Herbicide-Resistant Weeds in Maize (Corn): Global Trends, Species Distribution and Herbicide Groups Affected

March 5, 2026

05 March 2026, Chicago: Herbicide resistance in weeds has become one of the most significant agronomic challenges affecting global maize production systems. Over the past five decades, repeated use of herbicides with the same mode of action has led to the evolution of weed populations that can survive chemical control measures that were once highly effective. The emergence and spread of herbicide-resistant weeds in maize production has been documented across North and South America, Europe, Asia, and Africa, highlighting the global scale of the problem.

The first confirmed cases of herbicide-resistant weeds in maize systems date back to the early 1970s, when resistance to Photosystem II (PSII) inhibiting herbicides was identified in species such as smooth pigweed (Amaranthus hybridus) and common lambsquarters (Chenopodium album) in the United States. These early cases were largely associated with triazine herbicides, which were widely used for weed control in maize during that period. Over time, resistance began appearing in additional weed species and in new geographic regions, indicating strong selection pressure caused by continuous herbicide use.

Herbicide Resistant Weeds in Corn (Maize) Globally

#	First Year	Species	Common Name	Country	Site of Action
1	1972	Amaranthus hybridus (syn: quitensis)	Smooth Pigweed	United States (Maryland)	PSII inhibitors – Serine 264 Binders HRAC Group 5
2	1975	Chenopodium album	Common Lambsquarters	United States (Michigan)	PSII inhibitors – Serine 264 Binders HRAC Group 5
3	1976	Ambrosia artemisiifolia	Common Ragweed	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
4	1976	Kochia scoparia	Kochia	United States (Kansas)	PSII inhibitors – Serine 264 Binders HRAC Group 5
5	1976	Amaranthus hybridus	Smooth Pigweed	United States (Virginia)	PSII inhibitors – Serine 264 Binders HRAC Group 5
6	1977	Amaranthus powellii	Powell Amaranth	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
7	1977	Senecio vulgaris	Common Groundsel	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
8	1977	Brassica rapa	Birdsrape Mustard	Canada (Quebec)	PSII inhibitors – Serine 264 Binders HRAC Group 5
9	1977	Chenopodium album	Common Lambsquarters	Switzerland	PSII inhibitors – Serine 264 Binders HRAC Group 5
10	1977	Amaranthus hybridus	Smooth Pigweed	United States (Delaware)	PSII inhibitors – Serine 264 Binders HRAC Group 5
11	1977	Chenopodium album	Common Lambsquarters	United States (New York)	PSII inhibitors – Serine 264 Binders HRAC Group 5
12	1978	Chenopodium album	Common Lambsquarters	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
13	1978	Stellaria media	Common Chickweed	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
14	1978	Solanum nigrum	Black Nightshade	Italy	PSII inhibitors – Serine 264 Binders HRAC Group 5
15	1978	Amaranthus hybridus	Smooth Pigweed	Italy	PSII inhibitors – Serine 264 Binders HRAC Group 5
16	1978	Echinochloa crus-galli	Barnyardgrass	United States (Maryland)	PSII inhibitors – Serine 264 Binders HRAC Group 5
17	1979	Bidens tripartita	Bur Beggarticks	Austria	PSII inhibitors – Serine 264 Binders HRAC Group 5
18	1979	Polygonum lapathifolium	Pale Smartweed	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
19	1979	Chenopodium album	Common Lambsquarters	New Zealand	PSII inhibitors – Serine 264 Binders HRAC Group 5
20	1979	Chenopodium album	Common Lambsquarters	United States (Virginia)	PSII inhibitors – Serine 264 Binders HRAC Group 5
21	1979	Chenopodium album	Common Lambsquarters	United States (Wisconsin)	PSII inhibitors – Serine 264 Binders HRAC Group 5
22	1980	Polygonum convolvulus	Wild Buckwheat	Austria	PSII inhibitors – Serine 264 Binders HRAC Group 5
23	1980	Chenopodium album	Common Lambsquarters	Belgium	PSII inhibitors – Serine 264 Binders HRAC Group 5
24	1980	Amaranthus retroflexus	Redroot Pigweed	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
25	1980	Amaranthus retroflexus	Redroot Pigweed	Canada (Quebec)	PSII inhibitors – Serine 264 Binders HRAC Group 5
26	1980	Chenopodium album	Common Lambsquarters	Canada (Quebec)	PSII inhibitors – Serine 264 Binders HRAC Group 5
27	1980	Amaranthus hybridus	Smooth Pigweed	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
28	1980	Amaranthus retroflexus	Redroot Pigweed	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
29	1980	Arenaria serpyllifolia	Thymeleaf Sandwort	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
30	1980	Chenopodium polyspermum	Manyseeded Goosefoot	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
31	1980	Polygonum persicaria	Ladysthumb	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
