Biology Reference
In-Depth Information
Phomopsis
Phacidiopycnis
boycei ). Phomopsis Canker of lowland white fir.
Phomopsis discolor (see
boycei (see
Phragmodothella
Phacidiopycnis piri ,
Ascomycetes, Dothideales
see
Potabiamyces pyri ).
Pear branch canker and fruit rot.
Phomopsis
Teleomorph, see
elaeagni
(Syn.
Phomopsis
Asci in locules immersed in groups in
a cushionlike stroma; spores hyaline, many-
celled.
Dothiora ribesia (formerly Phragmodothella ).
Dieback , Black Pustule on currant, flowering cur-
rant, and gooseberry.
Phragmodothella
arnoldia ). Canker of Russian-olive.
Phomopsis gardeniae (Teleomorph, Diaporthe
gardeniae ). Gardenia Canker , Stem Gall , wide-
spread in greenhouses. Although not reported
until about 1933, this seems to be the most com-
mon gardenia disease. Symptoms start with
brown dead areas on stem, usually near the soil
line. The canker is first sunken, then, as the stem
enlarges, swollen with a rough, cracked outer
cork. The stem is bright yellow for a short dis-
tance above the canker, a contrast to its normal
greenish white. When stems are completely gir-
dled, the foliage wilts and dies; the plant may live
a few weeks in a stunted condition. Flower buds
fall before opening. When humidity is high, black
pycnidia on cankers exude yellowish spore
masses. Entrance is through wounds; spores
may be spread on propagating knives. Infection
often starts at leaf joints at the base of cuttings
after they have been placed in a rooting medium.
Because the cankers may be only slightly visible
on rooted cuttings, the disease may be widely
distributed by the sale of such cuttings.
Control Use sterilized rooting medium. Use
steam for a sand and peat mixture. Destroy
infected plants; sometimes it is possible to wait
until blooms are marketed.
Phomopsis lirella (Teleomorph, Diaporthe
vincae ). Canker , Dieback
Dothiora
ribesia ). Dieback , Black Pustule on currant,
flowering currant, and gooseberry.
ribesia (see
Physalospora
Blights .
Botryosphaeria corticis (formerly
Physalospora corticis ). Blueberry Cane Canker ,
in Southeast on cultivated blueberries. The fun-
gus enters through unbroken bark, probably
through lenticels, with cankers starting as red-
dish, broadly conical swellings, enlarging the
next year to rough, black, deeply fissured cankers
that girdle the shoots. The portions above cankers
are unfruitful and finally die. Avoid very suscep-
tible varieties like Cabot and Pioneer.
Botryosphaeria obtusa (formerly
Physalospora obtusa ( Sphaeropsis malorum )).
Dieback , Canker of hardwoods, New York
Apple-Tree Canker, Black Rot of Apple. The
fungus attacks leaves, twigs, and fruits, is more
important east of the Rocky Mountains, and is
found on many plants, including alder,
ampelopsis, birch, bignonia, bittersweet,
callicarpa, catalpa, ceanothus, chestnut, currant,
cotoneaster, hawthorn, Japanese quince, maple,
peach, pear, and persimmon. On hardwoods the
canker is similar to that caused by P. glandicola
on oaks. Limbs are girdled with large areas of
rough bark with numerous protruding black
pycnidia. For the fruit rot phase of this disease
of
vinca,
and
periwinkle.
Phomopsis lokoyae Phomopsis Canker of
Douglas-fir mostly on saplings in poor sites in
California and Oregon. Long, narrow cankers,
somewhat pointed at ends, develop during the
dormant season after young shoots are infected.
If the tree is not girdled during the first season, the
canker heals over.
Phomopsis mali Bark Canker of pear, and apple.
The bark is rough.
Phomopsis padina (Telomorph, Diaporthe
decorticans ). Canker , Twig Blight of sour cherry.
Phomopsis sp. Shoot Dieback on peach.
Rots .
Botryosphaeria quercuum (formerly
Physalospora glandicola ( Sphaeropsis quercina,
Anamorph )). Sphaeropsis Canker , Dieback of
 
 
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