Absorption and Translocation of MON 0818 Adjuvant in Field Bindweed (Convolvulus arvensis)

Abstract

To develop an understanding of how adjuvants might enhance glyphosate [N-(phosphonomethyl)glycine] activity, absorption and translocation of a polyethoxylated tallow amine amphoteric surfactant (MON 0818) were examined in field bindweed (Convolvulus arvensisL. # CONAR). Scanning electron microscopy did not reveal any physical disruption of the epicuticular waxes from spray applications of MON 0818, an oxysorbic (20 POE) (polyoxyethylene sorbitan monolaurate) surfactant, or glyphosate. Radioactive MON 0818 absorption was rapid during the first 6 h. Maximum absorption (84%) occurred by 24 h after application. Less than 3% of the applied radioactivity was recovered from the epicuticular wax of treated leaves. Movement of radioactivity away from the treated area was limited predominantly to movement within the treated leaf. Altering light intensity or humidity in which the plants developed before treatment did not influence MON 0818 absorption.