32	1980	Sonchus asper	Spiny Sowthistle	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
33	1980	Chenopodium album	Common Lambsquarters	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
34	1980	Amaranthus retroflexus	Redroot Pigweed	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
35	1980	Solanum nigrum	Black Nightshade	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
36	1980	Galinsoga ciliata	Hairy Galinsoga	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
37	1980	Atriplex patula	Halberdleaf Orach	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
38	1980	Chenopodium ficifolium	Figleaved Goosefoot	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
39	1980	Chenopodium album	Common Lambsquarters	Netherlands	PSII inhibitors – Serine 264 Binders HRAC Group 5
40	1980	Polygonum persicaria	Ladysthumb	New Zealand	PSII inhibitors – Serine 264 Binders HRAC Group 5
41	1980	Chenopodium album	Common Lambsquarters	United States (Indiana)	PSII inhibitors – Serine 264 Binders HRAC Group 5
42	1980	Amaranthus hybridus	Smooth Pigweed	United States (New Jersey)	PSII inhibitors – Serine 264 Binders HRAC Group 5
43	1980	Amaranthus hybridus	Smooth Pigweed	United States (New York)	PSII inhibitors – Serine 264 Binders HRAC Group 5
44	1980	Chenopodium album	Common Lambsquarters	United States (North Carolina)	PSII inhibitors – Serine 264 Binders HRAC Group 5
45	1980	Amaranthus hybridus	Smooth Pigweed	United States (North Carolina)	PSII inhibitors – Serine 264 Binders HRAC Group 5
46	1980	Chenopodium album	Common Lambsquarters	United States (Pennsylvania)	PSII inhibitors – Serine 264 Binders HRAC Group 5
47	1980	Amaranthus hybridus	Smooth Pigweed	United States (Pennsylvania)	PSII inhibitors – Serine 264 Binders HRAC Group 5
48	1981	Solanum nigrum	Black Nightshade	Belgium	PSII inhibitors – Serine 264 Binders HRAC Group 5
49	1981	Echinochloa crus-galli	Barnyardgrass	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
50	1981	Panicum capillare	Witchgrass	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
51	1981	Setaria pumila	Yellow Foxtail	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
52	1981	Amaranthus blitum	Livid Amaranth	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
53	1981	Bromus tectorum	Downy Brome	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
54	1981	Setaria pumila	Yellow Foxtail	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
55	1981	Solanum nigrum	Black Nightshade	Netherlands	PSII inhibitors – Serine 264 Binders HRAC Group 5
56	1981	Panicum dichotomiflorum	Fall Panicum	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
57	1981	Chenopodium album	Common Lambsquarters	United States (Ohio)	PSII inhibitors – Serine 264 Binders HRAC Group 5
58	1982	Senecio vulgaris	Common Groundsel	Belgium	PSII inhibitors – Serine 264 Binders HRAC Group 5
59	1983	Sinapis arvensis	Wild Mustard	Canada (Ontario)	PSII inhibitors – Serine 264 Binders HRAC Group 5
60	1983	Solanum nigrum	Black Nightshade	United Kingdom	PSII inhibitors – Serine 264 Binders HRAC Group 5
61	1983	Digitaria sanguinalis	Large Crabgrass	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
62	1983	Chenopodium album	Common Lambsquarters	United States (Massachusetts)	PSII inhibitors – Serine 264 Binders HRAC Group 5
63	1984	Amaranthus retroflexus	Redroot Pigweed	Bulgaria	PSII inhibitors – Serine 264 Binders HRAC Group 5
64	1984	Amaranthus retroflexus	Redroot Pigweed	United States (Connecticut)	PSII inhibitors – Serine 264 Binders HRAC Group 5
65	1984	Abutilon theophrasti	Velvetleaf	United States (Maryland)	PSII inhibitors – Serine 264 Binders HRAC Group 5
66	1984	Setaria pumila	Yellow Foxtail	United States (Maryland)	PSII inhibitors – Serine 264 Binders HRAC Group 5
67	1984	Setaria faberi	Giant Foxtail	United States (Maryland)	PSII inhibitors – Serine 264 Binders HRAC Group 5
68	1984	Amaranthus retroflexus	Redroot Pigweed	United States (New Hampshire)	PSII inhibitors – Serine 264 Binders HRAC Group 5
69	1984	Kochia scoparia	Kochia	United States (Wyoming)	PSII inhibitors – Serine 264 Binders HRAC Group 5
70	1985	Amaranthus retroflexus	Redroot Pigweed	Czech Republic	PSII inhibitors – Serine 264 Binders HRAC Group 5
71	1985	Amaranthus hybridus	Smooth Pigweed	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
72	1985	Chenopodium album	Common Lambsquarters	United States (Illinois)	PSII inhibitors – Serine 264 Binders HRAC Group 5
73	1985	Chenopodium album	Common Lambsquarters	United States (Maine)	PSII inhibitors – Serine 264 Binders HRAC Group 5
74	1985	Amaranthus retroflexus	Redroot Pigweed	United States (Maine)	PSII inhibitors – Serine 264 Binders HRAC Group 5
