Herbicide-Resistant Weeds in Rice: Global Cases, Species, and Herbicide Modes of Action

05 March 2026, Chicago: Herbicide resistance has become one of the most serious challenges affecting rice production systems worldwide. Rice is cultivated across diverse agro-ecological regions, and effective weed control is essential because weeds compete aggressively with the crop for nutrients, water, sunlight, and space. When herbicides are repeatedly used with the same mode of action, certain weed populations evolve resistance, making them difficult or sometimes impossible to control with previously effective herbicides.

Globally, more than 190 cases of herbicide-resistant weeds have been reported in rice production systems. These cases span across Asia, the Americas, Europe, and Australia, demonstrating that herbicide resistance is not confined to a single region but represents a widespread agronomic issue.

The most frequently reported resistant weed species in rice fields include barnyardgrass (Echinochloa crus-galli), junglerice (Echinochloa colona), late watergrass (Echinochloa phyllopogon), smallflower umbrella sedge (Cyperus difformis), and red rice (Oryza sativa var. sylvatica). Among these, barnyardgrass is particularly problematic due to its biological similarity to rice, rapid growth, and high seed production.

Herbicide Modes of Action Affected

A large proportion of herbicide resistance in rice weeds involves herbicides that inhibit acetolactate synthase (ALS), which belongs to HRAC Group 2. These herbicides have been widely used because of their high efficacy and low application rates. However, repeated reliance on ALS inhibitors has accelerated the evolution of resistant weed populations.

Other herbicide groups where resistance has emerged include:

• Acetyl-CoA Carboxylase (ACCase) inhibitors – HRAC Group 1
• Photosystem II inhibitors – HRAC Groups 5 and 6
• Auxin mimics – HRAC Group 4
• Glyphosate (EPSPS inhibitors) – HRAC Group 9
• Very long-chain fatty acid synthesis inhibitors – HRAC Group 15
• Cellulose synthesis inhibitors – HRAC Group 26

In several cases, weeds have developed multiple resistance, meaning they are resistant to two or more herbicide modes of action simultaneously. This significantly limits chemical control options and increases the risk of yield losses.

Regional Trends

Asia, particularly China, Japan, South Korea, and Southeast Asia, has reported numerous cases of ALS-resistant aquatic and semi-aquatic weeds. Many of these weeds are broadleaf aquatic species that thrive in flooded rice systems.

In North and South America, resistance has been widely documented in grasses such as Echinochloa spp., particularly in the United States, Brazil, and Colombia. Multiple herbicide resistance has become increasingly common in these regions.

European rice systems, particularly in Italy, Greece, and Portugal, have also experienced significant resistance issues, largely involving barnyardgrass and aquatic sedges.

Implications for Rice Production

Herbicide-resistant weeds can cause severe yield reductions. In heavily infested rice fields, uncontrolled weeds may reduce yields by 30–80 percent, depending on weed density and the timing of infestation. Resistant weeds also increase production costs because farmers often need additional herbicide applications or alternative management practices.

To address this issue, integrated weed management strategies are becoming essential. These strategies include crop rotation, the use of herbicides with different modes of action, mechanical weed control, water management, and the adoption of competitive rice varieties.

Research institutions and agricultural extension systems are also focusing on monitoring resistance evolution and developing early detection systems to help farmers respond before resistant populations spread widely.

