International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Rapistrum rugosum)

Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

Australia, New South Wales
Turnipweed (Rapistrum rugosum) is a dicot weed in the Brassicaceae family.  In New South Wales this weed first evolved resistance to Group 2 (Legacy B) herbicides in 2021 and infests Spring Barley.   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 imazamox, and imazapyr 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 Feb 23, 2021 )

Common NameTurnipweed
SpeciesRapistrum rugosum
GroupInhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Herbicidesimazamox, and imazapyr
LocationAustralia, New South Wales
Situation(s)Spring Barley
Contributors - (Alphabetically)Peter Boutsalis 
Edit this Case  |  Add New Case of Resistance  |  Add Note


Confirmation Tests

Greenhouse trials comparing a known susceptible Turnipweed biotype with this Turnipweed 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 Turnipweed 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 Turnipweed from New South Wales please update the database.
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  Help


Postdoctural Fellow/ Consultant
University Of Adelaide / Plant Science Consulting
Plant And Pest Science
800 N Lindbergh Blvd
Adelaide, 5064, South Australia
Email Peter Boutsalis


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in New South Wales have been instrumental in providing you this information. Particular thanks is given to Peter Boutsalis for providing detailed information.
Herbicide Resistant Turnipweed Globally
(Rapistrum rugosum)
Herbicide Resistant Turnipweed Globally
(Rapistrum rugosum)
Drag a column header and drop it here to group by that column
Herbicide Resistant Turnipweed Globally
(Rapistrum rugosum)
#CountryFirstYearSituationActive IngredientsSite of Action
1 Australia (Queensland) AustraliaQueensland1996 Cereals, and Wheat chlorsulfuron 1 Inhibition of Acetolactate Synthase (B/2)
142Rapistrum rugosumTurnipweed528
2 Australia (New South Wales ) AustraliaNew South Wales 2021 Spring Barley imazamox, and imazapyr 1 Inhibition of Acetolactate Synthase (B/2)
142Rapistrum rugosumTurnipweed19215
3 IranIran 2010 Winter wheat bispyribac-sodium, florasulam, flucarbazone-Na, and tribenuron-methyl 79 Inhibition of Acetolactate Synthase (B/2)
142Rapistrum rugosumTurnipweed5550
4 SpainSpain 2018 Winter barley, and Winter wheat iodosulfuron-methyl-Na, and tribenuron-methyl 38 Inhibition of Acetolactate Synthase (B/2)
142Rapistrum rugosumTurnipweed18171
Literature about Similar Cases

Page size:
Page: of 1
Items 1 to 4 of 4

Page size:
Page: of 1
Items 1 to 4 of 4
PERMISSION MUST BE OBTAINED FIRST if you intend to base a significant portion of a scientific paper on data derived from this site.
Cite this site as: Heap, I.  The International Survey of Herbicide Resistant Weeds.  Online.  Internet.  Sunday, August 14, 2022 .  Available
Copyright © 1993- 2022 All rights reserved. Fair use of this material is encouraged. Proper citation is requested.