International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
MULTIPLE RESISTANT RIGID RYEGRASS
(Lolium rigidum)


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)
Inhibition of Microtubule AssemblyHRAC Group 3 (Legacy K1)

Australia, Western Australia
INTRODUCTION RIGID RYEGRASS
Rigid Ryegrass (Lolium rigidum) is a monocot weed in the Poaceae family.  In Western Australia this weed first evolved multiple resistance (to 3 herbicide sites of action) in 1982 and infests Canola, Spring Barley, and Wheat.  Multiple resistance has evolved to herbicides in the Groups 1 (Legacy A), Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B), and Inhibition of Microtubule Assembly HRAC Group 3 (Legacy K1).  These particular biotypes are known to have resistance to chlorsulfuron, diclofop-methyl, fluazifop-butyl, sethoxydim, tralkoxydim, and trifluralin and they may be cross-resistant to other herbicides in the Groups 1 (Legacy A), Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B), and Inhibition of Microtubule Assembly HRAC Group 3 (Legacy K1).

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 Nov 20, 2000 )

Common NameRigid Ryegrass
SpeciesLolium rigidum
GroupInhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)

Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

Inhibition of Microtubule Assembly HRAC Group 3 (Legacy K1)
Herbicideschlorsulfuron, diclofop-methyl, fluazifop-butyl, sethoxydim, tralkoxydim, and trifluralin
LocationAustralia, Western Australia
Year1982
Situation(s)Canola, Spring Barley, and Wheat
Contributors - (Alphabetically)David Bowran, Gurgeet Gill, Stephen Powles, Jim Pratley, and Christopher Preston 
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NOTES ABOUT THIS BIOTYPE

AREAS FOUND

Stephen Powles
Weed Technology: Vol. 15, No. 2, pp. 242–248. High Levels of Herbicide Resistance in Rigid Ryegrass (Lolium rigidum) in the Wheat Belt of Western Australia RICK S. LLEWELLYN and STEPHEN B. POWLES A random survey of 264 cropping fields in the Western Australian wheat belt was conducted to determine the extent of rigid ryegrass resistance to commonly used acetolactate synthase- and acetyl-CoA carboxylase-inhibiting herbicides. Rigid ryegrass infestation density was assessed and seed samples collected and subsequently tested for resistance to diclofop-methyl, clethodim, chlorsulfuron, and sulfometuron. Of these randomly collected populations, 46% exhibited resistance to diclofop-methyl and 64% to chlorsulfuron, with 37% exhibiting multiple resistance to both herbicides. Only 28% of tested populations were classified as susceptible to both diclofop-methyl and chlorsulfuron, although all but one population were susceptible to clethodim. Large differences in the proportion of fields containing resistant populations were found between agronomic areas, reflecting different cropping and, therefore, herbicide use history. There was no significant association between resistance status and the density at which rigid ryegrass was present. Herbicide-resistant rigid ryegrass populations are now more common than susceptible populations across much of the Western Australian wheat belt.

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GENERAL

Stephen Powles
Cross-resistance to ALS inhibitors is quite common, however plants are generally retrarded and a large % fail to cope with water stress in the spring. Resistance to ALS inhibitors only is also becoming quite common.

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ACADEMIC ASPECTS

Confirmation Tests

Field, and Greenhouse trials comparing a known susceptible Rigid Ryegrass biotype with this Rigid Ryegrass 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, 2, 3 resistant Rigid Ryegrass 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

Studies on the mechanism of resistance of multiple resistant Rigid Ryegrass from Western Australia indicate that resistance is due to an altered target site, and enhanced metabolism.  There may be a note below or an article discussing the mechanism of resistance in the Fact Sheets and Other Literature
 
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 multiple resistant Rigid Ryegrass from Western Australia please update the database.
 
