421Table 1 Weed species with identified biotypes resistant to herbicides in dryland wheat production
systems from the U.S. Great Plains, Canadian Prairie Provinces, and Western U.S.A. as reported
by Heap ( 2016 )
Site of action (herbicide group no.a) Weed species with resistant biotypes
Accase inhibitors (A/1) Green foxtail, Setaria viridis (L.) Beauv.b
Italian ryegrass, Lolium perenne L. ssp. multiflorum
(Lam.) Husnotb
Persian darnel, Lolium persicum Boiss. & Hohen.
Ex. Boiss
Wild oat, Avena fatua L.b
ALS inhibitors (B/2) Ball mustard, Neslia paniculata (L.) Desv.
Cheat, Bromus secalinus L.
Common chickweed, Stellaria media (L.) Vill.
Common lambsquarters, Chenopodium album L.
Cowcockle, Vaccaria hispanica (P. Mill.) Rauschert
False cleavers, Galium spurium L.b
Field pennycress, Thlaspi arvense L.
Horseweed, Conyza canadensis (L.) Cronq.
Italian ryegrass, Lolium perenne L. ssp. multiflorum
(Lam.) Husnotb
Kochia, Kochia scoparia (L.) Schrad.b
Mayweed chamomile, Anthemis cotula L.
Pale smartweed, Polygonum lapathifolium L.
Prickly lettuce, Lactuca serriola L.
Redroot pigweed, Amaranthus retroflexus L.
Russian-thistle, Salsola tragus L.
Shepherd’s-purse, Capsella bursa-pastoris (L.)
Medik.
Smallseed falseflax, Camelina microcarpa Andrz.
ex DC.
Spiny sowthistle, Sonchus asper (L.) Hill
Wild buckwheat, Polygonum convolvulus L.
Wild oat, Avena fatua L.b
Microtubule assembly inhibitors (K/3) Green foxtail, Setaria viridis (L.) Beauv.b
Synthetic auxins (O/4) Common hempnettle, Galeopsis tetrahit L.
False cleavers, Galium spurium L.b
Kochia, Kochia scoparia (L.) Schrad.
Lipid synthesis inhibitors but not ACCase
inhibitors (N/8)Wild oat, Avena fatua L.bEPSP synthase inhibitors (G/9) Kochia, Kochia scoparia (L.) Schrad.b
Russian-thistle, Salsola tragus L.
Inhibitors of very-long-chain fatty acid
synthesis (K/15)Italian ryegrass, Lolium perenne L. ssp. multiflorum
(Lam.) Husnotb
aThe uppercase letter is the Herbicide Resistance Action Committee (HRAC) classification and the
number is the Weed Science Society of America classification
bOne or more biotypes of this species exhibit multiple herbicide resistance, i.e., resistance to two
or more herbicides with different sites of action
Dryland Agriculture in North America