International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
Most Recent Cases of Herbicide Resistant Weeds Entered into the Database
(click on a column header to sort or click on a country for details)
#Date Last UpdatedSpeciesCountryFirst YearSite of Action
1 April 24, 2025Conyza canadensisMexicoMexico 201829 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		61Horseweed31270
2 March 3, 2025Polygonum convolvulus (=Fallopia convolvulus)United States (Kansas) United StatesKansas202045 Inhibition of Acetolactate Synthase (B/2)
 		88Wild Buckwheat31269
3 February 24, 2025Brassica rapa (=B. campestris)MexicoMexico 202129 Multiple Resistance: 3 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
Auxin Mimics (O/4)
 		36Birdsrape Mustard31268
4 January 27, 2025Amaranthus palmeriUnited States (New York) United StatesNew York202445 Multiple Resistance: 2 Sites of Action
PSII inhibitors - Serine 264 Binders (C1 C2/5)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth30269
5 January 27, 2025Stellaria mediaEstoniaEstonia 202199 Inhibition of Acetolactate Synthase (B/2)
 		168Common Chickweed30270
6 January 27, 2025Conyza canadensisUnited States (New York) United StatesNew York202445 PS I Electron Diversion (D/22)
 		61Horseweed30268
7 December 7, 2024Amaranthus palmeriTurkeyTurkey 202371 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth29268
8 December 5, 2024Steinchisma laxumColombiaColombia 202310 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		1358Lax Panicgrass27271
9 December 2, 2024Setaria viridisUkraineUkraine 2024230 Inhibition of Acetolactate Synthase (B/2)
 		153Green Foxtail29269
10 November 27, 2024Alopecurus myosuroidesFranceFrance 202217 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		6Blackgrass29265
11 November 6, 2024Lolium rigidumTunisiaTunisia 202378 Inhibition of Acetolactate Synthase (B/2)
 		112Rigid Ryegrass29275
12 November 6, 2024Lolium rigidumAlgeriaAlgeria 2023115 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		112Rigid Ryegrass29277
13 November 6, 2024Lolium rigidumTunisiaTunisia 202378 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		112Rigid Ryegrass29276
14 October 24, 2024Atriplex patulaFranceFrance 201917 PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		26Halberdleaf Orach29266
15 October 10, 2024Lolium rigidumAlgeriaAlgeria 2023115 Inhibition of Acetolactate Synthase (B/2)
 		112Rigid Ryegrass29274
16 October 10, 2024Lolium rigidumAlgeriaAlgeria 2023115 Inhibition of Acetyl CoA Carboxylase (A/1)
 		112Rigid Ryegrass29273
17 October 9, 2024Galium spuriumAustriaAustria 20242 Inhibition of Acetolactate Synthase (B/2)
 		93False Cleavers29264
18 September 28, 2024Lolium rigidumMoroccoMorocco 2023166 Inhibition of Acetolactate Synthase (B/2)
 		112Rigid Ryegrass29272
19 September 28, 2024Lolium rigidumMoroccoMorocco 2023166 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		112Rigid Ryegrass29278
20 September 28, 2024Lolium rigidumMoroccoMorocco 2023166 Inhibition of Acetyl CoA Carboxylase (A/1)
 		112Rigid Ryegrass29271
21 September 23, 2024Echinochloa colonaPakistanPakistan 202486 Inhibition of Acetolactate Synthase (B/2)
 		78Junglerice29279
22 September 17, 2024Amaranthus albusIsraelIsrael 202323 Inhibition of Acetolactate Synthase (B/2)
 		7Tumble Pigweed29280
23 September 5, 2024Avena fatuaPakistanPakistan 202486 Inhibition of Acetyl CoA Carboxylase (A/1)
 		28Wild Oat29281
24 August 29, 2024Amaranthus palmeriUnited States (Kansas) United StatesKansas202145 Multiple Resistance: 6 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Serine 264 Binders (C1 C2/5)
Inhibition of Protoporphyrinogen Oxidase (E/14)
Inhibition of Hydroxyphenyl Pyruvate Dioxygenase (F2/27)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
Auxin Mimics (O/4)
 		14Palmer Amaranth24257
25 August 24, 2024Alopecurus myosuroidesFranceFrance 202017 Very Long-Chain Fatty Acid Synthesis inhibitors (K3 N/15)
 		6Blackgrass29267
26 August 11, 2024Schoenoplectus juncoidesChinaChina 20249 Inhibition of Acetolactate Synthase (B/2)
 		196Rock Bulrush29282
27 August 6, 2024Echinochloa crus-pavonisChinaChina 20249 Auxin Mimics (O/4)
