TOMATO - BACTERIA

BACTERIAL SOFT ROT

Causal organism: Erwinia carotovora subsp. carotovora, Erwinia carotovora subsp. atroseptica and Erwinia chrysanthemi.
Description: The bacteria are baculiform, 0,7 - 0,8 m wide and 1,5 - 5 m long. They are gram-negative, non-sporulating, and mostly formed in chains.
Host range: Wide range of crops such as potato, leaf and root vegetables, fruits, ornamental crops and several others.
Occurrence and importance: Bacteria are common soilborne pathogens that attack a wide range of root vegetables. They can also affect root vegetables in storage if conditions are not ideal. They are widely distributed in most soils, so bacterial inoculum is almost always present, in all countries studied. Bacteria do not represent a new emergent pest, but their importance in storage is increasing due to recent limitation of pesticide use. Farmers require reliable information on how to apply chemical-free (organic) preventative measures.
Symptoms: Bacterial soft rot appears as a soft, watery, and slimy decay of the taproot, usually with a distinct line between healthy a diseased tissue. The decay rapidly consumes the core of the carrot or parsley roots, frequently with a foul odour, that often leaves epidermis intact. Secondary fungi or bacteria may invade soft rot lesions. Aboveground symptoms include a general yellowing and wilting of the foliage.

Image
5. Figure: Erwinia carotovora subsp. carotovora – carrot

Source: own

Image
6. Figure: Erwinia carotovora subsp. carotovora carrot
Image
7. Figure Erwinia carotovora subsp. carotovora - potato
Source: https://agritech.tnau.ac.in
Image
8. Figure Ralstonia
Image
9. Figure: Erwinia carotovora subsp.

Source: https://krishijagran.com

BACTERIAL BROWN ROT - BACTERIAL RING ROT

Pest name:  Ralstonia solanacearum, Clavibacter michiganensis subsp. sepedonicus

Image
10. Figure: Distribution of Ralstonia solanacearum

Source EPPO Database (Yellow: present, purple: transient

Image
11. Figure. Distribution of Clavibacter michiganensis subsp. sepedonicus

Source: EPPO Database (yellow: present)

Description: R. solanacearum is a Gram-negative bacterium with rod-shaped cells and a single polar flagellum. It is distinguished by a positive staining reaction with Sudan black B or Nile blue. Ring Rot, caused by Clavibacter michiganensis subsp. sepedonicus, is widespread in North America, Europe, Denmark, Germany, Finland, and Greece. It is easily established in cool climates.
Host range: The disease can cause wilting of the potato plant, but the most symptoms appear in the tubers. The initially a brownish discoloration of the vascular ring (hence the name "brown" rot), which later rots completely. A grayish-white ooze may emanate from the eyes and corners of the potato.
Occurrence and importance: Brown rot, caused by Ralstonia solanacearum, is widespread in warm, temperate regions worldwide. In Europe, outbreaks have occurred in Portugal, Italy, Greece, and Sweden, and more recently Belgium and the Netherlands. Brown rot is invasive, abundant, and adaptable, with high reproductive potential.
Symptoms: Brown rot is a disease causing plant stunting, wilting and drying out of leaves in hot weather. Symptoms can occur at any stage of plant growth, with infected vascular bundles appearing as dark brown stripes. Infected plants may remain latently infected for long periods. A sticky, milky white exudate from stems indicates bacterial infection. This "stem-streaming" test is a valuable diagnostic tool for detecting brown rot in the field.
Image
12. Figure: Bacterial streaming in clear water from stem cross-section of plant infected by R. solanacearum

http://ephytia.inra.fr/en/D/7162

Image
13. Figure: Ralstonia solanacearum Source: http://ephytia.inra.fr/en/D/7162

Source: http://ephytia.inra.fr/en/D/7162

Image
14. Figure: Ralstonia

Source: http://ephytia.inra.fr/en/D/7162

Image
15. Figure Ralstonia

Source: http://ephytia.inra.fr/en/D/7162

Image
16. Figure: Ralstonia

Source: http://ephytia.inra.fr/en/D/7162

Image
17. Figure: Ralstonia

Source: http://ephytia.inra.fr/en/D/7162

Ring rot, a disease-causing plant wilting, is more common in tubers and can cause complete rot and cracking of potato skin. It spreads through vascular infection of daughter tubers from infected seeds, which can overwinter in storage, and debris from infected plants.

Image
18. Figure: Ralstonia

https://potatoes.ahdb.org.uk/knowledge-library/brown-rot

Disease cycle: Infection in fields is primarily caused by infected seed potatoes and contaminated waste materials, and spreads through irrigation water, by equipment, or insect or nematode transmission. In northern European outbreaks contaminated water is a key factor. Potato borers and solanaceous weeds like Bittersweet and Black Nightshade can also contribute to the spread of the disease.
Control: Obtain seed potato tubers and seeds from inspected crops, disease-free for the last two growing seasons. Avoid cutting seed potato tubers and use crop rotation, avoiding susceptible crops. Tolerant varieties of potatoes are available, but they must be carefully selected considering the pathogen's species and strain diversity. Regularly clean and disinfect all machinery, equipment, containers, vehicles and storage facilities. Isolate and destroy infected potatoes.
 
Dispose of waste on agricultural land and spread slurry for grazing and mowing instead of growing potatoes. Graded seed potatoes produced in the EU will have been inspected, using home-saved seed carries risk.
 
Legislation: According to the EU Plant Health Directive and the Plant Health Regulation 2006, the importation of materials carrying such diseases is prohibited. The Brown Rot Directive specifically defines control measures to eradicate this disease

Listo of Viruses:

  • IRIS YELLOW SPOT VIRUS [IYSV]

For more information on viruses, follow this link.

Listo of bacterial:
  • BACTERIAL SOFT ROT
  • BACTERIAL BROWN ROT
  • BACTERIAL RING ROT
For more information on the bacterium, follow this link.
Listo of fungi:
  • POWDERY MILDEW
  • SCLEROTONIA ROT
  • BOTRYTIS BLIGHT
  • VIOLET ROOT ROT
  • BLACK ROT
  • CERCOSPORA LEAF BLIGHT
  • PYTHIUM LEAF BLIGHT
  • CARROT ALTERNARIA LEAF BLIGHT 29
For more information on fungi, follow this link.
List of insects:
  • EUROPEAN MOLE CRICKETS
  • CLICK BEETLES, WIREWORMS
  • POTATO TUBER MOTH (TUBERWORM)
  • TURNIP MOTH
  • SPIDER MITES
  • THRIPS
  • CARROT FLY
  • APHIDS
For more information on insects, follow this link.
© 2024 INPACT project .