It explains in detail about the tikka disease of groundnut. Causal agent, mesures to control it is also mentioned.

1. Tikka Disease of
Groundnut
Keshav Narayan Pai
Msc I
DOS in Botany

2. Content
• Introduction
• Causal Organism
• Symptoms
• Disease Cycle.
• Favourable Condition.
• Disease Management
• Conclusion
• Reference

3. Introduction
 Groundnut is the most important oilseed crop of India.
 The Total area under ground nut is about 8 million
hectares .
 Tikka disease is the major disease of groundnut in
India.
 It occurs in every state in India and in every ground
of nutgrowing countries of the world.
 In Uttar Pradesh, the disease is locally known
as chitwa or haldai.

4. Causal organism
• The causal organism for the tikka disease of ground nut are
Cercospora personata and Cercospora arachidicola.
• The Symptoms caused by the two pathogens will differ.
• This disease is also called Leaf spot of Ground nut because it causes
leaf spots on the leaves.

5. • Symptoms appear when the plants are 1or 2 months old.
• Due to excessive spotting on the leaves, there is gradual
weakening of the foliage which results in defoliation.
• Consequently, fewer and smaller nuts are formed .
• According to Sundarram(1965) severe intensity of
infection leads upto 22%reduction in yield.

6. Symptoms
 According to Woodruff(1933) designated the disease
caused by C.arachidicola as early spot and that caused by
C.personata as late spot.
 The first symptom of both the leaf spots is the appearance
of pale areas on the upper surface of older leaves.
 As the lesions develop the two species can be distinguished.

8. Early Leaf Spot Symptoms
• Sub-circular dark brown spots are
produced on the upper leaflet surface.
• The spots are of lighter shade of brown on
the lower side of the leaflets.
• Yellow halo is seen around the brown
spots.

9. spot on stem

10. Infected leaf

11.  Lateleafspotsarenearlycircularanddarkerthanearlyleaf
spots.Yellowhalodevelopsaroundeachonlyinlaterstageof
development.
 Lateleafspotscanbedistinguishedfromthoseofearlyleaf
spots.Lateleafspotsaredarkerwithnoorlightyellowhalo.
Late leaf spot

13. • The mycelium of C.arachidicola is inter and intracellular,
brown,septate and without haustoria.
• Conidophores are yellowish brown and as the conidium
remains attached to geniculation on conidiophore.
• Conidiophores are 22-44 micron long and 3-5 micron broad
continuous or 1-2 septate.

14.  Cercospora personata produces an intercellular branched
mycelium.
 To absorb food from the host tissue, haustoria are
developed.
 Lesions appears 2-4 weeks later.
 Conidiophores of C. personata are 25-54 micron long,
5-8 micron broad continuous or 1-2 septate.
 Conidia are terminal and each conidiophores bear each
single conidium at the apex.
 It is potentially more damaging because it produces more
spots, spreads faster and causes earlier defoliation

15. Perennation
 Thediseaseperpetuatesthroughconidialyinginthesoilon
diseasedplantdebrisandthroughconidiabeing carriedinthe
shellofgroundnut.
PrimaryInfection
 Whenthenewcropofgroundnutstartsgrowing,theviable
conidiaarebroughttothehostsurfacebyvariousagencies,
germinateinfavourableconditionsandcauseprimaryinfection.

16. Cont.....
Secondary infection
 The secondary infection on healthy plants
in the same field or adjacent fields is
brought by conidia produced on primary
infected leaves.
 The conidia are dispersed by air or other
agencies , which bring them on the healthy
leaves.
 Later they germinate in favourable
conditions and cause infection.

17. • Relative humidity is the most important factor
for infection.
• A period of three days of high humidity is
essential for maximum infection.
• Prolonged low temperature and dew also favour
severe infection.

18. • The application of potash slightly decreases
disease incidence.
• Leaf spot development is minimal when gypsum
is applied as a source of calcium.

19. • As the disease is soil-borne, proper crop rotation is important.
• Plant disease debris should be burnt to avoid soil borneinoculum.
• Early planting,alternation in date of sowing and use of maturing
varities helps to escape rom the attack of the disease.
• Growing moderately resistant cultivars like ICGV 89104, ICGV
91114 (EM), ICGV 920920, ICGV 92093 (MM).
• Foliage spray with Bordeaux Mixture (4:4:50),Dithane M-45 (0.2%),
Benlate and Bavistin (0.1%) gives good results.

20. Disease Management
• Cultural Method
1.Grow tolerant varieties can be grown wherever early leaf spot
is severe.
2.Intercropping pearl millet or sorghum with groundnut (1 : 3)
is useful in reducing the intensity of early leaf spot.
3.Crop rotation with non-host crops preferably cereals.
• Mechanical Method
1.Deep burying of crop residues in the soil, and removal of
volunteer groundnut plants are important measures to reduce
the primary source of infection

21. Cont..
 Biological Method
Foliar application of aqueous neem leaf extract (2-5%)
or 5% neem seed kernel extract at 2 weeks interval 3
times starting from 4 weeks after planting is good.
 Chemical Method
Spray carbendazim 0.1% or mancozeb 0.2% or
chlorothalonil 0.2%.

22. Conclusion
• Tikka Disease is a common disease in ground nut caused by
Cercospora arachidicola and Cercospora personata.
• In the diseased condition, many circulars spots appear on the
surface of the leaf .
• The conidia of the fungus present in soil or those present in
the fruit shell is the source of infection.
• Use of fungicides controls the disease.

23.  Mehrotra.R.S.(1980).PlantPathology.TataMc.GrawHillPub.CO.Ltd.
Pg.no-455-465.
 Rangaswamy,GandMahadevan,A(2002).Diseasesofcropplantsin
India,PrenticeHallofindia,Pvt.Ltd.Pg.no-334-343.
 www.flickr.pathology.Tikkadisease.Com

24. Than
k You