Bacterial Diseases: Bacterial Soft & Brown Rot caused by Erwinia | Series 6


Typical symptoms were soft rots characterized by moist and watery decay of the one or whole leaves, which initiated as small water-soaked lesions and enlarged rapidly to the entire leaves. If unchecked, the infection will rapidly rot the leaves and roots and spread more slowly into the rhizomes or pseudobulbs. This wet rot may have a foul odour and has a water-soaked appearance. The bacteria are opportunistic organisms that can enter through wounds. 

Image result for Erwinia on orchidsImage result for Erwinia on orchids


Treatment of all fungal or bacterial diseases starts with the following:

  • Isolate the plant from other plants in your collection.
  • Remove or Cut all the infected leaves/canes/roots or parts of the plant with a sterilized tool.
  • Each time the cutting tool contacts infected tissue, it should be sterilized before making a second cut.
  • Chemical treatment with following on all plants in the collection.

Following chemicals are effective:

    • Chemical Name:
      • Kasugamycin (Brands: Biomycin, Kasu-B) | Dosage: 1ml per litre of water
      • Streptomycin and Tetracycline (Brands: Plantomycin) | Dosage: 1g per 10 litres of water (Do not overdose)

    Keeping the plants drier will help to keep the infection from spreading or appearing again. Isolate the plants and observe the plants for 1-2 weeks. And apply another round of control spray with any of the above fungicides. Spray the plants early morning and keep the plants dry after the spraying. Don't water the plants same day spray treatment is done.


    • Avoid Over-watering
    • Provide good circulation
    • Proper hygiene in the growing area
    • Sterilization of cutting tools before every use
    • Frequent Inspection 
    • Isolation of suspicious plants
    • Precautionary control sprays 
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    1 comment

    how often I can use Tetracycline on orchids? Can I use it as preventive measure? If yes what will be the dose and interval period?


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