Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00000195
11/12/99
BEGONIA DISEASE PROBLEMS
Powdery mildew causes formation of a white powdery growth
or dry, brown, papery leaf spots.
Oedema is a physiological condition that may be aggravated
by over-watering during periods of high humidity and low
light. Light brown corky growths form on the undersides
of the leaves and along the stem.
The first symptom of bacterial leaf spot is small,
blister-like spots which appear transparent when the
infected leaf is held up to strong light. These enlarge
and run together causing a blotched appearance. A slimy
substance oozes from broken lesions. If the water
conducting tissues are invaded, the whole plant may
collapse and die. Cut off and destroy lightly infected
tissue and discard heavily infected plants. Reiger
Elatior Begonias are especially susceptible to this
disease.
Blotch causes leaves and flower parts to become brown and
die. The disease is named for the well-marked, dead
blotches formed on infected tissue.
Several leaf spots attack begonias but most can be
controlled by removing the infested leaf and disposing of
it.
The stem rot fungus invades the plant crown causing a soft
rot which in turn causes the stems to collapse. There is
no control.
Related information.
Pesticide Recommendations
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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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