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 May 22, 2025Amaranthus palmeriArgentinaArgentina 202548 Inhibition of Protoporphyrinogen Oxidase HRAC Group 14 (Legacy E)
14Palmer Amaranth31274
2 May 22, 2025Rapistrum rugosumArgentinaArgentina 201848 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
142Turnipweed31273
3 May 14, 2025Conyza sumatrensisBoliviaBolivia 20244 PS I Electron Diversion HRAC Group 22 (Legacy D)
65Sumatran Fleabane31271
4 May 12, 2025Lolium rigidumSpainSpain 201538 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)
112Rigid Ryegrass31272
5 April 24, 2025Conyza canadensisMexicoMexico 201829 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
61Horseweed31270
6 March 3, 2025Polygonum convolvulus (=Fallopia convolvulus)United States (Kansas) United StatesKansas202045 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
88Wild Buckwheat31269
7 February 24, 2025Brassica rapa (=B. campestris)MexicoMexico 202129 Multiple Resistance: 3 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
Auxin Mimics HRAC Group 4 (Legacy O)
36Birdsrape Mustard31268
8 January 27, 2025Amaranthus palmeriUnited States (New York) United StatesNew York202445 Multiple Resistance: 2 Sites of Action
PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth30269
9 January 27, 2025Stellaria mediaEstoniaEstonia 202199 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
168Common Chickweed30270
10 January 27, 2025Conyza canadensisUnited States (New York) United StatesNew York202445 PS I Electron Diversion HRAC Group 22 (Legacy D)
61Horseweed30268
11 December 7, 2024Amaranthus palmeriTurkeyTurkey 202371 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth29268
12 December 5, 2024Steinchisma laxumColombiaColombia 202310 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
1358Lax Panicgrass27271
13 December 2, 2024Setaria viridisUkraineUkraine 2024230 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
153Green Foxtail29269
14 November 27, 2024Alopecurus myosuroidesFranceFrance 202217 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
6Blackgrass29265
15 November 6, 2024Lolium rigidumTunisiaTunisia 202378 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
112Rigid Ryegrass29275
16 November 6, 2024Lolium rigidumAlgeriaAlgeria 2023115 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)
112Rigid Ryegrass29277
17 November 6, 2024Lolium rigidumTunisiaTunisia 202378 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)
112Rigid Ryegrass29276
18 October 24, 2024Atriplex patulaFranceFrance 201917 PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
26Halberdleaf Orach29266
19 October 10, 2024Lolium rigidumAlgeriaAlgeria 2023115 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
112Rigid Ryegrass29274
20 October 10, 2024Lolium rigidumAlgeriaAlgeria 2023115 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
112Rigid Ryegrass29273
21 October 9, 2024Galium spuriumAustriaAustria 20242 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
93False Cleavers29264
22 September 28, 2024Lolium rigidumMoroccoMorocco 2023166 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
112Rigid Ryegrass29272
23 September 28, 2024Lolium rigidumMoroccoMorocco 2023166 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)
112Rigid Ryegrass29278
24 September 28, 2024Lolium rigidumMoroccoMorocco 2023166 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
112Rigid Ryegrass29271
25 September 23, 2024Echinochloa colonaPakistanPakistan 202486 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
78Junglerice29279
26 September 17, 2024Amaranthus albusIsraelIsrael 202323 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
7Tumble Pigweed29280
27 September 5, 2024Avena fatuaPakistanPakistan 202486 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
28Wild Oat29281
28 August 29, 2024Amaranthus palmeriUnited States (Kansas) United StatesKansas202145 Multiple Resistance: 6 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
Inhibition of Protoporphyrinogen Oxidase HRAC Group 14 (Legacy E)
Inhibition of Hydroxyphenyl Pyruvate Dioxygenase HRAC Group 27 (Legacy F2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
Auxin Mimics HRAC Group 4 (Legacy O)
14Palmer Amaranth24257
29 August 24, 2024Alopecurus myosuroidesFranceFrance 202017 Very Long-Chain Fatty Acid Synthesis inhibitorsHRAC Group 15 (Legacy K3 N)
6Blackgrass29267
30 August 11, 2024Schoenoplectus juncoidesChinaChina 20249 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
196Rock Bulrush29282
31 August 6, 2024Echinochloa crus-pavonisChinaChina 20249 Auxin Mimics HRAC Group 4 (Legacy O)
193Gulf Cockspur29283
32 August 3, 2024Amaranthus palmeriUnited States (Oregon) United StatesOregon202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth29270
33 July 21, 2024Chenopodium albumCanada (New Brunswick) CanadaNew Brunswick20187 PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
47Common Lambsquarters28276
34 July 14, 2024Ambrosia artemisiifoliaCanada (Prince Edward Island) CanadaPrince Edward Island20237 PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
18Common Ragweed28275
35 July 12, 2024Amaranthus retroflexusCanada (Prince Edward Island) CanadaPrince Edward Island20237 PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
16Redroot Pigweed28274
