Woody Ornamentals

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Amsonia - rust Azalea - flower gall Birch - Septoria Birch - Cryptocline Boxwood - Pseudonectria canker Cherry - Phloeosporella Cherry - rust Cherry - Cercospora Clematis - Ascochyta Crabapple - C/apple rust Crabapple - Fire blight Crabapple - vole injury Dogwood - Septoria Elm - leaf spot Elm - black spot Elm - Dutch elm disease Forsythia - Phomopsis gall Forsythia - Sclerotinia Holly - Web blight Honeylocust - Cercospora Hydrangea - Xanthomonas Kerria - Phloeosporella Leucothoe - Leaf spot Maple - Anthracnose? Maple - Verticillium wilt Maple - Monostichella Mulberry - Phloeospora Oak - Powdery mildew Oak - Marssonina Oak - rust Oak - Tubakia Oak - herbicide injury Paw Paw - Phyllosticta Paulownia - Phyllosticta Pear - herbicide injury Pecan - Botryosphaeria Photinia - Entomosporium Pine - sapsucker injury Planetree - Septoria Poplar - Septoria Privet - leaf spot Rose - Black spot Rose - Cercospora Spruce - Dothistroma Spruce - Stigmina needle Spruce - needle mold Taxus - Pestalotiopsis Walnut - White mold Willow - Cercospora

Send comments and questions to Paul Bachi
Last Modified: 29-Oct-2008
Copyright © 2004, University of Kentucky, College of Agriculture, Department of Plant Pathology

Plant: Amsonia (Amsonia sp.) (Apocynaceae) Back to List
Disease/Disorder: Leaf rust
Causal agent: Coleosporium sp.(fungus)
Signs: rust pustules with urediniospores on leaf surface
Symptoms: rust pustules on leaf surface.
Total image number: 6

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Plant: Azalea (Rhododendron sp.) (Ericaceae) Back to List
Disease/Disorder: Leaf and flower gall
Causal agent: Exobasidium vaccinii (fungus)
Signs: gall is fungal tissue
Symptoms: Leaf becomes galled tissue.
Total image number: 4

Plant: Birch (Betula sp.) (Betulaceae) Back to List
Disease/Disorder: Leaf spot
Causal agent: Septoria betulae (fungus)
Signs: raised spore-producing bodies ("pycnidia") can be seen within spots.
Symptoms: Leaf spots can coalesce to form blighted areas.
Total image number: 4

Plant: Birch (Betula sp.) (Betulaceae) Back to List
Disease/Disorder: Leaf spot
Causal agent: Cryptocline betularum (fungus)
Signs: spore-producing bodies ("acervuli") can be seen within spots
Symptoms: Tan to gray spots on leaves.
Total image number: 6

Plant: Cherry (Prunus sp.) (Rosaseae) Back to List
Disease/Disorder: Leaf spot
Causal agent: Phloeosporella padi (fungus)
Signs: Spore-producing bodies ("acervuli") may be swelled like a blister, sometimes not.
Symptoms: dark brown leaf spots with red border
Total image number: 8

Plant: Cherry (Prunus sp.) (Rosaseae) Back to List
Disease/Disorder: Rust
Causal agent: Tranzschelia sp. (fungus)
Signs: Pustules with spores ("urediniospores") [found on same leaf as with Phloeosporella padi above]
Symptoms: raised spots surrounded by light green/white leaf tissue
Total image number: 5

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Plant: Cherry (Prunus sp.) (Rosaseae) Back to List
Disease/Disorder: Leaf spot
Causal agent: Cercospora sp. (fungus)
Signs: Spore-producing hyphae ("conidiophores") grouped in clumps.
Symptoms: reddish-brown spots which can drop out and form shot-holes.
Total image number: 8

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Plant: Clematis (Clematis sp.) (Ranunculaceae) Back to List
Disease/Disorder: Leaf spot/blotch
Causal agent: Phoma or Ascochyta (fungus)
Signs: reddish-brown spore-producing bodies ("pycnidia") not well defined within spot/blotches.
Symptoms: brown to reddish-brown spots/blotches
Total image number: 7

Plant: Dogwood (Cornus florida) (Cornaceae) Back to List
Disease/Disorder: Septoria leaf spot
Causal agent: Septoria cornicola (fungus)
Signs: raised spore-producing bodies ("pycnidia") can be seen within spots.
Symptoms: darkened leaf spots
Total image number: 4

