ABSTRACT
The influence of four C13/C14 fatty alcohol surfactants with mean ethylene oxide contents of 6, 11, 15, and 20 on the foliar uptake of 14C-labeled solutions of methylglucose and phenylurea by field (broad) bean (Vicia faba L.) and wheat (Triticum aestivum L.) was investigated under controlled environment conditions. Surfactant concentration and ethylene oxide content were found to influence greatly the uptake of the two compounds. Uptake activation only occurred when a threshold concentration of surfactant was exceeded. Uptake of 14C-methylglucose was greatest in the presence of surfactants of high ethylene oxide content, while that of 14C-phenylurea was much less sensitive to surfactant structure. Marked differences in the amount of movement of radiolabel were observed between field bean and wheat following applications of 14C-phenylurea formulations, but these could not be ascribed to the properties of the surfactants added.
