International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
MULTIPLE RESISTANT SOURGRASS
(Digitaria insularis)


Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)

Paraguay, District of Hernandarias
INTRODUCTION SOURGRASS
Sourgrass (Digitaria insularis) is a monocot weed in the Poaceae family.  In Paraguay this weed first evolved multiple resistance (to 2 herbicide sites of action) in 2020 and infests Soybean.  Multiple resistance has evolved to herbicides in the Groups 1 (Legacy A), and Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G).  These particular biotypes are known to have resistance to clethodim, glyphosate, and haloxyfop-methyl and they may be cross-resistant to other herbicides in the Groups 1 (Legacy A), 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.

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QUIK STATS (last updated Aug 16, 2021 )

Common NameSourgrass
SpeciesDigitaria insularis
GroupInhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)

Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
Herbicidesclethodim, glyphosate, and haloxyfop-methyl
LocationParaguay, District of Hernandarias
Year2020
Situation(s)Soybean
Contributors - (Alphabetically)Alfredo Junior Paiola Albrecht, Leandro Paiola Albrecht, and Fabricio Krzyzaniak 
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ACADEMIC ASPECTS

Confirmation Tests

Greenhouse trials comparing a known susceptible Sourgrass biotype with this Sourgrass 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 1, 9 resistant Sourgrass 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 multiple resistant Sourgrass from Paraguay please update the database.
 
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CONTRIBUTING WEED SCIENTISTS

ALFREDO JUNIOR PAIOLA ALBRECHT
Professor and Researcher
Federal University of Paraná - UFPR
Department of Agronomic Sciences
Rua Pioneiro
2153
Palotina, 85950-000, Paraná State
Brazil
Email Alfredo Junior Paiola Albrecht
Web   : Web Site Link
LEANDRO PAIOLA ALBRECHT
Professor and Researcher
Federal University of Paraná - UFPR
Department of Agronomic Sciences
Rua Pioneiro
2153
Palotina, 85950-000 , Paraná State
Brazil
Email Leandro Paiola Albrecht
Web   : Web Site Link
FABRICIO KRZYZANIAK
RESEARCHER
FARM CONSULTORIA
ALTO PARANA
Rua Dozolina Rech Ferrari
42
Campo Mourão, 87.303-280, Paraná
Brazil
Email Fabricio Krzyzaniak
Web   : Web Site Link

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Paraguay have been instrumental in providing you this information. Particular thanks is given to Alfredo Junior Paiola Albrecht, Leandro Paiola Albrecht, and Fabricio Krzyzaniak for providing detailed information.
Herbicide Resistant Sourgrass Globally
(Digitaria insularis)
Herbicide Resistant Sourgrass Globally
(Digitaria insularis)
Drag a column header and drop it here to group by that column
Herbicide Resistant Sourgrass Globally
(Digitaria insularis)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ArgentinaArgentina 2014 Soybean glyphosate 48 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
239Digitaria insularisSourgrass13049
2 BrazilBrazil 2008 Corn (maize), and Soybean glyphosate 5 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
239Digitaria insularisSourgrass5350
3 BrazilBrazil 2016 Soybean fenoxaprop-ethyl, and haloxyfop-methyl 5 Inhibition of Acetyl CoA Carboxylase (A/1)
239Digitaria insularisSourgrass13043
4 BrazilBrazil 2020 Soybean fenoxaprop-ethyl, glyphosate, and haloxyfop-methyl 5 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
239Digitaria insularisSourgrass19212
5 ParaguayParaguay 2005 Corn (maize), Cotton, Soybean, and Sunflower glyphosate 46 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
239Digitaria insularisSourgrass5351
6 ParaguayParaguay 2020 Soybean clethodim, glyphosate, and haloxyfop-methyl 46 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
239Digitaria insularisSourgrass20223
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Cite this site as: Heap, I.  The International Survey of Herbicide Resistant Weeds.  Online.  Internet.  Monday, October 18, 2021 .  Available  www.weedscience.org
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