Biology Reference
In-Depth Information
Diplodia juglandis
Dieback
, widespread on
branches of walnut.
Diplodia mutila
Stem Canker
on Laburnum.
Branch Dieback
on juniper.
Diplodia
slightly darker, sunken areas, often at base of
twigs and limbs, and become elongated. The
bark is killed to the cambium; sapwood is
brown. If a stem is completely girdled, it dies;
otherwise, callus formation goes on through the
summer, over the canker. In time diseased bark
turns brown and cracks. Spores are extruded in
amber tendrils, drying to brown, and are washed
to wounds in the wood.
Control
Destroy infected stock in nurseries and
plantations; do not move stock from a nursery
where the disease is known. Avoid pruning and
other wounds so far as possible; sterilize tools
between cuts. Spraying nursery trees with bor-
deaux mixture in spring may be helpful.
Dothichiza
Lasiodiplodia
theobromae
).
Stem Canker
of prickly-ash;
Die-
back
of citrus twigs, also causing citrus stem-end
rot.
Diplodia quercina
Canker
and
Blight
of oaks.
Diplodia sophorae
Dieback
of pagoda tree.
Diplodia sycina
Canker
,
Dieback
of fig.
Lasiodiplodia theobromae (formerly
Diplodia
natalensis
).
Stem Canker
of prickly-ash;
Die-
back
of citrus twigs, also causing citrus stem-
end rot.
▶
natalensis (see
▶
Rots
.
Sphaeropsis hyalina (formerly
Diplodia
infuscans
).
Ash Canker
and
Dieback
, northeast-
ern states.
Discosporium
populeum
).
Dothichiza Canker
of poplar;
Euro-
pean Poplar Canker
, widespread but sporadic as
a branch and trunk canker.
populea (see
▶
Discella
Dothiora
Deuteromycetes, Coelomycetes
Ascomycetes, Pseudosphaeriales
Pycnidia cupulate or discoid; spores 2-celled,
hyaline.
Discella
Ascocarps
hairy
and
phragonosporous
or
muriform ascospores are colored.
Dothiora
carbonacea
(see
Discella
polyspora
(see
Sydowia
▶
▶
microsperma
).
Twig Canker
of willow.
Discella microsperma (formerly
dothideoides
).
Canker
of aspen.
Sydowia dothideoides (formerly
Dothiora
polyspora
).
Canker
of aspen.
Discella
carbonacea
).
Twig Canker
of willow.
Dothichiza
Dothiorella
Deuteromycetes, Coelomycetes
Deuteromycetes, Coelomycetes
Pycnidia innate, finally erumpent; conidiophores
lacking; conidia hyaline, one-celled.
Discosporium populeum (formerly
Dothichiza
populea
).
Dothichiza Canker
of poplar;
Euro-
pean Poplar Canker
, widespread but sporadic as
a branch and trunk canker. Lombardy poplars are
most susceptible, but hosts include black and
eastern cottonwoods, balsam, black and Norway
poplars. Japanese poplars are rather resistant.
Young trees in nurseries are most injured, can-
kers often starting around wounds. They start as
Pycnidia dark, globose, grouped in a subcortical
stroma; conidiophores simple, short; conidia hya-
line, one-celled, ovoid to ellipsoid; parasitic or
saprophytic on wood.
Botryodiplodia gallae (formerly
Dothiorella
quercina
).
Dothiorella Canker
of oak, very
destructive to red and white oaks in Illinois,
affecting twigs, branches, and occasionally
trunks. Cankers are dark brown, elongated,
sunken, often with cracks at the margin. Pustules
of pycnidia develop in bark and erupt through
