Biology Reference
In-Depth Information
first purplish, then brown, falling out to give the
shot-hole effect (see
Fig. 2
). If lesions are numer-
ous, the leaves turn yellow and fall by midsum-
mer, this premature defoliation reducing next
season's harvest. The fungus winters in fallen
leaves, producing disc-shaped apothecia for pri-
mary infection. Secondary infection comes from
conidia, formed in whitish masses on the spots in
moist weather, more numerous on the undersur-
face. New infection continues through the sum-
mer after harvest. Defoliation prior to ripening
reduces size and quality of fruit and exposes it to
sunscald. Some seasons shoots, spurs, and
branches are killed, followed by a light crop the
next year. Thousands of sour cherry trees have
been killed.
Control
An eradicant spray of a dinitro com-
pound, such as Elgetol, applied to the ground in
early spring, reduces the amount of primary
inoculum, but summer sprays are also necessary.
On sour cherry this may mean a spray at petal fall,
another 10 days later, two sprays in June, and
another just after fruit is picked, with more appli-
cations, especially on nursery trees, needed in
some seasons. Consult your state experiment
station for suitable materials and schedule for
your area.
Blumeriella jaapii (formerly
Coccomyces
lutescens
).
Leaf Spot
,
Shot Hole
on cherry-laurel,
black cherry, and chokecherry. Similar to the
disease caused by
C. hiemalis
.
Blumeriella jaapii (formerly
Coccomyces
prunophorae
).
Leaf Spot
,
Shot Hole
on
garden plum and apricot. Reddish to brown
spots, dark blue initially, produce pinkish spore
masses on underside of leaves in wet weather.
The shot-hole effect from dropping out of
dead tissue may be very prominent and accom-
panied by heavy fruit drop. Spray when shucks
are off young fruit, 2 or 3 weeks later, and before
fruit ripens, with lime sulfur, or with wettable
sulfur.
Blumeriella kerriae (formerly
Coccomyces
kerriae
and
Higginisia kerriae
).
Kerria Leaf
Spot
,
Twig Blight
, widespread on kerris from
eastern states to Texas. Leaves have small,
round to angular, light brown or reddish brown
spots with darker borders. When spots are numer-
ous, leaves turn yellow and die. Similar lesions on
young stems may run together into extended
cankers, the bark splitting to show black
pycnidia, from which ooze out masses of long,
white, curved spores. The fungus winters in old
dead leaves. Spraying with bordeaux mixture
may help.
Coccomyces hiemalis and Higginisia hiemalis
(see
Blumeriella jaapii
).
Cherry Leaf Spot
,
Blight
,
Shot Hole
, general on sweet and sour
cherries, the most common and destructive leaf
disease of cherries.
Coccomyces kerriae and Higginisia kerriae
(see
▶
Blumeriella kerriae
)
Kerria Leaf Spot
,
Twig Blight
, widespread on kerria from eastern
states to Texas.
Coccomyces
▶
Blumeriella
jaapii
).
Leaf Spot
,
Shot Hole
on cherry-laurel,
black cherry, and chokecherry.
Coccomyces prunophorae (see
lutescens (see
▶
Blumeriella
jaapii
).
Leaf Spot
,
Shot Hole
on garden plum
and apricot.
▶
Colletotrichum
Anthracnose
.
Colletotrichum acutatum
Fruit Spot
,
Crown
and Petiole Spot
on strawberry.
Colletotrichum coccodes
Leaf Spot
and
Slight
Blight
of velvetleaf.
Colletotrichum dematium f. sp. truncata
Leaf
Spot
and
Stem Canker
of
Stylosanthes
spp.
Colletotrichum elastica
▶
Colletotrichum
gloeosporioides
).
Leaf Spot
on fig (
Fiscus
carica
).
Leaf Spot
of basil, flowering dogwood,
cyclamen, jasmine, passion flower, leaf and stem
spot of calendula and dwarf mistletoe; on many
other hosts as anthracnose.
Colletotrichum gloeosporioides (formerly
Colletotrichum elastica
).
Leaf Spot
on fig
(
Fiscus carica
).
Leaf Spot
of basil, flowering
dogwood, cycla men, jasmine, passion
flower, leaf and stem spot of calendula and
dwarf mistletoe; on many other hosts as
anthracnose.
(see
▶
