HERBICIDE RESISTANT WEEDS IN CALIFORNIA |
| Weed | Situation | Herbicide Mode of Action | Year |
Common Groundsel
(Senecio vulgaris) | asparagus | C1/5 - Photosystem II inhibitors
(atrazine) | 1981 |
Perennial Ryegrass
(Lolium perenne) | railways, roadsides | B/2 - ALS inhibitors
(sulfometuron-methyl) | 1989 |
Smallflower Umbrella Sedge
(Cyperus difformis) | rice | B/2 - ALS inhibitors
(bensulfuron-methyl) | 1993 |
California Arrowhead
(Sagittaria montevidensis) | rice | B/2 - ALS inhibitors
(bensulfuron-methyl) | 1993 |
Russian Thistle
(Salsola iberica) | roadsides | B/2 - ALS inhibitors
(chlorsulfuron, sulfometuron-methyl) | 1994 |
Wild Oat
(Avena fatua) | barley, wheat | Z/27 - Unknown
(difenzoquat) | 1996 |
Redstem
(Ammania auriculata) | rice | B/2 - ALS inhibitors
(bensulfuron-methyl) | 1997 |
Ricefield Bulrush
(Scirpus mucronatus) | rice | B/2 - ALS inhibitors
(bensulfuron-methyl) | 1997 |
Late Watergrass
(Echinochloa phyllopogon) | rice | A/1 - ACCase inhibitors
(fenoxaprop-P-ethyl) | 1998 |
Late Watergrass
(Echinochloa phyllopogon) | rice | N/8 - Thiocarbamates and others
(thiobencarb = benthiocarb) | 1998 |
Rigid Ryegrass
(Lolium rigidum) | almonds | G/9 - Glycines
(glyphosate) | 1998 |
Long-Leaved loosestrife
(Ammania coccinea) | rice | B/2 - ALS inhibitors
(bensulfuron-methyl) | 2000 |
Barnyardgrass
(Echinochloa crus-galli) | rice | A/1 - ACCase inhibitors
(cyhalofop-butyl, fenoxaprop-P-ethyl, molinate, thiobencarb = benthiocarb) | 2000 |
Barnyardgrass
(Echinochloa crus-galli) | rice | N/8 - Thiocarbamates and others
(cyhalofop-butyl, fenoxaprop-P-ethyl, molinate, thiobencarb = benthiocarb) | 2000 |
Early Watergrass
(Echinochloa oryzoides) | rice | N/8 - Thiocarbamates and others
(molinate, thiobencarb = benthiocarb) | 2000 |
Late Watergrass
(Echinochloa phyllopogon) | rice | A/1 - ACCase inhibitors
(cyhalofop-butyl, fenoxaprop-P-ethyl, molinate, thiobencarb = benthiocarb) | 2000 |
Late Watergrass
(Echinochloa phyllopogon) | rice | N/8 - Thiocarbamates and others
(cyhalofop-butyl, fenoxaprop-P-ethyl, molinate, thiobencarb = benthiocarb) | 2000 |
Little Seed Canary Grass
(Phalaris minor) | onion | A/1 - ACCase inhibitors
(clethodim, fenoxaprop-P-ethyl, fluazifop-P-butyl, sethoxydim) | 2001 |
Smooth Crabgrass
(Digitaria ischaemum) | rice | O/4 - Synthetic Auxins
(quinclorac) | 2002 |
Horseweed
(Conyza canadensis) | roadsides | G/9 - Glycines
(glyphosate) | 2005 |
Hairy Fleabane
(Conyza bonariensis) | roadsides | G/9 - Glycines
(glyphosate) | 2007 |
Hairy Fleabane
(Conyza bonariensis) | roadsides, vineyards | D/22 - Bipyridiliums
(glyphosate, paraquat) | 2009 |
Hairy Fleabane
(Conyza bonariensis) | roadsides, vineyards | G/9 - Glycines
(glyphosate, paraquat) | 2009 |
Redstem (Ammania auriculata) is the most widespread resistant weed of California