Uptake, Translocation, and Fate of 2,4-D in Nightflowering Catchfly and Common Lambsquarters

Abstract

The uptake, translocation, and fate of (2,4-dichlorophenoxy)acetic acid (2,4-D) were compared in nightflowering catchfly (Silene noctiflora L.) and common lambsquarters (Chenopodium album L.), resistant and susceptible species, respectively. Nightflowering catchfly leaf sections absorbed more 2,4-D from 5 × 10-4 M and 5 × 10-6 M 2,4-D solutions at pH 3.0 than did leaf sections of common lambsquarters. Intact plants of both species accumulated 2,4-D in the stems and leaves below the treated leaf. At 72 hr after treatment, nightflowering catchfly released 2,4-D through the roots into the nutrient solution while common lambsquarters continued to accumulate 2,4-D. Nightflowering catchfly metabolized 2,4-D and the metabolite was recovered in the roots 24 hr after treatment, whereas common lambsquarters did not metabolize 2,4-D.