INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE

HRAC GROUP 9 (LEGACY G) RESISTANT WINDMILL GRASS
(Chloris truncata)


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

Spain, Extremadura
INTRODUCTION WINDMILL GRASS
Windmill Grass (Chloris truncata) is a monocot weed in the Poaceae family.  In Spain this weed first evolved resistance to Group 9 (Legacy G) herbicides in 2023 and infests Roadsides.   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 Mar 25, 2024 )

Common NameWindmill Grass
SpeciesChloris truncata
GroupInhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
Herbicidesglyphosate
LocationSpain, Extremadura
Year2023
Situation(s)Roadsides
Contributors - (Alphabetically)GERMAN MORA MARIN, Maria D. Osuna, and Joel Torra 
Edit this Case  |  Add New Case of Resistance  |  Add Note

NOTES ABOUT THIS BIOTYPE

GENERAL

Characterization of herbicide resistance of Spanish populations of Chloris truncata versus glyphosate Characterization of herbicide resistance of Spanish populations of Chloris truncata against glyphosate

German Mora,, Jordi Recasens, María Dolores Osuna, Miriam Gil Monreal & Joel Torra

Spain (E-mail: german.mora@udl.cat ) https://doi.org/10.19084/rca.35026

ABSTRACT Chloris truncatais a perennial grass with a C4 photosynthetic pathway. It is native to Australia, but it is currently distributed in other subtropical regions of the world. In Spain, it is considered a naturalized allochthonous species, mainly in Extremadura and Catalonia. Currently, there have been reported failures in its control with glyphosate. Previous studies report that herbicide resistance is based onEPSPSgene amplification. In 2022, seeds were collected from field plant survivors of glyphosate treatments in Talayuela – Extremadura (CTT-R); a population from Australia (CTA-S) was used as sensitive reference material. Preliminary tests (greenhouse) were carried out on seedlings with four leaves (BBCH 14), with doses of (1.5 and 3 L ha-1) 540 and 1080 g ai ha-1of glyphosate, with 100% survival. In the same year, dose-response trials were carried out with a dose range between 270 and 8,640 g ai ha-1. At 28 days after treatment (DAT), the survival percentage was evaluated and values   of: 1,146.7 and 321.34 g ai ha-1were determined with a Resistance Factor (RF) of 3.7 times according to GRfifty; for LDfifty, 1,882.9 and 712.5 g ai ha-1with RF of 2.6 for the CTT-R and CTA-S populations, respectively. Complementary dose-response experiments are currently being carried out with new populations collected in Extremadura and Catalonia, to confirm or not, the presence of other glyphosateresistant biotypes and to elucidate the resistance mechanism involved.

Edit this Note  |  Add New Note
 

ACADEMIC ASPECTS

Confirmation Tests

Greenhouse trials comparing a known susceptible Windmill Grass biotype with this Windmill Grass 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 Windmill Grass 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 Windmill Grass from Spain please update the database.
 
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  

CONTRIBUTING WEED SCIENTISTS

GERMAN MORA MARIN
PhD student
Universitat de Lleida
HBJ - Maleherbologia
Carrer ROCA LABRADOR
12. Piso 5, puerta 3A
Lleida, 25003, Cataluña
Spain
Email GERMAN MORA MARIN
Web   : Web Site Link
MARIA D. OSUNA
Researcher
CICYTEX
Crop Protection
Finca La Orden
Crta AV, km 372
Guadajira, 06187, Badajoz
Spain
Email Maria D. Osuna
Web   : Web Site Link
JOEL TORRA
Research Assistant
University Of Lleida
Depart. Hortofructicultura
Botànica I Jardineria
Rovira Roure
191, Etsea, Ed. 1
Lleida, 25198, Badajoz
Spain
Email Joel Torra
Web   : Web Site Link

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 GERMAN MORA MARIN, Maria D. Osuna, and Joel Torra for providing detailed information.
Herbicide Resistant Windmill Grass Globally
(Chloris truncata)
Herbicide Resistant Windmill Grass Globally
(Chloris truncata)
Drag a column header and drop it here to group by that column
Herbicide Resistant Windmill Grass Globally
(Chloris truncata)
#CountryFirstYearSituationActive IngredientsSite of Action
1 Australia (New South Wales ) AustraliaNew South Wales 2010 Fallow glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
262Chloris truncataWindmill Grass5509
2 Australia (Victoria) AustraliaVictoria2015 Roadsides glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
262Chloris truncataWindmill Grass11021
3 SpainSpain 2023 Roadsides glyphosate 38 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
262Chloris truncataWindmill Grass27293
Literature about Similar Cases

1
Page size:
select
Page: of 1
Items 1 to 3 of 3

1
Page size:
select
Page: of 1
Items 1 to 3 of 3

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, July 18, 2024 .  Available  www.weedscience.org Copyright © 1993- 2024 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.