Anthracnose - Westcott's Plant Disease - page 58

Infection is often secondary, in tissues weakened
from other causes. See also under ▶ Cankers and
Diebacks and under

spread by tools, insects, and workmen. Rotation
of crops and sanitary measures may be sufficient
control.
Glomerella cingulata (formerly Gloeosporium
limetticolum ). Lime Anthracnose Withertip ,only
on lime in southern Florida. Shoots, leaves, and
fruits are infected when young; mature tissues are
immune. Twigs wither and shrivel from one inch
to several inches back from the tip; young leaves
have dead areas or are distorted; buds fail to open
and may drop; fruits drop, or are misshapen, or
have shallow spots or depressed cankers.
Control Spray with bordeaux-oil emulsion as
fruit is setting, with two or three applications of
1 to 40 lime sulfur at 7-14 day intervals.
Glomerella cingulata (formerly Gloeosporium
apocryptum ). Maple Anthracnose Leaf Blight ,an
important leaf disease of silver maple, common
also on other maples and boxelder, appearing from
late May to August. The leaf spots are light brown,
often merging with the leaves, appearing scorched.
The effect may be confused with the physiological
scorch caused by hot weather. On Norway maples
the leaf lesions are confined to purple to brown
lines along the veins. In rainy seasons there may
be severe defoliation.
Control If trees have been affected more than
a year or so, feed to stimulate vigorous growth.
Spray with a copper fungicide two or three times at
14-day intervals, starting when buds break open.
Glomerella cingulata (formerly
Colletotrichum bletiae ) and other species. Orchid
Anthracnose Leaf Spot on orchids coming in from
the tropics. Lemon-colored acervuli are formed in
soft, blackish spots in ragged leaves. Burn diseased
plants or parts. Spray with a copper fungicide.
Glomerella cingulata (formerly
Colletotrichum pisi ). Pea Anthracnose Leaf and
Pod Spot commonly associated with Ascochyta
blight and often a secondary parasite. Spots on
pods, stems, and leaves are sunken, gray, circular,
with dark borders. Crop rotation is the best control.
Glomerella cingulata (formerly Gloeosporium
piperatum ). Pepper Anthracnose , Fruit Spot ,
sometimes a leaf and stem spot but more often
a disease of green or ripe fruit. Spots are dark,
sunken, with concentric rings of acervuli and
pink masses of spores, which are washed to

Rots .
On citrus, orange, lemon, grapefruit there is
a dying back or withertip of twigs. Leaf spots are
light green turning brown, with pinkish spore pus-
tules prominent in wet weather. Decayed spots are
produced on ripening fruits in storage. Similar
withertip symptoms may also appear on avocado,
aucuba, cherimoya, fig, loquat, roselle,
rosemallow, royal palm, dieffenbachia, rubber-
plant, strawberry and other ornamentals and fruits.
The disease has also been reported on European
white birch in Virginia. Lack of water and nutrient
deficiency predispose plants to infection by this
weak parasite. The fungus attacks blue lupine and
statice or sea-lavender; peach anthracnose became
important in Georgia when lupine was used as
a ground cover in orchards. Sweet pea anthracnose
is often more severe near apple orchards where the
fungus winters on cankered apple limbs and in
bitter rot mummies. Whitish lesions disfigure
sweet pea leaves, shoots, and flower stalks. Leaves
wither and fall; stalks dry up before blossoming;
seed pods shrivel. There may be general wilting
and shoot dieback.
Anthracnose and twig blight are widespread
on privet. Leaves dry and cling to the stem; can-
kers at the base of stems are dotted with pink
pustules. Bark turns brown and splits; death fol-
lows complete girdling of stems. European privet
is highly susceptible; California, Amur, Ibota,
and Regal privets are fairly resistant. Also found
on black locust in GA and SC and pecan in GA.
Control Remove infected twigs and branches
from trees and shrubs, taking care to make
smooth cuts at base of limbs and painting surfaces
with a wound dressing. Plant sweet peas, from
healthy pods, at a distance from apple and privet,
in clean soil; rake up and burn plant refuse at the
end of the season.
Glomerella cingulata (formerly Gloeosporium
melongenae ). (possibly identical with G.
piperatum ). Eggplant Anthracnose Ripe Rot ,an
occasional trouble. Yellow to brown spots on
leaves and small to medium depressed spots on
fruit show pink spore masses following rain or
heavy dew. Spores are splashed by rain and

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