Pest & Disease Anthracnose

Anthracnose

Elsinoe corni

What is Anthracnose (Elsinoe corni)?

Spot anthracnose, caused by the fungus Elsinoe. Early symptoms in spring include numerous small reddish-purple spots on white bracts and brown spots on unfurling pink or red bracts. Throughout spring, the disease progresses, causing spotting on new leaves, shoots, petioles, and fruit. Twisted or deformed bracts and leaves with spots are common, and heavily spotted bracts may shed early, impacting the floral display.

How does Anthracnose (Elsinoe corni) occur?

During the blooming periods, the fungal spores responsible for spot anthracnose are dispersed from infected shoots to flower and leaf buds. This dispersal is facilitated by a combination of splashing water and wind. The spread and colonization of the pathogen on bracts and young leaves are favored by extended periods of mild, wet, and humid weather.

Symptoms

1 - Impact on Plants

• Spot anthracnose primarily affects above-ground plant parts like leaves, bracts, shoots, and fruit. It can cause spotting, deformation, and premature shedding of leaves and bracts. • Severe outbreaks may impact the floral display but rarely reduce overall tree vigor or health. • Spot anthracnose does not directly affect the soil or environment.

Solutions

1 - Preventions

• Ensure adequate spacing between trees to promote airflow and minimize humidity around the foliage. • Water at the base of the plant to keep foliage dry and reduce fungal spread. • Prune and remove infected branches or twigs during dormancy to minimize disease spread.

2 - Selection of Plants

• Choose early-flowering plants for partial to full shade to minimize disease outbreaks. • Select later-flowering plants for full sun, as they generally have moderate to good resistance to spot anthracnose.

3 - Plant-resistant cultivars

• Choose cultivars known for resistance or tolerance to spot anthracnose

4 - Application of Fungicides

• Fungicides such as chlorothalonil, thiophanate-methyl, and mancozeb can be used to control spot anthracnose. It's important to read and follow the label instructions and dosage recommendations of the specific fungicide product you choose.

Susceptible Species

Flamingo Boxelder

Kelly's Gold Boxelder

Japanese Maple

River Birch

River Birch (clump)

Summer Cascade Weeping River Birch

Constellation Flowering Dogwood

Eddie's White Wonder Flowering Dogwood

Aurora Flowering Dogwood

Celestial Flowering Dogwood

Stellar Pink Flowering Dogwood

Venus Flowering Dogwood

Pagoda Dogwood

Variegated Pagoda Dogwood

Variegated Giant Dogwood

Cherokee Brave Flowering Dogwood

Cherokee Chief Flowering Dogwood

Cherokee Daybreak Flowering Dogwood

Cherokee Princess Flowering Dogwood

Cherokee Sunset Flowering Dogwood

Red Flowering Dogwood

Chinese Dogwood

Blue Shadow Chinese Dogwood

China Girl Chinese Dogwood

Heart Throb Chinese Dogwood

Milky Way Chinese Dogwood

National Chinese Dogwood

Samaritan Chinese Dogwood

Satomi Chinese Dogwood

Starlight Chinese Dogwood

Chinese Dogwood

Wolf Eyes Chinese Dogwood

Cornelian Cherry Dogwood

Golden Cornelian Cherry Dogwood

Variegated Cornelian Cherry Dogwood

Leprechaun Green Ash

Patmore Green Ash

Sweet Gum

Round Leaf Sweet Gum

Silver King Sweet Gum

Slender Silhouette Sweet Gum

Worplesdon Sweet Gum

Tuliptree

Arnold Tuliptree

Yellow Variegated Tuliptree

Fastigiatum Tuliptree

Alexandrina Saucer Magnolia

Rustica Rubra Magnolia

horse chestnut

horse chestnut

snapdragon

European white birch

silver birch

false aster

false aster

false chamomile

false aster

camellia

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

tatarian dogwood

dogwood

swamp dogwood

evergreen dogwood

dogwood

dogwood

dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

flowering dogwood

hybrid dogwood

kousa dogwood

kousa dogwood

kousa dogwood

kousa dogwood

Chinese dogwood

kousa dogwood

Chinese dogwood

kousa dogwood

cornelian cherry dogwood

mountain dogwood

gray dogwood

dogwood

dogwood

dogwood

dogwood

bloodtwig dogwood

bloodtwig dogwood

bloodtwig dogwood

red twig dogwood

red twig dogwood

yellowtwig dogwood

yellow twig dogwood

red twig dogwood

red twig dogwood

red twig dogwood

dogwood

winter creeper

white ash

European ash

European ash

European ash

flowering ash

English ivy

common hop

common St. John's wort

black walnut

common privet

Chinese tulip tree

big blue lilyturf

star magnolia

spearmint

oriental plane tree

common pear

white oak

scarlet oak

pin oak

pin oak

willow oak

English oak

English oak

English oak

red oak

weeping willow

dragon's claw willow

rough goldenrod

European mountain ash

snowberry

David viburnum

Red-Flowering Currant

Vine Maple

variegated bulbous oat grass

Constellation dogwood

silverleaf dogwood

Chinese dogwood

Silver King euonymus

Idaho fescue

narrow-leafed ash

Transvaal daisy

Oregon grape

peppermint

London plane

Garry oak

tomato

Pink Pagoda mountain ash

piggyback plant

Pink Dawn chitalpa

Red-barked Dogwood

Himalayan Strawberry tree

Giant Dogwood

Flowering Dogwood

Cornelian Cherry Dogwood

Dogwood

Rice Flower

Jamaica Dogwood