(Avena sterilis)

ACCase inhibitors (A/1)

Australia, New South Wales
Sterile Oat (Avena sterilis) is a monocot weed in the Poaceae family.  In New South Wales this weed first evolved resistance to Group A/1 herbicides in 1989 and infests Canola, Chickpea, and Wheat.   Group A/1 herbicides are known as ACCase inhibitors (Inhibition of acetyl CoA carboxylase (ACCase)).  Research has shown that these particular biotypes are resistant to diclofop-methyl, fluazifop-P-butyl, and sethoxydim and they may be cross-resistant to other Group A/1 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 Jan 22, 2014 )

Common NameSterile Oat
SpeciesAvena sterilis
GroupACCase inhibitors (A/1)
Herbicidesdiclofop-methyl, fluazifop-P-butyl, and sethoxydim
LocationAustralia, New South Wales
Situation(s)Canola, Chickpea, and Wheat
Contributors - (Alphabetically)Andrew Storrie 
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Andrew Storrie
20-30 properties north of Dubbo.

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Andrew Storrie
Selection has been with many ACCase inhibitors, usually several have been used in rotation. Varying levels of resistance to all ACCase inhibitors.

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Confirmation Tests

Greenhouse trials comparing a known susceptible Sterile Oat biotype with this Sterile Oat 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 Group A/1 resistant Sterile Oat 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 A/1 resistant Sterile Oat from New South Wales please update the database.
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Po Box 5444
Albany, 6332, Western Australia
Email Andrew Storrie
Web   : Web Site Link


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in New South Wales have been instrumental in providing you this information. Particular thanks is given to Andrew Storrie for providing detailed information.
Herbicide Resistant Sterile Oat Globally
(Avena sterilis)
Herbicide Resistant Sterile Oat Globally
(Avena sterilis)
Drag a column header and drop it here to group by that column
Herbicide Resistant Sterile Oat Globally
(Avena sterilis)
#CountryFirstYearSituationActive IngredientsSite of Action
1 Australia (South Australia) AustraliaSouth Australia1989 Canola, Chickpea, Clover, Faba beans, Lentils, Lupins, Peas, and Wheat diclofop-methyl, fluazifop-P-butyl, and sethoxydim 1 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat21
2 Australia (New South Wales ) AustraliaNew South Wales 1989 Canola, Chickpea, and Wheat diclofop-methyl, fluazifop-P-butyl, and sethoxydim 1 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat5029
3 CyprusCyprus 2010 Spring Barley diclofop-methyl 53 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat5643
4 FranceFrance 2006 Wheat iodosulfuron-methyl-sodium, mesosulfuron-methyl, metsulfuron-methyl, and pyroxsulam 17 ALS inhibitors (B/2)
29Avena sterilisSterile Oat9937
5 GreeceGreece 2009 Wheat clodinafop-propargyl, diclofop-methyl, fenoxaprop-P-ethyl, pinoxaden, and tralkoxydim 19 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat6740
6 IranIran 2008 Wheat pinoxaden 79 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat5378
7 IranIran 2009 Wheat iodosulfuron-methyl-sodium, and mesosulfuron-methyl 79 ALS inhibitors (B/2)
29Avena sterilisSterile Oat5376
8 IsraelIsrael 2006 Wheat clodinafop-propargyl, cycloxydim, and fenoxaprop-P-ethyl 23 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat5300
9 ItalyItaly 1992 Wheat clodinafop-propargyl, cycloxydim, diclofop-methyl, pinoxaden, sethoxydim, and tralkoxydim 24 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat1128
10 ItalyItaly 2004 Durum wheat clodinafop-propargyl, cycloxydim, iodosulfuron-methyl-sodium, mesosulfuron-methyl, and pinoxaden 24 Multiple Resistance: 2 Sites of Action
ACCase inhibitors (A/1)
ALS inhibitors (B/2)
29Avena sterilisSterile Oat5632
11 ItalyItaly 2007 Durum wheat iodosulfuron-methyl-sodium, and mesosulfuron-methyl 24 ALS inhibitors (B/2)
29Avena sterilisSterile Oat8908
12 TurkeyTurkey 1997 Wheat clodinafop-propargyl, diclofop-methyl, fenoxaprop-P-ethyl, and tralkoxydim 71 ACCase inhibitors (A/1)
29Avena sterilisSterile Oat5101
13 TurkeyTurkey 2008 clodinafop-propargyl, and pyroxsulam 71 Multiple Resistance: 2 Sites of Action
ACCase inhibitors (A/1)
ALS inhibitors (B/2)
29Avena sterilisSterile Oat5402
14 United KingdomUnited Kingdom 1993 Cereals, and Wheat fenoxaprop-P-ethyl, flamprop-methyl, fluazifop-P-butyl, imazamethabenz-methyl, iodosulfuron-methyl-sodium, mesosulfuron-methyl, and tralkoxydim 44 Multiple Resistance: 3 Sites of Action
ACCase inhibitors (A/1)
ALS inhibitors (B/2)
Antimicrotubule mitotic disrupter (Z/25)
29Avena sterilisSterile Oat354
Literature about Similar Cases

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Heap, I.  The International Herbicide-Resistant Weed Database.  Online.  Saturday, January 16, 2021 .  Available Copyright © 1993- 2021 All rights reserved. Fair use of this material is encouraged. Proper citation is requested.