Herbicide resistance

Discussion in 'Pesticide & Herbicide Application' started by phasthound, Dec 18, 2013.

  1. Skipster

    Skipster LawnSite Bronze Member
    Messages: 1,086

    Everything you need is contained here:


    See this also:


    Of course, you know that it would be very difficult to say with 100% certainty that a herbicide resistant weed population came only as a result of LCO applications on a particular property. Herbicide resistant Conyza canadensis and Amaranthus palmeri have been found (and DNA fingerprinted) in fields in which herbicides have never been applied. Some of this can be random variation and some of it can be the result of seed or plant material travel.

    But, when we see evidence of resistance in inner-city areas, where exposure to agriculture is limited, and only one mode of action has been used for many years, the problem becomes a little more clear.

    So, what is your position? There is no doubt that we're seeing more herbicide resistant weeds. In some areas of the southeast, herbicide resistant spotted spurge has taken over 50%+ of the area of many lawns. This weed is resistant to both the older cheaper chemistries and the newer more expensive ones. Do you suggest that we keep using thesame old cheap materials until you have nothign to do but hand pull 50% of your treated acreage?

    If resistance can be seen in a 20A farm field, why can't it be seen in thousands of LCO acres?
  2. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 10,132

    I have known about inherently resistant weeds being treated with non effective products causing a population shift and weeds where resistance was induced due to excessive use of one class of chemistry. The emerging nightmare in Hawaii is goosegrass resistant to both Revolver and Triazine herbicides. There are also specimens less susceptible to glyphosate as well. Revolver resistance is actually the most severe problem. This one could not be pinned on the lawn guys. 99% of the Revolver, simazine, and Sencor is sold to golf courses. Goosegrass thrives in saturated and compacted soils that are also nutrient poor. In an attempt to save money, fertilization was cut, instead relying on more water to keep grass green. Fast answer is to mechanically aerate. Well, I have discussed the effect of aerating soils where base content and ratios are incorrect. My chemical vendor is frustrated. Mention applying a soil appropriate product like gypsum or calcium nitrate and the sound of checkbooks slapping shut can be heard. Plenty of money to spend on Revolver, Specticle, Tower, and Sencor+MSMA if that does not work. The problem of resistance does become my problem. On a tiny island, odds of a goosegrass seed from a plant surviving every legal herbicide dropping into a residential lawn are high.
  3. Skipster

    Skipster LawnSite Bronze Member
    Messages: 1,086

    What do you think of the practice commonly posted here about blanketing POST controls over every lawn?

    ALS-inhibitor and triazine resistant goosegrass has been a problem in the southeast for at least 15 yrs. Every year, guys post on this board about how they blanket apply simazine or atrazine and how they blanket apply their flavor-of-the-month POST, like Revolver, Manor, Trimec, etc.

    EPA estimates that 30 million acres of lawns get treated with herbicide each year. There are 17,000 golf courses in the US (including HI), which occupy an average of 150 acres. This means that there are about 2.5 million acres of golf course in the US. Of the 150 acres that the average course occupies, only about 70 of those acres are routinely treated with herbicides (source: GCSAA), so you could say that golf is only responsible for ~1.2 million acres -- only about 4% of the area of treated lawns.

    If you guys haven't worked in golf before, herbicides aren't used nearly as much as they are in LCO. Golf courses treating goosegrass would use Illoxan anyhow -- much more effective and much cheaper than Revolver.
  4. ted putnam

    ted putnam LawnSite Platinum Member
    Messages: 4,748

    When these golf courses have herbicides "routinely" applied, Is it part of the routine to do broadcast applications or spot treatment? Something tells me they spend much more time with an 8ft boom than they do a spray wand. I apply a broadcast treatment 2 times per year. Once in the Spring and once in the Fall. The rest of my applications throughout the year are spot treatment only. I generally will apply 8-10,000 ft sq of actual spraying over a 3-5 acre area by spot treating only. However, this is only made possible by applying those broadcast applications the other 2 times per year. If I didn't, I'm pretty certain I would use much more herbicide through the course of the year.

    I try to rotate herbicides, insecticides and fungicides on a regular basis though I will admit I have a couple of staples. They are generally used in combination with other products and are not "stand alones".

    I do not consider myself to be a "flavor of the month" applicator. I know there are some out there but IMO that is bad for business in more way than one.
  5. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 10,132

    Good point. A set of effective broadcast applications means I will not need to apply more for the rest of the year. No need to even spot spray. My impression of lawns that are spot sprayed is that the weeds are never gone. I will apply to less than the total area if that is what is going to work. It is not exactly a spot spray because it is an application over a patch of weeds and several feet around that patch.
  6. Skipster

    Skipster LawnSite Bronze Member
    Messages: 1,086

    In the south, there are usually 1 or 2 PRE apps/yr. In the north, there is just one PRE /yr. About 75% of courses apply only to fairways, while the rest apply to fairways and roughs. POST apps are strictly on a spot basis. Herbicides are not a big thing in golf.

