Design and Application of Slow-Release Pesticide Formulations Embedded in a Biodegradable Matrix Based on Poly(3-Hydroxybutyrate)

Abstract

The latest trend in agriculture is the development and application of environmentally friendly pesticides with targeted and controlled release of active ingredients embedded in biodegradable polymer bases. In this work, a series of experimental slow-release pesticide formulations was produced using composites of degradable polyester poly(3-hydroxybutyrate) and natural materials as a matrix for embedding two agrochemicals – a fungicide (tebuconazole) and an herbicide (metribuzin). The structure, physicochemical properties and degradation rate of long-term formulations and the kinetics of active ingredient release from the matrix were studied in laboratory soil microecosystems. The experimental formulations allowed for a gradual release of agrochemicals into the soil for two months without abrupt emissions, providing long-term plant protection against pathogens and weeds. In contrast to the free forms of the agrochemicals, the analysis showed an absence of noticeable shifts and negative impacts on soil bacterial communities with the introduction of the developed formulations. The fungicidal action of long-term tebuconazole was confirmed on model Triticum aestivum plants infected with a complex of root rot pathogens (Alternaria, Fusarium, and Bipolaris). The efficacy of embedded metribuzin on model Melilotus albus weeds was comparable to that of the free forms of this herbicide. This work has produced new data on biodegradable polyhydroxyalkanoates for constructing long-term formulations of agropreparations. The fundamentals have been provided for constructing environmentally friendly and targeted controlled-release formulations of crop protection products against pathogens and weeds