Fig 1.
Images illustrating the occurrence of Palmer amaranth on roadside habitats in eastern Arkansas.
A) along a rural road adjacent to a cotton production field, B) along a state highway, C) among grain spill on road shoulders, and D) among cotton lint spill on road shoulders.
Table 1.
Results of dose-response analysis of selected roadside Palmer amaranth populations to glyphosate.
Fig 2.
Histograms showing frequency distribution of the surveyed populations.
A) survival (%) to 1X glyphosate, B) control ratings (%) to 1X glyphosate compared to a non-treated standard, C) survival (%) to 2X pyrithiobac, and D) control ratings (%) to 2X pyrithiobac compared to a non-treated standard. The field rates (1X) used were 73 g ai ha-1 for pyrithiobac and 870 g ae ha-1 for glyphosate. Applications of pyrithiobac also included a non-ionic surfactant at 0.25% v/v.
Fig 3.
Multiple resistance profiles of surveyed roadside Palmer amaranth populations to glyphosate (X axis) and pyrithiobac (Y axis).
Each data point represents the resistance status of each population for the two herbicides.