Herbicide-resistant weed species grouped by MOA
For the Mid-Atlantic and Northeast grouped by herbicide mode of action (MOA)
Certain populations of these weed species have evolved the ability to survive herbicide applications that would normally be lethal in one or more of these states: Connecticut, Delaware, Maryland, Massachusetts, Maine, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia
- Species with more than one mode of action (MOA) listed may not be resistant to all listed MOA’s in all states.
- Species with more than one mode of action (MOA) listed do not necessarily exhibit multiple resistance.
- Compiled from the International Herbicide-Resistant Weed Database and from correspondence with local weed scientists, September 2024.
- Follow links to weed profiles that provide key identification characteristics, ecology, management & references from Manage Weeds on Your Farm in most cases.
- View resistant species listed alphabetically.
ACCase Inhibitors (MOA 1)
Inhibits long chain fatty acid biosynthesis (e.g. quizalofop, diclofop, fluazifop, fluazifop, clethodim, sethoxydim, pinoxaden)
Ryegrass spp. (Lolium spp. )
States found: DE, MD, PA, VA
Italian ryegrass profile
Johnsongrass (Sorghum halepense)
States found: VA, WV
Johnsongrass profile
Smooth crabgrass (Digitaria ischaemum)
States found: NJ
Large crabgrass (related species) profile
ALS Inhibitors (MOA 2)
Inhibits production of branched chain amino acids (e.g. imazamox, imazapic, imazethapyr, imazaquin, nicosulfuron, metsulfuron, triasulfuron, primisulfuron, chlorimuron, tribenuron, chlorsulfuron, thifensulfuron, sulfosulfuron, halosulfuron, rimsulfuron, cloransulam‐methyl, diclosulam, pyrithiobac)
Common chickweed (Stellaria media)
States found: DE, MD, PA, VA
Chickweed profile
Common cocklebur (Xanthium strumarium)
States found: MD
Cocklebur profile
Common Ragweed (Ambrosia artemisiifolia)
States found: DE, MD, NJ, NY, PA
Ragweed profile
Horseweed (Conyza canadensis)
States found: DE, MD, NJ, PA, NY, VA, WV
Horseweed profile
Livid amaranth (Amaranthus blitum)
States found: NJ
Pigweeds profile
See also: Pigweed identification
Palmer amaranth (Amaranthus palmeri)
States found: CT, DE, MD, NJ, NY, PA, VA
Pigweeds profile
See also: Pigweed identification
Redroot pigweed (Amaranthus retroflexus)
States found: CT, DE MD, ME, NH, PA, VA, VT, WV
Pigweeds profile
See also: Pigweed identification
Smooth pigweed (Amaranthus hybridus)
States found: DE, MD, NJ, NY, PA, VA
Pigweeds profile
See also: Pigweed identification
Thale cress (Arabidopsis thaliana)
States found: VA
Waterhemp (Amaranthus tuberculatus)
States found: DE, PA, NY
Waterhemp profile
See also: Pigweed identification
Giant foxtail (Setaria faberi)
States found: MD, PA
Foxtails profile
Ryegrass spp. (Lolium spp. )
States found: DE, MD, PA, VA
Italian ryegrass profile
Johnsongrass (Sorghum halepense)
States found: VA, WV
Johnsongrass profile
Shattercane (Sorghum bicolor)
States found: PA, VA
Shattercane profile
PSII Inhibitors (MOA 5)
Photosystem II inhibitor (e.g. atrazine, simazine, prometryn, metribuzin, hexazinone, terbacil)
Common groundsel (Senecio vulgaris)
States found: NY
Groundsel profile
Common Ragweed (Ambrosia artemisiifolia)
States found: DE, MD, NJ, NY, PA
