First report of sweetpotato scurf caused by Monilochaetes infuscans in Italy.
In the last few years, in the Treviso area of Italy, the incidence and severity of a sweetpotato (Ipomoea batatas) disease has increased to become a serious economic threat to this crop. The symptoms are small, dark brown to black spots on the surface of fleshy storage roots that under high relative humidity coalesce to completely cover the root surface. Affected roots may also develop small cracks and shrink in storage. In August 1998, samples of roots were collected and examined for the presence of M. infuscans since the symptoms were similar to those incited by this pathogen. M. infuscans was consistently present in infected tissues. In pure culture on potato dextrose agar the pathogen formed typical, raised, dome-like, dark grey to black colonies. Conidiophores were brown to black, unbranched, and support straight or curled chains of hyaline conidia.