Multiple Resistance to Glyphosate and 2,4-D in Carduus acanthoides L. from Argentina and Alternative Control Solutions

Abstract

Carduus acanthoides L. is an invasive species native to Europe and distributed in other parts of the world, including North and South America. In Cordoba, Argentina, control failures of this species have been reported in Roundup Ready (RR) soybean crops where glyphosate and 2,4-D have frequently been applied, although there are no confirmed reports worldwide of resistance to glyphosate and 2,4-D in this species. Dose–response tests showed multiple-resistance to both active principles. The resistant population (R) had LD50 values of 1854.27 and 1577.18 g ae ha−1 (grams of acid equivalent per hectare), while the susceptible (S) population had LD50 values of 195.56 and 111.78 g ae ha−1 for glyphosate and 2,4-D, respectively. Low accumulations of shikimic acid (glyphosate) and ethylene (2,4-D) at different doses in the R population compared to the S population support the results observed in the dose–response curves. No significant differences in leaf retention were observed for glyphosate and 2,4-D in the R and S populations. However, the use of adjuvants increased the retention capacity of herbicides in both populations. Ten alternative herbicides with seven different action mechanisms (MOAs) were evaluated and the most effective active principles were dicamba, bromoxynil, atrazine, tembotrione, flazasulfuron, glufosinate, and paraquat. These findings are the first evidence of glyphosate and 2,4 D resistance in C. acanthoides.

Cytochrome P450s-Involved Enhanced Metabolism Contributes to the High Level of Nicosulfuron Resistance in Digitaria sanguinalis from China

“…In the current study, we also determined the resistance patterns of the R population to different herbicides and found that they exhibited low levels of cross-resistance to ALS inhibitors and multiple resistance to PSII inhibitors. Similarly, metabolic resistance was identified in diverse weed species, endowing them with uncertain patterns of multiple resistance, such as plumeless thistle ( Carduus acanthoides L.) [ 43 ], Italian ryegrass ( Lolium multiflorum L.) [ 44 ], and late watergrass Echinochloa phyllopogon (Stapf) Koss [ 45 ]. Although the R population, LJ-01, was also resistant to thifensulfuron-methyl, pyrazosulfuron-ethyl, bromoxynil octanoate, and atrazine, it remained susceptible to rimsulfuron, tembotrione, mesotrione, and topramezone.…”

Comparison of premix glyphosate and 2,4-D formulation and direct tank mixture for control of Conyza canadensis and Epilobium ciliatum

“…Syringes were incubated at 27°C in the dark for 4 hours. The ethylene (C 2 H 4 ) in 1 mL of the gas at the top of the syringe was analyzed by gas chromatography (Palma-Bautista et al 2020). The C 2 H 4 content was expressed as nL g -1 fresh weight h -1 .…”