Bacterial soft rot (so – called wet rot) is a disease that primarily affects the bow but can also develop and garlic. The causative agent of the disease is the bacterium Erwinia carotovora (and several others) that enter the plant through injury.




  • soft rot of garlic and onions
  • wet rot of garlic and onions
  • bacterial Soft Rot
  • French: Pourriture molle


бактериальная мягкая (мокрая) гниль чеснока и лука. симптомы на луковице, фото

Pathogens soft rot of garlic and onions


  • Erwinia carotovora subspecies carotovorum (synonyms Pectobacterium carotovorum or Bacillus carotovorus)
  • Erwinia chrysanthemi (synonym Dickeya chrysanthem)
  • Pseudomonas gladioli
  • Enterobacter cloacae


Bacterial soft (wet) rot affects also other vegetables:

  • carrots
  • potato
  • cabbage
  • pepper



бактериальная мягкая (мокрая) гниль чеснока и лука. симптомы на листке лука


Bacterial soft rot is characterized by softening and fluid saturation of one or more cloves of garlic bulb. At the bow are one or more juicy scales.

Affected are initially watery scales from pale yellow to light brown during infection Erwinia chrysanthemi, or gray when infected with Erwinia carotovora.

Bacterial soft rot is mainly manifested in mature follicles. That disease appears immediately before or during harvest or during storage.

Neck infested bulbs may be soft when you press and release a thick stinking liquid.


бактериальная мягкая (мокрая) гниль чеснока и лука. симптомы на листке лука, фото



Terms of illness

Most bacterial soft rot develops on the affected garlic or onions during storage or transport under inappropriate conditions.

However, the disease can spread quite in the field before harvest after heavy rains and drying of leaves.


By spreading bacteria:

  • insects
  • irrigation water (via irrigation)
  • rainwater

Bacteria get into the plants through wounds caused by mechanical damage or sunburn, and also because the larvae of insects that carry the bacteria during eating.

The development of bacterial soft rot of garlic or onions contribute warm and humid environmental conditions. The optimal temperature range of + 20-30 ° C.

However, during storage or transportation of bacterial soft rot can develop when temperatures above +3 ° C.




Control of bacterial soft rot disease

  • Upper avoid watering (irrigation)
  • pest insects
  • the use of bactericides based on copper
  • to avoid damage to the bulbs at harvest time
  • garlic lay deposited only after proper drying
  • the storage temperature and humidity 0 -2 no more than 65%



 Fungicides to combat bacterial diseases garlic


  • Perhado R 270 WG, VG – production Syngenta, Switzerland. Active substance: 25 g / kg: Mandipropamid, 245 g / kg of copper oxychloride. Breeding 4.5 liters of the drug per 1 ha and 200-400 liters of working solution. Apply the second half of the growing season or after hail, rain, insect damage.
  • Curzate R production DuPont, USA. The active substance tsymoksanil – 4.2% hlorokys copper – 39.8%. Breeding 2.5-3 kg of the drug per 1 ha and 400-600 liters of working solution. 3 processing at intervals of 8-10 days.


The video potato tuber, struck bacterial wet rot


Photo: Howard F. Schwartz, Colorado State University

The information was prepared by Andrew Marchenko

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