HRAC GROUP 1 (LEGACY A) RESISTANT PASTO AMARGO
(Eriochloa punctata)

Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)

Bolivia, Santa Cruz

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INTRODUCTION PASTO AMARGO Pasto Amargo (Eriochloa punctata) is a monocot weed in the Poaceae family.  In Bolivia this weed first evolved resistance to Group 1 (Legacy A) herbicides in 1997 and infests Soybean.   Group 1 (Legacy A) herbicides are known as Inhibition of Acetyl CoA Carboxylase (Inhibition of Acetyl CoA Carboxylase ).  Research has shown that these particular biotypes are resistant to fluazifop-butyl, and haloxyfop-methyl and they may be cross-resistant to other Group 1 (Legacy A) 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.

QUIK STATS (last updated Sep 15, 2000 ) Common Name Pasto Amargo Species Eriochloa punctata Group Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A) Herbicides fluazifop-butyl, and haloxyfop-methyl Location Bolivia, Santa Cruz Year 1997 Situation(s) Soybean Contributors - (Alphabetically) Pablo Franco  Edit this Case  |  Add New Case of Resistance  |  Add Note

NOTES ABOUT THIS BIOTYPE AREAS FOUND Pablo Franco Santa Cruz State; provinces (counties): Obispo Santiesteban, Sara, Guarayos, Ichilo, Chiquitos Edit this Note  |  Add New Note   GENERAL Pablo Franco The tropical grass, carib grass is frequently found in dry seeded rice, soya bean, maize, and cotton in Santa Cruz State, Bolivia. Dense populations of carib grass are found on most farms in soya bean following widespread and continued use of post-emergence herbicides which inhibit the enzyme ACCase. Farmers have recently reported difficulty in controlling carib grass with recommended doses of fluazifop-p. For fenoxaprop the resistance index was 8.8 times the LD of the biotype San Pedro. The resistance indexes of Monte Cristo were 1.04, 1.25, 1.5, 1.76, 2.5, 2.5, 4.5 for butroxydim, propaquizafop, clodinafop, quizalofop, haloxyfop, cyhalofop, cycloxydim, respectively. Edit this Note  |  Add New Note

ACADEMIC ASPECTS Confirmation Tests Greenhouse, and Laboratory trials comparing a known susceptible Pasto Amargo biotype with this Pasto Amargo 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 resistant Pasto Amargo 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 1 (Legacy A) resistant Pasto Amargo from Bolivia please update the database.   Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  Help

CONTRIBUTING WEED SCIENTISTS PABLO FRANCO BASF Bolivia Research and Development Av. San Martin No 1800 of 302 Santa Cruz, de la sierra 237, Santa Cruz Bolivia Email Pablo Franco

ACKNOWLEDGEMENTS The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Bolivia have been instrumental in providing you this information. Particular thanks is given to Pablo Franco for providing detailed information.

Herbicide Resistant Pasto Amargo Globally (Eriochloa punctata) Herbicide Resistant Pasto Amargo Globally (Eriochloa punctata) Drag a column header and drop it here to group by that column Herbicide Resistant Pasto Amargo Globally (Eriochloa punctata) # Country Country StateName FirstYear Situation Active Ingredients CountryID Site of Action WeedID Species CommonName ResistID 1 Bolivia Bolivia   1997 Soybean fluazifop-butyl, and haloxyfop-methyl 4 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A) 176 Eriochloa punctata Pasto Amargo 555

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