 		193Gulf Cockspur29283
28 August 3, 2024Amaranthus palmeriUnited States (Oregon) United StatesOregon202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth29270
29 July 21, 2024Chenopodium albumCanada (New Brunswick) CanadaNew Brunswick20187 PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		47Common Lambsquarters28276
30 July 14, 2024Ambrosia artemisiifoliaCanada (Prince Edward Island) CanadaPrince Edward Island20237 PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		18Common Ragweed28275
31 July 12, 2024Amaranthus retroflexusCanada (Prince Edward Island) CanadaPrince Edward Island20237 PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		16Redroot Pigweed28274
32 July 8, 2024Chenopodium albumCanada (Prince Edward Island) CanadaPrince Edward Island20187 PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		47Common Lambsquarters28273
33 June 15, 2024Oryza sativa var. sylvaticaArgentinaArgentina 201848 Inhibition of Acetolactate Synthase (B/2)
 		242Red Rice27289
34 June 8, 2024Conyza bonariensisUruguayUruguay 202273 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		60Hairy Fleabane27291
35 June 6, 2024Cyperus difformisPortugalPortugal 202334 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Histidine 215 Binders (C3/6)
 		71Smallflower Umbrella Sedge28270
36 May 24, 2024Bidens pilosaBrazilBrazil 20225 Inhibition of Protoporphyrinogen Oxidase (E/14)
 		32Hairy Beggarticks27288
37 May 24, 2024Digitaria sanguinalisSwitzerlandSwitzerland 202141 Inhibition of Acetolactate Synthase (B/2)
 		77Large Crabgrass27290
38 May 24, 2024Amaranthus hybridus (syn: quitensis)South AfricaSouth Africa 202437 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		12Smooth Pigweed27287
39 May 19, 2024Glebionis segetumGreeceGreece 202119 Inhibition of Acetolactate Synthase (B/2)
 		2358Corn Marigold28272
40 May 4, 2024Echinochloa phyllopogon (=E. oryzicola)PortugalPortugal 202034 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		178Late Watergrass28269
41 April 20, 2024Echinochloa phyllopogon (=E. oryzicola)PortugalPortugal 202034 Inhibition of Acetyl CoA Carboxylase (A/1)
 		178Late Watergrass28268
42 April 9, 2024Papaver rhoeasPortugalPortugal 201834 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Auxin Mimics (O/4)
 		123Corn Poppy28267
43 March 25, 2024Chloris truncataSpainSpain 202338 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		262Windmill Grass27293
44 March 18, 2024Conyza canadensisUnited States (Oregon) United StatesOregon202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		61Horseweed27286
45 March 18, 2024Conyza bonariensisUnited States (Oregon) United StatesOregon202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		60Hairy Fleabane27285
46 March 18, 2024Amaranthus palmeriUnited States (Iowa) United StatesIowa202245 Multiple Resistance: 4 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Serine 264 Binders (C1 C2/5)
Inhibition of Hydroxyphenyl Pyruvate Dioxygenase (F2/27)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth27284
47 March 5, 2024Papaver rhoeasPortugalPortugal 201834 Inhibition of Acetolactate Synthase (B/2)
 		123Corn Poppy28271
48 March 3, 2024Lolium perenne ssp. multiflorumPortugalPortugal 201934 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		110Italian Ryegrass28266
49 February 24, 2024Echinochloa crus-galli var. crus-galliPortugalPortugal 201834 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		79Barnyardgrass28265
50 February 20, 2024Amaranthus palmeriSpainSpain 202338 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth27292
51 January 21, 2024Bromus diandrusNew ZealandNew Zealand 202430 Inhibition of Acetolactate Synthase (B/2)
 		197Ripgut Brome27283
52 November 19, 2023Avena sterilisSpainSpain 202338 Inhibition of Acetyl CoA Carboxylase (A/1)
 		29Sterile Oat27282
53 November 9, 2023Amaranthus tuberculatus (=A. rudis)United States (Idaho) United StatesIdaho202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		219Tall Waterhemp27264
54 November 3, 2023Amaranthus hybridus (syn: quitensis)ItalyItaly 201824 Inhibition of Acetolactate Synthase (B/2)
 		12Smooth Pigweed27281