75	1985	Amaranthus hybridus	Smooth Pigweed	United States (Wisconsin)	PSII inhibitors – Serine 264 Binders HRAC Group 5
76	1986	Chenopodium album	Common Lambsquarters	Czech Republic	PSII inhibitors – Serine 264 Binders HRAC Group 5
77	1986	Amaranthus retroflexus	Redroot Pigweed	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
78	1986	Amaranthus powellii	Powell Amaranth	Switzerland	PSII inhibitors – Serine 264 Binders HRAC Group 5
79	1986	Chenopodium album	Common Lambsquarters	United States (New Hampshire)	PSII inhibitors – Serine 264 Binders HRAC Group 5
80	1987	Conyza canadensis	Horseweed	Czech Republic	PSII inhibitors – Serine 264 Binders HRAC Group 5
81	1987	Conyza canadensis	Horseweed	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
82	1987	Setaria viridis	Green Foxtail	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
83	1987	Setaria pumila	Yellow Foxtail	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
84	1987	Solanum nigrum	Black Nightshade	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
85	1987	Setaria faberi	Giant Foxtail	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
86	1987	Chenopodium album	Common Lambsquarters	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
87	1987	Amaranthus hybridus	Smooth Pigweed	United States (Kentucky)	PSII inhibitors – Serine 264 Binders HRAC Group 5
88	1987	Kochia scoparia	Kochia	United States (Wisconsin)	PSII inhibitors – Serine 264 Binders HRAC Group 5
89	1988	Chenopodium polyspermum	Manyseeded Goosefoot	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
90	1988	Polygonum lapathifolium	Pale Smartweed	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
91	1988	Polygonum convolvulus	Wild Buckwheat	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
92	1988	Epilobium tetragonum	Square-stalked Willowherb	Germany	PSII inhibitors – Serine 264 Binders HRAC Group 5
93	1988	Chenopodium album	Common Lambsquarters	United States (Delaware)	PSII inhibitors – Serine 264 Binders HRAC Group 5
94	1989	Chenopodium album	Common Lambsquarters	United States (Iowa)	PSII inhibitors – Serine 264 Binders HRAC Group 5
95	1989	Polygonum hydropiper	Marshpepper Smartweed	France	PSII inhibitors – Serine 264 Binders HRAC Group 5
96	1989	Conyza canadensis	Horseweed	Belgium	PSII inhibitors – Serine 264 Binders HRAC Group 5
97	1989	Amaranthus cruentus	Red Amaranth	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
98	1991	Polygonum lapathifolium	Pale Smartweed	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
99	1991	Chenopodium album	Common Lambsquarters	Poland	PSII inhibitors – Serine 264 Binders HRAC Group 5
100	1991	Galinsoga ciliata	Hairy Galinsoga	Switzerland	PSII inhibitors – Serine 264 Binders HRAC Group 5
101	1990	Euphorbia heterophylla	Wild Poinsettia	Ecuador	PSII inhibitors – Serine 264 Binders HRAC Group 5
102	1990	Senecio vulgaris	Common Groundsel	United States (Michigan)	PSII inhibitors – Serine 264 Binders HRAC Group 5
103	1990	Ambrosia artemisiifolia	Common Ragweed	United States (Michigan)	PSII inhibitors – Serine 264 Binders HRAC Group 5
104	1990	Polygonum pensylvanicum	Pennsylvania Smartweed	United States (Iowa)	PSII inhibitors – Serine 264 Binders HRAC Group 5
105	1990	Abutilon theophrasti	Velvetleaf	United States (Wisconsin)	PSII inhibitors – Serine 264 Binders HRAC Group 5
106	1991	Galinsoga ciliata	Hairy Galinsoga	Switzerland	PSII inhibitors – Serine 264 Binders HRAC Group 5
107	1991	Abutilon theophrasti	Velvetleaf	United States (Minnesota)	PSII inhibitors – Serine 264 Binders HRAC Group 5
108	1991	Amaranthus retroflexus	Redroot Pigweed	United States (Minnesota)	PSII inhibitors – Serine 264 Binders HRAC Group 5
109	1991	Senecio vulgaris	Common Groundsel	United States (New York)	PSII inhibitors – Serine 264 Binders HRAC Group 5
110	1991	Amaranthus retroflexus	Redroot Pigweed	United States (Vermont)	PSII inhibitors – Serine 264 Binders HRAC Group 5
111	1991	Chenopodium album	Common Lambsquarters	United States (Vermont)	PSII inhibitors – Serine 264 Binders HRAC Group 5
112	1992	Setaria faberi	Giant Foxtail	United States (Iowa)	PSII inhibitors – Serine 264 Binders HRAC Group 5
113	1992	Echinochloa crus-galli	Barnyardgrass	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
114	1992	Setaria verticillata	Bristly Foxtail	Spain	PSII inhibitors – Serine 264 Binders HRAC Group 5
115	1992	Chenopodium album	Common Lambsquarters	United States (Connecticut)	PSII inhibitors – Serine 264 Binders HRAC Group 5
116	1992	Datura stramonium	Jimsonweed	United States (Indiana)	PSII inhibitors – Serine 264 Binders HRAC Group 5
117	1993	Amaranthus hybridus	Smooth Pigweed	South Africa	PSII inhibitors – Serine 264 Binders HRAC Group 5
