Fusarium wilt of cotton is caused by the fungus Fusarium oxysporum f. sp. vasinfectum, which plugs the xylem vessels of the cotton plant leading to wilting symptoms. The disease is favored by warm temperatures between 20-30°C and spreads through contaminated soil. Management strategies include seed treatment, removing infected plant debris, growing resistant varieties, and spot treating with fungicides.

1. COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
FUSARIUM WILT OF COTTON
Course teacher: Student:
Dr. Parthasarathy. S Miss.Sharmitha.S
Asst.Professor (Plant Pathology) 2015021116

2. FUSARIUM WILT OF COTTON

3. CAUSAL ORGANISM
Fusarium oxysporum f. sp. vasinfectum
(W.C.Snyder & H.N.Hansen )
W.C. Snyder & H.N. Hansen, (1940

4. SYSTEMIC POSITION
• Kingdom : Fungi
• Phylum : Ascomycota
• Subphylum : Pezizomycotina
• Class : Sordariomycetes
• Subclass : Hypocreomycetidae
• Order : Hypocreales
• Family : Nectriaceae
• Genus : Fusarium
• Species : Fusarium oxysporum f. sp.
vasinfectum

5. ORIGIN
 Wilt is one of major disease of cotton, found
wherever this crop is grown.
 Fusarium wilt have been originated in Mexico
or Central America.

6. • In India the disease was reported from
Maharashtra, Tamil Nadu, Karnataka and other
states.
OTHER HOSTS
Bhendi, Tobacco, Brinjal and Chillli.

7. PATHOGEN
 The fungus is present both inter and intra
cellularly in the host tissue.
 The Mycelium plugs the xylem vessels
partially or completely.
 The macro conidia are 1-5 septate, hyaline,
thin walled, linear to falcate, tapering ends.

8. • Micro conidia are hyaline, thin elliptical to
spherical, single or two celled.
• Fungus also produces vivotoxin, fusaric acid
which is partially responsible for the wilting.

9. a) Microconidia
b) Macroconidia
c) Chlamydospores

10. SYMPTOMS
• Yellowing and browning of the cotyledons.
• Leaves lose their turgidity.
• First turn yellow and then brown and finally
drop off.
• The tap root stunted and laterals are less
abundant.

11. • Browning and blackening of vascular
tissues.
• Discolorations of leaves starts from the
margins and spread towards midribs.
• Wilting may be complete or partial.

12. YELLOWING AND DRYING OF LEAVES
©Agropedia

13. BROWNING OF VASCULAR TISSUES
©Agropedia

14. ©Cotton.tamu.edu

15. ©AgroAtlas

16. ©Agropedia

17. ©Agropedia

18. FAVOURABLE CONDITION
• Soil temperature of 20-30˚C.
• Hot and dry periods followed by rains.
• Heavy black soils with an alkaline reaction.
• Increased doses of nitrogen and phosphatic
fertilizers.

19. • F. oxysporum f. sp. vasinfectum grows and
develops at temperatures from 10 to 35°C.
• Optimum conditions are temperatures 18-
27°C.
• Soil humidity 40 to 70% and acidity of
environment near pH=5.3.

20. MODE OF SPREAD
 Fusarium wilt is spread over long distances in
contaminated soil.
 Contaminated soil can be carried on the roots of
host plants, boots and clothing, vehicles,
machinery and equipment.
 Fusarium can also be carried in contaminated
plant material, or on seeds.

21. FUSARIUM OXYSPORUM LIFE CYCLE

22. MANAGEMENT
• Treat the acid delinted seeds with Carboxin or
Carbendazim at 2 g/kg.
• Remove and burn the infected plant debris.
• Apply increased doses of potash with a
balanced dose of nitrogenous and phosphatic
fertilizers.

23. • Apply heavy doses of farm yard manure or other
organic manures.
• Grow disease resistant varieties of
G. hirsutum and G. barbadense like Varalakshmi,
Vijay Pratap, Jayadhar and Verum.
• Spot drench with Carbendazim 1g/litre.

24. REFERENCES
• http://agropedia.iitk.ac.in
• http://apsjournals.apsnet.org/pdfplus
• R.S.Singh, Ninth edition, 2013, Plant Diseases,
Oxford& IBH Publishing Company Pvt.Ltd,
New Delhi.