Plant
Disease and Insect Clinic
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Host
Information
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Pathogen
Information
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Snapdragon
Salvia |
Downy
Mildew
(Peronospora antirrhini Peronospora sp.) |
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| Downy mildew of snapdragon and salvia first appears as a diffuse yellowing of some leaves, followed by leaf distortion and necrotic (dead) spots. The fungus produces spores on the lower surface of the leaf. At a magnification of 200X, you can see the branching "tree" of the fungus and the ballon-like spores. This fungus is host specific. The sinister fungus can become systemic in the plant and causes new growth to be deformed. Cool humid conditions are ideal for the fungus, and spores are dispersed by wind or splashing water. This disease is frequently a problem for winter/spring crops of snapdragon grown for cut flower production. | |||
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Salvia
Snapdragon
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