Biology Reference
In-Depth Information
also serious on Italian cypress. Twigs, branches,
and whole trees turn sickly, lose their leaves, and
finally die. The fungus attacks living bark and
cambium, girdling twig and branch. Cankers
appear first at base of lateral twigs; they are
slightly sunken, dark, resinous, rough, with
black spore pustules. Conidia have dark median
cells, five cross-walls (see
Fig. 1
). They are
spread by tools, in nursery stock, by wind and
rain, and perhaps by birds and insects. Infection
appears first in upper parts of trees, usually in
spring during moist weather. Yellowing and
browning of foliage together with gummy ooze
at the cankers form conspicuous symptoms.
Control
Drastic surgery, removing wood well
below infected parts, and spraying foliage
heavily with bordeaux mixture help some, but
with heavy infection the price of saving healthy
trees is the removal and destruction of all dis-
eased specimens. California citizens, threatened
with the loss of the famous native stands of Mon-
terey cypress at Point Lobos and Cypress Point,
voluntarily destroyed their own plantings by the
thousands.
Amphiporthe castanae (formerly
Cryptodiaporthe castanea
).
Dieback
,
Canker
of
Asiatic Chestnut, widespread, chiefly on seed-
lings or on larger trees in poor sites. Canker starts
as a brown discoloration of bark of the trunk,
limb, or twig, often girdling twig and then invad-
ing larger branch. Leaves on girdled branches
wilt without yellowing, turn brown, and die.
Bark splitting over callus formation at edge of
diseased area forms pronounced canker. Conidia,
two-celled, fusoid, are formed in pustules in bark;
beaked perithecia are formed in groups by
midsummer.
Control
Maintain vigor; plant on well-drained,
fertile soil. Prune out diseased portions several
inches below affected area.
Crytodiaporthe aculeans,
Sporocybe rhois,
Anamorph (see
Amphiporthe aculeans
).
Die-
back
,
Canker
of sumac.
Cryptodiaporthe castanea (see
▶
Amphiporthe
castanae
).
Dieback
,
Canker
of Asiatic Chestnut,
widespread, chiefly on seedlings or on larger
trees in poor sites.
Cryptodiaporthe salicella
Twig and Branch
Canker
of willow.
▶
Cryphonectria
Cryptomyces
Ascomycetes, Diaporthales
Ascomycetes, Rhytismatales
Production of perithecial ascocarps produced in
a stroma of fungal and substrate tissues or directly
from somatic hyphae on the substrate. Asco-
spores are hyaline to brown and one-to-several-
septate.
Cryphonectria parasitica
Canker
on oak.
Apothecia effuse, splitting irregularly; paraphy-
ses present; spores hyaline, one-celled.
Cryptomyces maximus
Blister Canker
on com-
mon and purple osier.
Cryptosporella
Cryptodiaporthe
Ascomycetes, Diaporthales
Ascomycetes, Sphaeriales, Valsaceae
Perithecia in a circle in a stroma, with long necks
converging in a common canal; spores one-
celled, hyaline; conidia borne on surface of
stroma.
Cryptosporella umbrina
Rose Brown Canker
,
a widespread and serious rose disease, first
reported in Virginia in 1917 but known from
Like
Diaporthe
but without blackened zones in
substratum; spores hyaline, two-celled.
Amphiporthe aculeans (formerly
Cryptodiaporthe aculeans
;
Sporocybe rhois
,
Anamorph).
Dieback
,
Canker
of sumac.