36 July 8, 2024Chenopodium albumCanada (Prince Edward Island) CanadaPrince Edward Island20187 PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
47Common Lambsquarters28273
37 June 15, 2024Oryza sativa var. sylvaticaArgentinaArgentina 201848 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
242Red Rice27289
38 June 8, 2024Conyza bonariensisUruguayUruguay 202273 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
60Hairy Fleabane27291
39 June 6, 2024Cyperus difformisPortugalPortugal 202334 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
PSII inhibitors - Histidine 215 Binders HRAC Group 6 (Legacy C3)
71Smallflower Umbrella Sedge28270
40 May 24, 2024Bidens pilosaBrazilBrazil 20225 Inhibition of Protoporphyrinogen Oxidase HRAC Group 14 (Legacy E)
32Hairy Beggarticks27288
41 May 24, 2024Digitaria sanguinalisSwitzerlandSwitzerland 202141 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
77Large Crabgrass27290
42 May 24, 2024Amaranthus hybridus (syn: quitensis)South AfricaSouth Africa 202437 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
12Smooth Pigweed27287
43 May 19, 2024Glebionis segetumGreeceGreece 202119 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
2358Corn Marigold28272
44 May 4, 2024Echinochloa phyllopogon (=E. oryzicola)PortugalPortugal 202034 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)
178Late Watergrass28269
45 April 20, 2024Echinochloa phyllopogon (=E. oryzicola)PortugalPortugal 202034 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
178Late Watergrass28268
46 April 9, 2024Papaver rhoeasPortugalPortugal 201834 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Auxin Mimics HRAC Group 4 (Legacy O)
123Corn Poppy28267
47 March 25, 2024Chloris truncataSpainSpain 202338 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
262Windmill Grass27293
48 March 18, 2024Conyza canadensisUnited States (Oregon) United StatesOregon202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
61Horseweed27286
49 March 18, 2024Conyza bonariensisUnited States (Oregon) United StatesOregon202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
60Hairy Fleabane27285
50 March 18, 2024Amaranthus palmeriUnited States (Iowa) United StatesIowa202245 Multiple Resistance: 4 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
PSII inhibitors - Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
Inhibition of Hydroxyphenyl Pyruvate Dioxygenase HRAC Group 27 (Legacy F2)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth27284
51 March 5, 2024Papaver rhoeasPortugalPortugal 201834 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
123Corn Poppy28271
52 March 3, 2024Lolium perenne ssp. multiflorumPortugalPortugal 201934 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
110Italian Ryegrass28266
53 February 24, 2024Echinochloa crus-galli var. crus-galliPortugalPortugal 201834 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
79Barnyardgrass28265
54 February 20, 2024Echinochloa crus-galli var. crus-galliPortugalPortugal 201534 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
79Barnyardgrass28264
55 February 20, 2024Amaranthus palmeriSpainSpain 202338 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth27292
56 February 18, 2024Echinochloa phyllopogon (=E. oryzicola)PortugalPortugal 201534 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
178Late Watergrass27294
57 January 21, 2024Bromus diandrusNew ZealandNew Zealand 202430 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
197Ripgut Brome27283
58 November 19, 2023Avena sterilisSpainSpain 202338 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
29Sterile Oat27282
59 November 9, 2023Amaranthus tuberculatus (=A. rudis)United States (Idaho) United StatesIdaho202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
219Tall Waterhemp27264
60 November 3, 2023Amaranthus hybridus (syn: quitensis)ItalyItaly 201824 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
12Smooth Pigweed27281
61 October 30, 2023Amaranthus tuberculatus (=A. rudis)United States (Iowa) United StatesIowa202145 Auxin Mimics HRAC Group 4 (Legacy O)
219Tall Waterhemp27263
62 October 26, 2023Conyza bonariensisJordanJordan 202255 Multiple Resistance: 2 Sites of Action
PS I Electron Diversion HRAC Group 22 (Legacy D)
Inhibition of Protoporphyrinogen Oxidase HRAC Group 14 (Legacy E)
60Hairy Fleabane27269
63 October 25, 2023Echinochloa crus-galli var. crus-galliThailandThailand 202147 Inhibition of Cellulose Synthesis HRAC Group 29 (Legacy L)
79Barnyardgrass27275
64 October 18, 2023Poa annuaIrelandIreland 202181 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)
130Annual Bluegrass27262
65 September 26, 2023Monochoria vaginalisIndonesiaIndonesia 202222 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
202Arrowleafed Monochoria27274
66 September 14, 2023Ambrosia artemisiifoliaUkraineUkraine 2023230 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Protoporphyrinogen Oxidase HRAC Group 14 (Legacy E)
18Common Ragweed26266
67 September 5, 2023Echinochloa crus-galli var. crus-galliBrazilBrazil 20185 Multiple Resistance: 3 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Cellulose Synthesis HRAC Group 29 (Legacy L)
Auxin Mimics HRAC Group 4 (Legacy O)
79Barnyardgrass26265
68 September 5, 2023Bidens subalternansBrazilBrazil 20235 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
