Design of pheromone releasing nanofibers for plant protection

Plants tend to attract diseases quite similar to human beings. Pesticides tend to be used to control such diseases. An alternative route, at least as far as damages from insects is concerned, envisions the application of pheromones. These cause a disorientation of male insects so that they are no longer able to locate the females, which finally gives rise to suppression of reproduction. The approach considered in this paper is based on the release of pheromones from polymer carriers, in particular, from nanofibers webs as obtained by electrospinning. These may be distributed across the field quite similar to spider webs. The pheromones are required to be incorporated in sufficiently high concentrations in the nanofibers via electrospinning and to be released from the nanofibers for a sufficiently long time expanding over several weeks to months. Polyamide 6 as well as cellulose acetate was used as a polymer carrier in the investigations reported in this contribution. Studies reveal that fluid pheromones can, in fact, be incorporated in the nanofibers to more than 33 wt%. They may undergo a nanoscalar phase separation within the fibers during electrospinning. Furthermore, thermogravimetric studies revealed via in vitro release studies that the pheromones are released from the nanofibers in a nearly linear fashion over a period covering many weeks. Copyright (C) 2009 John Wiley & Sons, Ltd.