Biology Reference
In-Depth Information
The canker stain of London plane and Amer-
ican sycamore flared up in epidemic form around
Philadelphia in 1935, killing thousands of street
and ornamental trees from Newark to Baltimore
before it was learned the fungus was spread in
pruning and in tree paint as well as by certain
beetles. Pruning is now restricted to winter
months, and a disinfectant is added to the
wound dressing. Sycamore anthracnose is serious
in wet seasons, particularly when the mean daily
temperature for 2 weeks after bud-break is below
55
F.
C
ANKER
. Phytophthora cactorum, CA,
IN;
Ceratocystis
fimbriata,
CA;
Valsa
(
Cytospora
)
leucostoma,
dieback,
widespread.
L
EAF
C
URL
; Witches Broom. Taphrina spp.,
occasional;
T. communis, plum pockets;
T.
pruni,
pockets,
bladder
plums;
T. insititiae.
L
EAF
S
CORCH
. Xylella fastidiosa, Southern CA.
L
EAF
S
POT
; Shot Hole. Cercospora
circumscissa, CA, FL, MA, TX, WA;
Coccomyces prunophorae, widespread;
Coryneum carpophilum, CA to ID and
WA; Phyllosticta circumscissa, IA, WA;
Septoria pruni, TX.
M
ISTLETOE
. Phoradendron serotinum
(flavescens), TX; Viscum album, CA, on
Prunus salicina
(“Santa Rosa” Plum).
N
EMATODE
, Lesion. Pratylenchus pratensis;
P. vulnus.
N
EMATODE
, Root Knot. Meloidogyne
Plantain, Common (Plantago)
V
IRUS
. Tomato Ringspot, PA; Plantago Mottle,
NY; Ribgrass Mosaic, NY.
Platycodon (Balloon-Flower)
spp.,
FL, TX.
N
ONPARASITIC
. Brown Bark Spot. Arsenical poi-
soning, MT.
Chlorosis. Alkaline soil, mineral deficiency,
CA, FL.
Exanthema. Copper deficiency, CA, FL.
Gum Spot, Drought Spot. Irregular water supply,
NY, Pacific Northwest.
Little Leaf. Zinc deficiency, CA, OR, WA.
Marginal Scorch. Fluorine injury, WA.
Myrobalan Asteroid Spot. Cause unknown,
occasional.
Myrobalan Mottle. Genetic abnormality, occa-
sional in seed stocks.
Wind Scab. Caused by developing fruit rubbing
against other fruit, leaves and shoots during
strong wind, CA.
P
OWDERY
M
ILDEW
. Podosphaera oxyacanthae
var. tridactyla, occasional.
P
OX
, Plum. NY, PA.
R
OT
, Brown; Blossom Blight. Monilinia
fructicola, general; M. laxa, MA, NY, RI.
R
OT
, Fruit. Alternaria sp., OR; Botrytis cinerea,
CA, WA; Cladosporium sp.,
B
LIGHT
. Phytophthora cactorum, MN.
R
OT
, Root. Rhizoctonia solani, CT, PA;
Phymatotrichum omnivorum, TX.
Plum (Garden), Prune (Prunus
domestica)
B
ACTERIAL
Crown
Gall.
Agrobacterium
tumefaciens, widespread.
B
ACTERIAL
Fire Blight. Erwinia amylovora,
occasional, OR, WA.
B
ACTERIAL
Leaf Spot; Black Spot. Xanthomonas
pruni, eastern and southern states to WI, TX.
B
ACTERIAL
Shoot Blight; Gummosis. Pseudomo-
nas syringae, CA.
B
LACK
K
NOT
. Dibotryon morbosum, widespread
except far West.
B
LIGHT
, Blossom, Twig. Monilinia laxa, CA,
OR, WA; Botrytis cinerea.
B
LIGHT
, Thread. Pellicularia koleroga, LA.
B
LIGHT
, Twig. Diplodia spp., secondary.
B
LOTCH
,Leaf.Phyllosticta congesta,GA,TX.
B
LOTCH
, Sooty; Flyspeck. Zygophiala
cryptogama, Z. wisconsinensis, Pseudocer-
cosporella sp., Stomiopeltis spp., IA.
ID, OR;
Lambertella pruni, CA.
R
OT
, Heart. Fomes applanatus, OR; F. fulvus,
widespread;
Lenzites
saepiaria, Pacific
