Biology Reference
In-Depth Information
Ascochyta clematidina
Clematis Leaf
and
Stem Spot
, widespread. On out-door plants
stems are infected near the ground and are often
girdled, upper portions dying back. Spores for
initial infection probably come from pycnidia
on stumps of old stems. Leaf spots are more
common in greenhouses, small, water-soaked,
then buff with reddish margins. Remove and
destroy infected leaves and stems.
Ascochyta compositarum
Leaf Spot
on aster,
eupatorium, silphium, and sunflower.
Ascochyta cornicola
Dogwood Leaf Spot
.
Ascochyta cypripedii
Cypripedium Leaf Spot
,
reported on orchid from Wisconsin. Leaf lesions
are narrow, brownish, with a dark brown border.
Ascochyta juglandis
Walnut Ring Spot
. Very
small, round, brown leaf spots between veins,
ringed with targetlike ridges. The disease is
unimportant in trees sprayed for walnut blight.
Ascochyta
formed on leaves and stems, sometimes cankers
at base of young stems. Black pustules in center
of spots discharge spore tendrils in wet weather.
The fungus winters in old plant refuse, is a weak
parasite, and is ordinarily too unimportant for
control measures.
Stagonosporopsis hortensis (formerly
Ascochyta boltschauseri
).
Leaf Spot
,
Pod Spot
of beans, on snap, kidney, lima, and scarlet runner
beans, reported in Oregon. Spots on leaves and
pods are dark to drab, zonate; light to dark brown
pycnidia are numerous.
Asteroma
Deuteromycetes, Coelomycetes
Pycnidia globose with a radiate subicle, a com-
pact, crustlike growth of mycelium underneath;
without an ostiole; spores hyaline, one-celled.
Asteroma
lycopersici
(Didymella
lycopersici) (see
Phoma lycopersici
)
Leaf
Spot
,
Ascochyta Blight
of tomato, eggplant, and
potato.
Ascochyta phaseolorum (see
▶
garretianum
Black
Spot
on
primrose.
Asteroma solidaginis
Black Spot
,
Black Scurf
on goldenrod.
Asteroma
Phoma exigua
).
▶
Leaf Spot
of snap beans.
Ascochyta pisi
Leaf Spot
,
Pod Spot
of pea.
General, but rare in the Northwest. One of three
species causing the disease complex known as
Ascochyta blight (also see
tenerrimum
Black
Spot
on
erythronium.
Blights
). Foliage
spots are circular to irregular, pinhead size to
1/2 inch. Stem lesions, at nodes or base, are
brown to purplish black. Brown pycnidia exude
spore tendrils in wet weather.
Phoma exigua (formerly
Ascochyta althaeina
).
Leaf Spot
of hollyhock, rose-mallow.
Phoma exigua (formerly
Ascochyta asteris
).
Leaf Spot
of China aster. Spray foliage with
bordeaux mixture.
Phoma exigua (formerly
Ascochyta
phaseolorum
).
Leaf Spot
of snap beans. Recent
isolation and inoculation studies indicate that
the Ascochyta leaf blights of hollyhock, okra,
pepper, eggplant, and tomato are all caused by
strains of the bean pathogen.
Phoma lycopersici (formerly
Ascochyta
lycopersici
(
Didymella lycopersici
)).
Leaf Spot
,
Ascochyta Blight
of tomato, eggplant, and
potato. Brown spots with concentric rings are
▶
Asteromella (Stictochlorella)
Deuteromycetes, Coelomycetes
Pycnidia smooth, with ostiole, densely gregari-
ous in asteroma-like spots; spores hyaline, one-
celled.
Asteromella lupini
Leaf Spot
on lupine.
Botrytis
▶
Blights
.
Botrytis fabae
Chocolate Leaf Spot
on vetch.
Calonectria
See
Cylindrocladium under Blights.
▶