Global Chronology of Herbicide-Resistant Weeds in Rice

#	Species	Common Name	Country	First Year	Site of Action
1	Sphenoclea zeylanica	Gooseweed	Philippines	1983	Auxin Mimics HRAC Group 4 (Legacy O)
2	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Greece	1986	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
3	Echinochloa colona	Junglerice	Costa Rica	1987	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
4	Echinochloa colona	Junglerice	Colombia	1988	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
5	Fimbristylis miliacea	Globe Fringerush	Malaysia	1989	Auxin Mimics HRAC Group 4 (Legacy O)
6	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Arkansas)	1990	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
7	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Texas)	1991	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
8	Echinochloa crus-galli var. crus-galli	Barnyardgrass	China	1993	Very Long-Chain Fatty Acid Synthesis inhibitors HRAC Group 15 (Legacy K3 N)
9	Echinochloa crus-galli var. crus-galli	Barnyardgrass	China	1993	Very Long-Chain Fatty Acid Synthesis inhibitors HRAC Group 15 (Legacy K3 N)
10	Sagittaria montevidensis	California Arrowhead	United States (California)	1993	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
11	Cyperus difformis	Smallflower Umbrella Sedge	United States (California)	1993	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
12	Cyperus difformis	Smallflower Umbrella Sedge	Australia (New South Wales)	1994	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
13	Sagittaria montevidensis	California Arrowhead	Australia (New South Wales)	1994	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
14	Damasonium minus	Starfruit	Australia (New South Wales)	1994	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
15	Echinochloa colona	Junglerice	Costa Rica	1994	Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
16	Alisma plantago-aquatica	Common Waterplantain	Italy	1994	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
17	Monochoria korsakowii	Mizuaoi	Japan	1994	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
18	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Missouri)	1994	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
19	Limnocharis flava	Sawah Flowering Rush	Indonesia	1995	Auxin Mimics HRAC Group 4 (Legacy O)
20	Schoenoplectus mucronatus	Ricefield Bulrush	Italy	1995	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
21	Sphenoclea zeylanica	Gooseweed	Malaysia	1995	Auxin Mimics HRAC Group 4 (Legacy O)
22	Lindernia dubia	Low False-pimpernel	Japan	1995	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
23	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Louisiana)	1995	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
24	Alisma plantago-aquatica	Common Waterplantain	Portugal	1995	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
25	Limnophila sessiliflora	Limnophila	Japan	1996	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
26	Lindernia procumbens	Common False-pimpernel	Japan	1996	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
27	Lindernia micrantha	Azetogarashi	Japan	1996	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
28	Schoenoplectus juncoides	Rock Bulrush	Japan	1996	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
29	Elatine triandra var. pedicellata	Mizohakobe	Japan	1997	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
30	Rotala indica var. uliginosa	Kikashigusa	Japan	1997	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
31	Sagittaria trifolia	Threeleaf Arrowhead	Japan	1997	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
32	Ammannia auriculata	Eared Redstem	United States (California)	1997	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
33	Schoenoplectus mucronatus	Ricefield Bulrush	United States (California)	1997	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
34	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Sri Lanka	1997	PSII inhibitors – Serine 264 Binders HRAC Group 5 (Legacy C1 C2)
35	Echinochloa colona	Junglerice	Costa Rica	1998	Multiple Resistance: ACCase + ALS + PSII inhibitors
36	Monochoria vaginalis	Arrowleafed Monochoria	Japan	1998	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
37	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	United States (California)	1998	Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
