Host Plants - Westcott's Plant Disease - page 615

P OWDERY M ILDEW . Erysiphe polygoni, CA, MO,
TX.
R OT , Black Root. Aphanomyces raphani,MEto
FL, CA, IA, OK, OR; Pythium
aphanidermatum, IN, KS, MA, MI, NY,
OH, OK, PA, SC, WI.
R OT , Crown, Watery Soft. Sclerotinia
sclerotiorum, CA, IN, MN, NJ, TX.
R OT ,Pod.Phoma lingam, CA, FL.
R OT , Root. Ascochyta sp.; Phymatotrichum
omnivorum, TX.
R UST . Puccinia aristidae (0, I), AZ, CO.
S CAB . Streptomyces scabies, IN, MI, NJ, OH,
TX, WI.
S CAB , Acid. Streptomyces acidiscabies,ME.
V IRUS . Radish Mosaic; Beet Curly Top;
Tobacco Streak, CA; Tomato Spotted Wilt
(on wild radish), GA.
W HITE R UST . Albugo candida, general.
W ILT ; Yellows. Fusarium oxysporum f. sp.
raphani; F. oxysporum f. sp. conglutinans,
CA.
Radishes are so easily grown in home gardens
that not many gardeners worry about disease con-
trol. Seed should, however, be treated for
damping-off and root rots.

R OT , Fruit. Gliocephabotrichum simplex, HI;
G. bulbilium, HI; Lasmenia sp., HI, Puerto
Rico; Pestalotiopsis virgatula, HI.

Ranunculus (Buttercup, Crowfoot)

B ACTERIAL , MLO. California Aster Yellows.
B ACTERIAL N ECROTIC L ESION , L EAF , S TEM .
Xanthomonas campestris, CA.
B LIGHT , GrayMold. Botrytis cinerea,CA,NY,WI.
D OWNY M ILDEW . Peronospora ficariae, occa-
sional MA to MD, IA, MN; also CA.
G ALL , f. Synchytrium anomalum,
IA; S. aureum,CA.IL,WI;S. cinnamomeum,
WI.
L EAF S POT . Ascochyta infuscans, WI;
Cercospora ranunculi, IA, WI;
Cylindrosporium ficariae, WA; Didymaria
didyma, IL, IN, IA, MA, MI, MS, NY, WI;
Fabraea ranunculi, CA, NE, NY, WI;
Ovularia decipiens; Ramularia aequivoca,
IL, IA, OR, WI; R. didyma, CA;
Septocylindrium ranunculi, IL, NY, WA,
WI; Septoria sp.
N EMATODE , Leaf and Stem. Ditylenchus dipsaci,
OR.
P OWDERY M ILDEW . Erysiphe polygoni, frequent
in eastern and central states; Sphaerotheca
macularis, CO.
R OT , Leaf. Ceratobasidium anceps, WI.
R OT , Root. Phymatotrichum omnivorum, TX.
R OT , Stem. Sclerotinia sclerotiorum, AZ, CA;
Pythium sp., CA; Sclerotium rolfsii, CA.
R UST . Puccinia andina (III), IL, IN; P. eatoniae
var. ranunculi (0, I), CT to SC, CA, CO, MS,
ND; II, III, on Sphenopholis ; P. ranunculi
(III), AZ, CO, UT, WA, WY, P. recondita
(0, I), WI to TX, CA, WA; III on Hordeum ;
Uromyces dactylidis (0, I), CO, MA, TX;
U. jonesii (0, I, III), CA, CO, MT, WY.
S MUT , Leaf. Doassansia ranunculina, IN, WI;
Urocystis anemones, IL, UT, WY.
S MUT , White. Entyloma microsporum, IL, IN,
IA, KY, VA, WI; E. ranunculi.
V IRUS . Beet Curly Top; Ranunculus Mottle;
Ranunculus Mosaic; Impatiens Necrotic
Spot, NC; Tomato Spotted Wilt, PA.

Ragweed (Ambrosia)

B ACTERIAL Blight. Pseudomonas syringae pv.
tagetis, WI.
D OWNY M ILDEW . Plasmopara halstedii,ND.
G ALLS , Stem. Protomyces gravidus, LA.
L EAF S POT . Phoma sp.
R OT ,R OOT . Rhizoctonia solani, TX.

Rain-Lily (Cooperia)

L EAF S POT . Cercospora amaryllidis, TX.
R UST . Puccinia cooperiae (0, I, II, III), TX.

Rambutan (Nephelium lappaceum)

C ANKER , Stem. Dolabra nepheliae, HI, Puerto
Rico.