Clubroot of cabbage is caused by the soil-borne pathogen Plasmodiophora brassicae. It infects the roots of cabbage and other cruciferous crops, causing galls or clubs to form on the roots. The pathogen survives in the soil as resting spores which can persist for over 20 years. When conditions are favorable, the spores germinate and release zoospores which infect the roots. This leads to proliferation of root cells and formation of galls. More spores are produced within the galls and released into the soil to infect other plants, completing the disease cycle. Integrated management includes use of disease-free seedlings, crop rotation, lime application, and fungicide dips or

1. COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
CLUBROOT OF CABBAGE
Submitted by Course teacher
D.Priyadharshini. Dr.S.Parthasarathy
2015021100 Assistant Professor (Plant Pathology)

2. CLUBROOT OF CABBAGE
• INTRODUCTION
• DISTRIBUTION
• PATHOGEN
• SYMPTOMS
• SYSTEMIC POSITION
• DISEASE CYCLE
• MANAGEMENT

3. INTRODUCTION
• Cabbage is a leafy green, red, white biennial plant.
• Cabbage is a member of the genus Brassica and the
mustard family, Cruciferaceae.
• The sulforaphane found in cabbage may help protect
cancer.

4. DISTRIBUTION
• India, Nepal, China, West Bengal, Canada,
Bulgaria, Denmark and Hongkong.

5. HISTORY
• Historical reports of clubroot date back to the
13th century in Europe.
• In 19th century, a severe epidemic of clubroot
destroyed large proportions of the cabbage
crop in St. Petersburg.

6. • The Russian scientist Mikhail Woronin
eventually identified the cause of clubroot as
a “Plasmodiophorous organism” in 1875,
and gave it the name Plasmodiophora
brassicae.

7. ECONOMIC SIGNIFICANCE
• Clubroot can be a reccurring problem, for
years because it is easily spread from plant to
plant.
• P. brassicae is able to infect 300 species of
cruciferous plants.

8. SYMPTOMS
• Developing plants may not show any symptoms
but as the plants get older they will start to show
symptoms of chlorosis or yellowing.
• Wilting during hot days and stunted growth.
• The roots experience cell proliferation due to
increased auxin or growth hormone production.

9. • Gall formation occurs and restrict the xylem
tissue inhibiting efficient water uptake by the
plant.
• Galls appear like clubs or spindles on the roots.
• The roots will rot and the plant will die.

10. CLUBROOT OF CABBAGE
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11. SYSTEMIC POSITION
• Domain : Eukarya
• Kingdom : Protozoa
• Phylum : Cercozoa
• Class : Phytomyxea
• Order : Plasmodiophorales
• Family : Plasmodiophoraceae
• Genus : Plasmodiophora
• Species : P. brassicae

12. DISEASE CYCLE OF
Plasmodiophora brassicae
• In the spring, resting spores in the soil germinate
and produce zoospores and then these spores
swim and enter host plants through wounds or
root hairs.
• The plasmodium eventually divides and forms
secondary zoospores that are once again released
into the soil.

13. • The secondary infection by the zoospores can
infect the first host or surrounding hosts.
• The secondary zoospores form a secondary
plasmodium that affects plant hormones to
cause swelling in root cells.
• These cells turn into galls or “ club “.

14. • The secondary plasmodium forms the
overwintering resting spores which get
released into the soil as the “ club “ rot and
disintegrate.
• These resting spores can live in soil for upto
20 years while they wait for a root tip to
come in close proximity for them to infect.

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16. PATHOGEN
• Obligate parasite.
• Plasmodium shaped body.
• Can survive in soil as resting spores for many
years.
• Produce primary and secondary zoospores.
Zoospores are biflagellate.

17. ZOOSPORES
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18. MODE OF SPREAD
• Primary : Resting spores
• Secondary : Zoospores

19. FAVOURABLE CONDITION
• It prefers warmer temperature and moist
conditions.
• Soil temperature between 20 - 24°C.
• pH less than 6.5.

20. INTEGRATED DISEASE
MANAGEMENT
• Seedlings can carry the pathogen so the use of
disease free seedlings is therefore very
important.
• Remove the affected roots to reduce the
pathogen population in the soil.
• Practice long term crop rotation with potato,
tomato, bean and leeks.

21. • Incorporate lime into the field at the rate of
2.5t/ha two weeks before transplanting .
• Seed treatment with Captan or Thiram 4g/Kg,
followed by T. viride 4g/Kg.
• Soil drenching with Copper oxychloride 0.25%.

22. REFERENCES
• R.S.Singh, Diseases of Vegetable Crops, Published
by Scientific International Pvt. Ltd.
• www.aspnet.org