(Bidens pilosa)

PS I Electron Diversion HRAC Group 22 (Legacy D)

Hairy Beggarticks (Bidens pilosa) is a dicot weed in the Asteraceae family.  In Kenya this weed first evolved resistance to Group 22 (Legacy D) herbicides in 1991 and infests Coffee.   Group 22 (Legacy D) herbicides are known as PS I Electron Diversion (PSI Electron Diversion ).  Research has shown that these particular biotypes are resistant to paraquat and they may be cross-resistant to other Group 22 (Legacy D) 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 Sep 15, 2000 )

Common NameHairy Beggarticks
SpeciesBidens pilosa
GroupPS I Electron Diversion HRAC Group 22 (Legacy D)
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Malik, R. K. 1996. Herbicide resistant weed problems in the developing world and methods to overcome them. Second International Weed Control Congress. Copenhagen. Malik refers to a paper by Njoroge, J.M. 1991. Tolerance of Bidens pilosa and Parthenium hysterophorus to paraquat in Kenya. Kenya Coffee, The coffee Board of Kenya Monthly bulletin. 56 (651):999-1001.

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Confirmation Tests

Field, and Greenhouse trials comparing a known susceptible Hairy Beggarticks biotype with this Hairy Beggarticks biotype have been used to confirm resistance. For further information on the tests conducted please contact the local weed scientists that provided this information.

Genetic studies on HRAC Group 22 resistant Hairy Beggarticks 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 22 (Legacy D) resistant Hairy Beggarticks from Kenya please update the database.
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The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Kenya have been instrumental in providing you this information. 
Herbicide Resistant Hairy Beggarticks Globally
(Bidens pilosa)
Herbicide Resistant Hairy Beggarticks Globally
(Bidens pilosa)
Drag a column header and drop it here to group by that column
Herbicide Resistant Hairy Beggarticks Globally
(Bidens pilosa)
#CountryFirstYearSituationActive IngredientsSite of Action
1 BrazilBrazil 1993 Soybean chlorimuron-ethyl, imazaquin, imazethapyr, nicosulfuron, and pyrithiobac-sodium 5 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
32Bidens pilosaHairy Beggarticks42
2 BrazilBrazil 2016 Corn (maize), and Soybean atrazine, and imazethapyr 5 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
PSII inhibitors - Serine 264 Binders ( HRAC Group 5 (Legacy C1 C2)
32Bidens pilosaHairy Beggarticks14053
3 BrazilBrazil 2022 Soybean fomesafen 5 Inhibition of Protoporphyrinogen Oxidase ( HRAC Group 14 (Legacy E)
32Bidens pilosaHairy Beggarticks27288
4 KenyaKenya 1991 Coffee paraquat 26 PS I Electron Diversion ( HRAC Group 22 (Legacy D)
32Bidens pilosaHairy Beggarticks381
5 MexicoMexico 2014 Lime, and sour glyphosate 29 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
32Bidens pilosaHairy Beggarticks9923
Literature about Similar Cases

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