INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE

HRAC GROUP 1 (LEGACY A) RESISTANT WILD OAT
(Avena fatua)


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

Ireland, Kilkenny, Wexford
INTRODUCTION WILD OAT
Wild Oat (Avena fatua) is a monocot weed in the Poaceae family.  In Ireland this weed first evolved resistance to Group 1 (Legacy A) herbicides in 2019 and infests Spring Barley, and Winter barley.   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 cycloxydim, pinoxaden, and propaquizafop 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.

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QUIK STATS (last updated Sep 10, 2020 )

Common NameWild Oat
SpeciesAvena fatua
GroupInhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
Herbicidescycloxydim, pinoxaden, and propaquizafop
LocationIreland, Kilkenny, Wexford
Year2019
Situation(s)Spring Barley, and Winter barley
Contributors - (Alphabetically)Vijaya Bhaskar A.V., and Sarah Cook 
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NOTES ABOUT THIS BIOTYPE

GENERAL

Vijaya Bhaskar A.V.

First Report on Assessing the Severity of Herbicide Resistance to ACCase Inhibitors Pinoxaden, Propaquizafop and Cycloxydim in Six Avena fatua Populations in Ireland

 
Vijaya Bhaskar Alwarnaidu Vijayarajan  ,* , Patrick D. Forristal 1, Sarah K. Cook 2, Jimmy Staples 1, David Schilder 1, Michael Hennessy 1 and Susanne Barth 1
1 Crop Research Centre Oak Park, Teagasc, Carlow R93 XE12, Ireland; Dermot.Forristal@teagasc.ie (P.D.F.);
Jimmy.Staples@teagasc.ie (J.S.); David.Schilder@teagasc.ie (D.S.); Michael.Hennessy@teagasc.ie (M.H.); Susanne.Barth@teagasc.ie (S.B.)
2 Crop Protection Department, Weed Biology, ADAS Boxworth, Boxworth CB23 4NN, UK; sarah.cook@adas.co.uk
* Correspondence: Vijaya.Bhaskar@teagasc.ie; Tel.: +35-359-917-0248

Received: 25 August 2020; Accepted: 7 September 2020; Published: 10 September 2020

Abstract: In response to growers reports of poor weed control, resistance to ACCase inhibitors pinoxaden, propaquizafop and cycloxydim was investigated in populations of six wild oats, Avena fatua, collected from cereal-dominated crop rotations in Ireland. Glasshouse assays confirmed reduced sensitivity to all three ACCase inhibitors in four of the six populations, R2 to R5. R1 was cross-resistant to pinoxaden and propaquizafop and R6 was resistant to propaquizafop only. Dose-response studies confirmed significant differences in the severity of resistance amongst these populations (p < 0.05). For pinoxaden, the ED50 or GR50 resistance factor (RF) of R1, R3 and R5 were between 11.6 and 13.1 times or 25.1 and 30.2 times more resistant, respectively, compared with the susceptible populations. For propaquizafop, the ED50 and GR50 RF of R1, R2, R3, R5 and R6 were between >7.8 and >32 or 16.6 and 59 times more resistant, respectively. For cycloxydim, only R5 had both high ED50 and GR50 RF values of >43.2 and 98.4 respectively. In R2, although the ED50 values to both pinoxaden and cycloxydim and additionally, R3 to cycloxydim, were above recommended field rates, their GR50 values remained below, suggesting a shift towards cross-resistance. While R4 was the only population, where both ED50 and GR50 for all ACCase inhibitors remained below recommended field rates, they would not give effective control at these rates, strongly indicating evolving resistance. This is the first study reporting variable cross-resistance types and levels to ACCase inhibitors in A. fatua from Ireland.

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ACADEMIC ASPECTS

Confirmation Tests

Greenhouse trials comparing a known susceptible Wild Oat biotype with this Wild 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.
 
Genetics

Genetic studies on HRAC Group 1 resistant Wild 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 1 (Legacy A) resistant Wild Oat from Ireland please update the database.
 
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CONTRIBUTING WEED SCIENTISTS

VIJAYA BHASKAR A.V.
Researcher
Crop Research Centre Oak Park, Teagasc, Carlow R93 XE12, Ireland
Crop Science
Crop Research Centre Oak Park
Teagasc, Carlow R93 XE12, Ireland
Carlow, R93 XE12, Carlow
Ireland
Email Vijaya Bhaskar A.V.
Web   : Web Site Link
SARAH COOK
research consultant
ADAS UK Ltd
Crop Science
ADAS Boxworth
Boxworth
Cambridge, cb234nn, Cmbridgeshire
United Kingdom
Email Sarah Cook
Web   : Web Site Link