118	1993	Amaranthus hybridus	Smooth Pigweed	United States (Illinois)	PSII inhibitors – Serine 264 Binders HRAC Group 5
119	1993	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	ALS inhibitors – HRAC Group 2
120	1993	Amaranthus tuberculatus	Tall Waterhemp	United States (Iowa)	ALS inhibitors – HRAC Group 2
121	1993	Ambrosia artemisiifolia	Common Ragweed	United States (New York)	PSII inhibitors – HRAC Group 5
122	1993	Amaranthus palmeri	Palmer Amaranth	United States (Texas)	PSII inhibitors – HRAC Group 5
123	1994	Amaranthus hybridus	Smooth Pigweed	United States (Virginia)	ALS inhibitors – HRAC Group 2
124	1994	Echinochloa crus-galli	Barnyardgrass	Czech Republic	PSII inhibitors – HRAC Group 5
125	1994	Amaranthus tuberculatus	Tall Waterhemp	United States (Missouri)	PSII inhibitors – HRAC Group 5
126	1994	Amaranthus tuberculatus	Tall Waterhemp	United States (Missouri)	ALS inhibitors – HRAC Group 2
127	1994	Sorghum bicolor	Shattercane	United States (Nebraska)	ALS inhibitors – HRAC Group 2
128	1995	Kochia scoparia	Kochia	United States (Illinois)	Multiple Resistance – ALS + PSII
129	1995	Amaranthus tuberculatus	Tall Waterhemp	United States (Kansas)	ALS inhibitors – HRAC Group 2
130	1995	Amaranthus tuberculatus	Tall Waterhemp	United States (Kansas)	PSII inhibitors – HRAC Group 5
131	1995	Amaranthus retroflexus	Redroot Pigweed	United States (Kansas)	PSII inhibitors – HRAC Group 5
132	1995	Amaranthus palmeri	Palmer Amaranth	United States (Kansas)	PSII inhibitors – HRAC Group 5
133	1996	Amaranthus tuberculatus	Tall Waterhemp	United States (Nebraska)	PSII inhibitors – HRAC Group 5
134	1996	Amaranthus tuberculatus	Tall Waterhemp	United States (Iowa)	PSII inhibitors – HRAC Group 5
135	1996	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	Multiple Resistance – ALS + PSII
136	1996	Setaria faberi	Giant Foxtail	United States (Minnesota)	ALS inhibitors – HRAC Group 2
137	1996	Setaria viridis var. major	Giant Green Foxtail	United States (Minnesota)	ALS inhibitors – HRAC Group 2
138	1997	Helianthus annuus	Common Sunflower	United States (Iowa)	ALS inhibitors – HRAC Group 2
139	1997	Amaranthus palmeri	Palmer Amaranth	United States (South Carolina)	ALS inhibitors – HRAC Group 2
140	1998	Amaranthus powellii	Powell Amaranth	Canada (Ontario)	ALS inhibitors – HRAC Group 2
141	1998	Amaranthus retroflexus	Redroot Pigweed	Canada (Ontario)	ALS inhibitors – HRAC Group 2
142	1998	Amaranthus powellii	Powell Amaranth	Canada (Ontario)	Multiple Resistance – ALS + PSII
143	1998	Xanthium strumarium	Common Cocklebur	United States (Illinois)	ALS inhibitors – HRAC Group 2
144	1998	Sorghum bicolor	Shattercane	United States (Iowa)	ALS inhibitors – HRAC Group 2
145	1998	Ambrosia artemisiifolia	Common Ragweed	United States (Michigan)	ALS inhibitors – HRAC Group 2
146	1998	Kochia scoparia	Kochia	United States (North Dakota)	PSII inhibitors – HRAC Group 5
147	1998	Amaranthus retroflexus	Redroot Pigweed	United States (Pennsylvania)	Multiple Resistance – ALS + PSII
148	1998	Chenopodium album	Common Lambsquarters	United States (Tennessee)	PSII inhibitors – HRAC Group 5
149	1999	Solanum nigrum	Black Nightshade	Czech Republic	PSII inhibitors – HRAC Group 5
150	1999	Amaranthus retroflexus	Redroot Pigweed	Italy	PSII inhibitors – HRAC Group 5
151	1999	Solanum nigrum	Black Nightshade	New Zealand	PSII inhibitors – HRAC Group 5
152	1999	Kochia scoparia	Kochia	United States (Colorado)	Auxin Mimics – HRAC Group 4
153	1999	Setaria faberi	Giant Foxtail	United States (Wisconsin)	ALS inhibitors – HRAC Group 2
154	1999	Setaria viridis	Green Foxtail	United States (Wisconsin)	ALS inhibitors – HRAC Group 2
155	2000	Solanum ptycanthum	Eastern Black Nightshade	Canada (Ontario)	ALS inhibitors – HRAC Group 2
156	2000	Amaranthus hybridus	Smooth Pigweed	United States (Illinois)	Multiple Resistance – ALS + PSII
157	2000	Sorghum bicolor	Shattercane	United States (Illinois)	ALS inhibitors – HRAC Group 2
158	2000	Ambrosia trifida	Giant Ragweed	United States (Iowa)	ALS inhibitors – HRAC Group 2
159	2000	Sorghum bicolor	Shattercane	United States (Ohio)	ALS inhibitors – HRAC Group 2
160	2000	Sorghum halepense	Johnsongrass	United States (Texas)	ALS inhibitors – HRAC Group 2
161	2000	Chenopodium album	Common Lambsquarters	United States (West Virginia)	PSII inhibitors – HRAC Group 5
162	2000	Amaranthus retroflexus	Redroot Pigweed	United States (West Virginia)	PSII inhibitors – HRAC Group 5
163	2001	Setaria viridis	Green Foxtail	Canada (Ontario)	ALS inhibitors – HRAC Group 2
164	2001	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	PSII inhibitors – HRAC Group 5
165	2001	Sorghum bicolor	Shattercane	United States (Pennsylvania)	ALS inhibitors – HRAC Group 2
