Uptake and Translocation of Fluazifop in Green Foxtail (Setaria viridis)

Experiments were conducted on uptake and translocation of butyl ester of 14 C-fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy] propanoic acid} in green foxtail [ Setaria viridis (L.) Beauv. # SETVI]. Absorption of 14 C-fluazifop reached 67.6% 12 h after treatment with the petroleum oil additive compared to 44.0% when applied alone. Maximum 14 C-fluazifop absorption detected was 74.2% after 48 h with the oil additive compared to 58.6% after 72 h when applied alone. Translocation of 14 C-fluazifop was greater when applied with the oil additive than alone, but translocation did not increase after 12 h. Absorption and translocation of 14 C-fluazifop by green foxtail was greater when applied with the oil additive than alone in all environments. The oil additive overcame the reduced absorption of 14 C-fluazifop applied alone with low temperature (20 C), relative humidity (40%), and soil fertility (0.25× strength Hoagland's solution), but not the reduced absorption and translocation with an increase in stress to −10 bars. 14 C-fluazifop lost as vapors from the treated green foxtail leaf was 4.1% when applied alone compared to 0.6% when applied with an oil additive.