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Ireland have been instrumental in providing you this information. Particular thanks is given to Vijaya Bhaskar A.V., and Sarah Cook for providing detailed information.
Herbicide Resistant Wild Oat Globally
(Avena fatua)
Herbicide Resistant Wild Oat Globally
(Avena fatua)
Drag a column header and drop it here to group by that column
Herbicide Resistant Wild Oat Globally
(Avena fatua)
#CountryFirstYearSituationActive IngredientsSite of Action
1 ArgentinaArgentina 2010 Spring Barley, and Wheat clodinafop-propargyl, diclofop-methyl, and fenoxaprop-ethyl 48 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5587
2 Australia (Western Australia) AustraliaWestern Australia1985 Wheat diclofop-methyl 1 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat14
3 Australia (South Australia) AustraliaSouth Australia1988 Canola, Lupins, and Wheat diclofop-methyl, fluazifop-butyl, haloxyfop-methyl, and tralkoxydim 1 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat20
4 Australia (New South Wales ) AustraliaNew South Wales 1991 Canola, Chickpea, Faba beans, Lentils, Lupins, Spring Barley, and Wheat clethodim, clodinafop-propargyl, diclofop-methyl, and fenoxaprop-ethyl 1 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5
5 Australia (New South Wales ) AustraliaNew South Wales 2006 Chickpea, Spring Barley, and Wheat clodinafop-propargyl, diclofop-methyl, flamprop-methyl, and mesosulfuron-methyl 1 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Antimicrotubule mitotic disrupter ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat10966
6 Australia (Queensland) AustraliaQueensland2018 Chickpea glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
28Avena fatuaWild Oat18187
7 BelgiumBelgium 1996 Winter wheat clodinafop-propargyl, and fenoxaprop-ethyl 3 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat1146
8 BrazilBrazil 2010 Wheat clodinafop-propargyl 5 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5601
9 Canada (Alberta) CanadaAlberta1989 Cereals, and Spring Barley difenzoquat, and tri-allate 7 Multiple Resistance: 2 Sites of Action
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
Cell elongation inhibitors ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat66
10 Canada (Manitoba) CanadaManitoba1990 Canola, Cropland, Spring Barley, and Wheat clethodim, clodinafop-propargyl, diclofop-methyl, fenoxaprop-ethyl, sethoxydim, and tralkoxydim 7 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat50
11 Canada (Saskatchewan) CanadaSaskatchewan1990 Canola, Spring Barley, and Wheat fenoxaprop-ethyl, and sethoxydim 7 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5041
12 Canada (Alberta) CanadaAlberta1991 Canola, and Wheat diclofop-methyl, fenoxaprop-ethyl, quizalofop-ethyl, and tralkoxydim 7 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat67
13 Canada (Manitoba) CanadaManitoba1994 Canola, Cropland, Spring Barley, and Wheat fenoxaprop-ethyl, flamprop-methyl, imazamethabenz-methyl, and rimsulfuron 7 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Antimicrotubule mitotic disrupter ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat51
14 Canada (Saskatchewan) CanadaSaskatchewan1996 Cereals, and Cropland imazamethabenz-methyl 7 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat5072
15 Canada (Saskatchewan) CanadaSaskatchewan1996 Wheat tri-allate 7 Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
28Avena fatuaWild Oat5073
16 Canada (Saskatchewan) CanadaSaskatchewan1996 Canola, Lentils, Spring Barley, and Wheat fenoxaprop-ethyl, imazamethabenz-methyl, and tri-allate 7 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
28Avena fatuaWild Oat5074
17 Canada (Manitoba) CanadaManitoba1997 Wheat imazamethabenz-methyl 7 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat5077
18 Canada (Manitoba) CanadaManitoba1997 Wheat tri-allate 7 Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
28Avena fatuaWild Oat5078
19 Canada (Manitoba) CanadaManitoba1997 Wheat fenoxaprop-ethyl, flamprop-methyl, imazamethabenz-methyl, and tri-allate 7 Multiple Resistance: 4 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
Antimicrotubule mitotic disrupter ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat5079
20 Canada (Alberta) CanadaAlberta1998 Canola, Cereals, and Peas imazamethabenz-methyl 7 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat5075
21 Canada (Alberta) CanadaAlberta1998 Canola, Cereals, Peas, and Wheat fenoxaprop-ethyl, imazamethabenz-methyl, and tri-allate 7 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
28Avena fatuaWild Oat5076
22 Canada (Quebec) CanadaQuebec2012 Wheat, and Winter barley fenoxaprop-ethyl, and tralkoxydim 7 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat17129
23 Canada (Manitoba) CanadaManitoba2015 Spring wheat fenoxaprop-ethyl, imazamethabenz-methyl, imazapyr, pyroxasulfone, quizalofop-ethyl, sulfentrazone, and tri-allate 7 Multiple Resistance: 4 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Inhibition of Protoporphyrinogen Oxidase ( HRAC Group 14 (Legacy E)
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
28Avena fatuaWild Oat11033
24 ChileChile 1998 Wheat clodinafop-propargyl, diclofop-methyl, haloxyfop-methyl, and tralkoxydim 8 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5103
25 FranceFrance 1996 Wheat fenoxaprop-ethyl 17 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat548
26 FranceFrance 2006 Wheat iodosulfuron-methyl-Na, mesosulfuron-methyl, metsulfuron-methyl, and pyroxsulam 17 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat9938