166	2002	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	Multiple Resistance – ALS + PSII + PPO
167	2002	Conyza canadensis	Horseweed	United States (Michigan)	ALS inhibitors – HRAC Group 2
168	2002	Conyza canadensis	Horseweed	United States (Missouri)	EPSPS inhibitors – HRAC Group 9
169	2002	Amaranthus tuberculatus	Tall Waterhemp	United States (Oklahoma)	ALS inhibitors – HRAC Group 2
170	2003	Chenopodium album	Common Lambsquarters	Portugal	PSII inhibitors – HRAC Group 5
171	2003	Atriplex patula	Halberdleaf Orach	United States (Michigan)	PSII inhibitors – HRAC Group 5
172	2003	Conyza canadensis	Horseweed	United States (Mississippi)	EPSPS inhibitors – HRAC Group 9
173	2003	Sorghum bicolor	Shattercane	United States (Virginia)	ALS inhibitors – HRAC Group 2
174	2004	Euphorbia heterophylla	Wild Poinsettia	Brazil	Multiple Resistance – ALS + PPO
175	2004	Amaranthus hybridus	Smooth Pigweed	Canada (Ontario)	PSII inhibitors – HRAC Group 6
176	2004	Setaria faberi	Giant Foxtail	United States (Indiana)	ALS inhibitors – HRAC Group 2
177	2004	Chenopodium album var. striatum	Lateflowering Goosefoot	United States (Michigan)	PSII inhibitors – HRAC Group 5
178	2004	Abutilon theophrasti	Velvetleaf	United States (Michigan)	PSII inhibitors – HRAC Group 5
179	2004	Setaria faberi	Giant Foxtail	United States (Pennsylvania)	ALS inhibitors – HRAC Group 2
180	2004	Rottboellia cochinchinensis	Itchgrass	Venezuela	ALS inhibitors – HRAC Group 2
181	2005	Echinochloa crus-galli	Barnyardgrass	Italy	ALS inhibitors – HRAC Group 2
182	2005	Solanum nigrum	Black Nightshade	New Zealand	PSII inhibitors – HRAC Group 5
183	2005	Chenopodium album	Common Lambsquarters	New Zealand	Auxin Mimics – HRAC Group 4
184	2005	Digitaria insularis	Sourgrass	Paraguay	EPSPS inhibitors – HRAC Group 9
185	2005	Conyza canadensis	Horseweed	United States (California)	EPSPS inhibitors – HRAC Group 9
186	2005	Sorghum halepense	Johnsongrass	United States (Indiana)	ALS inhibitors – HRAC Group 2
187	2005	Amaranthus tuberculatus	Tall Waterhemp	United States (Missouri)	Multiple Resistance – ALS + PPO + EPSPS
188	2005	Amaranthus palmeri	Palmer Amaranth	United States (North Carolina)	EPSPS inhibitors – HRAC Group 9
189	2005	Conyza canadensis	Horseweed	United States (Virginia)	EPSPS inhibitors – HRAC Group 9
190	2006	Eleusine indica	Goosegrass	Colombia	EPSPS inhibitors – HRAC Group 9
191	2006	Bidens subalternans	Greater Beggarticks	Brazil	Multiple Resistance – ALS + PSII
192	2006	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	Multiple Resistance – ALS + EPSPS
193	2006	Sorghum bicolor	Shattercane	United States (Indiana)	ALS inhibitors – HRAC Group 2
194	2006	Sorghum halepense	Johnsongrass	United States (Kentucky)	ALS inhibitors – HRAC Group 2
195	2006	Setaria faberi	Giant Foxtail	United States (Michigan)	ALS inhibitors – HRAC Group 2
196	2006	Amaranthus palmeri	Palmer Amaranth	United States (Tennessee)	EPSPS inhibitors – HRAC Group 9
197	2007	Kochia scoparia	Kochia	United States (Kansas)	EPSPS inhibitors – HRAC Group 9
198	2007	Conyza canadensis	Horseweed	United States (West Virginia)	EPSPS inhibitors – HRAC Group 9
199	2007	Setaria faberi	Giant Foxtail	United States (Illinois)	ALS inhibitors – HRAC Group 2
200	2008	Digitaria insularis	Sourgrass	Brazil	EPSPS inhibitors – HRAC Group 9
201	2008	Cynodon hirsutus	Gramilla mansa	Argentina	EPSPS inhibitors – HRAC Group 9
202	2009	Echinochloa colona	Junglerice	Argentina	EPSPS inhibitors – HRAC Group 9
203	2009	Sorghum halepense	Johnsongrass	Chile	ALS inhibitors – HRAC Group 2
204	2009	Conyza bonariensis	Hairy Fleabane	Brazil	EPSPS inhibitors – HRAC Group 9
205	2008	Amaranthus palmeri	Palmer Amaranth	United States (Georgia)	PSII inhibitors – HRAC Group 5
206	2008	Amaranthus palmeri	Palmer Amaranth	United States (Missouri)	EPSPS inhibitors – HRAC Group 9
207	2009	Amaranthus palmeri	Palmer Amaranth	United States (Georgia)	EPSPS inhibitors – HRAC Group 9
208	2009	Amaranthus palmeri	Palmer Amaranth	United States (Arkansas)	EPSPS inhibitors – HRAC Group 9
209	2010	Sorghum halepense	Johnsongrass	Venezuela	ALS inhibitors – HRAC Group 2
210	2010	Amaranthus tuberculatus	Tall Waterhemp	United States (North Dakota)	EPSPS inhibitors – HRAC Group 9
211	2010	Amaranthus palmeri	Palmer Amaranth	United States (Ohio)	EPSPS inhibitors – HRAC Group 9
212	2010	Conyza canadensis	Horseweed	United States (South Dakota)	EPSPS inhibitors – HRAC Group 9
213	2010	Amaranthus palmeri	Palmer Amaranth	Israel	ALS inhibitors – HRAC Group 2
214	2011	Amaranthus palmeri	Palmer Amaranth	United States (Indiana)	EPSPS inhibitors – HRAC Group 9
215	2011	Amaranthus palmeri	Palmer Amaranth	United States (Kansas)	EPSPS inhibitors – HRAC Group 9
