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.

HerbicidePopulationLD50 (95% CI)R/S ratio (LD50)LD90 (95% CI)R/S ratio (LD90)
g ai ha−1g ai ha−1

Bispyribac-sodiumAR149(43–56)1594(78–122)8.3
AR23.0(1.8–4.8)0.98.6(5.3–26)0.8
MS124(14–43)7.281(44–312)7.1
Susceptible3.3(2.4–4.7)11(7.5–22)

ImazamoxAR1>1120>94>1120>52
AR2>1120>94>1120>52
MS139(34–45)3.373(61–94)3.4
Susceptible12(10–14)21(18–28)

PenoxsulamAR1>1120>94>1120>42
AR2358(297–437)301110(835–1669)41
MS1112(94–133)9.4308(245–422)12
Susceptible12(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.