Q4 Question???

Discussion in 'Pesticide & Herbicide Application' started by 31bro, Aug 1, 2008.

  1. 31bro

    31bro LawnSite Member
    from IN
    Messages: 126

    I am not having good results with Q4 on Crabgrass. Two properties I have sprayed with Q4 has killed nutsedge and the broad leaf weeds but not the crabgrass. I am running it through a z spray with the .32 nozzles. I am putting 128 ounces( I mixed it the same last year and it work great) of Q4 per tank. Am I doing something wrong? Do I need a sticker? Any help would be appreciated.
  2. Runner

    Runner LawnSite Fanatic
    Messages: 13,497

    The thing you have to understand about Q4, is that it contains quinclorac as the ai against crabgrass (the same ai in Drive). quinclorac only works in certain tiller stages of the cg, and does not work in others - requiring another visit and repeat application (3rd and 4th tiller stages).
    Also, (just incidentally), telling us that you are spraying 128 ounces per tank on your sprayer tells us NOTHing on your mix and ap rate.:)
  3. jbturf

    jbturf LawnSite Bronze Member
    Messages: 1,502

    agreed on the tiller stages,
    also- isnt sticker a must with quinclorac for good results
  4. cod8825

    cod8825 LawnSite Senior Member
    Messages: 501

    There right about the stages also I put down 1.5oz per 1000 I use hawkeye for the sticker but I use that mostly for the fact that I like the wintergreen mint smell after application.

  5. tremor

    tremor LawnSite Bronze Member
    Messages: 1,476

    The sole function of crabgrass is to reproduce. Once crabgrass gets into seed formation mode the plant produces a waxy leaf cuticle to prevent moisture loss. That layer is very difficult for herbicides to penetrate.

    The difficult period of penetration usually doesn't last more than 3 weeks but during this time we cannot get predictable control of crabgrass using Quinclorac unless the protective layer is broken.

    Since it was first registered, the Drive label at first required & now merely recommends the use of MSO (methylated seed oil) to break the cuticle. Not many LCOs go to the trouble to buy & stock MSO but it really helps.

    Before & after this difficult time you can get fair results using a cheap non-ionic spreader sticker.

    Q4 aside; we should examine why Drive (now Quinclorac) should ALWAYS be used with MSO. Quinclorac is a fine post-emergent herbicide. However it is also a pre-emergent. Common cheap spreader stickers do contain emulsifiers (the "spreader" part) but they also contain drying & sticking agents. These help make pesticide applications water-fast. But we don't want Drive (Quinclorac) to become water-fast. Once the active ingredient is absorbed by the leaves, we need the next irrigation event to move the active off the leaves & down onto the soil where the pre-emergent barrier can form.

    Using spreader sticker with Drive is throwing half of the Quinclorac benefit away.

    Q4 doesn't contain enough quinclorac for us to worry about a pre-emergent benefit but you still need to penetrate the leaves.
  6. FdLLawnMan

    FdLLawnMan LawnSite Bronze Member
    Messages: 1,246

    Tremor os right on with his comments and knowledge. I have had so-so results with Drive unless I use MSO, so now I always use MSO and have very good results.

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