Managing fall and winter bermuda installations

Discussion in 'Pesticide & Herbicide Application' started by ThreeWide, Jan 12, 2005.

  1. ThreeWide

    ThreeWide LawnSite Bronze Member
    Messages: 1,116

    Landscapers in our area often install Bermuda sod during the fall and winter months. I've seen three new properties this week in such a scenario. We've always been told no pre-emergent on new Bermuda sod, so that's the practice commonly observed.

    Today, I investigated one where the sod appeared to be installed around last September. It was well rooted in some locations, but in some areas the sod seams were still evident.

    This lawn is severely infested with henbit and a host of grassy weeds. Poa annua, Poa triv, you name it. Since the sod is was not fully established before dormancy came, I am concerned about weed control methods. It obviously had no pre-emergent to this point.

    I'm thinking that since both a post and pre-emergent is needed, Simazine would be a good option other than Glyphosate (will not put that in my tank - whole other subject). I do not think Simazine would be any threat to the greenup process this Spring, as long as it would control the existing weed problem.

    Any Simazine vets out there?
  2. Luscious Lawns

    Luscious Lawns LawnSite Member
    Messages: 133

    After your post yesterday I went out and bought a quart of Revolver ($175.00) to use on dormant bermuda for Poa & Goose Grass. I also looked into the Simozine product. It is much cheaper than Revolver.

    Gly. over dormant bermuda. No Way!

    I usually tell the customer we'll pre-M the turf and address the weeds at green up. If the sod is poor. (like much of the new construction around here)

  3. ThreeWide

    ThreeWide LawnSite Bronze Member
    Messages: 1,116

    Revolver is also great for removing fescue in actively growing Bermuda. You should get good use of that product this year. I will most likely be using it for perennial ryegrass removal in my own lawn this Spring.

    As the weather turns cold again this week, the Revolver might take a bit longer to produce results. Just keep that in mind.

    One thing about the pre-em. I've heard many theories on the use of pre-em on new bermuda, but you do want to avoid having it active during the Spring greenup process. One of my most trusted reps says that applying pre-ems at a reduced rate right now is just fine as it will lose efficacy before early April. Once the bermuda has greened up, then we can go with another round of pre-em. This does leave us vulnerable for crabgrass for a few weeks, but the greenup period is critical. It is possible that problems seen in the past were from traditional March 15 applications of pre-em, which is just before greenup. One could understand the problems potentially caused by that.

    UGA did a study on pre-ems with bermuda sod installed in February 2000 and 2001. They found that Pendulum and Dimension used at labeled rates caused very minimal to zero issues with greenup or root damage. Ronstar caused zero issues, but that product is not labeled for residential use. They only saw problems with 2X and 3X rates while simulating an actual overdose. This was with high quality sod under near perfect soil and moisture conditions. We can take that for what its worth, but what they found goes against the labels regarding new sod.

    You can read about the study here.
  4. quiet

    quiet LawnSite Senior Member
    Messages: 720

    Interesting study. Here's the summation:

    "While this data indicates that newly-installed bermudagrass and tall fescue sod is tolerant to commonly used preemergence and postemergence herbicides, it is strongly emphasized that all proper installation and maintenance practices (soil testing, fertilization, irrigation, mowing, etc.) were utilized in these experiments. Additionally, the sod used in these experiments was of high quality. In the event of droughts, improper irrigation practices, abnormally low or high temperatures, or the use poor quality sod the results could have been dramatically different."
  5. Luscious Lawns

    Luscious Lawns LawnSite Member
    Messages: 133

    Yes a very interesting read. One thing stands out though. Is the 400%+ disparity in the repeatability of the test sample from the 2000 sample to the 2001 sampling on Bermuda sod. This leads me to believe there were few control factors in place. For information to be statistically accurate there should be less than 20% variance from one yest plot to the next.

    This is a very important consideration for new installation. Hopefully GDA will have more data soon.

    Thanks for the infor TurfUnl

  6. YardPro

    YardPro LawnSite Gold Member
    Messages: 3,570

    you absolutely can

    we spray almost 30 acres/year with roundup.

    glyphosate has NO root or soil activity.

    it has to enter and be metabolized in a leaf to be translocated.

    there is NO adverse effect to spraying glyphosate on FULLY dormant bermuda
  7. Luscious Lawns

    Luscious Lawns LawnSite Member
    Messages: 133

    Yard Pro you areabsolutely right Gly is labeled for weed release for dormant bermuda. And in NC where you have cooler weather, where there is no doubt of dormacy this might be the thing to do.... It is cheap.

    However with the detailed turf we mantain, in a warmer climate, this is a risk my company is not willing to take.

  8. YardPro

    YardPro LawnSite Gold Member
    Messages: 3,570

    Luscious Lawns

    the bermuda here ( at the coast) does not go completely dormant every winter.
    we have to be careful as well with winter chem apps.

    we usw much more diquat ( SUPER CHEAP) if there is any question.

    it will not permanently dammage the bermuda, as it is just a defoliant.
  9. greenerpastures

    greenerpastures LawnSite Member
    Messages: 160

    Simazine would still give you some pre-emerge benefit at this point, especially on thistle, henbit, and other early spring broadleaves. I would wouldn't expect much from its post activity at this point unless it is very young poa. I would have little worry with simzine on new turf (less so than with pendemethalin). And, perhaps like you, I have seen very significant damage on bermuda, "believed" to be dormant, with glyphosates.
  10. YardPro

    YardPro LawnSite Gold Member
    Messages: 3,570

    we just use the trimec products for the broadleaf, and diquat on the poa.

    i am shy about the simazine. with our 18" water table i am paranoid it will have the same groundwater issues that atrazine had.

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