Host Plants - Westcott's Plant Disease - page 566

P OWDERY M ILDEW . Golovinomyces

Melothria

cichoracearum, general.
R OT , Charcoal. Macrophomina phaseoli, CA,
OR, TX.
R OT , Corky Dry. Fusarium semitectum, FL.
R OT , Fruit. Fusarium spp., general in market,
also Alternaria spp.; Monilia sitophila, IN,
NY; Mucor sp., NY; Penicillium spp., blue
mold; Phytophthora spp.; Rhizopus
stolonifer, cosmopolitan; Trichoderma
viride, green mold; Trichothecium roseum,
pink mold, occasional in market.
R OT , Root. Monosporascus cannonballus and
Acremonium sp., CA; Phymatotrichum
omnivorum, TX; Pythium periplocum, CA.
R OT ,

D OWNY M ILDEW . Pseudoperonospora cubensis,
GA, OH, TX.
N EMATODE , Root Knot. Meloidogyne sp., FL.
P OWDERY

M ILDEW . Golovinomyces

cichoracearum, WI.

Mentzelia (Blazing Star)

L EAF S POT . Phyllosticta mentzeliae, KS, TX;
Septoria mentzeliae, KS, TX, WA.
R OT , Root. Phymatotrichum omnivorum, TX;
Rhizoctonia solani, NJ.
R UST . Puccinia aristidae (0, I), AZ, CO; II, III on
grasses; Uredo floridana, FL.

Root; Cottony Leak. Pythium

aphanidermatum, AZ, CA, TX.
R OT , Stem. Sclerotinia sclerotiorum, AR, MA,
TX; Cephalosporium sp.
S CAB . Cladosporium cucumerinum, occasional,
East and central states.
V IRUS . Beet Curly Top, AZ, CA, ID, OR, TX,
WA; Cucumber Mosaic, general; Musk-
melon Mosaic, general; Tobacco Ring Spot,
KS, MD, NC, PA, WI; Squash Mosaic;
Watermelon Mosaic; Zucchini Yellow
Mosaic, CA, FL, NY; Lettuce Infectious Yel-
lows, AZ, CA, TX; Muskmelon Vein Necro-
sis, CA; Melon Necrotic Spot; Melon Leaf
Curl, CA; Papaya Ring Spot, LA; Water-
melon Mosaic, LA; Cucurbit Leaf Curl, AZ,
TX; Cucurbit Yellow Stunting, AZ,TX,
Mexico; Melon Severe Mosaic, Mexico,
State of Guerrero; Potyvirus, CA.
W ILT . Fusarium oxysporum f. sp. melonis, gen-
eral Race 1 Colima, Mexico; Verticillium
alboatrum, CA, OR.
Melons belong to the cucurbit family and in
general have the same diseases as cucumbers.
Downy mildew is a problem on the moist East
Coast, and powdery mildew may be a limiting
factor in the arid Southwest. Although there are
varieties resistant to powdery mildew, different
physiological races of the fungus keep things com-
plicated. Sulfur dust should not be used except on
sulfur-resistant melon varieties. Mosaic is trans-
mitted both by seed and aphids; purchase virus-
free seed, eliminate weeds, and keep down insects.

Menziesia

G ALL , Leaf. Exobasidium vaccinii, Pacific
Northwest, AL, NC, VA, WV.
L EAF S POT , Tar. Melasmia menziesii, MT, and
WY to AK, OR; Rhytisma sp.
P OWDERY M ILDEW . Microsphaera alni var.

vaccinii, AK, VA.
R UST . Pucciniastrum myrtilli (II, III), WV;
0, I on hemlock.

Mertensia (Bluebells, Virginia Cowslip)

D OWNY M ILDEW . Peronospora sp., MT.
L EAF S POT . Septoria poseyi, OR.
P OWDERY M ILDEW . Golovinomyces
cichoracearum, AL, CO, MT, PA, NV, NM,
UT, WY.
R OT , Stem. Sclerotinia sclerotiorum, CO.
R UST . Puccinia mertensiae (III), CO, NV, UT,
WY; P. recondita (0, I), ID, MT, OR; II, III on
grasses.
S MUT , Leaf. Entyloma serotinum, IN, IA, MD,
VA, WY.
V IRUS . Cucumber Mosaic, IL, NJ.