(Descurainia sophia)

Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

China, Shanxi and Hebei
Flixweed (Descurainia sophia) is a dicot weed in the Brassicaceae family.  In China this weed first evolved resistance to Group 2 (Legacy B) herbicides in 2005 and infests Cereals.   Group 2 (Legacy B) herbicides are known as Inhibition of Acetolactate Synthase (Inhibition of Acetolactate Synthase ).  Research has shown that these particular biotypes are resistant to tribenuron-methyl and they may be cross-resistant to other Group 2 (Legacy B) 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 Apr 07, 2006 )

Common NameFlixweed
SpeciesDescurainia sophia
GroupInhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
LocationChina, Shanxi and Hebei
Contributors - (Alphabetically)Jerry Green 
Edit this Case  |  Add New Case of Resistance  |  Add Note


Confirmation Tests

Greenhouse trials comparing a known susceptible Flixweed biotype with this Flixweed 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 2 resistant Flixweed 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 2 (Legacy B) resistant Flixweed from China please update the database.
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  


Pioneer Hi-Bred
17 Pope Ave
Newark, 19714-0030, Delaware
United States
Email Jerry Green


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in China have been instrumental in providing you this information. Particular thanks is given to Jerry Green for providing detailed information.
Herbicide Resistant Flixweed Globally
(Descurainia sophia)
Herbicide Resistant Flixweed Globally
(Descurainia sophia)
Drag a column header and drop it here to group by that column
Herbicide Resistant Flixweed Globally
(Descurainia sophia)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ChinaChina 2005 Cereals tribenuron-methyl 9 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
237Descurainia sophiaFlixweed5268
2 ChinaChina 2011 Winter wheat MCPA 9 Auxin Mimics ( HRAC Group 4 (Legacy O)
237Descurainia sophiaFlixweed5651
3 ChinaChina 2011 Winter wheat carfentrazone-ethyl 9 Inhibition of Protoporphyrinogen Oxidase ( HRAC Group 14 (Legacy E)
237Descurainia sophiaFlixweed5652
4 United States (Kansas) United StatesKansas2006 Winter wheat chlorsulfuron, imazamox, metsulfuron-methyl, pyroxsulam, sulfosulfuron, triasulfuron, and tribenuron-methyl 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
237Descurainia sophiaFlixweed5404
Literature about Similar Cases

Page size:
Page: of 3
Items 1 to 5 of 12

Page size:
Page: of 3
Items 1 to 5 of 12

PERMISSION MUST BE OBTAINED FIRST if you intend to base a significant portion of a scientific paper on data derived from this site. Citation:
Heap, I.  The International Herbicide-Resistant Weed Database.  Online.  Friday, July 12, 2024 .  Available Copyright © 1993- 2024 All rights reserved. Fair use of this material is encouraged. Proper citation is requested.