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Herbicide Resistant Weeds in Michigan, United States.

#	ResistID		Year	Species	Country	StateName	State	MOAs	Site of Action	Actives	Contacts
1	5084	Common Lambsquarters	1975	Chenopodium album Common Lambsquarters	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine, metribuzin, simazine	James Kells, Chad Lee, Steven Gower
2	5180	Common Groundsel	1990	Senecio vulgaris Common Groundsel	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine	Donald Penner, Steven Gower
3	5181	Common Ragweed	1990	Ambrosia artemisiifolia Common Ragweed	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine	Donald Penner, Steven Gower
4	378	Common Purslane	1991	Portulaca oleracea Common Purslane	United States (Michigan)	Michigan	MI	PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine, linuron	Bernard Zandstra, Joseph G. Masabni, Steven Gower
5	505	Wild Carrot	1993	Daucus carota Wild Carrot	United States (Michigan)	Michigan	MI	Auxin Mimics (O/4)	Auxin Mimics (O/4)	2,4-D	James Kells, Jeff Stachler
6	1115	Common Ragweed	1998	Ambrosia artemisiifolia Common Ragweed	United States (Michigan)	Michigan	MI	Inhibition of Acetolactate Synthase (B/2)	Inhibition of Acetolactate Synthase (B/2)	cloransulam-methyl, imazamox, imazethapyr	Paul Schmitzer, Steven Gower
7	5179	Tall Waterhemp	2000	Amaranthus tuberculatus (=A. rudis) Tall Waterhemp	United States (Michigan)	Michigan		Inhibition of Acetolactate Synthase (B/2)	Inhibition of Acetolactate Synthase (B/2)	chlorimuron-ethyl, imazethapyr, thifensulfuron-methyl	Steven Gower
8	5176	Powell Amaranth	2001	Amaranthus powellii Powell Amaranth	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine, diuron	Steven Gower
9	5177	Redroot Pigweed	2001	Amaranthus retroflexus Redroot Pigweed	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine, diuron	Steven Gower
10	5178	Ladysthumb	2001	Polygonum persicaria Ladysthumb	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine, simazine	Steven Gower
11	5133	Common Lambsquarters	2001	Chenopodium album Common Lambsquarters	United States (Michigan)	Michigan		Inhibition of Acetolactate Synthase (B/2)	Inhibition of Acetolactate Synthase (B/2)	imazamox, thifensulfuron-methyl	Donald Penner, Steven Gower
12	5170	Smooth Pigweed	2002	Amaranthus hybridus (syn: quitensis) Smooth Pigweed	United States (Michigan)	Michigan		Inhibition of Acetolactate Synthase (B/2)	Inhibition of Acetolactate Synthase (B/2)	chlorimuron-ethyl, imazamox, thifensulfuron-methyl	Steven Gower
13	5172	Horseweed	2002	Conyza canadensis Horseweed	United States (Michigan)	Michigan		Inhibition of Acetolactate Synthase (B/2)	Inhibition of Acetolactate Synthase (B/2)	chlorimuron-ethyl, cloransulam-methyl	Steven Gower
14	5173	Horseweed	2002	Conyza canadensis Horseweed	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine, diuron, simazine	Steven Gower
15	5174	Horseweed	2002	Conyza canadensis Horseweed	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	diuron	Steven Gower
16	5291	Halberdleaf Orach	2003	Atriplex patula Halberdleaf Orach	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine	Steven Gower
17	5286	Eastern Black Nightshade	2004	Solanum ptycanthum Eastern Black Nightshade	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine	Steven Gower
18	5288	Lateflowering Goosefoot	2004	Chenopodium album var. striatum (=C. strictum var. glaucophyllum) Lateflowering Goosefoot	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine	Steven Gower
19	5289	Velvetleaf	2004	Abutilon theophrasti Velvetleaf	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	atrazine	Steven Gower
20	5287	Kochia	2005	Kochia scoparia Kochia	United States (Michigan)	Michigan		Inhibition of Acetolactate Synthase (B/2)	Inhibition of Acetolactate Synthase (B/2)	imazamox, triflusulfuron-methyl	Steven Gower
21	5290	Giant Foxtail	2006	Setaria faberi Giant Foxtail	United States (Michigan)	Michigan		Inhibition of Acetolactate Synthase (B/2)	Inhibition of Acetolactate Synthase (B/2)	foramsulfuron, imazethapyr, nicosulfuron	Steven Gower
22	5312	Horseweed	2007	Conyza canadensis Horseweed	United States (Michigan)	Michigan		Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)	Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)	glyphosate	Steven Gower
23	5557	Palmer Amaranth	2011	Amaranthus palmeri Palmer Amaranth	United States (Michigan)	Michigan		Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)	Inhibition of Enolpyruvyl Shikimate Phosphate Synthase (G/9)	glyphosate	Christy Sprague
24	5736	Prostrate Pigweed	2012	Amaranthus blitoides Prostrate Pigweed	United States (Michigan)	Michigan		PSII inhibitors - Serine 264 Binders (C1 C2/5)	PSII inhibitors - Serine 264 Binders (C1 C2/5)	terbacil	Bernard Zandstra, Rick Boydston (Retired)
25	17106	Common Ragweed	2016	Ambrosia artemisiifolia Common Ragweed	United States (Michigan)	Michigan		Inhibition of Acetolactate Synthase (B/2), Inhibition of Protoporphyrinogen Oxidase (E/14)	Multiple Resistance: 2 Sites of Action Inhibition of Acetolactate Synthase (B/2) Inhibition of Protoporphyrinogen Oxidase (E/14)	cloransulam-methyl, fomesafen	Erin Hill
26	27277	Common Ragweed	2022	Ambrosia artemisiifolia Common Ragweed	United States (Michigan)	Michigan		Auxin Mimics (O/4)	Auxin Mimics (O/4)	clopyralid	Erin Hill

Contributing Weed Scientists

Steven Gower

Michigan State University
Former Weed Science Diagnostician (Now with Monsanto)
Diagnostic Services
578 Wilson Rd.
East Lansing Michigan 48824
United States
Email: steven.a.gower@monsanto.com

Erin Hill

Michigan State University
Weed Science Diagnostician
Plant, Soil and Microbial Sciences
578 Wilson Rd.
East Lansing Michigan 48824
United States
Email: hiller12@msu.edu
URL: Website

James Kells

Michigan State University
Department Chairperson
Department of Plant, Soil, and Microbial Sciences
Plant and Soil Sciences Building 1066 Bogue Street, Room A286
East Lansing Michigan 48824
United States
Email: kells@msu.edu
URL: Website

Donald Penner

Michigan State University
Professor
Department of Plant, Soil and Microbial Sciences
A470 Plant and Soil Sciences Building
East Lansing Michigan 48824
United States
Email: pennerd@msu.edu
URL: Website

Christy Sprague

Michigan State University
Associate Professor
Department of Plant, Soil and Microbial Sciences
A466 Plant and Soil Sciences Building
East Lansing Michigan 48824-1325
United States
Email: sprague1@msu.edu
URL: Website

Bernard Zandstra

Michigan State University
Professor
Department of Horticulture
A440 Plant & Soil Sciences Building 1066 Bogue Street
East Lansing Michigan 48824-1325
United States
Email: zandstra@msu.edu
URL: Website

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