38	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	United States (California)	1998	Very Long-Chain Fatty Acid Synthesis inhibitors HRAC Group 15
39	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Thailand	1998	Multiple Resistance: PSII + VLCFA inhibitors
40	Limnocharis flava	Sawah Flowering Rush	Malaysia	1998	Multiple Resistance: ALS + Auxin Mimics
41	Sagittaria montevidensis	California Arrowhead	Brazil	1999	Inhibition of Acetolactate Synthase HRAC Group 2
42	Echinochloa crus-pavonis	Gulf Cockspur	Brazil	1999	Auxin Mimics HRAC Group 4
43	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Brazil	1999	Auxin Mimics HRAC Group 4
44	Cyperus difformis	Smallflower Umbrella Sedge	Italy	1999	Inhibition of Acetolactate Synthase HRAC Group 2
45	Echinochloa colona	Junglerice	El Salvador	1999	PSII inhibitors HRAC Group 5
46	Echinochloa colona	Junglerice	Guatemala	1999	PSII inhibitors HRAC Group 5
47	Echinochloa colona	Junglerice	Honduras	1999	PSII inhibitors HRAC Group 5
48	Echinochloa colona	Junglerice	Panama	1999	PSII inhibitors HRAC Group 5
49	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Arkansas)	1999	Multiple Resistance: PSII + Auxin Mimics
50	Monochoria vaginalis	Arrowleafed Monochoria	South Korea	1999	Inhibition of Acetolactate Synthase HRAC Group 2
51	Echinochloa crus-galli var. crus-galli	Barnyardgrass	China	2000	Auxin Mimics HRAC Group 4
52	Cyperus difformis	Smallflower Umbrella Sedge	Brazil	2000	Inhibition of Acetolactate Synthase HRAC Group 2
53	Echinochloa colona	Junglerice	Colombia	2000	Auxin Mimics HRAC Group 4
54	Ischaemum rugosum	Saramollagrass	Colombia	2000	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
55	Sagittaria guayanensis	Guyanese Arrowhead	Malaysia	2000	Inhibition of Acetolactate Synthase HRAC Group 2
56	Bacopa rotundifolia	Disc Waterhyssop	Malaysia	2000	Inhibition of Acetolactate Synthase HRAC Group 2
57	Schoenoplectus wallichii	Taiwan-yamai	Japan	2000	Inhibition of Acetolactate Synthase HRAC Group 2
58	Ammannia coccinea	Redstem	United States (California)	2000	Inhibition of Acetolactate Synthase HRAC Group 2
59	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Italy	2000	PSII inhibitors HRAC Group 5
60	Alisma plantago-aquatica	Common Waterplantain	Spain	2000	Inhibition of Acetolactate Synthase HRAC Group 2
61	Sphenoclea zeylanica	Gooseweed	Thailand	2000	Auxin Mimics HRAC Group 4
62	Leptochloa panicoides	Amazon Sprangletop	United States (Louisiana)	2000	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
63	Fimbristylis miliacea	Globe Fringerush	Brazil	2001	Inhibition of Acetolactate Synthase HRAC Group 2
64	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Thailand	2001	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
65	Schoenoplectus juncoides	Rock Bulrush	South Korea	2001	Inhibition of Acetolactate Synthase HRAC Group 2
66	Leptochloa chinensis	Chinese Sprangletop	Thailand	2002	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
67	Lindernia dubia	Low False-pimpernel	South Korea	2000	Inhibition of Acetolactate Synthase HRAC Group 2
68	Oryza sativa var. sylvatica	Red Rice	United States (Arkansas)	2002	Inhibition of Acetolactate Synthase HRAC Group 2
69	Digitaria ischaemum	Smooth Crabgrass	United States (California)	2002	Auxin Mimics HRAC Group 4
70	Cyperus difformis	Smallflower Umbrella Sedge	South Korea	2002	Inhibition of Acetolactate Synthase HRAC Group 2
71	Limnophila erecta	Marshweed	Malaysia	2002	Multiple Resistance: ALS + Auxin Mimics
72	Conyza canadensis	Horseweed	United States (Mississippi)	2003	Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9
73	Monochoria korsakowii	Mizuaoi	China	2003	Inhibition of Acetolactate Synthase HRAC Group 2
74	Sagittaria montevidensis	California Arrowhead	China	2003	Inhibition of Acetolactate Synthase HRAC Group 2
75	Echinochloa erecta	Pollacci Barnyardgrass	Italy	2004	Multiple Resistance: PSII inhibitors + Cellulose synthesis inhibitors
76	Echinochloa erecta	Pollacci Barnyardgrass	Italy	2005	PSII inhibitors
77	Eleusine indica	Goosegrass	Bolivia	2005	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
78	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Philippines	2005	Multiple Resistance: PSII inhibitors + VLCFA inhibitors
79	Alisma plantago-aquatica	Common Waterplantain	Chile	2005	Inhibition of Acetolactate Synthase HRAC Group 2
80	Schoenoplectus mucronatus	Ricefield Bulrush	Chile	2005	Inhibition of Acetolactate Synthase HRAC Group 2