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CONTRIBUTING WEED SCIENTISTS

DAVID BOWRAN
Research Officer
Agriculture Wa
748 Railroad Hwy
Northam, Western Australia
Australia
Email David Bowran
GURGEET GILL
Research Officer
University Of Adelaide
Department Of Agronomy And Farming Systems
Crop, Soil
Environmental Sciences, 1366 W. Altheimer Dr,
Roseworthy, 5371, South Australia
Australia
Email Gurgeet Gill
STEPHEN POWLES
Professor And Research Director
University Of Western Australia
School Of Plant Biology
2276 Dahlk Circle
Crawley, 6009, Western Australia
Australia
Email Stephen Powles
Web   : Web Site Link
JIM PRATLEY
Dean, Faculty Of Science & Agriculture
Charles Sturt University
School Of Agriculture
Dept of Crop& Soil Sciences
PO Box 646420,
Wagga Wagga, 2678, New South Wales
Australia
Email Jim Pratley
Web   : Web Site Link
CHRISTOPHER PRESTON
Dean, Faculty Of Science & Agriculture
University Of Adelaide - Waite Campus
Crc For Australian Weed Management And School Of Agriculture
Box 2146
Adelaide, 5064, South Australia
Australia
Email Christopher Preston
Web   : Web Site Link

