Biology Reference
In-Depth Information
wind-borne at least 1/3 mile, but presumably
a large proportion of them land on opening petals
of the bush overhead. The sclerotia remain viable
in the soil at least 2 or 3 years, sending up more
apothecia each season. No conidia are known; so
there is no secondary infection from flower to
flower as with azalea blight. The amount of pri-
mary inoculum is very large, however. One after-
noon in New Orleans I collected nearly 1000
sclerotia that were producing apothecia from
under a single camellia.
Control
The first line of defense is exclusion.
Most southern states have quarantines against
known infected areas; they require that plants be
shipped bare-rooted, with all flower buds show-
ing color removed. Northern gardeners ordering
plants for greenhouses should insist on the same
precautions even without specific quarantines.
Practically all outbreaks of camellia flower blight
have been traced to plants shipped in cans, pre-
sumably carrying sclerotia in the soil. The disease
has also appeared on flowers shipped in by air for
camellia shows. Schedules should state that all
specimens become the property of the show com-
mittee, to be destroyed at the end of the show; no
blooms should be taken home for propagation.
Theoretically, because there is no conidial
stage to spread the fungus, this should be an
easy disease to eradicate, but it has not proved
so in practice. Camellias have thousands of
flowers produced over a period of months.
They drop into various ground covers, and it is
almost impossible to find and destroy all infected
blooms before rotting tissues release sclerotia
into the litter. Some cities have quarantined
infected properties and provided a host-free
period of 2 years, during which all flower buds
are removed from all camellias in the area, but
this approach has been only partially successful.
Various chemicals have been tried as ground
treatment to inhibit formation of apothecia.
Sclerotinia
Sclerotinia minor
Blight
of soybean, peanut,
and Eclipta.
Sclerotinia
(
Botryotinia
)
polyblastis (see
Botryotinia polyblastis
).
Narcissus Fire
.
A serious flower blight in England, known here
on the Pacific Coast.
Sclerotinia rolfsii
Southern Blight
on St.
Johnswort.
Sclerotinia sclerotiorum
Shoot and Twig
Blight
of lilac, grape, pistachio, soybean, peanut,
and malaviscus; flower blight of camellia resem-
bling that caused by
S. camelliae
but far less
serious. Tuber blight and storage rot; of Trillium.
This ubiquitous fungus more often causes stem
rots on its many different hosts.
▶
Rots
.
▶
Sclerotium
Deuteromycetes, Mycelia Sterilia
(Fungi Imperfecti)
Asexual fruit bodies and spores lacking; there is
merely a resting body, sclerotium, made up of
a compact, rounded mass of light-colored hyphae
with a brown to black rind; parasitic, often on
underground plant parts.
Pellicularia
has proved
to be the teleomorph state for some forms.
Sclerotium bataticola
Ashy Stem Blight
. See
▶
Macrophomina phaseoli
under Rots.
Sclerotium hydrophilum
Blight
of wild rice.
Sclerotium oryzae
Blight
of wild rice.
Sclerotium rhizodes
White Tip Blight
of grass.
▶
Snowmold
.
Sclerotium
rolfsii
Southern
Blight
.
Pellicularia rolfsii
.
▶
Septoria
Deuteromycetes, Coelomycetes
Ciberinia
camelliae
).
Camellia Flower Blight
, long known
in Japan, first noted in California in 1938, con-
firmed in Georgia in 1948, although probably
there several years previously, reported in Ore-
gon in 1949, Louisiana and North Carolina in
1950, South Carolina in 1954.
camelliae (see
▶
Pycnidia dark, separate, globose, ostiolate; pro-
duce in spots, erumpent; conidiophores short,
conidia hyaline, narrowly elongate to filiform,
several septate; parasitic, typically causing leaf
spots, but also blights and blotches (see
Fig. 1
).
There are about 1000 species.
