Biology Reference
In-Depth Information
Sirrococcus elavigignenti-juglandacear-
um
Canker
of black walnut and butternut.
Sirococcus strobilinus
Shoot Blight
of
Picea,
Abies, Pinus
, and
Tsuga
spp.
Sporodesmium scorzonerae (see
Alternaria
many circular ispots, varying from pin point to
1/4 inch, brown with red borders.
▶
Sphaeropsis
Stemphylium
▶
Cankers and Diebacks
.
Sphaeropsis sapinea
Shoot Blight
of pine.
▶
Leaf Spots
.
Stemphylium vesicarium
Stemphylium Blight
of onions. Lesions are nondelineated, light yel-
low to brown, water-soaked and range in length
from one centimeter to the entire leaf.
Dothiora (Sphaerulina)
Ascomycetes, Dothideales
Systremma
Perithecia innate or finally erumpent, not beaked;
paraphyses and paraphysoids lacking; spores
hyaline, several-celled.
Dothiora
Ascomycetes, Dothideales
Sphaerulina
wolfii (formerly
Asci in locules in an elongated stroma, which
is erumpent and superficial at maturity; spores
light brown, two-celled. Conidial state
Lecanosticta
with brown conidia, two to four
cells, formed on a conidial stroma resembling
an acervulus.
Mycosphaerella dearnessii (formerly
Systremma acicola).
Pine Brown Spot Needle
Blight
, on southern pines, most serious on
longleaf. The name and classification of the fun-
gus has been in dispute. The conidial stage,
known since 1876, was first listed as
Septoria
,
later placed in
Lecanosticta
. The teleomorph
state was named
Scirrhia acicola
in 1939 but
later transferred to
Systremma
because of its col-
ored spores.
Most injurious on seedlings, needle blight may
also injure large trees. Small, gray-green spots on
needles turn brown and form a narrow brown
band, the needle tips dying. Three successive
seasons of brown spot kill longleaf seedlings.
The fungus is more severe on trees in unburned
areas because of accumulation of inoculum.
Spray seedlings in plantations with bordeaux
mixture every 2 weeks from May to October or
November.
Systremma
polyspora
).
Twig Blight
of
sourwood, and
oxydendron.
Dothiora taxicola (formerly
Sphaerulina taxi
).
Needle Blight
of yew.
Sphaerulina polyspora (see
Dothiora wolfii
).
Twig Blight
of sourwood, and oxydendron.
Sphaerulina taxi
(see
▶
Dothiora taxicola
).
Nee-
▶
dle Blight
of yew.
Sporidesmium
Deuteromycetes, Hyphomycetes
Conidiophores clustered, dark, short, simple,
each bearing a terminal conidium; conidia dark,
quite large, muriform with many cells, oblong to
ovoid; usually saprophytic, sometimes parasitic.
Alternaria scorzonerae (formerly
Sporodesmium scorzonerae
).
Salsify Leaf Blight
.
Leaves have many circular ispots, varying from
pin point to 1/4 inch, brown with red borders.
Leaves or whole tops die; roots are small and
unsalable. The fungus winters as mycelium and
spores in plant refuse. May be the same as
Alternaria tenuis
.
Sporidesmium maclurae
Leaf Blight
of osage-
orange.
Mycosphaerella
dearnessii
).
Pine Brown Spot Needle Blight
,on
southern pines, most serious on longleaf.
acicola
(see
▶
