Host Plants - Westcott's Plant Disease - page 459

W ILT , Yellows. Fusarium oxysporum f. sp.
conglutinans, general.
A general control program starts with
choosing varieties resistant to Fusarium yellows,
purchasing disease-free seed or having it hot-
water treated against blackleg and black rot,
growing in soil free from club root and careful
cleaning up of all vegetable refuse at the end of
the season.

Cactus, Giant, Saguaro (Carnegiea)

B ACTERIAL Blight. Erwinia carnegieana, AZ.
B ACTERIAL

Crown Gall. Agrobacterium

tumefaciens, AZ.
R OT ,Dry.Poria carnegieae; Heart, Fomes
robustus.
R OT , Seedling. Fusarium solani; F. oxysporum.
V IRUS . Saguaro Cactus, AZ.
The bacterial blight is spread over the whole
giant cactus area in Arizona, with mortality heavi-
est in magnificent specimens 150 to 200 years old.

Cactus (Cereus)

A NTHRACNOSE . Mycosphaerella opuntiae, TX.
B ACTERIAL Soft Rot. Erwinia carotovora, TX.
B LIGHT , Gray Mold; Rot. Botrytis cinerea, occa-
sional when too damp, indoors.
L EAF S CORCH . Hendersonia opuntiae, TX.
L EAF S POT , Black. Diplotheca ( Stevensea )
wrightii, TX; Stem, Septoria cacticola, TX.
N EMATODE , Cyst. Heterodera cacti; Nacobbis
batatiformis.
N EMATODE , Root Knot. Meloidogyne sp.
R OT ,Dry.Poria sp., CA.
R OT ,

Cactus, Prickly Pear (Opuntia)

A NTHRACNOSE ; Zonate Spot. Gloesporium
cactorum, FL, MS; Black Rot, Mycosphaerella
opuntiae, AL, FL, LA, NY, SC, TX.
B ACTERIAL Rot. Erwinia aroideae, FL, MS, OK,
TX.
B LACK M ILDEW . Lembosia cactorum, FL.
L EAF S CORCH . Hendersonia opuntiae, AL, KS,
MT, NJ, TX.
L EAF S POT , Black. Diplotheca wrightii, FL, TX.
N EMATODE , Root Knot. Meloidogyne sp.
N ONPARASITIC . Oedema, causing glassiness or
scab, from overwatering.
R OT , Charcoal. Macrophomina phaseoli, TX.
R OT , Cladode. Aspergillus alliaceus, TX;
Diplodia opuntiae, MD, KS, PA;
Physalospora obtusa, NY; P. rhodina, FL;
Phyllosticta cacti,NM;P. concava, MO, NJ,
OK, TX; Septoria fici-indicae, TX.
R OT , Root. Armillaria mellea, CA.
R OT , Stem. Phytophthora parasitica, NY;
Pythium debaryanum, CA.
V IRUS . Mosaic,MD;Chlorotic Ring Spot, AZ,
CA, ID, MT, NM, UT, WA, WY; Opuntia
Sammons, AZ; Tomato Spotted Wilt, PA.

Stem and Branch. Aspergillus

alliaceus, TX.
R OT , Root and Stem. Fusarium oxysporum, AZ,
CA; Helminthosporium cactivorum, CA,
TX; Phymatotrichum omnivorum, TX.

Cactus (Leuchtenbergia principis and
Schlumbergera gaertneri “Makoyana”)

N EMATODE , Cyst. Heterodera cacti.
V IRUS . Tomato Spotted Wilt, PA.

Cactus, Fishhook, Pincushion
(Mammillaria)

A NTHRACNOSE ; Zonate Spot. Gloeosporium
cactorum; Mycosphaerella opuntiae; Spine
Spot, Phoma mammillariae, MT.
N EMATODE , Root Knot. Meloidogyne incognita,
Bermuda Bot. Gard; Meloidogyne

Cactus, Star, Sea-Urchin, Barrel
(Echinocactus)

sp., TX;

Cyst, Heterodera cacti.
R OT , Root. Phymatotrichum omnivorum, TX.

A NTHRACNOSE . Mycosphaerella opuntiae, TX.
L EAF S CORCH ; Scald. Hendersonia opuntiae, TX.