Ragweed profile
Common lambsquarters (Chenopodium album)
States found: CT, DE, MA, MD, ME, NH, NY, PA, RI, VA, VT, WV
Lambsquarters profile
Palmer amaranth (Amaranthus palmeri)
States found: CT, DE, MD, NJ, NY, PA, VA
Pigweeds profile
See also: Pigweed identification
Redroot pigweed (Amaranthus retroflexus)
States found: CT, DE MD, ME, NH, PA, VA, VT, WV
Pigweeds profile
See also: Pigweed identification
Smooth pigweed (Amaranthus hybridus)
States found: DE, MD, NJ, NY, PA, VA
Pigweeds profile
See also: Pigweed identification
Velvetleaf (Abutilon theophrasti)
States found: MD
Velvetleaf profile
Waterhemp (Amaranthus tuberculatus)
States found: DE, PA, NY
Waterhemp profile
See also: Pigweed identification
Annual bluegrass (Poa annua)
States found: VA
Annual bluegrass profile
Barnyard grass (Echinochloa crus-galli)
States found: MD
Barnyard grass profile
Giant foxtail (Setaria faberi)
States found: MD, PA
Foxtails profile
Yellow foxtail (Setaria pumila)
States found: MD
Foxtail profile
EPSPS Inhibitors (MOA 9)
Inhibits production of aromatic amino acids (e.g. glyphosate)
Common Ragweed (Ambrosia artemisiifolia)
States found: DE, MD, NJ, NY, PA
Ragweed profile
Horseweed (Conyza canadensis)
States found: DE, MD, NJ, PA, NY, VA, WV
Horseweed profile
Palmer amaranth (Amaranthus palmeri)
States found: CT, DE, MD, NJ, NY, PA, VA
Pigweeds profile
See also: Pigweed identification
Redroot pigweed (Amaranthus retroflexus)
States found: CT, DE MD, ME, NH, PA, VA, VT, WV
Pigweeds profile
See also: Pigweed identification
Waterhemp (Amaranthus tuberculatus)
States found: DE, PA, NY
Waterhemp profile
See also: Pigweed identification
Goosegrass (Eleusine indica)
States found: NJ, VA
Goosegrass profile
Ryegrass spp. (Lolium spp. )
States found: DE, MD, PA, VA
Italian ryegrass profile
PPO Inhibitors (MOA 14)
Cell membrane disruptors (e.g. acifluorfen, fomesafen, lactofen, oxyfluorfen, flumioxazin, flumiclorac, fluthiacet, carfentrazone, sulfentrazone, saflufenacil)
Common Ragweed (Ambrosia artemisiifolia)
States found: DE, MD, NJ, NY, PA
Ragweed profile
Palmer amaranth (Amaranthus palmeri)
States found: CT, DE, MD, NJ, NY, PA, VA
Pigweeds profile
See also: Pigweed identification
Goosegrass (Eleusine indica)
Herbicide group: MOA 9 (Aromatic amino acid inhibitors e.g. glyphosate)
Herbicide group: MOA 14 (Cell membrane disruptors e.g. saflufenacil)
States found: NJ, VA
Goosegrass profile
PSI Inhibitors (MOA 22)
Photosystem I electron diverters (e.g. paraquat, diquat)
Horseweed (Conyza canadensis)
States found: DE, MD, NJ, PA, NY, VA, WV
Horseweed profile
HPPD Inhibitors (MOA 27)
Inhibits hyrdoxyphenyl pyruvate dioxygenase (e.g soxaflutole, pyrasulfotole, topramezone, tolpyralate, bicyclopyrone, mesotrione, tembotrione)
Ryegrass spp. (Lolium spp. )
States found: NY
Italian ryegrass profile
Disclaimer
Disclaimer: Please read the pesticide label prior to use. The information contained at this web site is not a substitute for a pesticide label. Trade names used herein are for convenience only; no endorsement of products is intended, nor is criticism of unnamed products implied. In New York, use the New York State Department of Environmental Conservation’s NYSPAD tool to verify the latest product registration information.