Does your application mixture need to be more or less concentrated in the spring?

Discussion in 'Pesticide & Herbicide Application' started by Bluelude1, Feb 25, 2009.

  1. Bluelude1

    Bluelude1 LawnSite Member
    Messages: 70

    Most people I have talked with have their own personal opinion on how concentrated the mix rate, of products like Round Up, have to be at different times of the year. But I was wondering what the general consensus was regarding products like Drive75 w/ Quicksilver? Does henbit and other early season weeds respond well with average temps about 60 degrees or do they need a more concentrated mixture to make them effective?
  2. tombo82685

    tombo82685 LawnSite Senior Member
    Messages: 288

    I have not used those chemicals, nor have i sprayed for henbit. I would go with whatever rate is on the label. Usually in the middle of the label rates are good, since henbit has a fibrous root system it shouldn't be hard to rid of it. Unike your dandelions which have a tap root system. Henbit is a winter annual meaning it germinates in fall grows during the winter and flowers/seeds during the spring.
  3. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,665

    Good question. Since protox inhibitors like the carfentrazone in Quicksilver work in just a few hours (in the presence of sunlight), you should have your answer by tomorrow at this time. Go over some weeds twice to increase the dose. Let us know what happened. I don't know about the temperature effect on Drive 75.
  4. mrkosar

    mrkosar LawnSite Senior Member
    from Ohio
    Messages: 680

    follow the label. you can use the higher rates on the label when the weather is cooler. lower rates when it is hot.
  5. Bluelude1

    Bluelude1 LawnSite Member
    Messages: 70

    I know that the manufacturer documentation for Drive 75 states that it is effective down to 45 degrees, but doesn't really go into much detail past that.
  6. Jason Rose

    Jason Rose LawnSite Fanatic
    Messages: 5,858

    For broadleaf control in cooler temps look for products (2-4D) that are the ESTER formulation. You can use the 2-4D Ester up till the daytime high temps reach about 70 (though I think some push that). You will just get a lot better control.

    Now, winter annuals, like henbit, are reaching the end of their growth cycle in the spring. This makes them harder to get a kill on because if they are just ready to flower they have slowed growing and chemical uptake will be less.
  7. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    Higher temperatures and stronger rates will either impare growth or create discolored turf. Since both of the chemicals you listed are postemerge herbicides, stronger mixtures and temperature will affect the turf. Young weeds.........less ingredient! Adult weeds.....mid strength ingredient.............all following the label directions and recommendations according to the manufacturer.
  8. rcreech

    rcreech Sponsor
    Male, from OHIO
    Messages: 6,159

    This is a very hard question to provide an answer for...but a very good question.

    The key to "good" weed control is actively growing weeds and good environmental conditions (rain, temp, humidity etc).

    I guess I would say...if the conditions are not "ideal" then you may want to increase your rate (as long as you are within the label) or spike the product.

    Some other things you can do is:
    -Add surfactants/COC/AMS etc (depending on label and product of course)
    -Time of day
    -Wait until conditions are better (ex. During drought...wait for a rain or if its cold...wait until it warms up)

    As stated the key to good weed control is TIMING and growing conditions!
  9. Hogjaw

    Hogjaw LawnSite Senior Member
    Messages: 386

    Good topic for discussion!

    Often I do, but I know others don't, without thinking about ALL of the "ideal conditions" that should be present prior to the application.

    Thanks. Good food for thought

  10. tombo82685

    tombo82685 LawnSite Senior Member
    Messages: 288

    from what I have read, the ester spray is better but the drift potential is higher. So you may spray something right in front of you, but the drift that isnt being picked up to much by the human eye may kill something 20 feet away. You have to be really careful when using the ester, and make sure its a calm morning.

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