Microrganismos e substâncias antimicrobianas presentes em biofertilizantes para o controle de Phytophthora nicotianae

Abstract

Among the phytosanitary problems faced by citrus sector it is highlighted the root rot caused by Phytophthora spp. which affects all stages of development of the citrus trees. Preventive measures associated with chemicals are used to control the disease, but the problems arising from the intensive use of fungicides have increased the interest in developing alternative techniques aimed at agricultural sustainability, among them the use of biofertilizers . Because of these facts, this study aimed to: (i) assess the effect of microbiota and metabolites present in biofertilizers produced from aerobic digestion (BSA) and anaerobic (BSAN) of swine manure on the mycelial growth of P. nicotianae; (ii) determining the effect of the products on inoculate of P. nicotinae in soil and roots of citrus tree, (iii) observing the effect on germination of citrus rootstocks . The results obtained in this study showed that the existing microorganisms and metabolites in biofertilizers affected the development of the colony of P. nicotianae; biofertilizer produced by aerobic digestion of swine manure (BSA) had the best efficiency in the elimination of inoculum of P. nicotianae ; BSA at concentrations of 5 and 10% and BSAN at concentration of 10% favored the germination of mandarin Sunki in substrate infested by the pathogen. Moreover BSA at concentration of 5% had a promising effect on seed germination of Rangpur lime under the same conditions.