What Glyphosate has worked best for you?

Discussion in 'Pesticide & Herbicide Application' started by wildstarblazer, Mar 12, 2014.

  1. capetrees

    capetrees LawnSite Member
    from ma
    Posts: 217

    I'm trying to understand 2,3,4,5 and 8
    #2, stronger concentrations will kill better. That's why roundup for brush and ivy is a stronger concentration so I have to assume it's going to kill grass and weeds better
    #3, the direrctions tell us to spray the entire plant, underside too. I assume that could be called drenching or soaking.
    #4, if a plant is in a drought condition, any water detected will be absorbed faster and better for the plant to survive. With chemical in the water, I have to assume the plant will absorb the chemical faster also and will die quicker.
    #5, I'll go back to what I said in #3
    #8, Roundup quick pro is a highly concentrated product designed to be mixed to lesser dilutions. How can that product be "the bomb" if you're diluting it to the correct dilution rate as you recommend in #2, making it no better that any over the counter premixed Roundup product?
     
  2. White Gardens

    White Gardens LawnSite Fanatic
    Posts: 6,776

    In drought conditions, The stomata on the leaf has usually closed up as a protection against moisture loss through the leaf.

    So when drought conditions are present, then not only is it protecting against moisture loss, but it won't absorb as much moisture through the leaf tissue.

    When water or herbicide introduced in these conditions, the moisture doesn't stay on the leaf long enough to open the stomata.

    Only when moisture is introduced through the root system can then the plant "relax" and uptake moisture through the leaf.



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  3. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,077

    I don't think that stomata have anything to do with uptake. The openings are too small. They mainly connect with leaf blade intercellular spaces which allow the exchange of gases (like air and CO2). The spray solution often dries within minutes. Stomata close at night--does anyone believe that herbicides used at night will be ineffective?
    A phenoxy herbicide's main site of activity is the young apical meristem--the growing tip.
     
  4. turfmd101

    turfmd101 LawnSite Bronze Member
    Posts: 1,289

    #2. Woody stem ( brush, ivy) and soft stem ( monicot, dicot & sedges ) have different rates suggested for specific scientific reasons.
    #3. Spraying too heavily ( mostly under drought conditions) will inhibit intake. The plant will detect the alien chemical and try to protect itself from the unknown. Just as in #5.
    #4. Answered above.
    #8. The diquat will give a faster visual effect. The rain fast time is 40 min or less depending on conditions. Roundup quick pro will stay active in your sprayer for up to 3 days after mixed. As a standalone product. The liquid concentrations will not give these benefits.
    Posted via Mobile Device
     
  5. turfmd101

    turfmd101 LawnSite Bronze Member
    Posts: 1,289

    Riggle, I believe it has more to do with ACTIVE GROWTH. Herbicides require active growth to be absorbed. Drought conditions as well as night time conditions are not active growth conditions.
    Posted via Mobile Device
     
  6. White Gardens

    White Gardens LawnSite Fanatic
    Posts: 6,776

    Regardless if the Stomata is the actual culprit in the absorption process, it at least has some influence on the uptake of a herbicide in Drought conditions.

    Between the stomata, cell membranes, etc.... if like stated above, if a plant isn't actively growing such in the case of self preservation during a drought, then the herbicide isn't going to effectively work. Uptake root or leaf surface wise, transpiration, etc...

    In the case of the Stomata, if transpiration is minimized, nutrient uptake is minimized, and cell division is almost completely shut down, then it all is a major whammy against herbicide efficacy.

    A couple of seasons ago, with our severe drought, glyphosate effectiveness was severely hampered on unwanted weeds.



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  7. Skipster

    Skipster LawnSite Bronze Member
    Posts: 1,074

    The seminal research on herbicide uptake goes all the way back to MJ Buckovac’s work in California in the 1960s. Herbicide uptake in plant foliage is mediated entirely by the physical properties of the plant cuticle and the water/herbicide mixture applied to the plant. Herbicides do not enter plants through stomata. This has been known for more than 50 years.

    One of Charles McWhorter’s conclusions from research in the 1980s is probably what is being misinterpreted here. He found that conditions producing hydrated plant cuticles improve the penetration of both oil-soluble and water-soluble herbicides. These same conditions are also those that favor stomatal opening and increased plant metabolic activity.

    So, stomata have nothing to do with herbicide uptake, but the conditions that favor plant growth also produce cuticle conditions that favor herbicide penetration.
     
  8. ShaneW

    ShaneW LawnSite Member
    Posts: 63

    So do we have a winner yet in our Lawnsite D$%k Measuring Contest?
     

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