Biology Reference
In-Depth Information
on contact with the epidermis, enlarges at the tip
into a brown thick-walled appressorium. From this,
a peglike infection hypha penetrates the cuticle.
Colletotrichum acutatum
Anthracnose
Colletotrichum dematium f. sp. truncata
An-
thracnose
on tomato. Found in Georgia on
Dolichos
.
Colletotrichum
on
Glomerella
cingulata
).
Rhubarb Anthracnose
,
Stalk Rot
.
Colletotrichum
erumpens
(
▶
almond, strawberry and black gum.
Colletotrichum
Glomerella
cingulata
)
Snapdragon Anthracnose
, on snap-
dragon, chiefly in greenhouses, sometimes out-
doors in late summer.
Colletotrichum atramentarium (or
C.
coccodes
).
Potato Anthracnose
,
Black Dot Dis-
ease
on potato stems and stolons following wilt
and other stem diseases, occasionally on tomato,
eggplant, and pepper; general distribution but
minor importance. Starting below the soil surface,
brown dead areas extend up and down the stem.
The partial girdling causes vines to lose their fresh
color and lower leaves to fall. Infection may
extend to stolons and roots. The black dots embed-
ded in epidermal cells, inside hollow stems and on
tubers, are sclerotia to carry the fungus over winter
and to produce conidia the following spring.
The fungus is a wound parasite ordinarily not
serious enough to call for control measures
other than cleaning up old refuse and using
healthy seed potatoes.
Colletotrichum
antirrhini
(
Glomerella
cingulata
).
Strawberry Anthracnose
found in
Florida and Louisiana.
Colletotrichum fuscum
Foxglove Anthrac-
nose
small spots to 1/8 inch, circular to angular,
brown to purple brown, on leaves; sunken, fusi-
form lesions on petioles and veins; minute black
acervuli, with bristles, in center of spots. Seed-
lings damp-off, older plants are killed or stunted
in warm moist weather. Use clean seed or treat
with hot water (131
F for 15 min).
Colletotrichum gloeosporioides
fragariae
(
▶
▶
Glomerella
cingulata
).
Lime Anthracnose
,
Withertip
, only
on lime in southern Florida.
Colletotrichum graminicola (formerly
Colletotrichum sublineola
).
Anthracnose
on
wild rice (
Zizania
).
Colletotrichum graminicola
Cereal Anthrac-
nose
widely distributed on barley, oats, rye,
wheat, sorghum, wild rice (
Zizamia
) and also on
cultivated lawn grasses, causing a root decay and
stem rot. Leaf spots are small, circular to elliptical,
reddish purple, enlarging and fading with age; cen-
ters have black acervuli. The fungus winters on
seed and plant refuse in or on soil. Improved soil
fertility reduces damage from this disease. This
pathogen also causes fruit anthracnose of tomato.
Colletotrichum higginsianum
Turnip Anthrac-
nose
, also on rutabaga, mustard greens, radish,
and Chinese cabbage in southeastern states. Very
small, circular gray spots on leaves, and elongate
brown or gray spots on midrib, petiole, and stem,
show pink pustules in centers of dead tissue.
Heavily infected leaves turn yellow and die;
young seeds in diseased pods may be killed.
Mustard variety Southern Curled Giant is highly
resistant.
Colletotrichum
(
▶
Glomerella
cingulata
) and other species.
Orchid Anthrac-
nose
,
Leaf Spot
on orchids coming in from the
tropics.
Colletotrichum capsici
Ripe Fruit Rot
of
pepper.
Colletotrichum coccodes
Anthracnose
bletiae (
▶
on
soybean.
Colletotrichum dematium (formerly
Colletotrichum omnivorum
).
Anthracnose
on
aspidistra and hosta. Large, whitish spots with
brown margins are formed on leaves and stalks.
Remove and burn infected plant parts.
Colletotrichum dematium
Anthracnose
on
spinach.
Colletotrichum dematium f. sp.
spinaciae
Spinach Anthracnose
. Known on
spinach since 1880 but unimportant in most
years. Leaves have few to many circular spots,
water-soaked, turning gray or brown, with setae
prominent in spore pustules. The fungus is seed-
borne.
lagenarium (see
Colletotrichum orbiculare
).
Melon Anthrac-
nose
on muskmelon, watermelon, cucumber,
and other cucurbits.
Colletotrichum
▶
liliacearum (see
Colletotrichum lilii
). Found on dead stems of
▶