Plant: Elm (Ulmus carpinifolia 'Accolade') (Ulmaceae) Back to List
Disease/Disorder: Leaf spot
Causal agent: unknown (fungus) possibly Phyllosticta
Signs: spore-producing bodies ("pycnidia") can be seen within spots
Symptoms: Tan to gray spots on leaves.
Total image number: 4

Plant: Elm (Ulmus sp.) (Ulmaceae) Back to List
Disease/Disorder: Black spot
Causal agent: Stegophora ulmea (fungus)
Signs: raised spore-producing bodies ("acervulus") can be seen within spots.
Symptoms: small, raised black spots with a fine area of white tissue surrounding them, found mostly between the major veins of the leaves
Total image number: 4

Plant: Elm (Ulmus sp.) (Ulmaceae) Back to List
Disease/Disorder: Dutch elm disease (DED)
Causal agent: Ophiostoma ulmi (fungus)
Signs: Incubation of symptomatic pieces of elm branches, surface sterilized and placed in an incubation chamber produced the characteristic asexual stage or "synnemata" (conidiophores with clusters of colorless conidia) of the fungus.
Symptoms: Tree limbs will dieback and eventually the entire tree will die
Total image number: 9
Each of the last two rows of images is of a different sample.

Plant: Forsythia (Forsythia sp.) (Oleaceae) Back to List
Disease/Disorder: Twig dieback
Causal agent: Sclerotinia sp. (fungus)
Signs: hard, black survival structure called a “sclerotia” inside the stem
Symptoms: starts as a flower infection and work its way into the stem. On the stems, notice at the margin between healthy and diseased tissue you will see a copper/brown area on the stem. Within this area you can see a pattern of alternating lighter and darker copper/brown lines.
Total image number: 4

Plant: Apple, but can occur on Crabapple (Malus sp.) (Rosaceae) Back to List
Disease/Disorder: Fire blight.
Causal agent: Erwinia amylovora (bacterium)
Signs: May see droplets or oozings of bacteria from blighted tissue. Bacterial streaming from infected tissue.
Symptoms: Blighted shoot tips and/or flower blossom spurs.
Total image number: 4

Plant: Honeylocust (Gleditsia triacanthos var. inermis 'Skyline') (Fabaceae) Back to List
Disease/Disorder: Leaf spot
Causal agent: Cercospora sp. (fungus)
Signs: Spore-producing hyphae ("conidiophores") grouped in clumps.
Symptoms: brown spots with lighter center and darker brown boarder
Total image number: 7

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Plant: Hydrangea, Oakleaf (Hydrangea quercifolia) (Hydrangeaceae) Back to List
Disease/Disorder: spot/blotch
Causal agent: Xanthomonas sp. (bacterium)
Signs: none visible without dark-field magnification
Symptoms: reddish-brown spots and/or blotches on leaves.
Total image number: 4

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Plant: Kerria, Japanese (Kerria japonica) (Rosaceae) Back to List
Disease/Disorder: Leaf/twig blight
Causal agent: Blumeriella kerriae (teleomorph). Anamorph (Phloeosporella) seen in images below.
Signs: a ring of raised, spore-producing bodies ("acervuli") within spot.
Symptoms: On the leaves infection shows as reddish spots with dark borders and, if numerous, leaves yellow and fall. Stem cankers are produced as discolored more or less extended darkened areas which may crack open.
Total image number: 4

Plant: Leucothoe, drooping (Leucothoe fontanesiana) (Ericaceae) Back to List
Disease/Disorder: Leaf spot
Causal agent: Phyllosticta sp.
Signs: black, spore-producing bodies ("conidia") within spot.
Symptoms: Brown spots with a darker color border. A bull's eye pattern can be seen in the larger spots. Total image number: 9

Plant: Maple, 'Autumn Blaze' (Acer rubrum 'Autumn Blaze') (Aceraceae) Back to List
Disease/Disorder: Verticillium wilt
Causal agent: Verticillium spp. (fungus)
Signs:
Symptoms: Nursery trees shortly after transplanting showed poor growth. Sample of a darkened section of the vascular tissue of the stem below ground plated on a culture medium. After several days the fungal growth showed characteristic spore-producing structures for the fungus, Verticillium, species unknown.
Total image number: 9