POTENTIAL APPLICATION OF BIODEGRADABLE POLYMER – POLY(3-HYDROXYBUTYRATE) – IN DESIGNING OF NEW GENERATION FORMULATIONS OF AGROCHEMICALS

ABSTRACT

The work summarizes the results of research into fundamentals of design and application of slow-release and ecologically safe forms of agrochemicals used for protecting plants from pathogens and weeds. The potential of degradable polyester poly(3-hydroxybutyrate) [P(3HB)] for designing long-term formulations of fungicides (tebuconazole) and herbicides (metribuzin) is described. Experimental forms of agricultural preparations were compared with the commercial fungicide Raxil Ultra containing tebuconazole and Sencor Ultra, a herbicide containing metribuzin. Polymer/active ingredient blends in the form of solutions, emulsions and powders were used to construct slow-release formulations shaped as microparticles, microgranules, films and pellets and loaded with different amounts of agrochemicals. Release profiles of agrochemicals from experimental formulations were examined in aqueous and soil laboratory systems with respect to the geometry of formulations, type of embedded chemicals, load of polymer bases and degradation rate of polymer matrices. Efficiency of the obtained formulations with the model plants and weeds Triticum aestivum, Latuca sativa, Raphanus sativus, Agrostis stolonifera, Setaria macrocheata, Chenopodium album, Melilotus albus, Amaranthus retroflexus was studied in laboratory ecosystems. Soil microecosystems with crops (Triticum aestivum) infected by root rot pathogens Fusarium were used to assess the efficacy of the fungicides. The research has produced new data on degradable P(3HB) as a material for constructing slow-release formulations of agrochemicals. The studies showed that the slow-release herbicide and fungicide formulations were effective against weeds and plant pathogens and their effects were comparable with those of free forms of agrochemicals or even stronger. This research may be a promising avenue for constructing environmentally friendly and targeted controlled-release formulations of pesticides to protect crops against pests and pathogens.

Keywords: slow-released formulations, poly-3-hydroxybutyrate, antifungal activity, herbicidal effect, controlled release