Biology Reference
In-Depth Information
by high soil temperature. Some commercial pea
varieties are resistant to race 1 but not to race 2.
Delwiche Commando was the first variety intro-
duced resistant to both races.
Fusarium oxysporum f. sp. raphani
Radish
Wilt
. Young plants turn yellow and die; others
are stunted, with discoloration of roots.
Fusarium oxysporum f. sp. spinaciae -
Fusarium Wilt
of spinach. Plants are pale; leaves
roll inward, gradually die. The wilt is serious in
Texas and Virginia. One form of the mosaic-
resistant Savoy spinach is also resistant to wilt.
Fusarium oxysporum f. sp. tracheiphilum
Wilt
of cowpea.
Fusarium solani f. sp. pisi
Wilt
of chick-pea.
3 years old, seldom on older shrubs, most severe
on
Rhododendron ponticum
. The foliage is first
dull yellow, then permanently wilted, roots are
decayed; stems are brown at soil level and below.
Remove infected stock from frames immediately;
avoid excessive irrigation; keep soil acidity at pH
4.0 to 4.5; provide shade and mulch for young
plants. This pathogen also causes wilt of Japanese
umbrella tree.
See under
Rots
for this fungus at work on
many other plants.
▶
Pythium
Rots
.
Pythium myriotylum
Wilt
on peanut.
Pythium tracheiphilum
Wilt
on lettuce and
also leaf blight.
Pythium aphanidermatum
Wilt
of
Nicotiana
.
▶
Hendersonula
Deuteromycetes, Coelomycetes
Pycnidia dark, separate; spores dark with several
cells.
Hendersonula toruloidea
Branch Wilt
of wal-
nut.
Canker
, destructive to Persian walnuts but
associated with sunburn of affected branches.
The fungus is a wound parasite.
Rhizoctonia
Blights
.
Rhizoctonia solani
Wilt
of watermelon.
▶
Sclerotinia
Phialophora
Blights
.
Sclerotinia minor
Wilt
of
▶
Rots
.
Phialophora gregata
Wilt
of chick-pea.
lupine and wild
▶
garlic.
Phomopsis
Verticillium
Deuteromycetes, Coelomycetes
Blights
.
Phomopsis sp
Wilt
on ice plant.
▶
Conidia one-celled, hyaline, globose to ellipsoid,
formed at tips of whorled branches and separating
readily from tips.
Verticillium albo-atrum
Verticillium Wilt
,
Maple Wilt
of many ornamental trees, shrubs,
fruits, flowers and vegetables. The fungus was
first isolated from potatoes in Germany in 1870
but apparently was present in California as early
as 1850. It attacks nearly 300 cultivated plants of
Phytophthora
Blights
.
Phytophthora
▶
cactorum
Wilt
of
blue
laceflower and baby's breath.
Phytophthora cinnamomi
Rhododendron
Wilt
. A wilt of young stock, grafted plants 2 to
