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Tom Creswell, Lab Director The PPDL has received samples of Norway spruce, white pine, dawn redwood and several other woody ornamental species that exhibit symptoms similar to those that can be caused by synthetic auxin (growth regulator type) herbicides. Typical symptoms caused by these herbicides can include epinasty (twisting and curling) of needles, shoots and tips of branches. New growth may turn brown and die. On broadleaf plants, leaf cupping (upward or downward) may occur and in extreme cases, new leaves may appear irregular in size and shape (usually smaller than normal) and have abnormal leaf margins. Samples submitted to the PPDL as well as reports of injury in other areas of the country appear to be linked back to the common denominator of the herbicide aminocyclopyrachlor applied to surrounding lawns for broadleaf weed control. The damage appears to be from root uptake rather than from drift or volatilization. Herbicides with good soil activity may cause problems on nearby broadleaf ornamentals through root uptake if they are applied within root zones of non-target plants or if the chemical moves into the rootzone of non-target plants due to drainage issues. It is important to read all labels thoroughly to avoid applications that are not recommended on the label. Information Links: Imprelis® Update: 2012 Field Notes on Injury and Recovery (pdf file) Tree damage from Imprelis: One year later - Michigan State University, 2012 A Homeowner's Guide to Suspected Imprelis® Herbicide Injury in the Landscape (pdf file) A Turf Professional's Guide to Suspected Imprelis® Herbicide Injury in the Landscape (pdf file) Imprelis® Herbicide Injury to Landscape Trees and Ornamentals (pdf file) - Office of the Indiana State Chemist Avoid use of herbicide Imprelis, Purdue experts advise - Purdue University News Service - July 22, 2011 Herbicide damage on Spruce and Pine - Turf Tip - June 17, 2011 Stop sale order for Imprelis issued by the OISC (PDF) - Office of Indiana State Chemist - August 1, 2011 For additional information please refer to the following Office of the Indiana State Chemist website: http://www.isco.purdue.edu |
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Symptoms on Norway spruce growing near lawns treated with aminocyclopyrachlor
Symptoms on Norway spruce growing near lawns treated with aminocyclopyrachlor
Symptoms on white pine growing near lawns treated with aminocyclopyrachlor
Symptoms on Norway spruce growing near lawns treated with aminocyclopyrachlor
Symptoms on Norway spruce growing near lawns treated with aminocyclopyrachlor
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Site last updated:
17 May, 2013