its about how tikka disease spread in ground nut and how it can be prevented.

1. TIKKA DISEASE OF GROUNDNUT

2. INTRODUCTION
• Arachis hypogaea also known as groundnut or peanut is a legume plant of
Fabacea family with high nutritional values. It contains protein, vitamins,
minerals, carbohydrates, fats etc.
• Due to its high nutritional value it is consumed and produced in high
quantity in tropical and subtropical regions.
• As it is leguminous plant so its roots are in symbiotic relation with nitrogen
fixing bacteria present in root nodules.
• These are also grown in crop rotation to increase the nitrogen content or
to retain the soil fertility.

3. WHAT IS TIKKA DISEASE OF GROUNDNUT ?
• Tikka disease is a common fungal disease of groundnut.
• Losses due to tikka disease may go upto 15-20%.
• This disease is characterised by dark spots on aerial part of the plant ,
mainly leaves.
• The spots formed in this disease are of two types as two type of
fungal condia are responsible for causing this disease.

4. CAUSAL ORGANISM
• Cercospora personata , the conidial stage of Mycosphaerella
berkeleyii and Cercospora arachidicola the conidial stage of
Mycosphaerella arachidicola are the main causal organisms of tikka
disease of groundnut.
• They are fungi and hence posses mycelium.

5. SYMPTOMS
• Mainly the aerial part gets affected first with appearance of dark spots
on the leaflets of lower leaves. Later these dark spots are encircled by
yellow rings.
• The upper surface of leaflets have dark brown or almost black mature
• spots.
• Lower surface of leaf bear light coloured spots.
• These spots may also appear on stem as well and may also cause
defoliation.
• Shedding of leaf (defoliation) is the characteristic feature of this disease along with the spots.
• In critical condition the nuts may also get affected and the productivity and nut quality
decreases.

6. MECHANISMOF INFECTION(1)
• The mycelium of Cercospora personata is
infective in nature and is internal and it
intercellularly developes haustoria in the
Palisade and spongy mesophyll cells of host.
• The mycelium forms dense stroma which
produces long septate to non-septate geniculate hypophyllous
conidiospores.
• The conidiophores emerge in tufts by rupturing host epidermis.
• These conidia are pale brown in colour.

7. MECHANISMOF INFECTION(2)
• Cerospora arachidicola has both internal
and external ,inter and intracellular mycelium
without haustoria.
• The mycelium produces scaty stroma.
• They are usually amphigenous.
• They are geniculate , non-septate to septate and produce hyaline.
• The more dangerous and fast spreading is Cerospora personata
although it appears later than Cerospora arachidicola.

8. DISEASE CYCLE OF TIKKA DISEASE (DESCRIPTION)
1. Pathogen penetrates through conidia on diseased plant debris lying
in soil. These are responsible for primary infection.
2. Prolonged low temperature and dew favours infection.
3. Entrance of pathogen into host tissue occur through direct
penetration into the epidermal cell or by stomata.
4. It largely infect the leaf surface and forms stroma.
5. During stroma development the epidermis is ruputured by pressure
developed in host tissue.
6. Conidiophore emerges out of the stroma.

9. 7. Conidia produced on conidiophores.
8. Conidia forms secondary inoculum through which secondary
Infection is induced.
9. The disease spreads through wind, rain and insects. Conidia get
spread to leaves of other plant and cause disease.
10. Application of nitrogen and phosphatic fertilizers makes host
susceptible to infection.

10. DISEASE CYCLE OF TIKKA DISEASE ( DIAGRAM)

11. CONTROL OF TIKKA DISEASE
• Burning the debris of infectious plant to prevent spreading of primary
infection.
• Crop rotation helps to cut down the chance of disease.
• Seed disinfection can be done by treating seeds with 0.5% copper
sulphate solution can prevent growth of infectious plants.
• Spreading of secondary inoculum can be controlled by spraying of
Bordeaux mixture (4:4:50).
• Dusting with sulphur or sulphur contain 3.5% metallic copper is also
effective.
• Using resistant variety crop is also a good option.