Atrazine vs. Simazine for pre-emergent us on Bermuda grass

Discussion in 'Pesticide & Herbicide Application' started by bbush, Mar 12, 2009.

  1. bbush

    bbush LawnSite Member
    Messages: 1

    I am trying trying to figure out the pro's and con's between Atazine and Simazine for usage as a pre-emergent on Bermuda. What is big difference between the two as far as effectiveness and weeds controlled? I know that Atrazine has some post-emergent weed control while Simazine does not but what are the other big differences? Also, how does Atrazine and/or Simazine compare to Pendamethalin as far as a pre-emergent is concerned? Does Atrazine/Simazine cover some weeds that Pendamethalin doesn't control?
  2. RAlmaroad

    RAlmaroad LawnSite Silver Member
    from SC
    Messages: 2,257

    Neither one are true pre-emergent. Yes, they will fry the hair roots on germinating seed for a short period of time but they go quickly into the ground. They are meant for post-emergent weeds. They have got to be respected as to temperature, especially Simazine. Read the label. For a real pre-em use Gallery or Dimension; gallery being the least harmful to the root system. Roy
  3. Turfdoctor1

    Turfdoctor1 LawnSite Senior Member
    Messages: 707

    I would have to disagree.

    I'm not an expert on the differences between the two, but simazine used properly in the fall is a great solution for preventing annual bluegrass/henbit, etc., for me in my area.

    Want proof of how it can be used properly, take a look at my lawns right now. My fall application is straight Simazine, applied at 1.5 qts. per acre. Then, I follow in the spring with Barricade/Simazine mix. Timing for me is Nov/Feb. Simazine has plenty of longevity for that type of timing.
  4. DaughtryLC

    DaughtryLC LawnSite Senior Member
    Messages: 739

    I use Simazine ALOT and it is a VERY good product!
    Although it has gone up alot in the past 2 yrs.
    I put it down early spring and fall, All my customer love it!
  5. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 10,124

    Simazine is a spring and early summer application for me. Even on hybrid bermuda. That has to be qualified with the fact that I do not spray lawns that are without an irrigation system or are not fertilized by me. The height of cut is also important. Too high or too short and the grass is weak. Atrazine, on the other hand, is entirely different. Because of its different properties once it is applied, I do not use it on bermuda. Simazine is one of the options I use for goosegrass, smutgrass, paspalums, and various broadleaf weeds. It is a tool that I use to clean up lawns that have become mostly weeds.
  6. ted putnam

    ted putnam LawnSite Platinum Member
    Messages: 4,732

    Exactly what I do with mine Turfdoc with identical results. Ples Spradley (Arkansas State Plant Board)recommended that to a few of us that asked him in a small group having conversation. Watch that maximum annual use rate specified on the label! Other than that... excellent, affordable results.
  7. ted putnam

    ted putnam LawnSite Platinum Member
    Messages: 4,732

    Funny... I've seen entire lawns that were dead as a hammer except for a 1 inch strip around every sidewalk and driveway because TGCL used Atrazine to late in the Spring. Their local branch manager from one of the northern states didn't know any better. He just saw it on the fill sheets for Round 1 and filled the trucks with it. Killed whole routes of bermuda. That's why I've stressed in the past that the person in charge needs to know what they are doing... Atrazine...It can be BAD NEWS!
  8. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 10,124

    As far as I am concerned, atrazine on bermuda is a no go in my area period. Bermuda is never truly dormant here. It can be stressed from lack of sun or nights dropping to 60, but that is the exact time you will never apply a hot herbicide to bermuda if you know what you are doing. This is also why the idea of filling up a 500 gallon tank and hosing down everything with the same mix is not part of my practice. I can be visiting a bermuda, centipede, st augustine seashore paspalum, and zoysia lawn all in one day. A load containing atrazine would mean I owe people with bermuda or paspalum a new lawn, negating any time I saved by mixing a single tank.
  9. Turfdoctor1

    Turfdoctor1 LawnSite Senior Member
    Messages: 707

    that maximum annual use rate is tricky, Ted, I agree.

    I push the envelope with it certainly. I use 1.5 qts/acre in the fall, and 0.5 in the spring, but probably put out a little heavy honestly.

    I didn't notice any difference in 1.5 qts and 2.0 from the previous year, so, i'm going to back it down a little again next fall.
  10. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    Atrazine does state on the label--"The label that I occupy" Use on Dormant Bermuda!
    We used Simazine once as we were late in application due to heavy rains. The bermuda was semi-dormant and we treated for poa annua. The next week, it hit in the mid 80's in November, like it often does here and what do you know--------that Tifway 419 nearly died. It was sickly brown until the following spring. We had to apply 34-0-0 at 4 applications to bring it out of the root pruning it caused. Then we used 13-13-13, 16-16-16 and 32-3-7 on it to recover. This was at the lowest rate on the label.....
    We never will use it again..............
    Oh--The advice was from my supplier to use it and was not appreciated, however it was a lesson learned. It wasn't Lesco-- Northeast Arkansas sprayers know who I am talking about..

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