81	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Italy	2005	Inhibition of Acetolactate Synthase HRAC Group 2
82	Ischaemum rugosum	Saramollagrass	Venezuela	2004	Multiple Resistance: ACCase + ALS + PSII inhibitors
83	Ammannia coccinea	Redstem	Japan	2004	Inhibition of Acetolactate Synthase HRAC Group 2
84	Sagittaria pygmaea	Dwarf Arrowhead	Japan	2006	Inhibition of Acetolactate Synthase HRAC Group 2
85	Leptochloa chinensis	Chinese Sprangletop	Malaysia	2006	PSII inhibitors HRAC Group 5
86	Echinochloa colona	Junglerice	Bolivia	2006	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
87	Echinochloa colona	Junglerice	Bolivia	2006	Inhibition of Acetolactate Synthase HRAC Group 2
88	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	South Korea	2006	Multiple Resistance: ACCase + ALS inhibitors
89	Eleocharis acicularis	Needle Spikerush	South Korea	2006	Inhibition of Acetolactate Synthase HRAC Group 2
90	Blyxa aubertii	Roundfruit Blyxa	South Korea	2006	Inhibition of Acetolactate Synthase HRAC Group 2
91	Alisma canaliculatum	Hera-omodaka	Japan	2007	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
92	Rotala pusilla	Mizu-matsuba	Japan	2007	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
93	Dopatrium junceum	Dopatrium	Japan	2007	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
94	Bacopa rotundifolia	Disc Waterhyssop	Japan	2007	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
95	Eleocharis acicularis	Needle Spikerush	Japan	2008	Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
96	Echinochloa crus-galli var. formosensis	Taiwan barnyardgrass	Japan	2009	Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
97	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Japan	2010	Inhibition of Acetyl CoA Carboxylase HRAC Group 1 (Legacy A)
98	Echinochloa crus-galli var. formosensis	Taiwan barnyardgrass	Japan	2010	Multiple Resistance: ACCase + ALS inhibitors
99	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Egypt	2009	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
100	Cyperus difformis	Smallflower Umbrella Sedge	Greece	2009	Inhibition of Acetolactate Synthase HRAC Group 2
101	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	Greece	2009	Inhibition of Acetolactate Synthase HRAC Group 2
102	Echinochloa crus-galli var. crus-galli	Barnyardgrass	France	2013	Inhibition of Acetolactate Synthase HRAC Group 2
103	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	France	2013	Inhibition of Acetolactate Synthase HRAC Group 2
104	Oryza sativa var. sylvatica	Red Rice	Greece	2013	Inhibition of Acetolactate Synthase HRAC Group 2
105	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Uruguay	2013	Auxin Mimics HRAC Group 4
106	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Uruguay	2013	Inhibition of Acetolactate Synthase HRAC Group 2
107	Echinochloa colona	Junglerice	Costa Rica	2013	Multiple Resistance: ACCase + ALS inhibitors
108	Echinochloa colona	Junglerice	Colombia	2016	Multiple Resistance: ACCase + ALS + Cellulose inhibitors
109	Cyperus iria	Rice Flatsedge	Brazil	2014	Inhibition of Acetolactate Synthase HRAC Group 2
110	Cyperus difformis	Smallflower Umbrella Sedge	Turkey	2010	Inhibition of Acetolactate Synthase HRAC Group 2
111	Echinochloa colona	Junglerice	Egypt	2012	Inhibition of Acetolactate Synthase HRAC Group 2
112	Leptochloa chinensis	Chinese Sprangletop	South Korea	2012	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
113	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Italy	2011	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
114	Leptochloa chinensis	Chinese Sprangletop	China	2011	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
115	Echinochloa crus-galli var. crus-galli	Barnyardgrass	China	2011	Inhibition of Acetolactate Synthase HRAC Group 2
116	Ludwigia prostrata	False Loosestrife	South Korea	2011	Inhibition of Acetolactate Synthase HRAC Group 2
117	Sagittaria trifolia	Threeleaf Arrowhead	South Korea	2011	Inhibition of Acetolactate Synthase HRAC Group 2
118	Cyperus iria	Rice Flatsedge	United States (Arkansas)	2010	Inhibition of Acetolactate Synthase HRAC Group 2
119	Cyperus difformis	Smallflower Umbrella Sedge	United States (Arkansas)	2010	Inhibition of Acetolactate Synthase HRAC Group 2
120	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Thailand	2021	Inhibition of Cellulose Synthesis HRAC Group 26
