Blackleg on stems
infected seed tuber. Infected
stems usually have a strong
fishy smell caused by secondary
bacteria that invade infected
tissues. No white fungal growth
is present as in late blight lesions.
Aerial stem rot or stalk rot
wounded stems or petioles. No white
mycelium present.
Alternaria brown spot on stems
of the lesions is spotty. The Alternaria brown spot
fungus has been isolated from these lesions.
Black dot on stems
as brown lesions that usually
develop at the base of the stem.
Later, the lesions turn white and
tiny, black sclerotia are formed
on the lesions.
