.

1. WILD FIRE OF TOBACCO
COURSE TEACHER:
Dr. PARTHASARATHY S
Asst. Professor (Plant Pathology)
STUDENT:
Mr. NAVEENKUMAR P
ID. NO. 2016021022
COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562

2. • Common name: Tobacco
• Scientific name: Nicotiana tabacum
• Family: Solanaceae

3. https://www.pixel.com

4. WILD FIRE OF TOBACCO

5. DISEASE
CAUSAL ORGANISM:.
Pseudomonas syringae pv. tabaci

6. SIGNIFICANCE OF THE DISEASE
• This disease is the most important bacterial disease of
tobacco.
• Most serious on young plants in seedbed.
• First reported in Bulletin in 1922.

7. ECONOMIC LOSS
• This disease cause major yield loss in Africa.
• Disease incidence up to 76% was observed on
tobacco in Zimbabwe.

8. HOST PLANTS
 Many solanaceous weeds are hosts of this pathogen.
 Examples are
1. Apple of Peru (Nicandra physaloides)
2. Jimson weed / stinkblaar (Datura stramonium).

9. DISTRIBUTION
 It is occurs in Europe, Brazil, USA, Africa and some
Asian countires
 Currently, very serious in Malawi, Zimbabwe, Brazil
and Thailand

10. GLOBAL DISTRIBUTION
https://www.ipmimages.com

11. SYMPTOMS
 Wildfire results from the burnt appearance of heavily
infected tobacco plants.
 The leaf spots may occur at any stage of plant growth
including the nursery seedlings.
 Dark brown to black spots with a yellow halo spreads
quickly causing withering and drying of leaves.
 In the fields, initially numerous water soaked black spots
appear and latter become angular when restricted by the
veins and veinlets.

12. SYMPTOMS
 Wildfire is characterized by a small brown or black
watersoaked lesion, surrounded by a broad cholortic
halo.
 The formation of the chlorotic halo is due to the
diffusion of toxions ( Tabtoxin) released by
pathogens.
 This lesions increase in diameter and may coalesce
until the diseased tissue eventually falls out leaving
ragged holes.

13. SYMPTOMS OF WILD FIRE OF TOBACCO
https://www.ipmimages.org

14. SYMPTOMS OF WILD FIRE OF TOBACCO
https://www. uky. edu

15. CAUSAL ORGANISM
Kingdom: Bacteria
Phylum : Proteobacteria
Class : Gammaproteobacteria
Order : Pseudomodales
Family : Pseudomondaceae
Genus : Pseudomonas
Species : P. syringae pv. tabaci
Author : (Wolf & Foster) Young, Dye & Wilkie

16. PATHOGEN CHARACTER
 The bacterium is a rod, motile with a single polar
flagellum, non-capsulated, non spore forming and Gram
negative.
 It belongs to rRNA homology group 1.
 The bacterium produces a fluorescent pigments and a
protin toxin , called tabtoxin or wildfire toxin.
 A mere 0.05 milligrams of this toxin can produce a
yellow lesion on a tobacco leaf in the a absence of
bacteria.

17. LIFE CYCLE OF WILDFIRE
https://slideplayer.com/slide/734256/

18. Primary infection:
 The bacterium survives in the infected crop residues in
the soil, which is the primary source of infection.
Secondary infection:
 The secondary spread of the pathogen in the field is
through wind splashed rain water and implements.
 Wildfire is favoured by cloudy wet weather.
MODE OF SPREAD AND SURVIVAL

19.  This bacteria also associated with root systems of weeds
like Capsella bursa pastoris and Solanum nigrum.
 Spread of bacteria from one plant or from group of
diseased plants by water during the rain and sprinkler
irrigation.
 During windy weather the dissemination of bacteria to
non infested leaves by droplets.
 And also this bacteria reported in tobacco seeds.

20. FAVOURABLE CONDITIONS
 Close planting
 Humid wet weather
 Strong winds

21. MANAGEMENT
 Resistant Varieties
 Cultural method
 Chemical method

22. RESISTANT VARIETIES
 Burley 21
 KT212LC
 KT210LC
 KT209LC
 NC7LC

23. CULTURAL METHOD
 Site selection to avoid later planted crops downwind
of earlier planted ones.
 Complete destroy of infected plant risdues after
harvest.
 Rotation of seedbed sites.
 Proper fumigation of the seedbed areas.
 Use of certified seeds.

24.  Eradication of alternate host weeds, particularly those
near the seedbeds / floatbeds.
 Sterilization of seedbed tools.
 Correct topping, particularly avoiding low topping.
 Correct fertilization and pH; avoiding excessive N, low
K and high pH.
CULTURAL METHOD

25. CHEMICAL METHOD
 Seed treatment with silver nitrate, ideally as part of
the seed certification requirement.
 In seedbed, Spray combination of a copper based
compounds ( Kocidae 101, Copper oxychloride) and
the systemic acquried resistance ( Acibenzolar- S-
methyl)
 Field sprays of Acibenzolar-S-Methyl, preventatively
or when indicated by scouting.

26. REFERENCES
 Saha L R and Dhaliwal G S, 2009, Handbook of Plant
Protection, Kalyani publishers, New Delhi. Pp 275
 Tripathi D P, 2014, Introductory Plant Bacteriology,
Kalyani publishers, New Delhi. Pp 304
 https://www.plantwise.Org>datasheet
 ephytia.inra.fr/en/C/10808/ Tobacco-Wildfire-Angular-
leaf spot- disease- Pseudomonas syringae pv. tabaci

27. THANK YOU