194Greater Beggarticks26263
69 September 5, 2023Sagittaria montevidensisBrazilBrazil 20235 Auxin Mimics HRAC Group 4 (Legacy O)
146California Arrowhead26264
70 August 28, 2023Bromus diandrusAustralia (Western Australia) AustraliaWestern Australia20201 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
197Ripgut Brome26262
71 August 5, 2023Panicum miliaceum var. ruderale Kitag.ChinaChina 20239 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
1359Wild Panicgrass27273
72 July 13, 2023Echinochloa crus-galli var. crus-galliIndiaIndia 201721 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
79Barnyardgrass25264
73 July 11, 2023Amaranthus palmeriUnited States (Colorado) United StatesColorado202145 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth25265
74 July 6, 2023Digitaria sanguinalisNew ZealandNew Zealand 202230 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
77Large Crabgrass25262
75 June 29, 2023Hordeum jubatumCanada (Alberta) CanadaAlberta20227 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
358Foxtail Barley25263
76 June 23, 2023Ammannia multifloraChinaChina 20229 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
1360Many Flowered Ammannia27279
77 June 8, 2023Galium spuriumGreeceGreece 202219 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
93False Cleavers27278
78 June 5, 2023Plantago lanceolataSouth AfricaSouth Africa 202237 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)
220Buckhorn Plantain27276
79 June 3, 2023Ambrosia artemisiifoliaUnited States (Michigan) United StatesMichigan202245 Auxin Mimics HRAC Group 4 (Legacy O)
18Common Ragweed27277
80 May 9, 2023Echinochloa oryzoidesArgentinaArgentina 201648 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
261Early Watergrass25261
81 May 9, 2023Poa annuaUnited States (Georgia) United StatesGeorgia202245 Inhibition of Cellulose Synthesis HRAC Group 29 (Legacy L)
130Annual Bluegrass25260
82 April 25, 2023Kochia scopariaCanada (Saskatchewan) CanadaSaskatchewan20217 Inhibition of Protoporphyrinogen Oxidase HRAC Group 14 (Legacy E)
101Kochia25259
83 April 24, 2023Bromus commutatusUnited KingdomUnited Kingdom 202044 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
357Meadow Brome25258
84 April 23, 2023Bromus sterilisUnited KingdomUnited Kingdom 202044 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
289Poverty Brome25257
85 April 23, 2023Bromus diandrusUnited KingdomUnited Kingdom 202044 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
197Ripgut Brome25256
86 April 4, 2023Lolium perenne ssp. multiflorumChinaChina 20229 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)
110Italian Ryegrass27266
87 March 30, 2023Digitaria ciliarisChinaChina 20219 Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
225Southern Crabgrass27272
88 March 15, 2023Amaranthus retroflexusUnited States (North Carolina) United StatesNorth Carolina202245 Multiple Resistance: 3 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Protoporphyrinogen Oxidase HRAC Group 14 (Legacy E)
Inhibition of Hydroxyphenyl Pyruvate Dioxygenase HRAC Group 27 (Legacy F2)
16Redroot Pigweed24259
89 March 15, 2023Amaranthus retroflexusUnited States (North Carolina) United StatesNorth Carolina202245 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
16Redroot Pigweed24258
90 March 12, 2023Echinochloa phyllopogon (=E. oryzicola)ChinaChina 20239 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
178Late Watergrass27267
91 March 11, 2023Ammannia auriculataChinaChina 20239 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
183Eared Redstem27280
92 March 8, 2023Cyperus esculentusItalyItaly 201724 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
290Yellow Nutsedge24256
93 February 16, 2023Stellaria mediaUnited States (California) United StatesCalifornia202245 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
168Common Chickweed24253
94 February 2, 2023Leptochloa chinensisChinaChina 20239 Inhibition of Hydroxyphenyl Pyruvate Dioxygenase HRAC Group 27 (Legacy F2)
223Chinese Sprangletop27268
95 January 31, 2023Amaranthus palmeriUruguayUruguay 202273 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth24254
96 January 31, 2023Amaranthus hybridus (syn: quitensis)UruguayUruguay 202273 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
12Smooth Pigweed24255
97 December 20, 2022Lolium perenne ssp. multiflorumUnited States (North Carolina) United StatesNorth Carolina202245 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)
PS I Electron Diversion HRAC Group 22 (Legacy D)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
110Italian Ryegrass24251
98 December 4, 2022Amaranthus hybridus (syn: quitensis)ParaguayParaguay 202246 Multiple Resistance: 2 Sites of Action
Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
12Smooth Pigweed24252
99 November 22, 2022Chenopodium albumUkraineUkraine 2022230 Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
47Common Lambsquarters24250
100 April 9, 2022Amaranthus palmeriUnited States (Idaho) United StatesIdaho202345 Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9 (Legacy G)
14Palmer Amaranth27265
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 25, 2025 .  Available  www.weedscience.org
Copyright © 1993- 2025 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.