little help please

Discussion in 'Pesticide & Herbicide Application' started by richardcog, Nov 13, 2013.

  1. Victorsaur

    Victorsaur LawnSite Member
    Posts: 81

    It baffles me at times how confusingly the simple of math landscaping is presented. It seems like things are every which way and there is always something that one might have "missed". This is of course nonsensical as mathematical equations of this industry are very simple. The hard part is oftentimes obtaining the correct facts. You can't have an equation without accurate data.

    With math if you're ever confused all you have to do it set up an equation. Since 60% WDG (a type of active ingredient or AI) is 60 AI you have a ratio of active ingredient to total stuff sprayed. Since 6/10 of your spray is AI and you want to spray a total of 2 pounds of it by finding X (the amount of total stuff to spray) your formula looks like this: 2/X = 6/10 since they are both ratios. Multiply each side by X and 10 and the equation becomes 20 = 6X. Divide each side by 6 to find X. Middle school math (not to be condescending)
  2. lilmarvin4064

    lilmarvin4064 LawnSite Senior Member
    Posts: 757

    If you have one bucket that holds 2 gallons and one bucket that holds 7 gallons, how many buckets do you have ? :laugh:

    When I see the original question, to me, it sounds like this...

    You need to apply 100 lbs of 10-10-10 fertilizer to a lawn. How many pounds of fertilizer do you need?

    um.... let's see, 100 lbs.

    I sure hope they would use the word "active ingredient" instead of herbicide in the first sentence, otherwise it may be confusing, or just a stupid question.
  3. CL&T

    CL&T LawnSite Senior Member
    Posts: 493

    They do that to try and trip you up. You should know that the herbicide is the AI.
  4. wildstarblazer

    wildstarblazer LawnSite Senior Member
    Posts: 984

    I hate tests that make you think. We all know that you should not cut more than a 3rd of the grass blade when cutting grass. Okay, so instead of asking how much of the blade should be cut when cutting grass, they ask "If your grass is 3 1/2 inches long, what should be the final size of the blade after cutting?" Ya know? Camon, why make us think.
  5. Ric

    Ric LawnSite Fanatic
    Posts: 11,956

    I think it would be a little hard to end up with 3.33 Lb of active if you only started with 2 lb of product.

    I taught Material Calculation & Calibration at a local State College. Middle school math is all material calculation are. 7th & 8th grade word problems that preceded Algebra 1. I was totally surprise at the lack of math skills of College students. How ever I was teaching a night school class to yard boys, who don't exactly win scholarships.

  6. Victorsaur

    Victorsaur LawnSite Member
    Posts: 81

    And can you blame them? Most of the time what is really simple is presented in a way that is really confusing and wastes a lot of time. For example, the math behind phosphorous fertilizer required to achieve a target saturation percentage given numbers drawn from soil tests. Yes, complications arise including soil type, CEC, etc, but what about a conclusive base formula with alterations to the base given these factors?

    The reason why this industry is so confusing is that many times nothing is conclusive. Even if a conclusion is variable it is still a conclusion, and it is progress. Without this type of progress there is no systemic process for landscape professionals to do what should be easy.
  7. agrostis

    agrostis LawnSite Silver Member
    Posts: 2,294

    I highly recommend this book. If you shop around you can find a copy for $25 or less.


    Math 3.jpg

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