A Common Ragweed (Ambrosia artemisiifolia) Biotype in Southwestern Québec Resistant to Linuron

Abstract

The degree of resistance to linuron of a common ragweed biotype was investigated. Suspected linuron-resistant plants collected from a carrot field near Sherrington, Québec, were subjected to increasing rates of linuron under glasshouse conditions. Resistance to linuron of the common ragweed biotype was suspected because 33% of plants survived to reproduction after they were sprayed at a rate of 4.5 kg ai/ha, two times the dose rate recommended for linuron in carrots, and also because 3% of plants survived to reproduction after they were sprayed at a rate of 22.5 kg ai/ ha, 10 times the recommended dose. Susceptible plants collected from a field with no prior history of linuron use were all killed when sprayed at the lowest dose rate recommended, 1.125 kg ai/ha. The herbicide-resistance ratio was 29.0 for linuron, and for cross-resistance to atrazine, the ratio was 1.3, indicating that these plants exhibit greater resistance to linuron than to atrazine.

Is sunflower (Helianthus annuus) at risk to damage fromOphraella communa, a natural enemy of common ragweed (Ambrosia artemisiifolia)?

“…Several herbicides, including 2,4-D [(2,4-dichlorophenoxy) acetic acid], MCPA [(2 methyl-4-chlorophenoxy) acetic acid], and dicamba (3,6-dichloro-2-methoxybenzoic acid), have been the mainstay of common ragweed control strategies in urban environments, however, herbicide use has declined in several regions due to public concerns and legislation. Various herbicides and herbicide mixtures provide control in corn and soybean crops, but populations of common ragweed have developed resistance to triazines, ALS inhibitors, ureas, and glyines (Heap 1997;Patzoldt et al 2001;Saint-Louis et al 2005;Sellers et al 2005), thus restricting control options. Effective non-chemical strategies to control this weed in urban and agricultural environments would be highly attractive.…”

Weed Control and the Use of Herbicides in Sesame Production

“…Linuron, a substituted urea herbicide, has been used extensively in cotton and carrot (Daucus carota L.) as a preemergence or postemergence herbicide since the 1960's for control of annual broadleaf weeds such as pigweed spp., common ragweed (Ambrosia artemisiifolia L.), common groundsel (Senecio vulgaris L.), and common purslane (Portulaca oleracea L.) (Bell et al, 2000;Bellinder et al, 1997;Saint-Louis et al, 2005). Linuron can be used in combination with 2,4-DB to control sicklepod (Cassia obtusifolia L.) in soybean; however, a height differential must be established between soybean and sicklepod to cover the weeds without contacting more than the lower 25 to 30% of the soybean plant to reduced herbicide injury (Shaw & Coats, 1988).…”

Investigating mechanism of glyphosate resistance in a common ragweed (Ambrosia artemisiifolia L.) biotype from Nebraska

“…Common ragweed, a summer annual broadleaf weed, is found in diverse agroecosystems, wastelands, and roadsides (Bassett and Crompton 1975;Saint-Louis et al 2005;Jordan et al 2007). Common ragweed is a natural colonizer, producing 32 000 to 62 000 seeds plant −1 when permitted to grow for the entire season without competition from crop plants (Dickerson and Sweet 1971;Jordan et al 2007;Friedman and Barrett 2008).…”

“…Small seed size, specific requirements of light and temperature for germination, and a preference for undisturbed habitats has made common ragweed a predominant weed in reduced or no-till cropping systems in the midwestern United States (Jordan et al 2007). High selection pressure due to exclusive dependence on chemical weed control in no-till cropping systems combined with a wide genetic diversity has resulted in the evolution of resistance to several herbicide sites of action in common ragweed (Schultz et al 2000;Saint-Louis et al 2005;Brewer and Oliver 2009;Duke and Powles 2009;Rousonelos et al 2012). Glyphosate-resistant (GR) common ragweed was first reported in Missouri in 2004 and subsequently in 14 other states in the United States (Alabama, Arkansas, Indiana, Kansas, Kentucky, Minnesota, Mississippi, Nebraska, New Jersey, North Carolina, North Dakota, Ohio, Pennsylvania, and South Dakota) and in Ontario, Canada (Heap 2016).…”

“…Glyphosate-resistant (GR) common ragweed was first reported in Missouri in 2004 and subsequently in 14 other states in the United States (Alabama, Arkansas, Indiana, Kansas, Kentucky, Minnesota, Mississippi, Nebraska, New Jersey, North Carolina, North Dakota, Ohio, Pennsylvania, and South Dakota) and in Ontario, Canada (Heap 2016). Additionally, common ragweed biotypes resistant to acetolactate synthase, photosystem II, and protoporphrinogen oxidase inhibitors have been reported (Patzoldt et al 2001;Saint-Louis et al 2005;Chandi et al 2012;Rousonelos et al 2012;Heap 2016).…”