Host Plants - Westcott's Plant Disease - page 489

R OT , Collar. Fomes ribis, NY to IN, MN, UT.
R OT , Root. Armillaria mellea, CA, OR,
WA; Phymatotrichum omnivorum, TX;
Hypholoma perplexum, NY.
R UST , White Pine Blister. Cronartium ribicola
(II, III), ME to VA, IL, MN, OR, SD, WA.
Puccinia caricis (0, I), CT, IN, MD, NY, II, III
on Carex.
V IRUS . Currant Mosaic, MD, NY.
W ILT . Verticillum sp., NY.
Black currant is the most important host of
white pine blister rust and should not be grown;
red currants should be kept at least 300 feet from
pines. Cut out canes with cane blight.

Cunninghamia

L EAF S POT . Necrotic. Phomopsis sp., OR.

Cuphea

B LIGHT , Gray Mold. Botrytis cinerea, occasional
in greenhouses.
L EAF S POT . Septoria maculifera, NY, PA, VA,
WV.
N EMATODE , Root Knot. Meloidogyne sp., MD.
P OWDERY M ILDEW . Erysiphe polygoni, MD, VA.
R OT , Root. Rhizoctonia solani, IL.
W ILT , Root Rot. Sclerotinia sclerotiorum MN,
ND.

Currant, Flowering (Ribes)

A NTHRACNOSE . Pseudopeziza ribis, IL, IA,

MN, MT.
B ACTERIAL Leaf Spot. Pseudomonas ribicola.
B LIGHT ;D IEBACK . Botrytis cinerea, AK, IN.
C ANKER ;D IEBACK . Botryosphaeria ribis, KS;
Phragmodothella ribesia, NY;
Thyronectria berolinensis, KS; Nectria
cinnabarina, AK, KS.
L EAF S POT . Cercospora angulata, MN;
C. ribicola, OR, WA; Marssonina ribicola,
CO; Mycosphaerella aurea, NY to KS, SD,
WA; M. ribis, NY to KS, MN, UT;
Phyllosticta grossulariae,IN;Septoria san-
guinea,WA.
R UST . Coleosporium jonesii,MN;Cronartium
occidentale, MT to NM, CA, WA;
C. ribicola, ME to MD, CO, MN, NV, Pacific
states; Melampsora ribesii-purpureae; II, III
on willow; Puccinia caricina, NY to IA, AK,
CA, OR; P. micrantha; P. parkerae.
V IRUS . Viruslike vein-banding, CA, CT, MN, NJ,
NY, OR, RI, WA.

Currant (Ribes spp.)

A NTHRACNOSE ; Fruit Spot. Pseudopeziza ribis,
general.
B LIGHT , Cane. Bostryosphaeria ribis var.

chromogena, general.
B LIGHT , Gray Mold; Fruit Spot. Botrytis cinerea,
Northeast, OR, WA.
B LIGHT , Thread. Pellicularia koleroga, FL.
C ANKER , Cane Knot. Thyronectria berolinensis,
CT to IN, KS, UT.
C ANKER ; DIEBACK. Nectria cinnabarina,ME
to CO, WA; N. ditissima, MN, NY; Black
Pustule, Phragmodothella ribesia, North-
east, Pacific Northwest.
D OWNY M ILDEW . Plasmopara viticola, WI.
L EAF S POT . Alternaria sp., MI;
Cylindrosporium ribis, WI;
Mycosphaerella ribis, ME to MD, AR, OR,
WA.
L EAF S POT , Angular. Cercospora angulata,NY
to VA, KS, MN; C. ribis, AL, IN, IA.
P OWDERY M ILDEW . Microsphaera grossulariae,
MT, NE, NH; Sphaerotheca mors-uvae, AK,
CA, CT, MT, NE, OR, WA; Phyllactinia
corylea, MI.
R OT , Berry. Glomerella cingulata, CT, PA.

Cycad, Sago-Palm (Cycas)

C ORALLOID R OOTS . Anabaena cycadearum and
Nostoc commune, algae, and bacterium Azo-
tobacter are associated with roots but are
mostly innocuous.