Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00001556
11/12/99
ZINNIA DISEASE PROBLEMS
Blight starts as reddish brown spots with graying centers.
Dark brown cankers form on the stems and flowers are
spotted or completely blighted. The disease is also
called alternaria leaf spot.
Powdery mildew is found on zinnia, particularly late in
the season. The disease causes a white to grayish powdery
growth (Vis. 1) on the leaves.
Bacterial leaf spot causes reddish brown, angular spots on
the leaves and can cause plants to die out by mid-August.
No chemical control is listed for bacterial leaf spot.
Related information.
Pesticide Recommendations
Powdery Mildew
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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.
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