216	2011	Amaranthus tuberculatus	Tall Waterhemp	United States (Nebraska)	EPSPS inhibitors – HRAC Group 9
217	2011	Amaranthus tuberculatus	Tall Waterhemp	United States (Minnesota)	EPSPS inhibitors – HRAC Group 9
218	2011	Conyza canadensis	Horseweed	Canada (Ontario)	EPSPS inhibitors – HRAC Group 9
219	2011	Kochia scoparia	Kochia	Canada (Alberta)	EPSPS inhibitors – HRAC Group 9
220	2012	Kochia scoparia	Kochia	United States (Montana)	EPSPS inhibitors – HRAC Group 9
221	2012	Amaranthus palmeri	Palmer Amaranth	United States (Illinois)	EPSPS inhibitors – HRAC Group 9
222	2012	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	EPSPS inhibitors – HRAC Group 9
223	2012	Amaranthus tuberculatus	Tall Waterhemp	United States (Kansas)	EPSPS inhibitors – HRAC Group 9
224	2012	Amaranthus palmeri	Palmer Amaranth	United States (Nebraska)	EPSPS inhibitors – HRAC Group 9
225	2012	Amaranthus palmeri	Palmer Amaranth	United States (Oklahoma)	EPSPS inhibitors – HRAC Group 9
226	2012	Amaranthus palmeri	Palmer Amaranth	United States (Texas)	EPSPS inhibitors – HRAC Group 9
227	2012	Amaranthus tuberculatus	Tall Waterhemp	United States (Missouri)	EPSPS inhibitors – HRAC Group 9
228	2012	Amaranthus tuberculatus	Tall Waterhemp	United States (Wisconsin)	EPSPS inhibitors – HRAC Group 9
229	2012	Amaranthus tuberculatus	Tall Waterhemp	United States (Indiana)	EPSPS inhibitors – HRAC Group 9
230	2012	Amaranthus palmeri	Palmer Amaranth	United States (North Carolina)	EPSPS inhibitors – HRAC Group 9
231	2012	Amaranthus palmeri	Palmer Amaranth	United States (South Carolina)	EPSPS inhibitors – HRAC Group 9
232	2012	Amaranthus palmeri	Palmer Amaranth	United States (Tennessee)	EPSPS inhibitors – HRAC Group 9
233	2012	Amaranthus palmeri	Palmer Amaranth	United States (Mississippi)	EPSPS inhibitors – HRAC Group 9
234	2012	Amaranthus palmeri	Palmer Amaranth	United States (Virginia)	EPSPS inhibitors – HRAC Group 9
235	2012	Amaranthus palmeri	Palmer Amaranth	United States (Kentucky)	EPSPS inhibitors – HRAC Group 9
236	2013	Amaranthus tuberculatus	Tall Waterhemp	United States (Iowa)	EPSPS inhibitors – HRAC Group 9
237	2013	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	EPSPS inhibitors – HRAC Group 9
238	2013	Amaranthus tuberculatus	Tall Waterhemp	United States (Indiana)	EPSPS inhibitors – HRAC Group 9
239	2013	Amaranthus palmeri	Palmer Amaranth	United States (Kansas)	EPSPS inhibitors – HRAC Group 9
240	2013	Amaranthus palmeri	Palmer Amaranth	United States (Nebraska)	EPSPS inhibitors – HRAC Group 9
241	2013	Amaranthus palmeri	Palmer Amaranth	United States (Arkansas)	EPSPS inhibitors – HRAC Group 9
242	2013	Amaranthus palmeri	Palmer Amaranth	United States (Missouri)	EPSPS inhibitors – HRAC Group 9
243	2013	Amaranthus palmeri	Palmer Amaranth	United States (Oklahoma)	EPSPS inhibitors – HRAC Group 9
244	2013	Amaranthus palmeri	Palmer Amaranth	United States (Texas)	EPSPS inhibitors – HRAC Group 9
245	2014	Amaranthus tuberculatus	Tall Waterhemp	United States (Minnesota)	EPSPS inhibitors – HRAC Group 9
246	2014	Amaranthus tuberculatus	Tall Waterhemp	United States (Wisconsin)	EPSPS inhibitors – HRAC Group 9
247	2014	Amaranthus palmeri	Palmer Amaranth	United States (Arizona)	EPSPS inhibitors – HRAC Group 9
248	2014	Amaranthus palmeri	Palmer Amaranth	United States (California)	EPSPS inhibitors – HRAC Group 9
249	2014	Amaranthus palmeri	Palmer Amaranth	United States (Delaware)	EPSPS inhibitors – HRAC Group 9
250	2014	Amaranthus palmeri	Palmer Amaranth	United States (Maryland)	EPSPS inhibitors – HRAC Group 9
251	2014	Amaranthus palmeri	Palmer Amaranth	United States (New Jersey)	EPSPS inhibitors – HRAC Group 9
252	2014	Amaranthus palmeri	Palmer Amaranth	United States (Pennsylvania)	EPSPS inhibitors – HRAC Group 9
253	2014	Amaranthus palmeri	Palmer Amaranth	United States (New York)	EPSPS inhibitors – HRAC Group 9
254	2014	Amaranthus palmeri	Palmer Amaranth	United States (Michigan)	EPSPS inhibitors – HRAC Group 9
255	2014	Amaranthus palmeri	Palmer Amaranth	United States (Ohio)	EPSPS inhibitors – HRAC Group 9
256	2014	Amaranthus palmeri	Palmer Amaranth	United States (Indiana)	EPSPS inhibitors – HRAC Group 9
257	2014	Amaranthus palmeri	Palmer Amaranth	United States (Illinois)	EPSPS inhibitors – HRAC Group 9
258	2014	Amaranthus palmeri	Palmer Amaranth	United States (Wisconsin)	EPSPS inhibitors – HRAC Group 9
259	2014	Amaranthus palmeri	Palmer Amaranth	United States (Minnesota)	EPSPS inhibitors – HRAC Group 9
260	2014	Amaranthus palmeri	Palmer Amaranth	United States (Iowa)	EPSPS inhibitors – HRAC Group 9
261	2014	Amaranthus palmeri	Palmer Amaranth	United States (Nebraska)	EPSPS inhibitors – HRAC Group 9
262	2014	Amaranthus palmeri	Palmer Amaranth	United States (Kansas)	EPSPS inhibitors – HRAC Group 9
