Biology Reference
In-Depth Information
B
LIGHT
, Blossom; Gray Mold; Cutting Rot.
Botrytis cinerea, cosmopolitan.
L
EAF
S
POT
. Alternaria sp., secondary; Ascochyta
sp., CT, NJ; Cercospora brunkii, FL, MD,
OH, NH, TX; Pleosphaerulina sp., PA.
M
OLD
, Leaf. Botryosporium pulchrum, occa-
sional in greenhouses.
N
EMATODE
, Dagger. Xiphinema americanum.
N
EMATODE
, Leaf. Aphelenchoides sp., NY.
N
EMATODE
, Root Knot. Meloidogyne spp., CT,
FL, NJ, OH, OR.
N
ONPARASITIC
. Oedema, Dropsy. Intumescence
from excessive soil moisture and retarded
transpiration.
Crook-Neck. Chimeral mutation.
P
ETAL
Gazania (Treasure Flower)
R
OT
, Crown. Sclerotinia sclerotiorum, LA.
Genista (Wood-waxen)
D
IEBACK
. Diplodia sp., CA, NJ.
L
EAF
S
POT
. Pleiochaeta setosa, OR.
P
OWDERY
M
ILDEW
. Erysiphe polygoni, MO.
R
UST
.
Uromyces
genistae-tinctoriae
(II, III), CA.
R
UST
, Soybean. Phakopsora pachyrhizi, South-
ern U.S.
A
ND
L
EAF
S
POT
.
Bipolaris
(
Helminthosporium
) setariae, FL.
R
OT
, Blackleg, Stem and Cutting Rot. Pythium
debaryanum, P. mamillatum, P. splendens,
P. ultimum, P. vexans, cosmopolitan; Rhi-
zoctonia solani, cosmopolitan; Aspergillus
fischeri, CA; Fusarium sp., IN, NY, WA.
R
OT
, Root. Thielaviopsis basicola, CT;
Armillaria mellea, CA; Pythium
aphanidermatum, PA; P. dissotocum, PA:
P. ultimum, PA; P. heterothallicum, PA;
P. irregulare, PA; P. myriotylum, PA.
R
UST
, Pelargonium. Puccinia pelargonii-zonalis
(II), CA, FL, NY, PA.
V
IRUS
. Pelargonium Leaf Curl (Geranium Crin-
kle), general; Geranium Mosaic; Cucumber
Mosaic; Beet Curly Top; Tomato Spotted
Wilt, CA, OK, TX; Tomato Ring Spot;
Tobacco Ring Spot; Pelargonium Flower
Break; Pelargonium Line Pattern.
W
ILT
. Verticillium albo-atrum, CA, NY, OR.
The dry air of the average home makes
foliage diseases due to pathogenic organisms
unlikely but sometimes a water-logged soil and
cloudy weather, with less evaporation, leads to
oedema, small swellings in leaves, corky ridges
on petioles. Botrytis blight and bacterial leaf
spots may be expected in greenhouses unless
plants are spaced widely, have proper air circu-
lation, little overhead watering, and all infected
plants or parts speedily removed. Start with
clean cuttings from a culture-indexed mother
block.
Gentian (Gentiana)
B
LIGHT
, Stem Canker. Botrytis cinerea, NY.
L
EAF
S
POT
. Asteromella andrewsii
(
Mycosphaerella andrewsii
), DE, IL, IA,
NE, NJ, D, PA, WV, WI; Cercospora
gentianae, NY, ND, VT; C. gentianicola,
DE, WI.
R
OT
, Root. Fusarium solani,MD.
R
UST
. Puccinia gentianae (0, I, II, III), NY to IN,
NE, MN; western states to AK, CA, WA;
P. haleniae,WY;Uromyces gentianae (II,
III), CO, IA, NV, NM, NC, VT, WA, WY;
Pucciniastrum alaskanum, AK.
Geranium (Pelargonium)
B
ACTERIAL
Crown
Gall.
Agrobacterium
tumefaciens,MD,MA,OH.
B
ACTERIAL
Fasciation. Clavibacter fascians, IN,
MA, OH, OR.
B
ACTERIAL
Leaf Spot. Xanthomonas pelargonii,
MA to VA, CA, MS, OH, WA; Pseudomonas
cichorii, FL.
B
ACTERIAL
Wilt, Southern. Pseudomonas
solanacearum, NC; Ralstonia
solanacearum, Race 3, Biovar 2, CT, DE, PA.