121	Cyperus esculentus	Yellow Nutsedge	Italy	2017	Inhibition of Acetolactate Synthase HRAC Group 2
122	Echinochloa crus-galli var. crus-galli	Barnyardgrass	India	2017	Inhibition of Acetolactate Synthase HRAC Group 2
123	Cyperus difformis	Smallflower Umbrella Sedge	India	2017	Inhibition of Acetolactate Synthase HRAC Group 2
124	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Viet Nam	2017	Multiple Resistance: ALS + Cellulose inhibitors
125	Oryza sativa var. sylvatica	Red Rice	Argentina	2018	Inhibition of Acetolactate Synthase HRAC Group 2
126	Oryza sativa var. sylvatica	Red Rice	Colombia	2018	Inhibition of Acetolactate Synthase HRAC Group 2
127	Oryza sativa var. sylvatica	Red Rice	Malaysia	2018	Inhibition of Acetolactate Synthase HRAC Group 2
128	Chloris radiata	Radiate Fingergrass	Colombia	2019	Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9
129	Polygonum pensylvanicum	Pennsylvania Smartweed	United States (Arkansas)	2020	Inhibition of Acetolactate Synthase HRAC Group 2
130	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	Portugal	2020	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
131	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	Portugal	2020	Multiple Resistance: ACCase + ALS inhibitors
132	Digitaria ciliaris	Southern Crabgrass	China	2021	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
133	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Australia	2021	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
134	Monochoria vaginalis	Arrowleafed Monochoria	Indonesia	2022	Inhibition of Acetolactate Synthase HRAC Group 2
135	Ammannia multiflora	Many Flowered Ammannia	China	2022	Inhibition of Acetolactate Synthase HRAC Group 2
136	Sagittaria montevidensis	California Arrowhead	Brazil	2023	Auxin Mimics HRAC Group 4
137	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	China	2023	Inhibition of Acetolactate Synthase HRAC Group 2
138	Cyperus difformis	Smallflower Umbrella Sedge	Portugal	2023	Multiple Resistance: ALS + PSII inhibitors
139	Steinchisma laxum	Lax Panicgrass	Colombia	2023	Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9
140	Schoenoplectus juncoides	Rock Bulrush	China	2024	Inhibition of Acetolactate Synthase HRAC Group 2
141	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Brazil	2009	Multiple Resistance: Inhibition of Acetolactate Synthase HRAC Group 2 + Auxin Mimics HRAC Group 4
142	Sagittaria montevidensis	California Arrowhead	Brazil	2009	Multiple Resistance: Inhibition of Acetolactate Synthase HRAC Group 2 + PSII inhibitors HRAC Group 6
143	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Brazil	2015	Multiple Resistance: ACCase + ALS + Cellulose Synthesis inhibitors
144	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Brazil	2018	Multiple Resistance: ALS + Cellulose + Auxin Mimics
145	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Turkey	2009	Multiple Resistance: ACCase + ALS inhibitors
146	Echinochloa oryzoides	Early Watergrass	Turkey	2009	Multiple Resistance: ACCase + ALS inhibitors
147	Oryza sativa var. sylvatica	Red Rice	Turkey	2020	Inhibition of Acetolactate Synthase HRAC Group 2
148	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Ukraine	2017	Inhibition of Acetolactate Synthase HRAC Group 2
149	Cyperus esculentus	Yellow Nutsedge	United States (Arkansas)	2013	Inhibition of Acetolactate Synthase HRAC Group 2
150	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Arkansas)	2008	Inhibition of Deoxy-D-Xylulose Phosphate Synthase HRAC Group 13
151	Echinochloa colona	Junglerice	United States (Arkansas)	2011	Multiple Resistance: ALS + PSII + Cellulose inhibitors
152	Cyperus iria	Rice Flatsedge	United States (Louisiana)	2013	Inhibition of Acetolactate Synthase HRAC Group 2
153	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Louisiana)	2013	Inhibition of Acetolactate Synthase HRAC Group 2
154	Leptochloa fusca spp. fascicularis	Bearded Sprangletop	United States (California)	2020	Inhibition of Deoxy-D-Xylulose Phosphate Synthase HRAC Group 13
155	Cyperus difformis	Smallflower Umbrella Sedge	United States (California)	2013	PSII inhibitors HRAC Group 5
156	Schoenoplectus mucronatus	Ricefield Bulrush	United States (California)	2014	PSII inhibitors HRAC Group 5
157	Echinochloa colona	Junglerice	Venezuela	2000	PSII inhibitors HRAC Group 5
158	Ischaemum rugosum	Saramollagrass	Venezuela	2004	Multiple Resistance: ACCase + ALS + PSII inhibitors