55 October 30, 2023Amaranthus tuberculatus (=A. rudis)United States (Iowa) United StatesIowa202145 Auxin Mimics (O/4)
 		219Tall Waterhemp27263
56 October 26, 2023Conyza bonariensisJordanJordan 202255 Multiple Resistance: 2 Sites of Action
PS I Electron Diversion (D/22)
Inhibition of Protoporphyrinogen Oxidase (E/14)
 		60Hairy Fleabane27269
57 October 25, 2023Echinochloa crus-galli var. crus-galliThailandThailand 202147 Inhibition of Cellulose Synthesis (L/26)
 		79Barnyardgrass27275
58 October 18, 2023Poa annuaIrelandIreland 202181 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		130Annual Bluegrass27262
59 September 26, 2023Monochoria vaginalisIndonesiaIndonesia 202222 Inhibition of Acetolactate Synthase (B/2)
 		202Arrowleafed Monochoria27274
60 September 14, 2023Ambrosia artemisiifoliaUkraineUkraine 2023230 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Protoporphyrinogen Oxidase (E/14)
 		18Common Ragweed26266
61 September 5, 2023Echinochloa crus-galli var. crus-galliBrazilBrazil 20185 Multiple Resistance: 3 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Cellulose Synthesis (L/26)
Auxin Mimics (O/4)
 		79Barnyardgrass26265
62 September 5, 2023Bidens subalternansBrazilBrazil 20235 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		194Greater Beggarticks26263
63 September 5, 2023Sagittaria montevidensisBrazilBrazil 20235 Auxin Mimics (O/4)
 		146California Arrowhead26264
64 August 28, 2023Bromus diandrusAustralia (Western Australia) AustraliaWestern Australia20201 Inhibition of Acetyl CoA Carboxylase (A/1)
 		197Ripgut Brome26262
65 August 5, 2023Panicum miliaceum var. ruderale Kitag.ChinaChina 20239 Inhibition of Acetolactate Synthase (B/2)
 		1359Wild Panicgrass27273
66 July 13, 2023Echinochloa crus-galli var. crus-galliIndiaIndia 201721 Inhibition of Acetolactate Synthase (B/2)
 		79Barnyardgrass25264
67 July 11, 2023Amaranthus palmeriUnited States (Colorado) United StatesColorado202145 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth25265
68 July 11, 2023Amaranthus powelliiCanada (Ontario) CanadaOntario20197 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Auxin Mimics (O/4)
 		15Powell Amaranth24243
69 July 6, 2023Digitaria sanguinalisNew ZealandNew Zealand 202230 Inhibition of Acetolactate Synthase (B/2)
 		77Large Crabgrass25262
70 June 29, 2023Hordeum jubatumCanada (Alberta) CanadaAlberta20227 Inhibition of Acetyl CoA Carboxylase (A/1)
 		358Foxtail Barley25263
71 June 23, 2023Ammannia multifloraChinaChina 20229 Inhibition of Acetolactate Synthase (B/2)
 		1360Many Flowered Ammannia27279
72 June 8, 2023Galium spuriumGreeceGreece 202219 Inhibition of Acetolactate Synthase (B/2)
 		93False Cleavers27278
73 June 5, 2023Plantago lanceolataSouth AfricaSouth Africa 202237 Multiple Resistance: 2 Sites of Action
PS I Electron Diversion (D/22)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		220Buckhorn Plantain27276
74 June 3, 2023Ambrosia artemisiifoliaUnited States (Michigan) United StatesMichigan202245 Auxin Mimics (O/4)
 		18Common Ragweed27277
75 May 9, 2023Echinochloa oryzoidesArgentinaArgentina 201648 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		261Early Watergrass25261
76 May 9, 2023Poa annuaUnited States (Georgia) United StatesGeorgia202245 Inhibition of Cellulose Synthesis (L/29)
 		130Annual Bluegrass25260
77 April 25, 2023Kochia scopariaCanada (Saskatchewan) CanadaSaskatchewan20217 Inhibition of Protoporphyrinogen Oxidase (E/14)
 		101Kochia25259
78 April 24, 2023Bromus commutatusUnited KingdomUnited Kingdom 202044 Inhibition of Acetolactate Synthase (B/2)
 		357Meadow Brome25258
79 April 23, 2023Bromus sterilisUnited KingdomUnited Kingdom 202044 Inhibition of Acetolactate Synthase (B/2)
 		289Poverty Brome25257
80 April 23, 2023Bromus diandrusUnited KingdomUnited Kingdom 202044 Inhibition of Acetolactate Synthase (B/2)
 		197Ripgut Brome25256
81 April 4, 2023Lolium perenne ssp. multiflorumChinaChina 20229 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		110Italian Ryegrass27266
82 March 30, 2023Digitaria ciliarisChinaChina 20219 Inhibition of Acetyl CoA Carboxylase (A/1)
 		225Southern Crabgrass27272
