Biology Reference
In-Depth Information
C ANKER , Felt Fungus. Septobasidium spp., NC.
L EAF S POT . Alternaria sp.; Ascochyta
negundinis, IL, NC: Cercosporanegundinis,
KS, NE, WI; Piggotia negundinis, WI;
Phyllosticta minima, general; P. negundinis,
ME to AL, TX, WI; Septoria aceris, general;
S. negundinis; Cylindrosporium
negundinis; Cristulariella pyramidalis.
L EAF S POT , Tar. Rhytisma punctatum, CA, NY;
R. acerinum, OR, WA.
P OWDERY M ILDEW . Phyllactinia corylea, SD;
Microsphaera alni, Uncinula circinata;
Sawadaea bicornis, WI.
R OT , Root. Phymatotrichum omnivorum, CA,
TX; Helicobasidium purpureum, TX.
W ILT . Verticillium albo-atrum, occasional.
N EMATODE , Stubby Root. Trichodorus sp.
N ONPARASITIC . Freezing. Ice standing on stems
causes bark to slough off and branches die
back for months thereafter.
Sunscald. Injury in late winter or early spring
when covering is removed in bright sun or
high wind.
R OT , Root. Armillaria mellea, NJ; Fusarium
oxysporum and F. solani, MD, perhaps sec-
ondary; Phymatotrichum omnivorum, TX;
Phytophthora parasitica, MD, NC;
P. cactorum, NC; P. citrophthora, NC;
Pythium sp., MA; Rhizoctonia solani, cos-
mopolitan after nematode injury.
R OT , Heart; Trunk. Ganoderma lucidum,
VA; Fomes igniarius, VA; Poria punctata,
VA.
R OT , Root; Decline. Paecilomyces buxi and
some Fusaria, VA.
V IRUS . Variegation, cause unknown, MD, NY,
VA.
Salmon-pink pustules appearing on backs
of leaves, along twigs, and on main stems are
indications of Volutella buxi , controlled by thor-
ough cleaning, then spraying. Much of the die-
back, bronzing, general unhealth of boxwood is
due to nematodes, especially spiral and root
lesion or meadow.
Boxwood (Buxus)
B LIGHT , Box. Cylindrocladium pseudona-
viculatum, NC.
B LIGHT , Leaf Cast. Hyponectria buxi, general;
Verticillium buxi, cosmopolitan on dead
leaves, often associated with Hyponectria .
B LIGHT , Leaf Tip. Phoma conidiogena, MD, NJ,
NY, OK.
C ANKER , “Nectria”; Leaf Blight. Volutella buxi,
general; considered imperfect stage of
Pseudonectria rouselliana but unconfirmed
connection.
C ANKER ;D IEBACK . Fusarium buxicola ( Nectria
desmazierii) , AL, MD, PA; F. lateritium (see
Brachiaria (Broadleaf signalgrass)
R OT , Root. Pythium arrhenomanes, LA.
Gibberella baccata ), secondary, MD, SC,
VA.
L EAF S POT . Phyllosticta auerswaldii, MD, MA,
NJ, NY, VA, WA; Macrophoma candollei,
prominent, general on dead leaves following
winter injury or disease.
N EMATODE ,Dagger.Xiphinema americanum.
N EMATODE , Lesion. Pratylenchus pratensis; P.
vulnus, NC.
N EMATODE , Root Knot. Meloidogyne hapla; M.
incognita; M. incognita acrita; M. javanica;
M. arenaria, NC.
N EMATODE , Spiral. Helicotylenchus nannus;
Rotylenchus buxophilus.
Brachycome (Swan River Daisy)
B ACTERIAL , MLO. Western Aster Yellows, CA.
V IRUS . Tomato Spotted Wilt, PA.
Brachypodium (Slender False-Brome)
A NTHRACNOSE . Colletotrichum graminicola,
MD.
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