Table 1.
Sequences of primers and internal primers designed for RT-PCR amplification and sequencing of PPX2 cDNAs from waterhemp.
Table 2.
Mean waterhemp biomass after treatment with field-use rates of PPO-inhibiting herbicides in the greenhouse.
Fig 1.
Waterhemp populations treated with a field-use rate of carfentrazone-ethyl (CE).
Plants in the front row of the 3 and 10 DAT pictures were treated with 14 g ai ha-1 of CE (plus adjuvants) when seedlings were 9–11 cm tall. The corresponding nontreated controls for each population are positioned to the back-left of treated plants.
Fig 2.
Carfentrazone-ethyl (CE) dose-response study with the ACR, SIR, and SEN populations at 10 DAT.
The rates of CE (plus adjuvants) applied when seedlings were 9–11 cm tall are listed below each pot in g ai ha-1, while control plants were only treated with 1% (v/v) COC and 2.5% (v/v) AMS. The field-use rate for CE is 14 g ai ha-1.
Fig 3.
Quantitative dose-response analysis of carfentrazone-ethyl (CE) with the ACR, SIR, and SEN populations at 10 DAT.
The fold-resistance ratio (R/S ratio) is the quotient of the GR50 from the specified resistant population (ACR or SIR) and the GR50 of SEN. The field-use rate for CE is 14 g ai ha-1, and seedlings were 9–11 cm tall at time of treatment. Vertical bars represent the standard error of the mean. Dry weights are expressed as a percentage of the nontreated control.
Fig 4.
SIR plants 10 days after treatments with carfentrazone-ethyl (CE) and malathion applied alone and in combinaton.
Plants at a height of 9–11 cm were treated with either adjuvants only (control), 2000 g ai ha-1 malathion (one hour before CE) plus a 5 mM malathion solution soil drench (50 mL pot-1) two days later, 14 g ai ha-1 CE, or malathion plus CE with the corresponding adjuvants described in Methods. Pictures of injury were taken and aboveground biomass was harvested at 10 DAT to determine dry weight accumulations per treatment. Two independent experiments were conducted with five replications each. Combined means for each treatment (expressed as a percentage of the adjuvant-only control) were 90.8% for malathion-only, 36.5% for CE-only, and 15.2% for the combination of malathion plus CE. A Fisher’s protected LSD value of 13.0 (α = 0.05) was used to determine significant differences among treatments.