Amaranthus palmeri a New Invasive Weed in Spain with Herbicide Resistant Biotypes

Extrachromosomal circular DNA-based amplification and transmission of herbicide resistance in crop weed Amaranthus palmeri

Gene amplification has been observed in many bacteria and eukaryotes as a response to various selective pressures, such as antibiotics, cytotoxic drugs, pesticides, herbicides, and other stressful environmental conditions. An increase in gene copy number is often found as extrachromosomal elements that usually contain autonomously replicating extrachromosomal circular DNA molecules (eccDNAs). A...

Bioassay and Characterization of Several Palmer Amaranth (Amaranthus palmeri) Biotypes with Varying Tolerances to Glyphosate

The wide distribution of Palmer amaranth (Amaranthus palmeri) in the southern US became a serious weed control problem prior to the extensive use of glyphosate-resistant crops. Currently glyphosate-resistant populations of Palmer amaranth occur in many areas of this geographic region creating an even more serious threat to crop production. Investigations were undertaken using four biotypes (one...

Characterization of Herbicide- Resistant Biotypes of Barnyardgrass

Barnyardgrass (Echinochloa crus-galli) biotypes, resistant to different herbicides, have been reported. An experiment was conducted to compare the growth characteristics of various barnyardgrass biotypes, (i.e., propanil-resistant from Poinsett County, Ark., quinclorac-resistant from Louisiana., quinclorac/propanil-resistant barnyardgrass from Craighead County, Ark., and susceptible barnyardgra...

Herbicide-Resistant Palmer amaranth (Amaranthus palmeri S. Wats.) in the United States — Mechanisms of Resistance, Impact, and Management

Palmer amaranth, a dioecious summer annual species, is one of the most trouble‐ some weeds in the agronomic crop production systems in the United States. In the last two decades, continuous reliance on herbicide(s) with the same mode of action as the sole weed management strategy has resulted in the evolution of herbicideresistant (HR) weeds, including Palmer amaranth. By 2015, Palmer amaranth ...

Weed Management: Implications of Herbicide Resistant Crops