International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
HRAC GROUP 9 (LEGACY G) RESISTANT COMPACT BROME
(Bromus madritensis)

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

Spain
INTRODUCTION COMPACT BROME
Compact Brome (Bromus madritensis) is a monocot weed in the Poaceae family.  In Spain this weed first evolved resistance to Group 9 (Legacy G) herbicides in 2018 and infests Grapes, and Olive.   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.

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QUIK STATS (last updated Nov 26, 2020 )

Common NameCompact Brome
SpeciesBromus madritensis
GroupInhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
Herbicidesglyphosate
LocationSpain
Year2018
Situation(s)Grapes, and Olive
Contributors - (Alphabetically)Rafael De Prado, and Joel Torra 
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NOTES ABOUT THIS BIOTYPE

GENERAL

Additional cases of Glyphosate-Resistance in Bromus madritensis  

Alfredo Manicardi, Clara Jiménez Martínez, Germán Mora Marín, Vijaya Bhaskar, José María Montull, Josep M. Llenes and Joel Torra     

  • Year and location seed was collected In 2025 four populations were collected from three winter cereals fields (R1. R2, R3) and from one orchard (R4) located in north-east Spain (Lleida, Catalonia). One population proceeding from uncultivated area was used as sensitive control (S).   

Date of collection

S   Lleida 2016

R1 Cereals  :    Marcovall 06/25

R2 Cereals  :    Torrefeta 04/25

R3 Cereals  :    Cervera 03/25

R4 Orchard :    Borges Blanques 01/25

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ACADEMIC ASPECTS

Confirmation Tests

Greenhouse trials comparing a known susceptible Compact Brome biotype with this Compact Brome 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 Compact Brome 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 Compact Brome from Spain please update the database.
 
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CONTRIBUTING WEED SCIENTISTS

RAFAEL DE PRADO
Universidad De Cordoba
Qvimica Agricola Y Edafologa
E T S Ingenieros Agronomos
PO Box 119
Cordoba, E-14080, Andalusia
Spain
Email Rafael De Prado
JOEL TORRA
Research Assistant
University Of Lleida
Depart. Hortofructicultura
Botànica I Jardineria
Rovira Roure
191, Etsea, Ed. 1
Lleida, 25198, Andalusia
Spain
Email Joel Torra

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Spain have been instrumental in providing you this information. Particular thanks is given to Rafael De Prado, and Joel Torra for providing detailed information.
Herbicide Resistant Compact Brome Globally
(Bromus madritensis)
Herbicide Resistant Compact Brome Globally
(Bromus madritensis)
Drag a column header and drop it here to group by that column
Herbicide Resistant Compact Brome Globally
(Bromus madritensis)
#CountryFirstYearSituationActive IngredientsSite of Action
1 SpainSpain 2018 Grapes, and Olive glyphosate 38 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
 		352Bromus madritensisCompact Brome18209
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