Groundnut, also known as peanut, is an important legume crop grown for its edible seeds. It is widely affected by various fungal and viral diseases such as early leaf spot, rust, bud necrosis, stem rot, and Alternaria leaf disease. These diseases can be managed through fungicide sprays, removing infected plants, intercropping with other plants, and seed treatment.

1. YADNESH CHAUDHARI AND SAKSHI MORE
And its major diseases
GROUNDNUT

2. INTRODUCTION
- Groundnut, also known as peanut or monkey nut, is a legume crop grown mainly for its
edible seeds.
- It is widely grown in tropics and subtropics, being important to both small and large
commercial producers.
- It is classi
fi
ed as both a grain and and a legume, and due to its high oil content, an oil
crop.
- It is a fabaceae crop that grows annually.

3. - Infection starts about a month after sowing.
- Small chlorotic spots appear on lea
fl
ets,
with time they enlarge and turn brown to
black and assume sub circular shape on
upper leaf surface.
- On lower surface of leaves light brown
colouration is seen.
- Lesions also appear on petioles, stems,
stipules.
- In severe cases several lesions coalesce
and result in premature senescnce.
- It can be managed by spraying
carbendazim 500g/ha, Mancozeb 1000g/
ha, chlorothalonil 1000g/ha
EARLYLEAFSPOT

4. EARLYLEAFSPOT
- The fungi can appear in overwinter in peanut crop debris. The old lesions on previously
infected peanut leaves and stems produce spores that can infect the new peanut crop
or peanut volunteers.
- High humidity and temperatures between about 65 to 90 degrees F are very favourable
for infection. Lesions become visible around 10 to 12 days after infection. Under
favourable conditions, the lesions being to sport ltd 2 to 4 days later and continue to
sport late for up to two weeks.
- Defoliation begins as lesions accumulate on leaves. Defoliated leaves and infected
leaves and stems from plants threshed at harvest are a source of i oculus for later
peanut crops.

5. - Pustules appear
fi
rst on the lower surface
and in highly suspectible cultivars. The
original pustules may be surrounded by
colonies of secondary pustules.
- Pustules may also appear on the upper
surface of the lea
fl
et.
- They may be formed on all aerial plant
parts apart from
fl
ower and pegs.
Severely infected leaves turn necrotic and
desiccate but are attached to the plant.
- It can be managed by spraying:-
Mancozeb 1000g/ha.
Chlorothalonil 1000g/ha.
Wet table sulphur 2500g/ha.
Tridemorph 500ml/ha
RUSTPUCCINIA ARACHIDIS

6. RUST
- Favourable conditions for rust are high RH (above 85%), heavy rainfall, low temperature
(20-25degree Celsius)
- The pathogen survives uredospores on volunteer groundnut plants.
- The fungus also survives in infected plant debris in soil.
- The uredospores also spread as contamination of seeds and pods.
- Rain splash and implements also help in dissemination.
- The fungus can also survive on the collateral hosts like Arachis marginata, A.
Nambyquarae and A. Prostate.

7. - Chlorotic spots appear on young lea
fl
ets
and necrotic rings and streaks are
developed.
- Terminal bud necrosis occurs when
temperature is relatively high.
- As the plant matures it becomes stunted
with short internodes and proliferation
of auxiliary shoots.
- The virus is mainly transmitted by thrips.
- It is managed by adopting a close
spacing of 15*15cm and spray of
Monocrotophos 36 WSC 500ml/ha.
Before spraying, infected plants must be
removed.
BUDNECROSISPBNV

8. - Chlorotic spots appear on young lea
fl
ets
and necrotic rings and streaks are
developed.
- Terminal bud necrosis occurs when
temperature is relatively high.
- As the plant matures it becomes stunted
with short internodes and proliferation
of auxiliary shoots.
- The virus is mainly transmitted by thrips.
- It is managed by adopting a close
spacing of 15*15cm and spray of
Monocrotophos 36 WSC 500ml/ha.
Before spraying, infected plants must be
removed.
BUDNECROSISPBNV

9. BUDNECROSIS
- It is cause by Peanut Bud Necrosis Virus (PBNV). The virus particles are spherical,
30nm in diameter, enveloped, ssRNA with mulitpartite genome.
- The virus perpetuates in the weed hosts, viz, Biden pilosa, Erigon bonareinsis.
- Tagetes minuta and Trifolium subterraneum. The virus is transmitted by thrips viz,
Thrips palms, T. tabaci and Frankliniella sp.

10. - The sudden drying of branch which is
completely or partially in contact with the
soil.
- The leaves turn brown and dry but remain
attached to the plant. Near soil on stems
while growth of fungus mycelium is
appeared.
- As the disease advances while mycelium
web spreads over the soil and the basal
canopy of the plant.
- It can be managed by seed treatment with
Trichoderma viridea @ 4g/kg seed and soil
application @ 2.5kg/ha, mixed with 50kg
FYM.
- Seed treatment with 3G Thiram + Carbenzim
is also recommended.
STEMROTSCLEROTIUM ROLFSII

11. - The sudden drying of branch which is
completely or partially in contact with the
soil.
- The leaves turn brown and dry but remain
attached to the plant. Near soil on stems
while growth of fungus mycelium is
appeared.
- As the disease advances while mycelium
web spreads over the soil and the basal
canopy of the plant.
- It can be managed by seed treatment with
Trichoderma viridea @ 4g/kg seed and soil
application @ 2.5kg/ha, mixed with 50kg
FYM.
- Seed treatment with 3G Thiram + Carbenzim
is also recommended.
STEMROTSCLEROTIUM ROLFSII

12. STEMROT
- Prolonged rainy season at seedling stage and low lying areas.
- The fungus remains dormant as sclerotia for a long period in the soil and ini infected
plant debris.
- The primary infection is through soil-borne and seed-borne sclerotia.
- The secondary spread of sclerotia is aided by irrigation water, human agency,
implements and cattle, etc.

13. - Lesions produces by A. Arachidis are
brown, irregular in shape, surrounded by
yellowish halos.
- Lesions produced by A. Alternata are
small, chlorotic, water soaked, that
spread over the surface of the leaf.
- A
ff
ected leaves slow chlorosis and in
severe attacks become prematurely
senescent.
- Lesions can coalesce, give the leaf a
ragged and blighted appearance.
- It can be managed by folia application of
Mancozeb (0.3%) or Copper oxychloride
(0.3%) or Carbendazim (0.1%).
ALTERNARIALEAFDISEASE

14. - Lesions produces by A. Arachidis are
brown, irregular in shape, surrounded by
yellowish halos.
- Lesions produced by A. Alternata are
small, chlorotic, water soaked, that
spread over the surface of the leaf.
- A
ff
ected leaves slow chlorosis and in
severe attacks become prematurely
senescent.
- Lesions can coalesce, give the leaf a
ragged and blighted appearance.
- It can be managed by folia application of
Mancozeb (0.3%) or Copper oxychloride
(0.3%) or Carbendazim (0.1%).
ALTERNARIALEAFDISEASE

15. ALTERNARIALEAFDISEASE
- This pathogen propagated itself via asexual spores called conidia.These conidia are
produced in lesions on mature or dying leaves.
- Their production can begin in as few as ten days after the
fi
rst symptoms appear, and
can continue for to up to
fi
fty days.
- The conidia disperse via air currents, and their release from the lesions can be triggered
by rainfall, or even just a sudden drop in humidity. When the conidia lands on a leaf, it
will wait until the nighttime dew, and then germinate.
- It can enter through stomata, or penetrate directly through the top of the leaf.

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