Method of production of controlled release silica nanoparticles for plant growth and/or defense enhancement

Abstract

A tunable one-pot method for producing nanoparticles for plant defense and growth enhancement that include components that collectively exhibit multiple release profiles of active ingredients when exposed to release conditions, such as contact with water, or sufficient moisture, or changes in pH, or the presence of plant roots. In a preferred embodiment, the method produces round or substantially round amorphous hydroxylated (and thus water soluble and low toxicity) nanoparticles having i) a silica-based core that exhibits a slow release rate and ii) silica mono- and/or oligomer based nanodomains and/or one or more active ingredients associated with the core, entrapped in nanopores or nanodomains, and/or adsorbed to the surface, etc., that exhibit at least a second, faster release rate under release conditions, wherein the active ingredient includes one or more of a silica monomer and/or oligomer and/or additional active ingredients such as a pesticide, nutrient, prebiotic, or phytostimulant Methods for producing nanoparticles for agricultural use are disclosed, including colloidal synthesis steps that provide precise, tunable control of the architecture of the nanoparticles. Advantageously, the nanoparticles resulting from this process are suitable for use as plant growth and defense enhancers through delivery of the silica mono- and/or oligomers and/or active ingredients, by hormesis/plant nanopriming, or by mixture with conventional agrochemicals.