Table 3: Bispyribac-sodium, imazamox, and penoxsulam dose required to kill 50% (LD50) and 90% (LD90) of ALS-resistant (AR1, AR2, and MS1) and -susceptible E. crus-galli populations (with 95% CI in parenthesis)a,b,c,d.

Herbicide Population LD50 (95% CI) R/S ratio (LD50) LD90 (95% CI) R/S ratio (LD90) g ai ha−1   g ai ha−1 Bispyribac-sodium AR1 49 (43–56) 15 94 (78–122) 8.3 AR2 3.0 (1.8–4.8) 0.9 8.6 (5.3–26) 0.8 MS1 24 (14–43) 7.2 81 (44–312) 7.1 Susceptible 3.3 (2.4–4.7)   11 (7.5–22)   Imazamox AR1 >1120   >94 >1120   >52 AR2 >1120   >94 >1120   >52 MS1 39 (34–45) 3.3 73 (61–94) 3.4 Susceptible 12 (10–14)   21 (18–28)   Penoxsulam AR1 >1120   >94 >1120   >42 AR2 358 (297–437) 30 1110 (835–1669) 41 MS1 112 (94–133) 9.4 308 (245–422) 12 Susceptible 12 (10 to 14)   27 (22 to 35)

aLD50 and LD90 were determined by conducting Probit analysis in SAS. bR/S ratio was calculated by dividing the LD50 and LD90 dose of resistant population by the LD50 and LD90 dose, respectively, of susceptible population. cAll imazamox and penoxsulam treatments contained a nonionic surfactant at 0.25% v/v. dBispyribac-sodium treatments contained a nonionic spray adjuvant and deposition aid at 2.5% v/v.