Azadirachtin-based formulation in combination with mesoporous silica materials as a plague control agent

Abstract

Azadirachtin is the most important active ingredient of neem oil, a standout product among essential oils. These substances are an interesting family of active products because of their non-toxicity to vertebrates, their specificity against certain pests and the fact that they do not induce resistance. The encapsulation of essential oils and insecticides of natural origin is a widely used strategy to improve their properties. In this work, the ability of silica materials with different topologies and functionalizations to encapsulate and release neem oil and an azadirachtin-based formulation was evaluated. A material containing titanium has also been prepared as a potential protector against UV radiation. It is observed that the presence of the textural pores of the UVM-7 material favors the capture and modulates the release. On the other hand, the mesopores offer a minor contribution. Regarding functionalization, coatings with amine and alkane groups were tested, which did not improve their properties. The UVM-7 material with and without titanium loaded with Zenith A26 was tested in the field against E. banksi in citrus, showing values of incidence and severity close to the conventional treatment with citrulline. Conversely the presence of titanium offered only a minor improvement. Thus, these types of materials could be an interesting approach towards more sustainable agriculture.