Phomosis: what it is, how it originates, and how to eliminate it effectively

Phoma betae (Pleospora betae) is a phytopathogenic fungus that mainly affects sugar beet. This pathogen has an asexual phase (Phoma) and a sexual phase (Pleospora), which allows it to survive in different environmental conditions and in crop remains. It produces pycnidia, fruiting structures containing asexual spores (conidia), which are released and dispersed by wind, rainwater, and physical contact. Under favorable conditions of high humidity and moderate temperatures, conidia germinate and produce hyphae that invade plant tissues, causing lesions and necrosis. The sexual phase, which produces ascospores, develops in infected plant residues and contributes to the dispersal and genetic variability of the fungus. These spores are hardy and can survive in the soil for long periods, infecting new plants in subsequent seasons. The ability of Phoma betae to persist in soil and plant debris makes disease management a considerable challenge for farmers.