International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Hordeum murinum ssp. glaucum)

PS I Electron Diversion HRAC Group 22 (Legacy D)

Australia, Victoria
Smooth Barley (Hordeum murinum ssp. glaucum) is a monocot weed in the Poaceae family.  In Victoria this weed first evolved resistance to Group 22 (Legacy D) herbicides in 1984 and infests Alfalfa, and Cereals.   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 diquat, and 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.

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 06, 2002 )

Common NameSmooth Barley
SpeciesHordeum murinum ssp. glaucum
GroupPS I Electron Diversion HRAC Group 22 (Legacy D)
Herbicidesdiquat, and paraquat
LocationAustralia, Victoria
Situation(s)Alfalfa, and Cereals
Contributors - (Alphabetically)Christopher Preston 
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Christopher Preston
Victoria, South Australia

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Christopher Preston
Also resistant to diquat. First case of resistance in cereals, where paraquat and diquat are used as pre-plant knockdowns occurred in 1999.

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Confirmation Tests

Field, and Greenhouse trials comparing a known susceptible Smooth Barley biotype with this Smooth Barley 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 Smooth Barley 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 Smooth Barley from Victoria please update the database.
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University Of Adelaide - Waite Campus
Crc For Australian Weed Management And School Of Agriculture
Box 2146
Adelaide, 5064, South Australia
Email Christopher Preston


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Victoria have been instrumental in providing you this information. Particular thanks is given to Christopher Preston for providing detailed information.
Herbicide Resistant Smooth Barley Globally
(Hordeum murinum ssp. glaucum)
Herbicide Resistant Smooth Barley Globally
(Hordeum murinum ssp. glaucum)
Drag a column header and drop it here to group by that column
Herbicide Resistant Smooth Barley Globally
(Hordeum murinum ssp. glaucum)
#CountryFirstYearSituationActive IngredientsSite of Action
1 Australia (Victoria) AustraliaVictoria1984 Alfalfa, and Cereals diquat, and paraquat 1 PS I Electron Diversion ( HRAC Group 22 (Legacy D)
97Hordeum murinum ssp. glaucumSmooth Barley19
2 Australia (South Australia) AustraliaSouth Australia1990 Alfalfa, and Cereals diquat, and paraquat 1 PS I Electron Diversion ( HRAC Group 22 (Legacy D)
97Hordeum murinum ssp. glaucumSmooth Barley5031
3 Australia (South Australia) AustraliaSouth Australia2000 Pastures, and Winter pulses fluazifop-butyl, and quizalofop-ethyl 1 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
97Hordeum murinum ssp. glaucumSmooth Barley5095
4 Australia (Western Australia) AustraliaWestern Australia2005 Wheat sulfometuron-methyl, and sulfosulfuron 1 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
97Hordeum murinum ssp. glaucumSmooth Barley5251
5 Australia (South Australia) AustraliaSouth Australia2016 Around Buildings glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
97Hordeum murinum ssp. glaucumSmooth Barley17118
Literature about Similar Cases

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