Host Plants - Westcott's Plant Disease - page 491

R OT , Charcoal. Macrophomina phaseoli, OK,
SC.
R OT ,

Cypress-Vine (Quamoclit)

Root. Armillaria mellea, CA;

N EMATODE , Root Knot. Meloidogyne sp., AL.
R OT , Root. Phymatotrichum omnivorum,
TX.
R UST . Coleosporium ipomoeae (II,

Phymatotrichum omnivorum; TX.
R OT , Stem. Sclerotinia sclerotiorum, CA, ME,
NY.
R OT , Stem, Root, Cutting. Pythium spp.; Rhizoc-
tonia solani; Fusarium roseum.
S CAB . Streptomyces scabies, NC.
S MUT , Leaf. Entyloma dahliae, CA, NJ, OR.
V IRUS . Dahlia Mosaic, general; Tomato Spotted
Wilt, CA, MI, NJ, NY, NC, OK, TX, WI;
Cucumber Mosaic; Tobacco Ring Spot.
W ILT . Fusarium oxysporum; Verticillium albo-
atrum ( V. dahliae ) IL, MI, MO, NJ, OH, TX.
Leafhopper injury, hopperburn, looks
like a true disease. Margins of leaves turn brown,
and there may be general stunting and yellowing.
The spotted wilt virus causes yellow ring spots in
dahlia foliage. Heavy, wet soil contributes to bac-
terial and fungus rots and wilts. Mildew is often
prevalent in late summer.

III), IL,

SC, TN.
W HITE R UST . Albugo ipomeae-panduratae,
MS, NM.

Cyrilla (Leatherwood)

C ANKER , Brown Felt. Septobasidium sinuosum,
FL.
L EAF S POT . Phyllosticta cyrillae, FL.
R UST . Aecidium cyrillae, FL, LA, MS.

Dahlia

B ACTERIAL Crown Gall. Agrobacterium

tumefaciens, CT, IL.
B ACTERIAL , MLO. Aster Yellows,MD.
B ACTERIAL Rot. Erwinia carotovora, MS, WA;
E. cytolitica,NY.
B ACTERIAL Wilt. Pseudomonas solanacearum,
DE, MI, MS, NJ, NC, OK, TX.
B LIGHT , Blossom. Choanephora americana, FL;
Stemphylium floridanum.
B LIGHT , Gray Mold. Botrytis cinerea, cosmopol-
itan on flower buds.
B LIGHT , Southern. Sclerotium rolfsii, FL, KS,
MS, NJ, NC, TX.
L EAF S POT . Alternaria sp., VA to AL, MO, MI,
secondary; Cercospora sp., FL, MS.
N EMATODE , Bulb. Ditylenchus destructor, OR.
N EMATODE , Leaf. Aphelenchoides ritzemabosi,
CA.
N EMATODE ,

Daisy, Oxeye (Leucanthemum vulgare)

B ACTERIAL , MLO. Aster Yellows, KS, NJ, NY.
B LIGHT , Southern. Sclerotium rolfsii, TX.
L EAF S POT . Cylindrosporium chrysanthemi,
OK; Septoria chrysanthemella;
S. leucanthemi, blotch, CT, NY.
N EMATODE , Root Knot. Meloidogyne sp.
N EMATODE , Stem. Ditylenchus dipsaci, NY.
R OT , Root. Phymatotrichum omnivorum, TX.
R OT , Stem. Fusarium roseum and F. solani, TX;
Sclerotinia sclerotiorum, TX.
V IRUS . Potato Yellow Dwarf, NY.

Dalibarda (Dewdrop)

Root. Paratrichodorus

pachydermus, MI.
N EMATODE , Root Knot. Meloidogyne sp., NC to
AL, AZ, CA, MO, TX.
P OWDERY M ILDEW . Golovinomyces
cichoracearum, general; Ersiphe polygoni,
CA, DE, GA, IA, MO, NJ, PA, VA; Uncinula
sp., NC.

L EAF S POT . Septoria dalibardae, ME, MI, NH,
NY, VT.

Dandelion (Taraxacum)

V IRUS . Tomato Ringspot, PA.