Evaluación de cepas de Bacillus spp. en el control de Colletotrichum spp. en frutos de Solanum betaceum en la fase de post cosecha

Abstract

Anthracnose is one of the most important postharvest diseases affecting tree tomato (Solanum betaceum) fruits, causing significant economic losses in production and commercialization, particularly in Ecuador. This disease is mainly caused by fungi of the genus Colletotrichum, which exhibit high infective capacity, latent behavior, and increasing resistance to conventional chemical fungicides. These limitations have driven the search for sustainable and environmentally friendly alternatives to manage postharvest diseases. In this context, biological control using antagonistic microorganisms has emerged as an effective strategy to reduce chemical inputs while preserving fruit quality. The aim of this study was to evaluate the effectiveness of different Bacillus spp. strains in controlling Colletotrichum spp. in postharvest Solanum betaceum fruits, as well as to assess their influence on fruit physicochemical quality and bacterial survival during storage. Experimental in vivo assays were conducted, in which healthy fruits were artificially inoculated with the pathogen and treated with selected Bacillus spp. strains under preventive and curative applications. Diseaserelated variables such as incidence and severity of anthracnose were evaluated, along with fruit quality parameters including firmness, weight loss, total soluble solids, pH, and titratable acidity. The results indicated that specific Bacillus spp. strains, particularly Bacillus megaterium, significantly reduced disease incidence and severity compared to the pathogen control, showing performance comparable to or better than chemical treatments. Moreover, the application of Bacillus spp. did not negatively affect the physicochemical quality of the fruits during storage and demonstrated satisfactory bacterial survival on the fruit surface. These findings suggest that Bacillus spp. constitute a promising biological alternative for the postharvest management of anthracnose in tree tomato, contributing to the development of sustainable agricultural practices, reducing environmental impact, and promoting food safety