INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE

HRAC GROUP 9 (LEGACY G) RESISTANT RUSSIAN-THISTLE
(Salsola tragus)

Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)

United States, Oregon
INTRODUCTION RUSSIAN-THISTLE
Russian-thistle (Salsola tragus) is a dicot weed in the Chenopodiaceae family.  In Oregon this weed first evolved resistance to Group 9 (Legacy G) herbicides in 2016 and infests Fallow.   Group 9 (Legacy G) herbicides are known as Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (Inhibition of EPSP synthase).  Research has shown that these particular biotypes are resistant to glyphosate and they may be cross-resistant to other Group 9 (Legacy G) 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 Oct 23, 2016 )

Common NameRussian-thistle
SpeciesSalsola tragus
GroupInhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
Herbicidesglyphosate
LocationUnited States, Oregon
Year2016
Situation(s)Fallow
Contributors - (Alphabetically)Carol Mallory-Smith 
Edit this Case  |  Add New Case of Resistance  |  Add Note

ACADEMIC ASPECTS

Confirmation Tests

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

Genetic studies on HRAC Group 9 resistant Russian-thistle 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 9 (Legacy G) resistant Russian-thistle from Oregon please update the database.
 
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  

CONTRIBUTING WEED SCIENTISTS

CAROL MALLORY-SMITH
Professor
Oregon State University
Department of Crop And Soil Science
331B Crop Science Bldg
Corvallis, 97331, Oregon
United States
Email Carol Mallory-Smith
Web   : Web Site Link

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Oregon have been instrumental in providing you this information. Particular thanks is given to Carol Mallory-Smith for providing detailed information.
Herbicide Resistant Russian-thistle Globally
(Salsola tragus)
Herbicide Resistant Russian-thistle Globally
(Salsola tragus)
Drag a column header and drop it here to group by that column
Herbicide Resistant Russian-thistle Globally
(Salsola tragus)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ArgentinaArgentina 2019 Soybean glyphosate 48 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
 		147Salsola tragusRussian-thistle19218
2 Canada (Saskatchewan) CanadaSaskatchewan1989 Wheat chlorsulfuron 7 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		147Salsola tragusRussian-thistle5067
3 Canada (Alberta) CanadaAlberta2007 Spring Barley, and Wheat thifensulfuron-methyl, and tribenuron-methyl 7 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		147Salsola tragusRussian-thistle7831
4 United States (Washington) United StatesWashington1987 Wheat chlorsulfuron 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		147Salsola tragusRussian-thistle231
5 United States (Montana) United StatesMontana1987 Cropland, and Wheat chlorsulfuron 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		147Salsola tragusRussian-thistle411
6 United States (Idaho) United StatesIdaho1990 Wheat chlorsulfuron 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		147Salsola tragusRussian-thistle512
7 United States (Oregon) United StatesOregon1993 Wheat chlorsulfuron, metsulfuron-methyl, and triasulfuron 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		147Salsola tragusRussian-thistle1173
8 United States (California) United StatesCalifornia1994 Roadsides chlorsulfuron, and sulfometuron-methyl 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
 		147Salsola tragusRussian-thistle1036
9 United States (Montana) United StatesMontana2015 Fallow, and Wheat glyphosate 45 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
 		147Salsola tragusRussian-thistle12032
10 United States (Washington) United StatesWashington2015 Fallow glyphosate 45 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
 		147Salsola tragusRussian-thistle18160
11 United States (Oregon) United StatesOregon2016 Fallow glyphosate 45 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
 		147Salsola tragusRussian-thistle13055
Literature about Similar Cases

1
Page size:
select
Page: of 1
Items 1 to 1 of 1

1
Page size:
select
Page: of 1
Items 1 to 1 of 1
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.  Tuesday, July 8, 2025 .  Available  www.weedscience.org Copyright © 1993- 2025 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.