Bacterial Wilt of Potato (Bacterial Disease)

Bacterial wilt of potato is caused by a soil-borne bacterium named Ralstonia solanacearum. The bacterium mainly inhabits the roots and enters the root system at points of injury caused by farm tools or equipment and soil pests. Symptoms of bacterial wilt of potatoes include sudden wilting of one or more stems of the potato plant, stunted growth, yellowing, and brown discoloration in the vascular tissues of the stem and tubers.

1. BACTERIAL WILT OF POTATO B. LOKESHWARI II M. Sc MICROBIOLOGY SACRED HEART COLLEGE (AUTONOMOUS) TIRUPATTUR

2. Bacterial Wilt of Potato Bacterial wilt is caused by a soil-borne bacterium named Ralstonia solanacearum . Potato wilt bacterium mainly inhabits the roots, and enters the root system and soil pests. On potato, bacterial wilt is also known as: Brown Rot Southern Wilt Sore Eye Jammy Eye

3. Host Plants

4. Weed hosts

5. Environmental Conditions Temperatures b etween 2 5 ° C a n d 3 7 ° C is genera l ly f avou red by the b a cterial w i lt of potato. It usually doesn't cause problems below 15°C. Under conditions of optimum temperature, Ph, optimum temperature, wetness of soil. Once infection has occurred, symptoms will often be more severe with hot and dry conditions, which hastens wilting.

6. Spread of disease Irrigation water and flood waters Contaminated soil Nematodes Infected equipment (seed-cutters, or second-hand bags or half-tonne bins) Seed dissemination The wilt bacterium is able to survive for periods up to 2 to 3 years in bare fallow soils

7. 5 Bacterial ooze from freshly-cut section of a geranium stem infected by R. solanacearum. 6 Bacterial ooze exuding from eye of potato tuber infected by R. solanacearum . 2 Symptoms of brown rot of potato caused by R. solanacearum showing wilting and stunting of the plant. 4 Grey-brown discoloration of vascular tissues and bacterial ooze in potato tuber infected by R. solanacearum Symptom of brown rot of potato caused by R. solanacearum showing wilting of youngest leaves of plant. 1 7 Bacterial streaming in clear water from stem cross-section of plant infected by R. solanacearum. 3 Brown discoloration of stem tissues caused by R. solanacearum

8. 1 . Wilting Of Youngest Leaves Of Plant

9. 2. Wilting And Stunting Of The Plant.

10. 3 . Brown discoloration of stem tissues

11. 4. GREY – BROWN DISCOLOURATION OF VASCULAR TISSUES AND BACTERIAL OOZE IN POTATO TUBER

12. 5. Bacterial ooze

13. 6. Bacterial Ooze Exuding From Eye Of Potato Tuber

14. 7. Bacterial streaming in clear water from cross section of a plant

15. Causal Organism Ralstonia solanacearum is a gram-negative , rod-shaped, strictly aerobic bacterium that is 0.5- 0.7 x 1.5-2.0 µ m in size. One polar flagellum Agar colonies are small, roundish, smooth wet, shining become brown trough formation of black water soluble pigment. I t is v ery s e ns i t iv e t o d e s iccatio n a nd is i nhi b i t e d b y l o w c o ncen t rat io ns (2 % ) o f sod i u m chloride (NaCl). The optimal growth temperature is 82-90º. R. solanacearum is widespread in the subtropics around the world

16. Epidemiology R. solanacearum is a soilborne and waterborne pathogen. The bacterium can survive and disperse for various periods in infested soil or water, which can form a reservoir source of inoculum. In potato, the brown rot pathogen is also commonly tuberborne. Bacterial wilt is one of the most destructive diseases of the potato. The disease can cause total loss of a crop and prevent the use of land for potato production for several years.

17. Life Cycle Of Bacterial Wilt Of Potato

18. Prevention and Control Use disease- free tubers Use certified soil and avoid infested soil Sulfur lime stone is used for treatment Field sanitati o n Crop rotation