International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
MULTIPLE RESISTANT RADIATE FINGERGRASS
(Chloris radiata)


Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)

Colombia, Ibagué, Tolima
INTRODUCTION RADIATE FINGERGRASS
Radiate Fingergrass (Chloris radiata) is a monocot weed in the Poaceae family.  In Colombia this weed first evolved multiple resistance (to 2 herbicide sites of action) in 2019 and infests Rice.  Multiple resistance has evolved to herbicides in the Groups 2 (Legacy B), and Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G).  These particular biotypes are known to have resistance to glyphosate, and imazamox and they may be cross-resistant to other herbicides in the Groups 2 (Legacy B), and Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G).

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 05, 2021 )

Common NameRadiate Fingergrass
SpeciesChloris radiata
GroupInhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
Herbicidesglyphosate, and imazamox
LocationColombia, Ibagué, Tolima
Year2019
Situation(s)Rice
Contributors - (Alphabetically)Rafael De Prado, Veronica Hoyos, and Guido Plaza 
Edit this Case  |  Add New Case of Resistance  |  Add Note

NOTES ABOUT THIS BIOTYPE

GENERAL

Veronica Hoyos

Agronomy 2021, 11, 496. https://doi.org/10.3390/agronomy11030496  

 Confirmation of Multiple Resistant Chloris radiata Population, Harvested in Colombian Rice Fields Verónica Hoyos , Guido Plaza, José G. Vázquez-Garcia, Candelario Palma-Bautista,  Antonia M. Rojano-Delgado and Rafael De Prado

Abstract: This paper reports the first C. radiata population with resistance to glyphosate and multiple resistance to the acetolactate synthase (ALS) inhibitor, imazamox. Two populations, one putative resistant (R) and one susceptible (S), were used in the studies. Dose–response experiments were performed to evaluate the resistance factor (RF). Shikimic acid accumulation, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) and ALS enzyme activities were studied together with chemical integrated weed management (adjuvants and alternative herbicides). The resistance to glyphosate and imazamox was confirmed based on the dry weight reduction, visual evaluation and survival. The results of dose–response curve assays showed for the R population intermedium RF for glyphosate (5.1 and 9.7 for amount of herbicide needed to reduce the dry weight by 50% GR50 and lethal dose of 50% LD50, respectively) and high RF for imazamox (34.9 and 37.4, respectively). The low shikimic acid accumulation in R population confirmed the glyphosate resistance. The glyphosate concentration which inhibited the EPSPS enzyme in 50% (I50) was approximately 20 times higher for R population than the S population, while the imazamox I50 in ALS enzyme for the R plants was 89 times greater than the S plants. In the chemical integrated weed management, the foliar retention and effectivity assays showed that the use of adjuvants improves the retention of glyphosate and imazamox, and the reduction in dry weight of weeds. The alternative herbicides study showed that the acetyl-CoA carboxylase (ACCase) inhibitors, paraquat and glufosinate, had better results for control in this species. However, poor control was observed with bispyribac-sodium, metsulfuron-methyl and quinclorac, indicating possible cross-resistance for ALS-inhibitors and also multiple resistance for auxinic herbicides (quinclorac). Nevertheless dose–response experiments are required to confirm this assumption.

Edit this Note  |  Add New Note
 

ACADEMIC ASPECTS

Confirmation Tests

Greenhouse, and Laboratory trials comparing a known susceptible Radiate Fingergrass biotype with this Radiate Fingergrass 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, 9 resistant Radiate Fingergrass 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 multiple resistant Radiate Fingergrass from Colombia 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 multiple resistant Radiate Fingergrass from Colombia please update the database.
 
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  Help

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
VERONICA HOYOS
Universidad del Magdalena
Engineering School
Calle 32 22-08
Santa Marta, 470004, Magdalena
Colombia
Email Veronica Hoyos
GUIDO PLAZA
Associate Professor
Universidad Nacional de Colombia
Agronomy Department
Carrera 30 45-03 Edificio 500 Of 236
Bogotá, 111321, Cundinamarca
Colombia
Email Guido Plaza
Web   : Web Site Link

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Colombia have been instrumental in providing you this information. Particular thanks is given to Rafael De Prado, Veronica Hoyos, and Guido Plaza for providing detailed information.
Herbicide Resistant Radiate Fingergrass Globally
(Chloris radiata)
Herbicide Resistant Radiate Fingergrass Globally
(Chloris radiata)
Drag a column header and drop it here to group by that column
Herbicide Resistant Radiate Fingergrass Globally
(Chloris radiata)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ColombiaColombia 2019 Rice glyphosate 10 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
340Chloris radiataRadiate Fingergrass18165
2 ColombiaColombia 2019 Rice glyphosate, and imazamox 10 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
340Chloris radiataRadiate Fingergrass19224
Literature about Similar Cases

1
Page size:
select
Page: of 0
Items 0 to 0 of 0

1
Page size:
select
Page: of 0
Items 0 to 0 of 0
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.  Monday, November 29, 2021 .  Available  www.weedscience.org
Copyright © 1993- 2021 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.