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
