Fall pre...one app or two?

Discussion in 'Pesticide & Herbicide Application' started by grassmasterswilson, Oct 30, 2012.

  1. grassmasterswilson

    grassmasterswilson LawnSite Platinum Member
    from nc
    Posts: 4,519

    I normally hold off and do a late app of simazine on my warm season turf.

    I was talking to the local golf super about his pre(he was spraying a few weeks ago). He said he did a qt of simazine per acre in October and 1 qt of atrazine per acre in December. We would then do spring pre in February.
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  2. clemsonturf

    clemsonturf LawnSite Member
    from SC
    Posts: 109

    and your point is...
     
  3. grassmasterswilson

    grassmasterswilson LawnSite Platinum Member
    from nc
    Posts: 4,519

    Well I wa just asking if anyone had tried this. He say it works great. I thought I may tie it a try but it would mean adding another round to my program.
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  4. clemsonturf

    clemsonturf LawnSite Member
    from SC
    Posts: 109

    the answer to your question lies in sound agronomic reasoning, knowledge of chemicals and your variables.
     
  5. Turf Logic

    Turf Logic LawnSite Member
    Posts: 243

    Sounds like allot of pre-emerge to me. If Im not mistaken, a full rate is a qt per acre, and a split is a pint on most atrazine and simazine products. We dont have any cool season turf here so I may be wrong. we dont do any pre-emerging on warm season turf in december here.
     
  6. Skipster

    Skipster LawnSite Bronze Member
    Posts: 1,074

    What is a "full rate"? The label doesn't use that term. Most labels give a range of possible rates, with suggestions on target rates. but I don't think any labels say "full rate," "half rate," or anything like that.

    The Princep 4L label recommends 1 qt of product (1# ai/A) applied after October 1 when annual bluegrass is the main target. But, if you want to control other weeds, the label recommends 1 to 2# ai/A, beginning after September 1.

    Research has shown that split applications of PRE herbicides give better and longer control than single application. So, if you're trying to control grasses AND broadleaves, it would probably work better to traget a total application rate of 1 to 2# ai/A simazine and split the app. Since the label recommends 1# ai/A for grasses, your total rate should probably be more than 1# if you're also targeting broadleaves. So, I would recommend a total of 2# ai/A for the fall.

    When you split that application, you get two apps of 1# ai/A each, with the first beginning after Sept 1 and the second coming at whatever service interval you choose.

    I would stay away from the atrazine, since it has some resistance issues in areas where it's been used for years and years (it is also a RUP, which customers don't like to see on their invoices).
     
  7. Skipster

    Skipster LawnSite Bronze Member
    Posts: 1,074

    On the subject of simazine, I'm not really that crazy about it. It's got a very short residual period and it's been used a lot, so it has a lot of opportunity for resistance and for cross-resistance from atrazine, since both have the same mode of action.

    Simazine has also had some label changes over the last few years that make it hard to use. Can't spray when wind is more than 10 mph, can't mix or load within 50 feet of all wells (including abandoned wells; a lot of guys mix and load on their own property with a well nearby), can't spray within 66 feet of perennial or intermittent streams (includes drainage ditches), and can't spray within 200 feet of natural or impounded bodies of water (includes retention ponds in subdivisions AND home swimming pools).

    Just makes it hard to use.
     
  8. Turf Logic

    Turf Logic LawnSite Member
    Posts: 243

    When I refer to full rate I m meaning a one time app per season. If we use a split rate we go with a pint per acre. Hey but what do I know. Your first post pretty much explained what we consider a full rate and a split rate. Splitting the rate will generally give you 4 to 6 weeks more control. As for RUP, I wouldn't worry to much about that, Top Choice is a RUP product as well and contractors and clients love it. We have alway had great success in St augustine with it. I dont know that I would use anything else for st augustine. Keep in mind I have a agricultural thought process.
     
  9. GreenerSolution

    GreenerSolution LawnSite Member
    from PA
    Posts: 67

    I'm a little more north than you with cool season grasses. We do our pre-m in the spring time. But I have the same question. How do you guys feel about splitting applications for 1st and 2nd round and half rating each with barricade?
     

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