ACKNOWLEDGEMENTS

The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Western Australia have been instrumental in providing you this information. Particular thanks is given to David Bowran, Gurgeet Gill, Stephen Powles, Jim Pratley, and Christopher Preston for providing detailed information.
Herbicide Resistant Rigid Ryegrass Globally
(Lolium rigidum)
Herbicide Resistant Rigid Ryegrass Globally
(Lolium rigidum)
Drag a column header and drop it here to group by that column
Herbicide Resistant Rigid Ryegrass Globally
(Lolium rigidum)
#CountryFirstYearSituationActive IngredientsSite of Action
1 Australia (Western Australia) AustraliaWestern Australia1982 Canola, Spring Barley, and Wheat chlorsulfuron, diclofop-methyl, fluazifop-butyl, sethoxydim, tralkoxydim, and trifluralin 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)
Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
112Lolium rigidumRigid Ryegrass15
2 Australia (South Australia) AustraliaSouth Australia1982 Spring Barley, and Wheat chlorpropham, chlorsulfuron, clomazone, diclofop-methyl, ethalfluralin, fluazifop-butyl, imazapyr, metolachlor, metsulfuron-methyl, quizalofop-ethyl, sethoxydim, tralkoxydim, tri-allate, triasulfuron, and trifluralin 1 Multiple Resistance: 6 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
Inhibition of Deoxy-D-Xylulose Phosphate Synthase ( HRAC Group 13 (Legacy F4)
Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
Inhibition of Microtubule Organization ( HRAC Group 23 (Legacy K2)
Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
112Lolium rigidumRigid Ryegrass389
3 Australia (Western Australia) AustraliaWestern Australia1984 Cropland, Spring Barley, and Wheat chlorsulfuron, and metsulfuron-methyl 1 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
112Lolium rigidumRigid Ryegrass324
4 Australia (Western Australia) AustraliaWestern Australia1984 Cropland, and Pasture seed trifluralin 1 Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
112Lolium rigidumRigid Ryegrass330
5 Australia (South Australia) AustraliaSouth Australia1984 Cropland metolachlor 1 Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
112Lolium rigidumRigid Ryegrass398
6 Australia (Victoria) AustraliaVictoria1984 Pastures, Spring Barley, and Wheat chlorsulfuron, diclofop-methyl, fluazifop-butyl, metsulfuron-methyl, quizalofop-ethyl, sethoxydim, and trifluralin 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)
Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
112Lolium rigidumRigid Ryegrass5042
7 Australia (New South Wales ) AustraliaNew South Wales 1985 Canola, Chickpea, Faba beans, Lentils, Lupins, Peas, Spring Barley, and Wheat chlorsulfuron, diclofop-methyl, fluazifop-butyl, haloxyfop-methyl, metsulfuron-methyl, quizalofop-ethyl, sethoxydim, tralkoxydim, triasulfuron, and trifluralin 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)
Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
112Lolium rigidumRigid Ryegrass4
8 Australia (Western Australia) AustraliaWestern Australia1988 Railways, and Roadsides amitrole 1 Inhibition of Lycopene Cyclase ( HRAC Group 34 (Legacy F3)
112Lolium rigidumRigid Ryegrass316
9 Australia (Western Australia) AustraliaWestern Australia1988 Cropland, Pasture seed, Railways, Roadsides, and Triazine-tolerant canola atrazine, and simazine 1 PSII inhibitors - Serine 264 Binders ( HRAC Group 5 (Legacy C1 C2)
112Lolium rigidumRigid Ryegrass480
10 Australia (South Australia) AustraliaSouth Australia1994 Cereals trifluralin 1 Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
112Lolium rigidumRigid Ryegrass5226
11 Australia (Victoria) AustraliaVictoria1996 Canola, Cereals, Fencelines, and Wheat glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass380
12 Australia (New South Wales ) AustraliaNew South Wales 1997 Apples, Around Buildings, Canola, Cereals, Fencelines, Irrigation Channels, Roadsides, and Wheat glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5094
13 Australia (South Australia) AustraliaSouth Australia1999 Alfalfa, Cereals, Clover, Fencelines, Grapes, Irrigation Channels, and Roadsides glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5188
14 Australia (Victoria) AustraliaVictoria1999 Wheat chlorsulfuron, diclofop-methyl, glyphosate, and trifluralin 1 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 Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
Inhibition of Microtubule Assembly ( HRAC Group 3 (Legacy K1)
112Lolium rigidumRigid Ryegrass5363
15 Australia (Western Australia) AustraliaWestern Australia2003 Cereals, Fencelines, Grapes, Railways, and Roadsides glyphosate 1 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5325
16 Australia (South Australia) AustraliaSouth Australia2008 Grapes amitrole, and glyphosate 1 Multiple Resistance: 2 Sites of Action
Inhibition of Lycopene Cyclase ( HRAC Group 34 (Legacy F3)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5515
17 Australia (South Australia) AustraliaSouth Australia2010 Pasture seed clethodim, and paraquat 1 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
PS I Electron Diversion ( HRAC Group 22 (Legacy D)
112Lolium rigidumRigid Ryegrass5489
18 Australia (South Australia) AustraliaSouth Australia2010 Pasture seed atrazine, chlorsulfuron, clethodim, glyphosate, haloxyfop-methyl, imazapyr, iodosulfuron-methyl-Na, and paraquat 1 Multiple Resistance: 5 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
PSII inhibitors - Serine 264 Binders ( HRAC Group 5 (Legacy C1 C2)