    I would expect that PRE apps are broadcast, but I find that POST apps are rarely needed to be done as broadcast. Do we really need to spray POST products where there are no weeds?

    Rotating modes of action is the critical part here. Applying Manor, then Celsius, then Tribute Total, then Monument would only making things worse.

    Combining products when the combinations aren't needed can make resistance worse. In combination products, the combination doesn't usually kill any weed faster or better, it just broadens the spectrum of activity. Adding dicamba to 2,4-D doesn't make the 2,4-D work better. It just picks up some things that 2,4-D misses. Dicamba is weak on the perennial clovers that 2,4-D controls, but D is weak on the thistles and plantains that dicamba controls really well.

    What combinations do you like to put together?

    What I meant by "flavor-of-the-month" was that some guys add a POST to their tank (Trimec, Manor, Celsius) and broadcast treat lawns simply because it is a particular time of year and that's what they've always done. "Well, it's February and the weather's warming up, so I better broadcast 3-way now. Uh oh, it's June now, so I need to broadcast the Celsius."

    I see a lot of guys on this board who think that POST materials must be applied broadcast to get the best control. And they will apply the same things multiple times/yr every year to every lawn, whether there are weeds present or not. I'd like to see more of an IPM approach that understands that not every lawn needs to be blanketed. I have very few weed calls and I only blanket about 15% of my customer base with PRE. On the 85% that don't get blanketed, we apply only in high-risk areas and we vigorously scout that lawns and document any weed breakthroughs. I buy less than quarter of the herbicide that my smallest competitor does and I have cleaner lawns.
  7. ted putnam

    ted putnam LawnSite Platinum Member
    Messages: 4,748

    You are in Billings, MT. I am in Central Arkansas with semi-tropical conditions and a 9 month growing season not to mention the extreme weed pressure. We carry a three pronged mini cultivator as well as an A.M Leonard soil knife for digging weeds on our ride on units....they get used.

    [/B]We do only what we must do to keep our lawns weed free...Nothing more, nothing less.
    Last edited: Dec 30, 2013
  8. rcreech

    rcreech Sponsor
    Male, from OHIO
    Messages: 6,163

    Your sites say there are resistant weeds. We all l one that!

    Where is the data that states it STARTED due to LCO's?
    Also you state there have been "loads of weeds" resistant to 3 way products. What are those weeds?
    You say the latest research say trizene resistance started in turf. Where is that data? Trizenes are used on almost every corn acre.

    Again I know resistance is a problem but asking you to support your comment on being started by LCO's.
    Posted via Mobile Device
  9. rcreech

    rcreech Sponsor
    Male, from OHIO
    Messages: 6,163


    The more u say the more I question you!!!!
    The combination of products such a 3 way has many synergistic effects. Using them alone none of them do a great job but when combines are Lethal!!!

    If u look at MCPP and Quicksilver it is not used alone?
    Why? I'm
    The products are WEAK when used alone, but when combines with other products they are awesome.

    Adding another combination such as quicksilver even adds more "heat" and it DOES speed up the kill which is totally against what u state.
    Heck even adding a coc can speed up kill and it's not a herbicide.

    U say dicamba won't kill clover but 2-4,D will?????
    2-4,D won't touch CloverLook at any University data and I will see that. It will burn it back but not kill it!

    How does using multiple products/ai's make resistance worse??

    U are totally out there buddy!!!!

    Skipster said:

    "In combination products, the combination doesn't usually kill any weed faster or better, it just broadens the spectrum of activity. Adding dicamba to 2,4-D doesn't make the 2,4-D work better. It just picks up some things that 2,4-D misses. Dicamba is weak on the perennial clovers that 2,4-D controls, but D is weak on the thistles and plantains that dicamba controls
    Posted via Mobile Device
  10. rcreech

    rcreech Sponsor
    Male, from OHIO
    Messages: 6,163

    This thread is just one example of how one must be careful what theyread on here. There are several people that post on here and don't have a clue.
    This forum is great for learning from each others experiences and what's working etc.
    But as far as technical information there are MANY statments and info that is posted on here that just is not accurate.
    Don't post something unless its accurate and you can back it up!
    Makes me sick and this just shows that your competition can act like they know what they are talking about when they don't!!!! Bad thing is most people/customers can't tell the difference and that is very sad!!!!

    I'm don't ranting. :)
    Posted via Mobile Device

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