Agriculture: Carrot Pest Management Guidelines

Bacterial Soft Rot

  • Pectobacterium (=Erwinia) carotovorum ssp. carotovorum
  • Symptoms and Signs

    Bacterial soft rot is recognized as a soft, watery, and slimy decay of the carrot root, not associated with any fungal growth and accompanied by a foul odor. The decay rapidly consumes the core of the carrot, often leaving the epidermis intact. Aboveground symptoms include a general yellowing, wilting, and collapse of the foliage. Soft rot can occur in the field and during storage.

    Comments on the Disease

    Pectobacterium carotovora is a common soilborne bacterium that attacks a wide range of fruits and vegetables. The bacterium enters carrots through various kinds of wounds. In the field, soft rot is most often associated with warm temperatures and extended periods of standing water resulting from poor drainage, low areas, or leaky irrigation pipes. Mature carrot roots are most susceptible to infection.

    Management

    In the field, maintain good drainage and avoid practices that could wound roots. Avoid prolonged irrigation of mature carrots during warm months of the year. In the packinghouse, handle carrots carefully to avoid bruising and store them under cool conditions. Chlorine added to the wash water helps to eliminate the soft rot bacteria from carrot surfaces.

    Text Updated: 03/24
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