DISEASES | CAUSAL ORGANISM |
Tikka early leaf spot | Cercospora arachidicola |
Tikka late leaf spot | Phaeoisariopsis personata |
Rust | Puccinia arachidis |
Crown rot / Collar rot | Aspergillus niger and A. flavus |
Dry root rot | Macrophomina phaseolina |
Stem and pod rot | Sclerotoum rolfsii |
Anthracnose | Colletotrichum dematium |
Bacterial wilt | Pseudomonas solanacearum |
Bud necrosis or ring mosaic | Tomato spotted wilt virus [TSWV] |
Rosette virus | Ground nut rosette virus [GRV] |
1. TIKKA LEAF SPOT

Symptoms
a. Tikka early leaf spot – Cercospora arachidicola
The leaf spot appear 3-4 weeks after sowing. Circular to irregular reddish brown to dark brown spots appear on the upper surface with a light yellow, circular halo. On the lower surface, the lesions are light brown in colour. Later, the colour of the lesion on the upper surface turns to reddish brown to black colour.
b. Tikka late leaf spot – Phaeoisariopsis personata
The late leaf spot disease appears 5-7 weeks after sowing. Circular and darker colour spots appear on the lower surface without halo. The colour of the lesion in upper surface turns to brown to black colour. Late leaf spot attack in usually coincides with rust disease.
Mode of spread and survival
The pathogen spread through air borne conidia and survive in the infected plant debris
Epidemiology
Prolonged high RH, low temperature with dew and rain splash encourage the disease development
Management
- Field sanitation
- Seed treatment with thiram or carbendazim @ 2 g/kg of seed
- Spray mancozeb @1kg/ha or carbendazim @250 g/ha or chlorothalonil @ 1 kg/ha
- Grow resistant varieties.
Early leaf spot – PI 109839, 162857, NC 5, 3033
Late leaf spot – PI 261893, 262090, 371521, ALR 1
For both the leaf spot – PI 259747 and NCAC 3139
COMPARISON OF EARLY AND LATE LEAF SPOT
Characteristics | Early leaf spot | Late leaf spot |
Seasonal development | Early | Late |
Shape of spot | Circular to irregular | Usually circular |
Leaf surface where first and most spores produced | Upper | Lower |
Colour of spot on upper leaf surface | Light brown to black tending towards brown | Brown to black tending towards black |
Colour of spot on lower leaf surface | Brown | Black |
2. RUST – Puccinia arachidis
Rust is now considered as an economically important disease in almost all groundnut growing areas of the world
Symptoms
Orange coloured pustules (uredosori) appear on the lower surface of the leaves and ruptures, release masses of reddish brown uredospores. Severe infection leads to production of small and shriveled seeds. Only uredial and telial stages were known to occur.
Mode of spread
Air borne uredospores spread the disease
Survival
The pathogen survives in the volunteer groundnut plants and infected plant debris
Epidemiology
High RH, optimum temperature (200 -300 C) and heavy rainfall favour the disease development
Management
- Volunteer groundnut plants and ground keepers should be eradicated
- Spray chlorothalonil @ 1 kg/ha or tridemorph @ 500 ml/ha or mancozeb @ 1 kg/ha
- Grow resistant ICRSAT-bred lines ICG(FDRS) 4, 10 and Tifrust 12, 13
3. CROWN ROT/COLLAR ROT –Aspergillus niger and A. flavus
Symptoms
The infected areas become water-soaked and turn light brown and are soon covered with black fungal spores [sooty like appearance]. The fungus sporulate on the surface of mature pods resulting in patches of black sooty spores. A.flavus causing seedling disease produces ‘’Aflatoxin’’
Mode of spread and survival
The pathogen is seed and soil borne and survives in the infected seeds and plant debris
Epidemiology
High RH, temperature of 300 -350 C encourages the disease development
Management
- Avoiding mechanical damage to the pods and kernels
- Harvested pods should be dried promptly
- Deep ploughing and crop rotation with chick pea and wheat
- Seed treatment with thiram or captan or carbendazim @ 3 g/kg
- Grow resistant genotypes – EC 21115
4. DRY ROOT ROT – Macrophomina phaseolina
Symptoms
Initially reddish brown water – soaked lesions on the stem appear. Later, these lesions change in to light brown in colour. The infected roots become black, rott and the tap roots shreds. The fungal hyphae spread to form a white mat of mycelium over the kernels and turn grey and eventually turn black
