International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Daucus carota)

Auxin Mimics HRAC Group 4 (Legacy O)

United States, Ohio
Wild Carrot (Daucus carota) is a dicot weed in the Apiaceae family.  In Ohio this weed first evolved resistance to Group 4 (Legacy O) herbicides in 1994 and infests Soybean.   Group 4 (Legacy O) herbicides are known as Auxin Mimics (Auxin Mimics ).  Research has shown that these particular biotypes are resistant to 2,4-D and they may be cross-resistant to other Group 4 (Legacy O) herbicides.

The 'Group' letters/numbers that you see throughout this web site refer to the classification of herbicides by their site of action. To see a full list of herbicides and HRAC herbicide classifications click here.

If we do not have a picture for this weed, or you can provide a better picture (scan, digital camera etc) please please e-mail it to us.

QUIK STATS (last updated Jan 31, 2005 )

Common NameWild Carrot
SpeciesDaucus carota
GroupAuxin Mimics HRAC Group 4 (Legacy O)
LocationUnited States, Ohio
Contributors - (Alphabetically)Jeff Stachler 
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Confirmation Tests

Greenhouse trials comparing a known susceptible Wild Carrot biotype with this Wild Carrot biotype have been used to confirm resistance. For further information on the tests conducted please contact the local weed scientists that provided this information.

Genetic studies on HRAC Group 4 resistant Wild Carrot have not been reported to the site.  There may be a note below or an article discussing the genetics of this biotype in the Fact Sheets and Other Literature
Mechanism of Resistance

The mechanism of resistance for this biotype is either unknown or has not been entered in the database.  If you know anything about the mechanism of resistance for this biotype then please update the database.
Relative Fitness

There is no record of differences in fitness or competitiveness of these resistant biotypes when compared to that of normal susceptible biotypes.  If you have any information pertaining to the fitness of Group 4 (Legacy O) resistant Wild Carrot from Ohio please update the database.
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Extension Agronomist - Sugarbeet/weed Science
North Dakota State University, University of Minnesota
Plant Sciences
Loftsgard Hall 474E NDSU Dept #7670
PO Box 6050
Fargo, 58108-6050, North Dakota
United States
Email Jeff Stachler
Web   : Web Site Link


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Ohio have been instrumental in providing you this information. Particular thanks is given to Jeff Stachler for providing detailed information.
Herbicide Resistant Wild Carrot Globally
(Daucus carota)
Herbicide Resistant Wild Carrot Globally
(Daucus carota)
Drag a column header and drop it here to group by that column
Herbicide Resistant Wild Carrot Globally
(Daucus carota)
#CountryFirstYearSituationActive IngredientsSite of Action
1 Canada (Ontario) CanadaOntario1957 Roadsides 2,4-D 7 Auxin Mimics ( HRAC Group 4 (Legacy O)
76Daucus carotaWild Carrot307
2 United States (Michigan) United StatesMichigan1993 Cropland, and Roadsides 2,4-D 45 Auxin Mimics ( HRAC Group 4 (Legacy O)
76Daucus carotaWild Carrot505
3 United States (Ohio) United StatesOhio1994 Soybean 2,4-D 45 Auxin Mimics ( HRAC Group 4 (Legacy O)
76Daucus carotaWild Carrot5234
Literature about Similar Cases

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