INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE

HRAC GROUP 2 (LEGACY B) RESISTANT RED RICE
(Oryza sativa var. sylvatica)


Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

Argentina
INTRODUCTION RED RICE
Red Rice (Oryza sativa var. sylvatica) is a monocot weed in the Poaceae family.  In Argentina this weed first evolved resistance to Group 2 (Legacy B) herbicides in 2018 and infests Rice.   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 imazapic, imazapyr, and imazethapyr 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 May 24, 2024 )

Common NameRed Rice
SpeciesOryza sativa var. sylvatica
GroupInhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Herbicidesimazapic, imazapyr, and imazethapyr
LocationArgentina
Year2018
Situation(s)Rice
Contributors - (Alphabetically)Alejandro Presotto, and Román Boris Vercellino 
Edit this Case  |  Add New Case of Resistance  |  Add Note

ACADEMIC ASPECTS

Confirmation Tests

Greenhouse, and Laboratory trials comparing a known susceptible Red Rice biotype with this Red Rice 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 2 resistant Red Rice 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

Studies on the mechanism of resistance of Group 2 (Legacy B) resistant Red Rice from Argentina indicate that resistance is due to an altered target site.  There may be a note below or an article discussing the mechanism of resistance in the Fact Sheets and Other Literature
 
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 Red Rice from Argentina please update the database.
 
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  

CONTRIBUTING WEED SCIENTISTS

ALEJANDRO PRESOTTO
Adjunct Researcher
Universidad Nacional del Sur; CERZOS-CONICET
Departamento de Agronomía
San Andrés 800
Bahía Blanca, 8000, Buenos Aires
Argentina
Email Alejandro Presotto
Web   : Web Site Link
ROMÁN BORIS VERCELLINO
Adjunct Researcher
Universidad Nacional del Sur
Departamento de Agronomía
Panama 838 PB 11
Bahía Blanca, 8000, Buenos Aires
Argentina
Email Román Boris Vercellino
Web   : Web Site Link

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Argentina have been instrumental in providing you this information. Particular thanks is given to Alejandro Presotto, and Román Boris Vercellino for providing detailed information.
Herbicide Resistant Red Rice Globally
(Oryza sativa var. sylvatica)
Herbicide Resistant Red Rice Globally
(Oryza sativa var. sylvatica)
Drag a column header and drop it here to group by that column
Herbicide Resistant Red Rice Globally
(Oryza sativa var. sylvatica)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ArgentinaArgentina 2018 Rice imazapic, imazapyr, and imazethapyr 48 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice27289
2 BrazilBrazil 2006 Rice imazapic, and imazethapyr 5 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice5372
3 ColombiaColombia 2018 Rice imazamox, and imazapyr 10 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice18170
4 Costa RicaCosta Rica 2010 Rice imazapic, and imazapyr 11 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice7885
5 GreeceGreece 2013 Rice imazamox, and imazethapyr 19 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice13054
6 ItalyItaly 2010 Rice imazamox 24 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice5614
7 MalaysiaMalaysia 2018 Rice imazapic, and imazapyr 28 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice17145
8 TurkeyTurkey 2020 Rice imazamox 71 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice19217
9 United States (Arkansas) United StatesArkansas2002 Rice imazamox, imazapyr, imazaquin, imazethapyr, and pyrithiobac-sodium 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
242Oryza sativa var. sylvaticaRed Rice13046
Literature about Similar Cases

Page size:
select
Page: of 25
Items 1 to 5 of 124

Page size:
select
Page: of 25
Items 1 to 5 of 124

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.  Thursday, June 13, 2024 .  Available  www.weedscience.org Copyright © 1993- 2024 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.