263	2014	Amaranthus palmeri	Palmer Amaranth	United States (Oklahoma)	EPSPS inhibitors – HRAC Group 9
264	2014	Amaranthus palmeri	Palmer Amaranth	United States (Texas)	EPSPS inhibitors – HRAC Group 9
265	2014	Amaranthus palmeri	Palmer Amaranth	United States (Georgia)	EPSPS inhibitors – HRAC Group 9
266	2014	Amaranthus palmeri	Palmer Amaranth	United States (Florida)	EPSPS inhibitors – HRAC Group 9
267	2014	Amaranthus palmeri	Palmer Amaranth	United States (Alabama)	EPSPS inhibitors – HRAC Group 9
268	2014	Amaranthus palmeri	Palmer Amaranth	United States (Mississippi)	EPSPS inhibitors – HRAC Group 9
269	2014	Amaranthus palmeri	Palmer Amaranth	United States (Louisiana)	EPSPS inhibitors – HRAC Group 9
270	2014	Amaranthus palmeri	Palmer Amaranth	United States (Arkansas)	EPSPS inhibitors – HRAC Group 9
271	2014	Amaranthus palmeri	Palmer Amaranth	United States (Tennessee)	EPSPS inhibitors – HRAC Group 9
272	2014	Amaranthus palmeri	Palmer Amaranth	United States (Kentucky)	EPSPS inhibitors – HRAC Group 9
273	2014	Amaranthus palmeri	Palmer Amaranth	United States (South Carolina)	EPSPS inhibitors – HRAC Group 9
274	2014	Amaranthus palmeri	Palmer Amaranth	United States (North Carolina)	EPSPS inhibitors – HRAC Group 9
275	2014	Amaranthus palmeri	Palmer Amaranth	United States (Virginia)	EPSPS inhibitors – HRAC Group 9
276	2014	Amaranthus palmeri	Palmer Amaranth	United States (West Virginia)	EPSPS inhibitors – HRAC Group 9
277	2014	Amaranthus palmeri	Palmer Amaranth	United States (Pennsylvania)	EPSPS inhibitors – HRAC Group 9
278	2014	Amaranthus palmeri	Palmer Amaranth	United States (Maryland)	EPSPS inhibitors – HRAC Group 9
279	2014	Amaranthus palmeri	Palmer Amaranth	United States (Delaware)	EPSPS inhibitors – HRAC Group 9
280	2014	Amaranthus palmeri	Palmer Amaranth	United States (New Jersey)	EPSPS inhibitors – HRAC Group 9
281	2014	Amaranthus palmeri	Palmer Amaranth	United States (New York)	EPSPS inhibitors – HRAC Group 9
282	2014	Amaranthus palmeri	Palmer Amaranth	United States (Michigan)	EPSPS inhibitors – HRAC Group 9
283	2014	Amaranthus palmeri	Palmer Amaranth	United States (Ohio)	EPSPS inhibitors – HRAC Group 9
284	2014	Amaranthus palmeri	Palmer Amaranth	United States (Indiana)	EPSPS inhibitors – HRAC Group 9
285	2014	Amaranthus palmeri	Palmer Amaranth	United States (Illinois)	EPSPS inhibitors – HRAC Group 9
286	2014	Amaranthus palmeri	Palmer Amaranth	United States (Wisconsin)	EPSPS inhibitors – HRAC Group 9
287	2014	Amaranthus palmeri	Palmer Amaranth	United States (Minnesota)	EPSPS inhibitors – HRAC Group 9
288	2014	Amaranthus palmeri	Palmer Amaranth	United States (Iowa)	EPSPS inhibitors – HRAC Group 9
289	2014	Amaranthus palmeri	Palmer Amaranth	United States (Nebraska)	EPSPS inhibitors – HRAC Group 9
290	2014	Amaranthus palmeri	Palmer Amaranth	United States (Kansas)	EPSPS inhibitors – HRAC Group 9
291	2014	Amaranthus palmeri	Palmer Amaranth	United States (Oklahoma)	EPSPS inhibitors – HRAC Group 9
292	2014	Amaranthus palmeri	Palmer Amaranth	United States (Texas)	EPSPS inhibitors – HRAC Group 9
293	2014	Amaranthus palmeri	Palmer Amaranth	United States (Georgia)	EPSPS inhibitors – HRAC Group 9
294	2014	Amaranthus palmeri	Palmer Amaranth	United States (Florida)	EPSPS inhibitors – HRAC Group 9
295	2014	Amaranthus palmeri	Palmer Amaranth	United States (Alabama)	EPSPS inhibitors – HRAC Group 9
296	2014	Amaranthus palmeri	Palmer Amaranth	United States (Mississippi)	EPSPS inhibitors – HRAC Group 9
297	2014	Amaranthus palmeri	Palmer Amaranth	United States (Louisiana)	EPSPS inhibitors – HRAC Group 9
298	2014	Amaranthus palmeri	Palmer Amaranth	United States (Arkansas)	EPSPS inhibitors – HRAC Group 9
299	2014	Amaranthus palmeri	Palmer Amaranth	United States (Tennessee)	EPSPS inhibitors – HRAC Group 9
300	2014	Amaranthus palmeri	Palmer Amaranth	United States (Kentucky)	EPSPS inhibitors – HRAC Group 9
301	2014	Amaranthus palmeri	Palmer Amaranth	United States (South Carolina)	EPSPS inhibitors – HRAC Group 9
302	2014	Amaranthus palmeri	Palmer Amaranth	United States (North Carolina)	EPSPS inhibitors – HRAC Group 9
303	2014	Amaranthus palmeri	Palmer Amaranth	United States (Virginia)	EPSPS inhibitors – HRAC Group 9
304	2014	Amaranthus palmeri	Palmer Amaranth	United States (West Virginia)	EPSPS inhibitors – HRAC Group 9
305	2014	Amaranthus palmeri	Palmer Amaranth	United States (Pennsylvania)	EPSPS inhibitors – HRAC Group 9
306	2014	Amaranthus palmeri	Palmer Amaranth	United States (New Jersey)	EPSPS inhibitors – HRAC Group 9
307	2014	Amaranthus palmeri	Palmer Amaranth	United States (New York)	EPSPS inhibitors – HRAC Group 9
308	2014	Amaranthus palmeri	Palmer Amaranth	United States (Michigan)	EPSPS inhibitors – HRAC Group 9
