low volume is the way to go nowdays. I would check the label to make sure what your trying to control is listed first. Then follow some of the other tips given.
  8. Loosa

    Loosa LawnSite Member
    Posts: 4

    Dallas Turf,

    I think maybe your high volume suspicion is on the right track. The weeds do look sickly after they have be sprayed but they are not dying. Therefore if Im spraying a 3 gall per 1k, and I have less product mixed because of that it could be washing alot of it off. To me that tie together why they look sick but a not dying. I might try 2 gal per 1k and check the results. Thanks everyone for your input.
  9. GreenUtah

    GreenUtah LawnSite Senior Member
    from SLC, UT
    Posts: 866

    This is absolutely correct and in fact, many product labels show mix rates as high as 8 gallons per thousand mix rates, so I would not be leaning at a water rate issue, but more toward a spray pattern/walking speed or other environmental issues. Back in the tanker day, Chemlawn found it necessary to run at a higher water rate to lessen the possiblity of striping and burn by inexperienced technicians. The higher water rates gave a little better "flow" once on the grass, hiding many mistakes in the application itself. Why? A 50% technician turnover rate coupled with a need for 40 lawns per day pretty much from second day of hire to keep on the timetable that maximizes the number of apps per customer each season. Add to that a high N program with little else and you have your reason. But as TN says, the weeds died, service calls are expensive, at those higher rates of water with no adjuvants ( I promise..lol). I would measure off 1000 sq feet and have someone time you as you cover it in your normal spray habits and see if it takes you 1 minute to cover it. Eliminate this before you make any other changes. If it's not 1k per min, all your mix rates are off.
  10. Ric

    Ric LawnSite Fanatic
    Posts: 11,956


    I think old chemistry and new chemisty in Herbicide play a factor in carrier volume. I find quicksiliver to work great at the lower rate if a low volume mix is used. I find the old atrazine to work better as a high volume carrier mix.

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