83 March 15, 2023Amaranthus retroflexusUnited States (North Carolina) United StatesNorth Carolina202245 Multiple Resistance: 3 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Protoporphyrinogen Oxidase (E/14)
Inhibition of Hydroxyphenyl Pyruvate Dioxygenase (F2/27)
 		16Redroot Pigweed24259
84 March 15, 2023Amaranthus retroflexusUnited States (North Carolina) United StatesNorth Carolina202245 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		16Redroot Pigweed24258
85 March 15, 2023Amaranthus retroflexusUnited States (North Carolina) United StatesNorth Carolina202045 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Protoporphyrinogen Oxidase (E/14)
 		16Redroot Pigweed22235
86 March 12, 2023Echinochloa phyllopogon (=E. oryzicola)ChinaChina 20239 Inhibition of Acetolactate Synthase (B/2)
 		178Late Watergrass27267
87 March 11, 2023Ammannia auriculataChinaChina 20239 Inhibition of Acetolactate Synthase (B/2)
 		183Eared Redstem27280
88 March 8, 2023Cyperus esculentusItalyItaly 201724 Inhibition of Acetolactate Synthase (B/2)
 		290Yellow Nutsedge24256
89 February 16, 2023Stellaria mediaUnited States (California) United StatesCalifornia202245 Inhibition of Acetolactate Synthase (B/2)
 		168Common Chickweed24253
90 February 2, 2023Leptochloa chinensisChinaChina 20239 Inhibition of Hydroxyphenyl Pyruvate Dioxygenase (F2/27)
 		223Chinese Sprangletop27268
91 January 31, 2023Amaranthus palmeriUruguayUruguay 202273 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth24254
92 January 31, 2023Amaranthus hybridus (syn: quitensis)UruguayUruguay 202273 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		12Smooth Pigweed24255
93 December 20, 2022Lolium perenne ssp. multiflorumUnited States (North Carolina) United StatesNorth Carolina202245 Multiple Resistance: 4 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
PS I Electron Diversion (D/22)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		110Italian Ryegrass24251
94 December 4, 2022Amaranthus hybridus (syn: quitensis)ParaguayParaguay 202246 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		12Smooth Pigweed24252
95 November 22, 2022Chenopodium albumUkraineUkraine 2022230 Inhibition of Acetolactate Synthase (B/2)
 		47Common Lambsquarters24250
96 November 3, 2022Alopecurus myosuroidesSwitzerlandSwitzerland 201941 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		6Blackgrass20228
97 November 3, 2022Lolium perenne ssp. multiflorumSwitzerlandSwitzerland 202041 Multiple Resistance: 3 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		110Italian Ryegrass24249
98 November 3, 2022Conyza canadensisSwitzerlandSwitzerland 202141 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		61Horseweed24248
99 November 3, 2022Conyza bonariensisSwitzerlandSwitzerland 202041 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		60Hairy Fleabane24247
100 October 24, 2022Panicum dichotomiflorumUnited States (Illinois) United StatesIllinois201945 Inhibition of Acetolactate Synthase (B/2)
 		122Fall Panicum24246
101 October 24, 2022Amaranthus tuberculatus (=A. rudis)UruguayUruguay 202273 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		219Tall Waterhemp24245
102 October 24, 2022Amaranthus palmeriUnited States (North Carolina) United StatesNorth Carolina202245 Inhibition of Glutamine Synthetase (H/10)
 		14Palmer Amaranth24244
103 October 6, 2022Amaranthus tuberculatus (=A. rudis)Canada (Ontario) CanadaOntario20217 Multiple Resistance: 5 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Serine 264 Binders (C1 C2/5)
Inhibition of Protoporphyrinogen Oxidase (E/14)
Inhibition of Hydroxyphenyl Pyruvate Dioxygenase (F2/27)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		219Tall Waterhemp24242
104 July 26, 2022Amaranthus palmeriSouth AfricaSouth Africa 201837 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth23244
105 July 11, 2022Amaranthus hybridus (syn: quitensis)ArgentinaArgentina 202148 Inhibition of Protoporphyrinogen Oxidase (E/14)
 		12Smooth Pigweed23243
106 July 6, 2022Echinochloa crus-galli var. crus-galliViet NamViet Nam 201774 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
Inhibition of Cellulose Synthesis (L/26)
