Napropamide Fluxes in Corn (Zea mays) Root Tissue

Abstract

Napropamide [2 - (α - naphthoxy)-N,N- diethylpropionamide] influx was studied using excised root segments of corn (Zea maysL.). An initial rapid influx was followed by a slower, steady influx rate. Total influx was separated into a component that eluted from the tissue (exchangeable fraction) and a nonexchangeable fraction (residual fraction). After 5 min the residual fraction was responsible for the continued influx. In further studies with root segments this fraction was nonsaturating, increased with increased temperature, and was reduced by anaerobic conditions. The exchangeable fraction was controlled by diffusional processes. The overall influx process was attributed to an initial passive diffusion supplemented with time by a binding of napropamide into the residual fraction.