159	Echinochloa colona	Junglerice	Venezuela	2008	Multiple Resistance: ACCase + EPSPS inhibitors
160	Fimbristylis miliacea	Globe Fringerush	Venezuela	2010	Inhibition of Acetolactate Synthase HRAC Group 2
161	Echinochloa colona	Junglerice	Venezuela	2010	Multiple Resistance: ACCase + ALS + PSII inhibitors
162	Leptochloa scabra	Rough Sprangletop	Venezuela	2013	PSII inhibitors HRAC Group 5
163	Cyperus odoratus	Fragrant Flatsedge	Venezuela	2014	Inhibition of Acetolactate Synthase HRAC Group 2
164	Cyperus iria	Rice Flatsedge	Venezuela	2015	Inhibition of Acetolactate Synthase HRAC Group 2
165	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (California)	2000	Multiple Resistance: Inhibition of Acetyl CoA Carboxylase HRAC Group 1 + Very Long-Chain Fatty Acid Synthesis inhibitors HRAC Group 15
166	Echinochloa phyllopogon (=E. oryzicola)	Late Watergrass	United States (California)	2000	Multiple Resistance: Inhibition of Acetyl CoA Carboxylase HRAC Group 1 + Very Long-Chain Fatty Acid Synthesis inhibitors HRAC Group 15
167	Echinochloa oryzoides	Early Watergrass	United States (California)	2000	Very Long-Chain Fatty Acid Synthesis inhibitors HRAC Group 15
168	Digitaria ischaemum	Smooth Crabgrass	United States (California)	2002	Auxin Mimics HRAC Group 4
169	Cyperus difformis	Smallflower Umbrella Sedge	United States (California)	2013	PSII inhibitors – Serine 264 Binders HRAC Group 5
170	Schoenoplectus mucronatus (=Scirpus mucronatus)	Ricefield Bulrush	United States (California)	2014	PSII inhibitors – Serine 264 Binders HRAC Group 5
171	Leptochloa fusca spp. fascicularis	Bearded Sprangletop	United States (California)	2020	Inhibition of Deoxy-D-Xylulose Phosphate Synthase HRAC Group 13
172	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Louisiana)	1998	Auxin Mimics HRAC Group 4
173	Leptochloa panicoides	Amazon Sprangletop	United States (Louisiana)	2009	Inhibition of Acetyl CoA Carboxylase HRAC Group 1
174	Cyperus iria	Rice Flatsedge	United States (Louisiana)	2013	Inhibition of Acetolactate Synthase HRAC Group 2
175	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Louisiana)	2013	Inhibition of Acetolactate Synthase HRAC Group 2
176	Conyza canadensis	Horseweed	United States (Mississippi)	2003	Inhibition of Enolpyruvyl Shikimate Phosphate Synthase HRAC Group 9
177	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Mississippi)	2011	Multiple Resistance: ACCase + ALS + PSII + Cellulose inhibitors
178	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Missouri)	1994	PSII inhibitors – Serine 264 Binders HRAC Group 5
179	Echinochloa crus-galli var. crus-galli	Barnyardgrass	United States (Texas)	1991	PSII inhibitors – Serine 264 Binders HRAC Group 5
180	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Uruguay	2013	Auxin Mimics HRAC Group 4
181	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Uruguay	2013	Inhibition of Acetolactate Synthase HRAC Group 2
182	Echinochloa colona	Junglerice	Venezuela	2000	PSII inhibitors – Serine 264 Binders HRAC Group 5
183	Ischaemum rugosum	Saramollagrass	Venezuela	2004	Multiple Resistance: ACCase + ALS + PSII inhibitors
184	Echinochloa colona	Junglerice	Venezuela	2008	Multiple Resistance: ACCase + EPSPS inhibitors
185	Fimbristylis miliacea	Globe Fringerush	Venezuela	2010	Inhibition of Acetolactate Synthase HRAC Group 2
186	Echinochloa colona	Junglerice	Venezuela	2010	Multiple Resistance: ACCase + ALS + PSII inhibitors
187	Leptochloa scabra	Rough Sprangletop	Venezuela	2013	PSII inhibitors – Serine 264 Binders HRAC Group 5
188	Cyperus odoratus	Fragrant Flatsedge	Venezuela	2014	Inhibition of Acetolactate Synthase HRAC Group 2
189	Cyperus iria	Rice Flatsedge	Venezuela	2015	Inhibition of Acetolactate Synthase HRAC Group 2
190	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Viet Nam	2017	Multiple Resistance: ALS + Cellulose synthesis inhibitors
193	Echinochloa crus-galli var. crus-galli	Barnyardgrass	Viet Nam	2017	Multiple Resistance: Inhibition of Acetolactate Synthase HRAC Group 2 + Inhibition of Cellulose Synthesis HRAC Group 26
191	Echinochloa colona	Junglerice	Pakistan	2024	Inhibition of Acetolactate Synthase HRAC Group 2
192	Ischaemum rugosum	Saramollagrass	Brazil	2024	Inhibition of Acetolactate Synthase HRAC Group 2
194	Echinochloa crus-pavonis	Gulf Cockspur	China	2024	Auxin Mimics HRAC Group 4 (Legacy O)

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