PS I Electron Diversion ( HRAC Group 22 (Legacy D)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5510
19 Australia (Western Australia) AustraliaWestern Australia2013 Grapes glyphosate, and paraquat 1 Multiple Resistance: 2 Sites of Action
PS I Electron Diversion ( HRAC Group 22 (Legacy D)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass6754
20 Australia (Victoria) AustraliaVictoria2015 Wheat tri-allate 1 Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
112Lolium rigidumRigid Ryegrass11023
21 Australia (New South Wales ) AustraliaNew South Wales 2015 Wheat tri-allate 1 Very Long-Chain Fatty Acid Synthesis inhibitors ( HRAC Group 15 (Legacy K3 N)
112Lolium rigidumRigid Ryegrass11031
22 ChileChile 1997 Canola, Cereals, Lupins, Spring wheat, and Winter wheat clethodim, clodinafop-propargyl, diclofop-methyl, haloxyfop-methyl, sethoxydim, and tralkoxydim 8 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass5102
23 ChileChile 2003 Wheat clethodim, clodinafop-propargyl, diclofop-methyl, flucarbazone-Na, haloxyfop-methyl, iodosulfuron-methyl-Na, pinoxaden, and tepraloxydim 8 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)
112Lolium rigidumRigid Ryegrass5427
24 FranceFrance 1993 Wheat diclofop-methyl 17 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass550
25 FranceFrance 2005 Cereals, Grapes, Orchards, and Rapeseed glyphosate 17 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5285
26 FranceFrance 2006 Wheat flupyrsulfuron-methyl-Na, iodosulfuron-methyl-Na, mesosulfuron-methyl, and propoxycarbazone-Na 17 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
112Lolium rigidumRigid Ryegrass5330
27 GreeceGreece 1997 Winter wheat diclofop-methyl 19 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass553
28 GreeceGreece 2009 Winter wheat chlorsulfuron 19 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
112Lolium rigidumRigid Ryegrass13053
29 GreeceGreece 2016 Orchards glyphosate 19 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass17137
30 GreeceGreece 2017 Grapes, Olive, and Orchards glufosinate-ammonium 19 Inhibition of Glutamine Synthetase ( HRAC Group 10 (Legacy H)
112Lolium rigidumRigid Ryegrass17136
31 IranIran 2007 Winter wheat clodinafop-propargyl, diclofop-methyl, and pinoxaden 79 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass5340
32 IsraelIsrael 1979 Orchards, and Roadsides atrazine, and simazine 23 PSII inhibitors - Serine 264 Binders ( HRAC Group 5 (Legacy C1 C2)
112Lolium rigidumRigid Ryegrass97
33 IsraelIsrael 1998 Alfalfa, and Wheat clodinafop-propargyl, diclofop-methyl, pinoxaden, and quizalofop-ethyl 23 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass5109
34 IsraelIsrael 2007 Wheat chlorsulfuron, clodinafop-propargyl, florasulam, flumetsulam, glyphosate, imazapyr, iodosulfuron-methyl-Na, mesosulfuron-methyl, metosulam, pinoxaden, propoxycarbazone-Na, sulfometuron-methyl, and tribenuron-methyl 23 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)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5556
35 IsraelIsrael 2013 Carrots, and Wheat clethodim, clodinafop-propargyl, cycloxydim, haloxyfop-methyl, iodosulfuron-methyl-Na, mesosulfuron-methyl, pinoxaden, propoxycarbazone-Na, and sulfometuron-methyl 23 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)
112Lolium rigidumRigid Ryegrass10992
36 ItalyItaly 2007 Grapes, and Orchards glyphosate 24 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5370
37 Saudi ArabiaSaudi Arabia 1992 Cereals, and Wheat clodinafop-propargyl, diclofop-methyl, and tralkoxydim 35 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass551
38 South AfricaSouth Africa 1993 Wheat clodinafop-propargyl, diclofop-methyl, fluazifop-butyl, haloxyfop-methyl, imazamox, sethoxydim, 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)
112Lolium rigidumRigid Ryegrass192
39 South AfricaSouth Africa 2001 Grapes glyphosate 37 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5093
40 South AfricaSouth Africa 2002 Fruit, and Grapes paraquat 37 PS I Electron Diversion ( HRAC Group 22 (Legacy D)
112Lolium rigidumRigid Ryegrass5119
41 South AfricaSouth Africa 2003 Grapes glyphosate, haloxyfop-methyl, paraquat, and tepraloxydim 37 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
PS I Electron Diversion ( HRAC Group 22 (Legacy D)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5239
42 SpainSpain 1992 Wheat chlorotoluron, and diclofop-methyl 38 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
PSII inhibitors - Serine 264 Binders ( HRAC Group 5 (Legacy C1 C2)
112Lolium rigidumRigid Ryegrass172
43 SpainSpain 1992 Wheat diclofop-methyl 38 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass173
44 SpainSpain 1992 Orchards simazine 38 PSII inhibitors - Serine 264 Binders ( HRAC Group 5 (Legacy C1 C2)
112Lolium rigidumRigid Ryegrass174
45 SpainSpain 2006 Orchards glyphosate 38 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass5332
46 SpainSpain 2016 Olive glyphosate, and oxyfluorfen 38 Multiple Resistance: 2 Sites of Action
Inhibition of Protoporphyrinogen Oxidase ( HRAC Group 14 (Legacy E)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass17105
47 TunisiaTunisia 1996 Cereals diclofop-methyl 78 Inhibition of Acetyl CoA Carboxylase ( HRAC Group 1 (Legacy A)
112Lolium rigidumRigid Ryegrass5028
48 United States (California) United StatesCalifornia1998 Almonds, and Orchards glyphosate 45 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase ( HRAC Group 9 (Legacy G)
112Lolium rigidumRigid Ryegrass1034
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