Biology Reference
In-Depth Information
Elsino¨ quercicola Spot Anthracnose on water
oak, Florida.
Elsino¨ quercus-falcatae Spot Anthracnose on
southern red oak, Georgia, South Carolina.
Blackish brown leaf spots are few to abundant,
scattered over upper surface.
Elsino¨ randii Pecan Anthracnose , Nursery
Blight on pecans in the Southeast, an important
nursery disease, limiting factor in production of
budded pecans in wet seasons. Small reddish
lesions develop on both leaf surfaces, those on
the upper surface later turning ash gray. Diseased
tissues become brittle and fall out, leaving ragged
margins and perforations. Spray trees with bor-
deaux mixture when first leaves are half grown;
follow with three sprays of bordeaux at 3-to 4-
week intervals.
Elsino¨ rosarum Rose Anthracnose , wide-
spread on rose, collected on wild roses as early
as 1898, in most areas more important on
climbing roses than on hybrid teas. Leaf spots
are scattered or grouped, sometimes running
together, usually circular, up to 1/4 inch.
Young spots are red, varying brown or dark pur-
ple on upper leaf surface, showing up to 2 to 6
days after inoculation but not visible on under
surface for 2 to 4 weeks, then dull reddish
brown to pale purple. On aging, the center of
the spot turns ashen white, with a dark red
margin. Leaves may turn yellow or reddish in
area of spots, may have slits or perforations as
the centers fall out.
Cane spots are circular to elongated, raised,
brown or purple, with depressed light centers and
acervuli in barely visible dark masses. The fun-
gus winters in cane spots; spores are produced
and spread only in rainy periods. A single leaf
lesion may produce 10,000 spores within an hour
after wetting and will continue production as long
as the rain lasts.
Control Where possible, prune out infected
canes in spring. Keep foliage protected as for
blackspot. Sulfur and copper compounds are
effective.
Elsino¨ solidaginis Goldenrod Scab in Florida,
South Carolina, and Georgia. New growth is
affected as it develops. Lesions formed on mid-
rib, veins, petioles, and leaf blades are raised on
one surface, sunken on the other, with white to
gray centers and brown borders.
Elsino¨ tiliae Linden Spot Anthracnose
reported from Nova Scotia and Virginia. Gray
spots with black margins are numerous on leave
blades and petioles.
Elsino¨ veneta Bramble Anthracnose , general
on blackberry, dewberry, raspberry, being most
common on black raspberry. Circular, reddish
brown sunken spots with purple margins and
light gray centers, up to 3/8 inch in diameter,
appear on young shoots. On older canes these
grow together into large cankers. Similar spots,
not always with purple margins, are formed on
fruit, leaf, and flower stalks. Leaf spots are first
yellowish, then with a red margin around a light
center, which may drop out. Leaves may drop
prematurely; fruit may dry up as a result of loss
of water from infected canes. Primary spring
infection comes from ascospores produced in
old lesions on canes; secondary spread is by
conidia.
Control Cut old canes or “handles” from black
raspberries after setting; remove and burn old
fruiting canes after harvest. In some cases the
single late dormant spray has controlled anthrac-
nose without later sprays; in others three foliage
sprays have been effective without a dormant
spray. Black raspberry Quillen is quite resistant.
Sphaceloma
Deuteromycetes, Coelomycetes
Acervuli disc-or cushion-shaped, waxy; conidio-
phores simple, closely grouped or compacted,
arising from a stromalike base; spores one-celled,
hyaline, ovoid or oblong. Teleomorph state
where known is Elsinoe¨.
Aralia Scab on Hercules club ( Aralia spinosa ),
Maryland and Missouri.
Sphaceloma hederae English Ivy Scab . Leaf
spots are raised with red-brown margins, pale
depressed centers, often numerous.
Sphaceloma lippiae Lippia Spot Anthracnose
on fog-fruit. Closely resembling mint anthrac-
nose and found in same fields in Indiana, also
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