INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE
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 December 16, 2020Bromus rubensSpainSpain 201838 EPSP synthase inhibitors (G/9)
 		324Red Brome18210
2 November 26, 2020Bromus madritensisSpainSpain 201838 EPSP synthase inhibitors (G/9)
 		352Compact Brome18209
3 November 13, 2020Eleusine indicaItalyItaly 201924 EPSP synthase inhibitors (G/9)
 		81Goosegrass18208
4 October 20, 2020Amaranthus tuberculatus (=A. rudis)IsraelIsrael 201923 ALS inhibitors (B/2)
 		219Tall Waterhemp18207
5 October 7, 2020Amaranthus palmeriUnited States (Connecticut) United StatesConnecticut201945 Multiple Resistance: 2 Sites of Action
ALS inhibitors (B/2)
EPSP synthase inhibitors (G/9)
 		14Palmer Amaranth18206
6 October 1, 2020Apera spica-ventiBelgiumBelgium 20193 ALS inhibitors (B/2)
 		20Silky Windgrass18199
7 September 21, 2020Poa annuaNew ZealandNew Zealand 202030 ACCase inhibitors (A/1)
 		130Annual Bluegrass18203
8 September 10, 2020Avena fatuaIrelandIreland 201981 ACCase inhibitors (A/1)
 		28Wild Oat18200
9 July 3, 2020Conyza canadensisFranceFrance 201917 EPSP synthase inhibitors (G/9)
 		61Horseweed18198
10 June 22, 2020Chloris barbata = (C. inflate)MexicoMexico 201829 EPSP synthase inhibitors (G/9)
 		53Swollen Fingergrass18197
11 June 22, 2020Sorghum halepenseAustralia (Queensland) AustraliaQueensland20191 EPSP synthase inhibitors (G/9)
 		166Johnsongrass18193
12 June 22, 2020Hordeum murinum ssp. leporinumSpainSpain 201838 EPSP synthase inhibitors (G/9)
 		98Hare Barley18192
13 May 20, 2020Eleusine indicaUnited States (Alabama) United StatesAlabama201945 PSI Electron Diverter (D/22)
 		81Goosegrass18191
14 January 22, 2020Avena fatuaAustralia (Queensland) AustraliaQueensland20181 EPSP synthase inhibitors (G/9)
 		28Wild Oat18187
15 November 28, 2019Amaranthus hybridus (syn: quitensis)BrazilBrazil 20185 Multiple Resistance: 2 Sites of Action
ALS inhibitors (B/2)
EPSP synthase inhibitors (G/9)
 		12Smooth Pigweed18184
16 November 28, 2019Secale cerealeUnited States (Colorado) United StatesColorado201845 ALS inhibitors (B/2)
 		351Feral Rye18182
17 November 28, 2019Echinochloa crus-galli var. crus-galliArgentinaArgentina 201948 EPSP synthase inhibitors (G/9)
 		79Barnyardgrass18183
18 November 22, 2019Avena sterilis ssp. ludovicianaAustralia (New South Wales ) AustraliaNew South Wales 20181 EPSP synthase inhibitors (G/9)
 		30Sterile oat18186
19 October 24, 2019Capsella bursa-pastorisNorwayNorway 201931 ALS inhibitors (B/2)
 		41Shepherd's-purse18169
20 October 1, 2019Carduus acanthoidesArgentinaArgentina 201948 Multiple Resistance: 2 Sites of Action
EPSP synthase inhibitors (G/9)
Synthetic Auxins (O/4)
 		348Plumeless Thistle18173
21 September 24, 2019Oryza sativa var. sylvaticaColombiaColombia 201810 ALS inhibitors (B/2)
 		242Red Rice18170
22 September 2, 2019Rapistrum rugosumSpainSpain 201838 ALS inhibitors (B/2)
 		142Turnipweed18171
23 August 19, 2019Conyza sumatrensisTurkeyTurkey 201971 EPSP synthase inhibitors (G/9)
 		65Sumatran Fleabane18164
24 August 5, 2019Lithospermum arvenseChinaChina 20199 ALS inhibitors (B/2)
 		341Corn Gromwell18168
25 July 31, 2019Chloris radiataColombiaColombia 201910 EPSP synthase inhibitors (G/9)
 		340Radiate Fingergrass18165
26 May 13, 2019Galinsoga parvifloraFranceFrance 201817 ALS inhibitors (B/2)
 		339Gallant Soldier18162
27 May 13, 2019Conyza sumatrensisAustralia (Queensland) AustraliaQueensland20181 EPSP synthase inhibitors (G/9)
 		65Sumatran Fleabane18161
28 January 9, 2019Amaranthus palmeriUnited States (Kansas) United StatesKansas201845 Synthetic Auxins (O/4)
 		14Palmer Amaranth18151
29 December 15, 2018Lolium perenne ssp. multiflorumUnited States (Washington) United StatesWashington201845 Long chain fatty acid inhibitors (K3/15)
 		110Italian Ryegrass17154
30 December 15, 2018Lolium perenne ssp. multiflorumUnited KingdomUnited Kingdom 201844 Long chain fatty acid inhibitors (K3/15)
 		110Italian Ryegrass17153
31 December 15, 2018Lolium perenne ssp. multiflorumFranceFrance 201817 Long chain fatty acid inhibitors (K3/15)
 		110Italian Ryegrass17152
32 December 15, 2018Lolium perenne ssp. multiflorumUnited States (Oregon) United StatesOregon201845 Long chain fatty acid inhibitors (K3/15)
 		110Italian Ryegrass17151
33 November 9, 2018Bidens subalternansParaguayParaguay 201846 EPSP synthase inhibitors (G/9)
 		194Greater Beggarticks17150
34 October 10, 2018Conyza canadensisUnited States (Oklahoma) United StatesOklahoma201845 ALS inhibitors (B/2)
 		61Horseweed17149
35 October 2, 2018Conyza sumatrensisAustralia (Queensland) AustraliaQueensland20181 PSI Electron Diverter (D/22)
 		65Sumatran Fleabane17148
36 July 16, 2018Oryza sativa var. sylvaticaMalaysiaMalaysia 201828 ALS inhibitors (B/2)
 		242Red Rice17145
37 April 2, 2018Amaranthus palmeriUnited States (Oklahoma) United StatesOklahoma201845 EPSP synthase inhibitors (G/9)
 		14Palmer Amaranth17134

PERMISSION MUST BE OBTAINED FIRST if you intend to base a significant portion of a scientific paper on data derived from this site. Citation:
Heap, I.  The International Herbicide-Resistant Weed Database.  Online.  Friday, January 22, 2021 .  Available  www.weedscience.org Copyright © 1993- 2021 WeedScience.org All rights reserved. Fair use of this material is encouraged. Proper citation is requested.