Biology Reference
In-Depth Information
healthy plants for new date gardens. Soil can
be
Nigrospora
treated with carbon disulfide,
as
for
Armillaria rot.
Omphalia pigmentata (Omphalia tralucida)
(see
Deuteromycetes, Hyphomycetes
Marasmiellus pigmentatus
).
Decline Dis-
ease
of date palms.
▶
All hyphae more or less creeping, hyaline; conid-
iophores short, dark, cells somewhat inflated;
conidia
black,
one-celled,
situated
on
Oospora (Geotrichum)
a flattened, hyaline vesicle at
top of
the
conidiophore.
Nigrospora oryzae
Ripe Fruit Rot
of tomato,
Nigrospora Cob Rot
of corn. Corn cobs are
shredded, with the pith completely disintegrated;
kernels are filled with masses of black spores.
Corn on poor soil is more susceptible; stalks
break over at any point. Rapid drying checks
infection of seed corn.
Deuteromycetes, Hyphomycetes
Slender branched or unbranched mycelium
breaking up into ellipsoidal or spherical hyaline
or light-colored conidia called “oidia.”
Geotrichum citriaurantii (formerly
Oospora
citri-aurantii
).
Sour Rot
of citrus. This is a soft,
putrid slimy rot of fruit, mostly of stored lemons,
where it is spread by contact. The mycelium
forms a thin, compact, somewhat wrinkled layer
over the surface. Fruitflies help to spread the
spores. Fruit should be stored as short a time as
possible and frequent inspections made during
storage.
Geotrichum candidum (formerly
Oospora
lactis
).
Sour Rot
,
Watery Fruit Rot
of tomato,
common in transit and market, especially on
fruit from the South. There is a velvety or granu-
lar coating over the surface or a fluffy growth
along the margin of cracks, and a disagreeable
odor and flavor. The rot is common on ripe fruit
touching the ground, occasional on green fruit.
The fungus is a weak parasite, entering through
wounds.
Oospora
Olpidium
Chytridiomycetes, Spizellomycetales
Endobiotic, living in host cells or tissues, living
or dead.
Olpidium brassicae Sometimes found in outer
cells of rootlets of cabbage and other crucifers,
tomato, lettuce and other plants, producing
zoosporangia and resting spores in the cells. The
effect on the host is usually merely a slight
unthriftiness. Olpidium has been found associ-
ated with a disease of lettuce, Big Vein, now
thought due to a virus.
citri-aurantii
(see
Geotrichum
▶
Omphalia
citriaurantii
).
Sour Rot
of citrus.
Oospora lacti
Geotrichum candidum
).
Sour Rot
,
Watery Fruit Rot
of tomato, common
in transit and market, especially on fruit from the
South.
(see
▶
Basidomycetes, Agaricales
Gills decurrent, cap sunken in center, somewhat
funnel-shaped; central cartilaginous stem; spores
white.
Marasmiellus pigmentatus (formerly
Omphalia pigmentata
). Omphalia tralucida.
Decline Disease
of date palms. Growth is
retarded; roots decay; leaves die prematurely;
fruit is worthless. Deglet Noor variety is
most susceptible. Select thrifty offshoots from
Ophiosphaerella
Deuteromycetes, Hyphomycetes
Ophiosphaerella sp.
Large Brown Patch Rot
on
bermudagrass and creeping bentgrass.
