Rhizopus soft rot

Web-like outgrowth on storage root (W. Martin, APS).

• Emits a pleasant fermented odour that attracts fruit flies.

• Exposure of storage roots to sunlight and chilling can initiate the disease.

• Infection takes place in a wide temperature range of 20 to 30°C.

• Found in different regions of the world.

Diagnostic summary

• What you see on plants

-  water-soaked lesions develop after storage root has been wounded or bruised during harvest or handling.

-  lesions become covered by a web-like outgrowth with scattered pinhead-like structures.

-  entire inner tissues of the root rot become soft, slimy and watery as they liquefy. However, periderm remains almost intact except for small cracks and wrinkled appearance.

-  black brush-like domes with whisker-like appearance emerge from periderm cracks.

• Rotting usually starts at both ends from wounds during harvest but any bruise or a slight scratch can initiate rotting.

• Like bacterial rot, it produces a watery, flesh decaying rot. 

Taxonomy

Economic importance

Geographical distribution

Morphology

Symptoms

Biology and ecology

Host range

Detection

Management

References

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