The galls are soft and fall apart easily. Destroy infected plants. No effective chemical control is available.
Blight causes ash gray spots on the bud scales and stems.
This causes the plant to die back several nodes from the top. The causal organism is Botrytis cinerea. Aster yellows may infect plants which should then be destroyed. No chemical control is available. Fasciation causes formation of distorted and aborted shoots at soil level.