 		79Barnyardgrass23242
107 June 13, 2022Amaranthus palmeriUnited States (North Carolina) United StatesNorth Carolina202245 PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		14Palmer Amaranth23241
108 June 12, 2022Anthriscus caucalisGermanyGermany 201718 Inhibition of Acetolactate Synthase (B/2)
 		356Bur Chervil23240
109 April 27, 2022Digitaria sanguinalisArgentinaArgentina 201948 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		77Large Crabgrass23239
110 April 9, 2022Amaranthus palmeriUnited States (Idaho) United StatesIdaho202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		14Palmer Amaranth27265
111 March 18, 2022Sorghum halepenseUnited States (Missouri) United StatesMissouri201945 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		166Johnsongrass23238
112 March 14, 2022Cyperus difformisIndiaIndia 201721 Inhibition of Acetolactate Synthase (B/2)
 		71Smallflower Umbrella Sedge23236
113 March 11, 2022Poa annuaUnited States (Tennessee) United StatesTennessee201745 Multiple Resistance: 7 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Serine 264 Binders (C1 C2/5)
Inhibition of Protoporphyrinogen Oxidase (E/14)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
Inhibition of Glutamine Synthetase (H/10)
Inhibition of Microtubule Assembly (K1/3)
Inhibition of Cellulose Synthesis (L/29)
 		130Annual Bluegrass23237
114 February 8, 2022Lolium perenne ssp. multiflorumCanada (Ontario) CanadaOntario20217 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		110Italian Ryegrass22236
115 December 14, 2021Lolium perenne ssp. multiflorumIrelandIreland 202181 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		110Italian Ryegrass21237
116 December 14, 2021Alopecurus myosuroidesIrelandIreland 202181 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		6Blackgrass21236
117 November 23, 2021Tripleurospermum perforatum (=T. inodorum)Czech RepublicCzech Republic 202112 Inhibition of Acetolactate Synthase (B/2)
 		116Scentless Chamomile21235
118 October 25, 2021Bromus tectorumCanada (Alberta) CanadaAlberta20217 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		40Downy Brome (Cheatgrass)21234
119 October 8, 2021Zea mays ssp. mexicanaFranceFrance 202017 Inhibition of Acetyl CoA Carboxylase (A/1)
 		354Mexican teosinte21231
120 September 27, 2021Aster squamatusMexicoMexico 202129 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)
 		353Saltmarsh Aster21229
121 August 30, 2021Amaranthus retroflexusUkraineUkraine 2020230 Inhibition of Acetolactate Synthase (B/2)
 		16Redroot Pigweed20231
122 August 30, 2021Polygonum pensylvanicumUnited States (Arkansas) United StatesArkansas202045 Inhibition of Acetolactate Synthase (B/2)
 		135Pennsylvania Smartweed20230
123 August 30, 2021Amaranthus palmeriUnited States (Arkansas) United StatesArkansas202045 Inhibition of Glutamine Synthetase (H/10)
 		14Palmer Amaranth20229
124 August 11, 2021Lolium perenne ssp. multiflorumSwitzerlandSwitzerland 201841 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		110Italian Ryegrass20226
125 August 11, 2021Lolium perenne ssp. multiflorumSwitzerlandSwitzerland 201841 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase (B/2)
PSII inhibitors - Serine 264 Binders (C1 C2/5)
 		110Italian Ryegrass20227
126 August 11, 2021Sorghum halepenseSerbiaSerbia 2018245 Multiple Resistance: 2 Sites of Action
Inhibition of Acetyl CoA Carboxylase (A/1)
Inhibition of Acetolactate Synthase (B/2)
 		166Johnsongrass20225
127 August 11, 2021Ambrosia artemisiifoliaSerbiaSerbia 2019245 Inhibition of Acetolactate Synthase (B/2)
 		18Common Ragweed20224
128 July 11, 2021Leptochloa fusca spp. fasicularisUnited States (California) United StatesCalifornia202045 Inhibition of Deoxy-D-Xylulose Phosphate Synthase (F4/13)
 		355Bearded Sprangletop21233
PERMISSION MUST BE OBTAINED FIRST if you intend to base a significant portion of a scientific paper on data derived from this site.
Cite this site as: Heap, I.  The International Survey of Herbicide Resistant Weeds.  Online.  Internet.  Sunday, May 4, 2025 .  Available  www.weedscience.org
Copyright � 1993- 2025 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.