Possible Herbicide Injury to Spruces and Pines

I’ve received a couple of calls about Dupont Imprelis and injury to Spruces and White Pines. And there have been some recent blog posts on the subject. I’ve spoken with Ryan Lawn and Tree, Bruce Steward (Dupont Rep) and it was discussed at last week’s NCERA-192 meeting I attended. Dupont is supposed to be putting out a news release
on their website ASAP at but it is not up yet. But I did get the following letter from them.

I haven’t taken any pictures yet, but here are some pictures and descriptions from other blogs.

Nebraska Turf Notes has a good summary.

Buckeye Lawn and Garden Online

IAturf Blog Imprelis damage pictures

IAturf Blog Imprelis damage on trees

Ohio.com Home and Garden

The Lawnsite Forum

The herbicide is an excellent herbicide. It has a very low use rate and it controls a wide variety of broadleaf weeds. The issue with the tree damage we are seeing seem to be due to its root absorption characteristics.

I’m adding some good points I received from Judy O’Mara at the KSU Plant Diagnostic Clinic, “it sounds like in situations where it (Imprelis) has been used in the landscape near Norway spruce and white pine trees, it may be having a negative impact on those trees. I just want to throw some caution into the mix. I have been seeing loads of spruce trees across the state with a range of symptoms of needle browning, defoliation and branch dieback. Some of it has been due to spider mites, a small amount due to Rhizosphaera needle cast and a lot I have attributed to environmental stress (drought in the west, low temperatures, dessicating winds, …). It is possible Imprelis is playing a bigger role, but I still think in many locations environmental stress is the biggest factor. A lot of the spruce problems started last fall when we had hot, dry conditions at the end of the summer and into the fall. I think some of the damage is a continuation of that stressful period.

Megan also wanted to add, “At the disease clinic we don’t do herbicide testing. All we can do is look for disease agents and send to Ent to look for insects/mites, etc.

But, if people suspect Imprelis damage, they should take photos and collect all their pesticide records. They should have records, anyway, with date, rate, method of application, weather conditions, were any other products applied at the same time, etc.

And I agree with Nick’s statements from the IAturf blog;, “It is important to note that there are many locations where the product was used and no tree damage has occurred. Also, not all trees on the treated areas are damaged.

We will keep you posted as we learn more.

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  • http://www.ksuturf.com Rodney

    Here’s a few more links I received in an email from Dr. Patton this morning.
    Rod,
    Here are a couple more posts here at Purdue that provide similar information:

    http://www.agry.purdue.edu/turf/tips/2011/06172011_Imprelis.html

    http://www.ppdl.purdue.edu/PPDL/hot11/6-10.html


    Aaron J. Patton, Ph.D.
    Assistant Professor/ Turfgrass Extension Specialist
    Purdue University
    Department of Agronomy
    Lilly Hall of Life Sciences, Rm. 2-347
    915 West State Street
    West Lafayette, IN 47907-2054
    (765) 494-9737
    Fax: (765) 496-6335
    http://www.agry.purdue.edu/turf

  • http://ryanlawn.com Larry Ryan

    Rodney,
    I read Mike McDermot of DuPont’s letter (This a different Mike McDermot than the owner/president of Grass Pad)and sent him a reply stating I hope he does not take the British Petroleum route. We have oil leaking into our Gulf. DuPont must stand behind this product.

    My second issue is with research. DuPont said they did more than 400 studies. I am guessing they did not test the product when trees were actively growing and most susceptible to damage. I don’t know this but reviewed some of their research conclusions yesterday and it is not stated what time of year the research was done.

    Concluding thoughts: this could hurt the image of our industry. We must all work to give the best customer service possible. As an industry, we must learn from this all that is learn-able. As Einstein said, to solve a problem, one must rise to a level of thinking higher than the level at which the problem was created.
    Larry Ryan, President
    Ryan Lawn & Tree

    .

  • Amy Rush

    Is Ryan Lawn & Tree using Imprelis?

    • http://www.ksuturf.com Rodney

      You’d have to ask them to be sure. I don’t know.

  • Amy Rush

    Has Imprelis been linked to animals becoming sick or having seizures?

    • http://www.ksuturf.com Rodney

      No. I have not heard of any. It has a very low use rate so it is supposed to be safer to humans and pets than other herbicides.

  • http://Www.brownsburgtreecare.net Kathy Loveland

    Kudos go to Purdue University, with a special THANK YOU to Gail Ruhl, for their/her assistance in identifying and confirming the link between our client’s declining Norway Spruce and the application of Imprelis on her lawn. I contacted RTV6 here in Indianapolis to bring it to the public’s attention as so many of our new clients were told (not by us) the condition of their trees was due to the drought. We have since been on several estimates in which it is immediately evident to us the injury is chemical related. After asking a few questions, Imprelis use on their lawn is confirmed. The worst part is not knowing or being able to tell the client who needs to replace their tree, the lawn care company who should then seek reimbursement from DuPont or straight to DuPont. We have one client with 14 10 year Spruce and Pine trees that are dying