FIG 1 .

Killing curves. On the x axis, antibiotic concentrations (μg/ml) are plotted. Blue bars, no herbicide; orange bars, herbicide present. Herbicide concentrations used were as follows: for Kamba, 1,830 ppm/1,950 ppm (E. coli/S. Typhimurium); for 2,4-D: 1,830 ppm/1,950 ppm; and for Roundup, 1,240 ppm/1,240 ppm. Error bars are standard errors of the means (SEM). Asterisks indicate P values (see Materials and Methods for details). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, not significant.