Effects of poly- and monodisperse surfactants on14C-epoxiconazole diffusion in isolated cuticles of Prunus laurocerasus
Article first published online: 9 OCT 2012
© 2012 Society of Chemical Industry
Pest Management Science
Volume 69, Issue 4, pages 512–519, April 2013
How to Cite
Gutenberger, A., Zeisler, V. V., Berghaus, R., Auweter, H. and Schreiber, L. (2013), Effects of poly- and monodisperse surfactants on14C-epoxiconazole diffusion in isolated cuticles of Prunus laurocerasus. Pest. Manag. Sci., 69: 512–519. doi: 10.1002/ps.3402
- Issue published online: 20 MAR 2013
- Article first published online: 9 OCT 2012
- Accepted manuscript online: 20 AUG 2012 03:23AM EST
- Manuscript Accepted: 20 AUG 2012
- Manuscript Revised: 8 MAY 2012
- Manuscript Received: 18 JAN 2012
- foliar uptake;
- monodisperse alcohol ethoxylate;
- polydisperse surfactant;
Surfactants are known to enhance the foliar uptake of agrochemicals. It was the aim of this study to compare the enhancing effect of three polydisperse surfactants (Brij 30, Plurafac LF300 and Wettol LF700) and five monodisperse alcohol ethoxylates (C12E3, C12E4, C12E5, C12E6 and C12E8) on 14C-epoxiconazole diffusion in cuticles isolated from cherry laurel (Prunus laurocerasus L.).
Rate constants (k*) of 14C-epoxiconazole diffusion were measured in the presence and in the absence of the surfactants. Polydisperse surfactants increased the rates of foliar penetration of 14C-epoxiconazole by factors of between 8 and 16. With monodisperse surfactants, enhancing effects on cuticular penetration were 2–16-fold. Effects were highest with alcohol ethoxylates of intermediate size, whereas they were lower for the smaller, more lipophilic and the larger, more polar monomers. In addition, diffusion of four monodisperse alcohol ethoxylates (C12E3, C12E4, C12E5 and C12E6) across cuticles was measured. Rate constants of alcohol ethoxylates decreased with decreasing lipophility and increasing molecular weight.
The results indicate that enhancement of foliar penetration across cuticles by surfactants was most efficient when both 14C-epoxiconazole and surfactants had similar mobilities in the transport-limiting barrier of the cuticles. This observation should be of interest in future strategies to optimise foliar uptake of agrochemicals using surfactants.