Pectobacterium carotovorum subsp. carotovorum
(Jones 1901) Hauben et al. (1999)
bacterial rot
General
- Bacterium widespread worldwide, especially in production areas with humid and rather hot climatic conditions: tropical and equatorial areas par excellence.
- Responsible for damp and foul-smelling rots on various organs of vegetables.
- Extremely polyphagous bacterium that can affect many vegetables.
- Observed in the open field as well as under shelter.
- Susceptible botanical family(s) :
Solanaceae | Cucurbits | Composed |
Umbelliferae | Alliums | Malvaceae |
Brassicas | Fabaceae |
Biology
- Conservation : persists for several years in many soils, especially in plant debris and in the aqueous phase, for example in washing or water storage tanks. Also maintained on a fairly large number of cultivated and non-cultivated hosts, especially herbaceous broadleaf weeds. It affects many vegetables (Solanaceae, salads, celeriac, cabbage, basil, fennel, etc.).
- Infection : penetrates the various organs mainly through wounds (peduncular scar, mechanical injuries, insect-related damage, effects of sand, etc.), following various cultural operations during cultivation or after harvest (harvesting in wet periods , fruit washing). May also invade tissues secondarily after other pathogens.
- Development - Dissemination : multiplies in large quantities in infected tissues; easily disseminated by water in splashes and runoff. Insects, as well as tools during cultural interventions, contribute to its dispersal.
- Favorable conditions :
- Mainly favored by humid and warm conditions. Cloudy and rainy periods increase the risk of seeing this bacteria proliferate. It seems capable of developing at temperatures between 5 and 37°C, its optimum being between 25 and 30°C.
- Poor control of the storage temperature of certain vegetables, the presence of wounds, the use of dirty water during washing favor the expression of its parasitism.
- Very vigorous plants seem more susceptible.
Protection
- Implement crop rotations , a measure that is not easy to manage given its very many potential hosts.
- Think about integrating plants that are not very sensitive, even resistant (soybeans, grasses, rice, etc.) into the rotation.
- Plant preferably in plots located in well ventilated places.
- Promote soil drainage and avoid excess humidity; monitor the sanitary quality of the water.
- Ensure a balanced manure, avoid excess nitrogen , and destroy weeds .
- Avoid injury and water stress.
- Quickly eliminate diseased plants .
- Lower the hygrometry of the vegetation and avoid as much as possible the ground being too wet, ventilate the shelters.
- Avoid overhead irrigation ; if it is not possible to proceed otherwise, such irrigations will be carried out rather in the morning than in the evening, so that the plants dry quickly during the day.
- Do not work in the plots when the plants are wet: the risk of transmission of bacteria by contact is then high.
- Harvest vegetables or fruits in dry weather and taking care to limit injuries as much as possible. Refrigerate them quickly or store them in a cool, dry place.
- Eliminate and destroy the affected plants at the end of cultivation, and in particular the root systems and stems, avoid burying them in the ground.