Research was conducted to evaluate absorption, translocation, and metabolism of foliar-applied trifloxysulfuron in flue-cured tobacco. The majority of ¹⁴C-trifloxysulfuron was absorbed by 4 h, with an accumulation in the plant of 43% of the radioactivity after 72 h. Translocation of radioactivity did not significantly differ between harvest timings of 4 to 72 h after treatment. Not more than 4% of applied ¹⁴C-trifloxysulfuron moved out of the treated leaves of tobacco, whereas less than 1.9% accumulated in any one part. Tobacco metabolized ¹⁴C-trifloxysulfuron rapidly, with 60.9% of the absorbed herbicide remaining in the parent herbicide form 4 h after treatment, whereas only 12.1% remained after 72 h. These data suggest that limited absorption and translocation, as well as rapid metabolism, are the basis for tobacco tolerance to foliar-applied trifloxysulfuron and illustrate the potential safe and effective use of trifloxysulfuron in tobacco for POST weed control.

Nomenclature: Trifloxysulfuron; flue-cured tobacco, Nicotiana tabacum L. ‘NC 72’.