Síntese e avaliação de vidros polifosfatos com potencial antimicrobiano para aplicação agrícola

Abstract

The increasing resistance of phytopathogenic microorganisms to conventional agricultural pesticides has driven the search for sustainable alternatives to control plant diseases. Among these alternatives, polyphosphate and borophosphate glasses have stood out due to their antimicrobial properties and potential as controlled-release fertilizers. In this context, this work aimed to synthesize and apply polyphosphate glasses with and without the addition of boron in different phytopathogenic microorganisms (Rhizoctonia solani and Clavibacter michiganensis), in order to evaluate the antimicrobial activity of these materials. Two glasses were tested: a pure polyphosphate and a polyphosphate with 10% boron (w/w), both synthesized by the melting–quenching technique at 400 °C for 1 hour. The glasses were evaluated by microbiological tests, including the determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC). In addition to microbiological tests, the glasses were applied to tomatoes (Solanum lycopersicum 'Roma') contaminated with C. michiganensis, demonstrating potential in inhibiting the bacteria without causing visible damage to the fruit. The results of the microbiological tests were satisfactory and demonstrated that both glasses used have activity against the microorganisms tested, with borophosphate glass being the one that showed the best performance. These findings suggest a possible application of these glasses in agriculture in the form of compounds capable of protecting crops such as corn and tomatoes against microbiological pests and, at the same time, meeting the plants' need for micronutrients, such as phosphorus and boron, as well as zinc and molybdenum when doped with these elements.