Application of Bacillus velezensis 160 for the biocontrol of Botrytis cinerea in pomegranate

Botrytis cinerea is the causal agent of gray mold, a disease that attacks many plants worldwide. This phytosanitary problem was reported in orchards in the State of Mexico, Mexico, specifically in pomegranate crops. This study isolated this phytopathogen from fruits collected in the municipality of Chilcuautla, state of Hidalgo, Mexico, indicating that the disease is spreading across the country. Two strains of phytopathogens, MIC and MID, were obtained after conducting Koch’s postulates. These strains were identified molecularly by amplifying and analyzing the concatenated sequence of the regions that correspond to the internal transcript spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (G3PDH), and DNA-dependent RNA polymerase subunit II (RPB2). In vitro confrontation tests demonstrated that B. velezensis 160 inhibited the development of both strains of B. cinerea under study through the action of nonvolatile thermostable and volatile metabolites. Applying this bacteria to pomegranate orchards for two consecutive years (2022, 2023) decreased the incidence, severity, and progression of the disease. We conclude that this bacterium can be used as a fungicide to control gray mold in pomegranate crops.