Erwinia carotovora

Soft Rot

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Erwinia spp. are similar to many Fungi, but are actually bacteria that enter through wounds and natural openings. They produce a particularly vicious enzyme, which is encouraged by conditions of high humidity and warmth. These enzymes cause the plant to become mushy, affecting photosynthesis and respiration, and causing rapid deterioration. Black, wet areas of rot frequently appear at the base of the plant first, gradually rising upward, and the plant eventually collapses and dies. The rot can smell like rotten fish.

The top of the plant is often yellowish

Erwinia infection is extremely difficult to treat, and plants with severe infection rarely recover.


Avoiding high humidity, if possible, is an important preventative, especially if a plant is wounded. Treating wounds with copper fungicide can also help avoid entry. Careful watering is also important, as splashing spreads the bacteria.
If these bacteria are suspected, specimens should be isolated immediately.

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There is no chemical control. Badly infected plants should be disposed of.

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