|
Damage Symptoms
This fungal disease
affects all crucifers as well as many other vegetables. On cabbage,
rapidly developing water soaked areas develop on the stem, leaves,
or head. Soon thereafter a white fluffy mycelial growth develops
on the surface of the infected tissue which may encompass the
entire head. Hard, black sclerotia develop in the white mycelial
growth. Disease development can occur in the field or during
transit and storage. Crucifer plants with stem infections may
be girdled and killed. Sclerotia frequently form in the pith
of these stems.
Conditions
for Development
Sclerotinia can persist
in crop debris, on many alternate hosts, or as sclerotia in the
soil. Cool, moist conditions are favorable for disease spread
and development. Infection may occur at temperature from 0 to
28°C, but the optimum temperature range is 16 to 21°C.
Control
Avoid fields known to have
a high incidence of white mold. Rotate crucifer crops with less
susceptible crops such as cereals, grasses, or onion. Deep plow
to bury the sclerotia. Flooding has a deleterious effect on sclerotia,
therefore rotation with flooded rice should be of benefit. Fungicidal
sprays provide some protection against infection.
|
