Distribution of Root-Absorbed Picloram

Abstract

We studied changes in the concentration of 4-amino-3,5,6-trichloropicolinic acid (picloram) with time in roots, stems, and leaves of 20-day-old seedlings of huisache (Acacia farnesiana (L.) Willd.) and honey mesquite (Prosopis juliflora (Swartz) DC. var. glandulosa (Torr.) Cockerell). Exposing root systems to aqueous solutions of picloram (1.0 ppm huisache and 10.0 ppm honey mesquite) for 24 hr killed approximately 60% of the treated plants. In honey mesquite, picloram was redistributed and eventually lost over a 5-day period, whereas neither redistribution nor loss occurred in huisache.