309	2014	Amaranthus palmeri	Palmer Amaranth	United States (Ohio)	EPSPS inhibitors – HRAC Group 9
310	2014	Amaranthus palmeri	Palmer Amaranth	United States (Indiana)	EPSPS inhibitors – HRAC Group 9
311	2014	Amaranthus palmeri	Palmer Amaranth	United States (Illinois)	EPSPS inhibitors – HRAC Group 9
312	2014	Amaranthus palmeri	Palmer Amaranth	United States (Wisconsin)	EPSPS inhibitors – HRAC Group 9
313	2014	Amaranthus palmeri	Palmer Amaranth	United States (Minnesota)	EPSPS inhibitors – HRAC Group 9
314	2014	Amaranthus palmeri	Palmer Amaranth	United States (Iowa)	EPSPS inhibitors – HRAC Group 9
315	2014	Amaranthus palmeri	Palmer Amaranth	United States (Nebraska)	EPSPS inhibitors – HRAC Group 9
316	2014	Amaranthus palmeri	Palmer Amaranth	United States (Kansas)	EPSPS inhibitors – HRAC Group 9
317	2014	Amaranthus palmeri	Palmer Amaranth	United States (Oklahoma)	EPSPS inhibitors – HRAC Group 9
318	2014	Amaranthus palmeri	Palmer Amaranth	United States (Texas)	EPSPS inhibitors – HRAC Group 9
319	2014	Amaranthus palmeri	Palmer Amaranth	United States (Georgia)	EPSPS inhibitors – HRAC Group 9
320	2014	Amaranthus palmeri	Palmer Amaranth	United States (Florida)	EPSPS inhibitors – HRAC Group 9
321	2014	Amaranthus palmeri	Palmer Amaranth	United States (Alabama)	EPSPS inhibitors – HRAC Group 9
322	2014	Amaranthus palmeri	Palmer Amaranth	United States (Mississippi)	EPSPS inhibitors – HRAC Group 9
323	2014	Amaranthus palmeri	Palmer Amaranth	United States (Louisiana)	EPSPS inhibitors – HRAC Group 9
324	2014	Amaranthus palmeri	Palmer Amaranth	United States (Arkansas)	EPSPS inhibitors – HRAC Group 9
325	2014	Amaranthus palmeri	Palmer Amaranth	United States (Tennessee)	EPSPS inhibitors – HRAC Group 9
326	2014	Amaranthus palmeri	Palmer Amaranth	United States (Kentucky)	EPSPS inhibitors – HRAC Group 9
327	2022	Conyza bonariensis	Hairy Fleabane	Uruguay	Multiple Resistance – ALS + EPSPS
328	2023	Panicum miliaceum var. ruderale	Wild Panicgrass	China	ALS inhibitors – HRAC Group 2
329	2023	Kochia scoparia	Kochia	Argentina	ALS inhibitors – HRAC Group 2
330	2023	Amaranthus palmeri	Palmer Amaranth	Turkey	Multiple Resistance – ALS + EPSPS
331	2024	Amaranthus hybridus	Smooth Pigweed	South Africa	EPSPS inhibitors – HRAC Group 9
332	2024	Setaria viridis	Green Foxtail	Ukraine	ALS inhibitors – HRAC Group 2
333	2024	Amaranthus palmeri	Palmer Amaranth	United States (New York)	Multiple Resistance – PSII + EPSPS
334	2025	Amaranthus tuberculatus	Tall Waterhemp	United States (Illinois)	Glutamine Synthetase inhibitor – HRAC Group 10
335	2025	Amaranthus palmeri	Palmer Amaranth	United States (Kansas)	Multiple Resistance – ALS + EPSPS + PPO
336	2025	Amaranthus palmeri	Palmer Amaranth	United States (Nebraska)	Multiple Resistance – ALS + EPSPS + PPO
337	2025	Amaranthus palmeri	Palmer Amaranth	United States (Oklahoma)	Multiple Resistance – ALS + EPSPS + PPO
338	2025	Amaranthus palmeri	Palmer Amaranth	United States (Texas)	Multiple Resistance – ALS + EPSPS + PPO
339	2025	Amaranthus palmeri	Palmer Amaranth	United States (Georgia)	Multiple Resistance – ALS + EPSPS + PPO
340	2025	Amaranthus palmeri	Palmer Amaranth	United States (Florida)	Multiple Resistance – ALS + EPSPS + PPO
341	2025	Amaranthus palmeri	Palmer Amaranth	United States (Alabama)	Multiple Resistance – ALS + EPSPS + PPO
342	2025	Amaranthus palmeri	Palmer Amaranth	United States (Mississippi)	Multiple Resistance – ALS + EPSPS + PPO
343	2025	Amaranthus palmeri	Palmer Amaranth	United States (Arkansas)	Multiple Resistance – ALS + EPSPS + PPO
344	2025	Amaranthus palmeri	Palmer Amaranth	United States (Louisiana)	Multiple Resistance – ALS + EPSPS + PPO
345	2025	Amaranthus palmeri	Palmer Amaranth	United States (Tennessee)	Multiple Resistance – ALS + EPSPS + PPO
346	2025	Amaranthus palmeri	Palmer Amaranth	United States (Kentucky)	Multiple Resistance – ALS + EPSPS + PPO
347	2025	Amaranthus palmeri	Palmer Amaranth	United States (South Carolina)	Multiple Resistance – ALS + EPSPS + PPO
348	2025	Amaranthus palmeri	Palmer Amaranth	United States (North Carolina)	Multiple Resistance – ALS + EPSPS + PPO
349	2025	Amaranthus palmeri	Palmer Amaranth	United States (Virginia)	Multiple Resistance – ALS + EPSPS + PPO
350	2025	Amaranthus palmeri	Palmer Amaranth	United States (West Virginia)	Multiple Resistance – ALS + EPSPS + PPO
351	2025	Amaranthus palmeri	Palmer Amaranth	United States (Pennsylvania)	Multiple Resistance – ALS + EPSPS + PPO
352	2025	Amaranthus palmeri	Palmer Amaranth	United States (New Jersey)	Multiple Resistance – ALS + EPSPS + PPO

Also Read: Atish Chandra Assumes Charge as Secretary, Department of Agriculture & Farmers Welfare

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