Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00000363
11/12/99
CHRYSANTHEMUM DISEASE PROBLEMS
Fasciation causes development of short, thick stems with
misshapen leaves near the crown. Infected plants should
be removed and destroyed.
Bacterial leaf spot causes dark brown to black spots on
the leaves. The spots are slightly sunken and have
concentric zonations.
Verticillium wilt causes the leaves to yellow and turn
brown, starting with the lowest leaves. Infected plants
are stunted and fail to bloom. Avoid infested soil and
destroy infected plants. No chemical controls are
available.
Rust symptoms are blister-like swellings which break open
and discharge masses of brown powdery spores. Severely
infested plants are weakened and fail to bloom properly.
A number of leaf spot diseases can attack chrysanthemum.
The leaves are spotted and in severe cases, may die and
drop. Pick off and destroy infected leaves.
Blight or gray mold attacks the flowers, flower buds and
leaf tips. Symptoms on flowers are small water-soaked
spots which enlarge rapidly, followed by development of a
gray mold. Infected plants and plant parts are removed
and destroyed.
Powdery mildew causes a powdery white coating on the
leaves.
Related information.
Pesticide Recommendations
Powdery Mildew
Botrytis Blight
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mentioned. This information becomes public property upon
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This file was generated from data base ZZ on 01/19/00.
Data base ZZ was last revised on 11/12/99.
For more information about this data base or its contents please contact
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