Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00000834
11/12/99
LATHYRUS DISEASE PROBLEMS
Anthracnose causes whitish spots on leaves and flower
shoots. The infected parts shrivel up and the seed pods
shrivel and lose color. Wilting progresses down infected
shoots which may break off. Old plants are not easily
killed. Infected plants are destroyed after flowering.
Black rot attacks the plant crown within a few inches of
the ground. The roots are destroyed and the ends are
stubby and black. Infected plants are dwarfed, pale
yellow and sickly. The stems are easily removed from
crowns. The disease is worse in heavy cold soils. Avoid
replanting where the disease is a problem.
Downy mildew may cover the leaves with a gray mold
during moist weather.
A number of leaf spots attack sweet pea causing spotting
of various types. These are usually not serious
and spotted leaves may be removed.
Fasciation causes masses of short, thick, aborted stems,
with misshapen leaves, to form at the base of the plant.
The upper parts of the stem appear normal but the plant is
dwarfed. No controls have been developed.
The pea mosaic virus can infect seedlings three or four
weeks old. The leaves are curled, mottled, and yellowed
and the plants are dwarfed. The few flowers that form
will have color breaks. Control the insects which carry
the virus.
The spotted wilt virus causes mottled leaves and purplish
spots on stems and leaves. The blossoms have discolored
or bleached spots. Destroy infected plants and control
the insects which carry the virus.
Bud drop is caused by poor culture and is made worse by
low phosphorous and potassium, high nitrogen, and
inadequate light.
Powdery mildew covers the plant with a white, powdery
growth.
Related information.
Pesticide Recommendations
Powdery Mildew
Fungal and Bacterial Leaf Diseases
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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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