27 GermanyGermany 2009 Sugar beets cycloxydim, fenoxaprop-ethyl, flupyrsulfuron-methyl-Na, mesosulfuron-methyl, and pinoxaden 18 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat6745
28 GermanyGermany 2012 Sugar beets clodinafop-propargyl, fenoxaprop-ethyl, and pinoxaden 18 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5662
29 IranIran 2007 Wheat clodinafop-propargyl, and diclofop-methyl 79 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5341
30 IrelandIreland 2019 Spring Barley, and Winter barley cycloxydim, pinoxaden, and propaquizafop 81 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat18200
31 MexicoMexico 1998 Wheat clodinafop-propargyl, cycloxydim, diclofop-methyl, fenoxaprop-ethyl, fluazifop-butyl, sethoxydim, and tralkoxydim 29 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5476
32 New ZealandNew Zealand 2014 Clover, and Wheat fenoxaprop-ethyl, and haloxyfop-methyl 30 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat14054
33 PolandPoland 2011 Spring Barley, and Spring wheat fenoxaprop-ethyl, and pinoxaden 33 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat6761
34 PolandPoland 2011 Spring Barley, and Spring wheat iodosulfuron-methyl-Na, mesosulfuron-methyl, propoxycarbazone-Na, and sulfometuron-methyl 33 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat6762
35 PolandPoland 2011 Spring Barley, and Spring wheat fenoxaprop-ethyl, iodosulfuron-methyl-Na, metsulfuron-methyl, pinoxaden, propoxycarbazone-Na, and sulfometuron-methyl 33 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat6763
36 South AfricaSouth Africa 1986 Wheat clodinafop-propargyl, diclofop-methyl, fenoxaprop-ethyl, fluazifop-butyl, imazamox, iodosulfuron-methyl-Na, sethoxydim, sulfosulfuron, and tralkoxydim 37 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat392
37 SyriaSyria 2015 Faba beans, Potatoes, and Wheat clodinafop-propargyl, and fenoxaprop-ethyl 69 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat15060
38 TurkeyTurkey 2011 Wheat diclofop-methyl, fenoxaprop-ethyl, and tralkoxydim 71 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5641
39 United KingdomUnited Kingdom 1994 Canola, Cereals, and Wheat fenoxaprop-ethyl, flamprop-m, fluazifop-butyl, imazamethabenz-methyl, mesosulfuron-methyl, pinoxaden, pyroxsulam, and tralkoxydim 44 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Antimicrotubule mitotic disrupter ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat355
40 United States (Oregon) United StatesOregon1990 Wheat diclofop-methyl, and fenoxaprop-ethyl 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat319
41 United States (Montana) United StatesMontana1990 Spring Barley difenzoquat, and tri-allate 45 Multiple Resistance: 2 Sites of Action
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
Cell elongation inhibitors ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat412
42 United States (Oregon) United StatesOregon1990 Cropland propyzamide/pronamide 45 Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
28Avena fatuaWild Oat475
43 United States (Minnesota) United StatesMinnesota1991 Sugar beets, and Wheat diclofop-methyl 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat247
44 United States (North Dakota) United StatesNorth Dakota1991 Cereals, and Wheat diclofop-methyl, and fenoxaprop-ethyl 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat485
45 United States (Washington) United StatesWashington1991 Wheat diclofop-methyl, fenoxaprop-ethyl, pinoxaden, quizalofop-ethyl, and sethoxydim 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat521
46 United States (Idaho) United StatesIdaho1992 Cereals, and Wheat clodinafop-propargyl, diclofop-methyl, and fenoxaprop-ethyl 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat235
47 United States (Idaho) United StatesIdaho1993 Cereals difenzoquat, and tri-allate 45 Multiple Resistance: 2 Sites of Action
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
Cell elongation inhibitors ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat234
48 United States (Montana) United StatesMontana1996 Cereals imazamethabenz-methyl 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat558
49 United States (North Dakota) United StatesNorth Dakota1996 Wheat imazamethabenz-methyl 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat1048
50 United States (California) United StatesCalifornia1996 Spring Barley, and Wheat difenzoquat 45 Cell elongation inhibitors ( HRAC Group 0 (Legacy Z)
28Avena fatuaWild Oat1176
51 United States (Colorado) United StatesColorado1997 Spring Barley, and Wheat diclofop-methyl 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat1052
52 United States (Montana) United StatesMontana2002 Cropland, Sugar beets, and Wheat clodinafop-propargyl, diclofop-methyl, fenoxaprop-ethyl, and tralkoxydim 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5246
53 United States (South Dakota) United StatesSouth Dakota2009 Cereals fenoxaprop-ethyl 45 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
28Avena fatuaWild Oat5637
54 United States (South Dakota) United StatesSouth Dakota2011 Cereals mesosulfuron-methyl 45 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat5638
55 United States (South Dakota) United StatesSouth Dakota2012 Wheat fenoxaprop-ethyl, and mesosulfuron-methyl 45 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
28Avena fatuaWild Oat5663
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