Plant Protection - Dogwood Anthracnose
Host: Flowering Dogwood (Cornus florida)
Disease common name: Dogwood Anthracnose
Disease scientific name: Discula spp.
Severity: Often fatal; mortality in forests has gone from 5% to 100% in 4 years
Symptoms:
Gross: Yearly twig and branch death, beginning in the lower part of the canopy and progressing upwards
Specific:
Leaves -
Small purple-rimmed spots
Larger brown blotches
Shot holes
Dead leaves may hang on through winter
Twigs and shoots -
Tips turn gray-tan
Purple zone between healthy and infected areas
Cankers at twig bases showing cracked bark
Brown discolored areas beneath bark cankers
Contributing factors:
Presence of pathogen on plant debris
Cool, wet weather
Control:
Good cultural care
Removal of blighted twigs and branches
Cleanup of debris beneath tree
Removal of epicormic growths
Chemical protection - Daconil 2787 applied every 10 days during leaf expansion
Disease resistant species such as Cornus kousa
Discula disease of dogwood is a very serious disease that has eliminated the dogwood as an understory forest tree in northern Maryland and eastern Pennsylvania. Treatment must begin immediately upon observation of symptoms. Avoid importing dogwood liners, seedlings, or trees from the Northeast where the disease is prevalent. If you find this disease in your nursery, notify the Georgia Department of Agriculture.
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