Host Plants - Westcott's Plant Disease - page 432

spp.; Colletotrichum fructus; Rhizopus
nigricans,

S POT A NTHRACNOSE . Elsino¨ piri, OR, WA.
V IRUS . Apple Chlorotic Leaf Spot; Apple Stem
Growing; Apple Mosaic; Tulare Apple
Mosaic, CA; Tobacco Mosaic; Dapple
Apple, NH; Green Mottle, NY; Stem-
pitting; Tomato Ringspot, NY; Decline and
Graft Union Necrosis, WA.
W ILT . Verticillium albo-atrum.
If this appalling list of diseases should make
you think twice before planting apples in the
backyard with the expectation of getting cheap
and abundant fruit, that is all to the good.
There is no easy, or cheap, road to perfect
fruit. The commercial grower may, in a wet
season, apply nearly 20 sprays to keep scab
under control. The homeowner thinks one or
two are enough. State experiment stations offer
abbreviated schedules for home gardeners, tai-
lored for the area, and if these are followed
carefully, a fairly good crop can be expected.
There are also all-purpose mixtures available
for fruit trees, which may work reasonably
well. Scab is the most important apple disease,
and proper timing of early season sprays is
most essential. Bitter rot, black rot, sometimes
rust need attention. Fire blight control is pri-
marily a question of proper pruning to remove
infected wood, with an antibiotic spray during
bloom.

cosmopolitan; Phytophthora

syringae, OR.
R OT , Fruit (Postharvest). Botrytis cinerea,
Phomopsis mali, core rot, CA, NY;
Trichoderma harzianum,MD;Sphaeropsis
pyriputrescens, WA; Phacidiopycnis
washingtonensis; Potebniamyces pyri, WA.
R OT , Heartwood. Fomes fomentarius;
F. igniarius; F. pinicola; Ganoderma
applanatum.
R OT , Mushroom Root. Armillaria mellea, prev-
alent on Pacific Coast; Clitocybe tabescens,
AR, FL, TX, VA.
R OT , Postharvest Speck. Phacidiopycnis

washingtonensis,WA.
R OT , Root. Botryodiplodia theobromae,
AL; Hymatotrichum omnivorum, AK, AZ,
NM, TX; Fusarium oxysporum, ID;

F. solani, ID.
R OT , Silverleaf. Stereum purpureum, KS, ME,
MN, NY, Pacific Northwest.
R OT , White Root. Corticium galactinum,DEto
VA; AR, IL; Rosellinia necatrix, CA.
R OT , Wood. Daedalea confragosa; Poria spp.;
Pleurotus ulmarius; Pholiota adiposa;
Polyporus spp.; Stereum sp.; Schizophyllum
commune; Trametes spp.
R USSET , Fruit. Aureobasidium pullulans and
Rhodotorula glutinis, NY.
R UST . Gymnosporangium libocedri. (0, I), on
leaves, fruit; III on incense cedar, CA, OR;
Gymnosporangium nidus-avis (0, I), on
leaves, fruit, stems, IN, MD, MS, NJ; III on
red-cedar.
R UST , Cedar-Apple. Gymnosporangium
juniperivirginianae (0, I) on leaves, fruit;
general east of Great Plains; III on red-cedar
and Rocky Mountain juniper.
R UST , Hawthorn. Gymnosporangium globosum
(0, I) on leaves; III on red-cedar, ME to AK,
KS, NE.
R UST , Quince. Gymnosporangium clavipes
(0, I), on fruit; III on common juniper and
red-cedar.
S CAB . Venturia inaequalis, general.
S OOTY M OLD . Fumago vagans, occasional.

Apple-of-Peru (Nicandra)

L EAF S POT . Cercospora physaloides,IN.
R OT , Root. Phymatotrichum omnivorum, TX.
V IRUS . Mosaic. Unidentified, ID, IA, KY,
WA, WI. Experimentally infected with
several viruses; Tomato Leaf Curl, CA,

Mexico.

Apricot (Prunus armeniaca)

B ACTERIAL canker; Gummosis. Pseudomonas
syringae,CA,OR;Criconema mutabile,CA.