Mode of spread
The pathogen is soil borne
Survival
The pathogen survives as sclerotia in the soil and infected plant debris
Epidemiology
Low soil moisture and a temperature of 290 -350 C favour the development
Management
- Field sanitation
- Seed treatment with thiram or carbendazim at 2 g/kg or T.viride at 4 g/kg of seed
- Crop rotation with non-host crops
5. STEM AND POD ROT – Sclerotoum rolfsii
Symptoms
The first symptom of stem rot are yellowing and wilting of branches near the base of the plant. Sheets of white mycelium develop at or near the soil line around the affected areas of the stem which become shredded. Diseased pods are completely covered with a white mycelial mat and show a characteristic bluish – grey discolouration of the testa, known as ‘’blue damage’’
Mode of spread and survival
The pathogen is seed borne and survives as sclerotia in soil
Epidemiology
High temperature and high soil moisture help the disease development
Management
- Field sanitation
- Crop rotation with cotton or wheat or onion
- Application of triazoles like propiconazole through irrigation water
- Grow resistant genotypes like ICGV 86416, 87359, NC 9 and GAT 141.
6. ANTHRACNOSE – Colletotrichum dematium
Symptoms
Small, water-soaked yellowish spots appear on the lower leaves which later turn in to circular brown lesions with yellow margin
Mode of spread and survival
The pathogen spreads through wind borne conidia and survives in the infected tissues
Epidemiology
Cloudy weather encourages the disease
Management
- Spray with mancozeb 0.2% or copper oxy chloride 0.25 % or Bordeaux mixture 0.4%
7. BACTERIAL WILT – Pseudomonas solanacearum
Symptoms
Infection of young plants results in rapid wilting of stem and foliage. Infection of mature plants results in loss of turgidity and leaves become light green, chlorotic and curl at the tips. The characteristic symptom are dark brown discolouration in the xylem and pith and the streaming of ‘’bacterial ooze’’ from the cut ends of infected root and stem.
Mode of spread
Seed borne inoculum spreads the disease
Survival
Long term survival of the pathogen is favoured by continuous cropping of susceptible host.
Epidemiology
High soil moisture and wet soil favour the disease development
Management
- Field sanitation
- Crop rotation with wheat or sorghum or cotton or rice or sugar cane
- Use disease free seeds
- Soil application of urea, mineral ash and organic manure
- Applying chloropicrin @ 30 kg/ha 10 days before sowing
- Grow resistant varieties like Anoa, Rusa, Tupai and Banteng
8. BUD NECROSIS –Tomato spotted wilt virus [TSWV]

It is also called as Ring mosaic, groundnut mosaic, bunchy top, chlorosis, ring mottle and bud blight.
Symptoms
Initial symptoms appear on young leaflets as chlorotic spots. Terminal bud necrosis occurs when temperature is high. Early infection results in stunting and proliferation of axillary shoots. The seeds produced by the infected plants are small, shriveled and mottled.
Vector
Thrips – Thrips tabaci and Frankliniella sp. transmits the disease
Management
Remove and destroy the infected plants up to 6 weeks after sowing and Inter cropping with sorghum or pearl millet reduces the incidence. Spray monocrotophos @ 500 ml/ha or spraying with antiviral principles [AVP] from sorghum or coconut leaves either alone or in combination.
– Grow resistant cultivars – ICGV 86030, 86031, 86032, 86033, and 86538.
9. ROSETTE VIRUS – Ground nut rosette virus [GRV]
Symptoms
The infected plants appear as dense clump and produce dwarf shoots with tuft of small leaves. The infected plants exhibit chlorosis and mosaic mottling. The infected plants remain stunted and produce few flowers but none bear seed.
Vector
Aphid – Aphis craccivora transmits the disease in a persistent manner
Management
- Use heavy seed rate and rogue out periodically the infected plants.
- Spray monocrotophos or methyl dematon @ 500 ml/ha to control vector population.
- Grow resistant cultivars like RMP 12, 91.