This document discusses several diseases that affect pepper plants, including bacterial spot, bacterial canker, damping-off, powdery mildew, fusarium wilt, phytophthora blight, southern blight, mosaic, blossom-end rot, and tomato spotted wilt virus. For each disease, the document provides information on symptoms caused by the disease and the causal organism (bacterium, fungus, oomycete, or virus). The document includes pictures showing examples of symptoms on pepper leaves, stems, and fruit for most of the diseases.

2. Pepper bell Diseases
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan

4. Bacterial spot
Xanthomonas campestris
Symptoms
• Water-soaked lesions that
dry out and turn brown
forming on the underside of
the leaves; raised brown
cankers on stems; cracked
brown lesions on fruit
• Cause
• Bacterium
Symptoms of bacterial spot on
pepper leaf

5. Bacterial spot
Symptoms of bacterial spot on
pepper fruit
Symptoms of bacterial spot on
pepper foliage

6. Bacterial spot
Symptoms of bacterial spot on
pepper foliage
Symptoms of bacterial spot on
pepper foliage

7. Bacterial spot
A shot hole appearance on a leaf
infected with bacterial spot
Symptoms of bacterial spot on
pepper foliage

8. Bacterial canker
Clavibacter michiganensis
Symptoms
• Small, raised, white lesions
on leaves that grow larger,
turn brown and necrotic
and may have a yellow halo;
raised white lesions on fruit
which coalesce to form
larger spots, often with
white halo
• Cause
• Bacterium

9. Damping-off
Pythium spp.
Rhizoctonia solani
Symptoms
• Seeds did not germinate;
seedlings collapsing and
dying; dark stems which are
shriveled near the soil line;
water-soaked lesions on the
stem; water-soaked
discolored roots
• Cause
• Fungi

10. Damping-off
Damping-off of pepper seedling Damping-off of pepper seedling

11. Powdery mildew
Leveillula taurica
Symptoms
• Patches of white, powdery
fungal growth on the
underside of the leaves; yellow
to brown discoloration of the
upper leaf; edges of leaves
may curl upwards exposing the
underside of the leaf; leaves
may begin dropping from plant
• Cause
• Fungus
Pepper leaf infected with
powdery mildew

12. powdery mildew
Pepper leaf infected with
powdery mildew
Powdery mildew symptoms on
pepper leaf

13. Fusarium wilt
Fusarium oxysporum most
Symptoms
• Yellowing of foliage and
wilting upper leaves; wilting
spread to all parts of plant;
leaves remain attached to
plant and are dark green in
color; red-brown
discoloration of vascular
tissue; plant death
• Cause
• Fungus

14. Phytophthora blight
Phytophthora caspsici
Symptoms
• Black lesions on stems;
wilting plant; circular gray-
brown lesions on leaves;
dark lesions on fruit which
may be covered in white
sporangia
• Cause
• Oomycete
Phytophthora blight symptoms
on pepper fruit

15. Phytophthora blight
Pepper plant infected with
Phytophthora blight
Symptoms of the disease includes wilting of the plant. However,
other diseases can also cause this symptom and the plants needs
to be carefully analyzed for confirmation

16. Phytophthora blight
Field infestation of Phytophthora
blight
The pathogen can easily spread through
rain splash or running water and wind.

17. Phytophthora blight
A characteristic symptom is the crown rot and
black lesion at the crown region which is
indicative of the disease. Such symptoms
develop especially during high rainfall conditions
or in areas with water logging or excessive
moisture.
Pepper plants infected with
Phytophthora blight

18. Southern blight
Sclerotium rolfsii
Symptoms
• Sudden wilting of leaves;
yellowing foliage; browning
stem above and below soil;
browning branches; stem
may be covered with fan-
like mycelial mat
• Cause
• Fungus
Stem lesions on pepper caused
by Southern blight

19. Pepper plant infected with Southern
blight

20. Southern blight grows best in warm, humid conditions. The first symptom is
the wilting of the the plant to wilt. At the collar region of the stem you will
notice a brown blighted section

21. The fungus can often be seen growing as a white mycelial mat growing on the stem
and the surrounding soil. The mycelia will develop sclerotia which are light tan to dark
brown pathogen survives in the soil or in plant debris, volunteers and weeds

22. Discolored pepper stem

23. As the disease progresses the plant will continue to wilt and leaves will eventually turn brown.
Because the canopy is being destroyed fruit will become more susceptible to sunscald and
secondary pathogens.

24. Mosaic
Cucumber mosaic virus (CMV)
Potato virus Y (PVY)Symptoms
• Alternating light and green
areas or mosaic patterns on
the leaves; leaves distorted
and curled; slow plant
growth
• Cause
• Virus

25. Blossom-end rot
Symptoms
• Small water-soaked area on
end of fruit where the
blossom was occurring or
on the side of unripe fruit;
lesion enlarges and turns
sunken, tan brown and
leathery in appearance
• Cause
• Low calcium concentration
in fruit
Blossom-end rot on pepper fruit

26. Blossom-end rot
Blossom-end rot on pepper fruit
As the fruit grows the spot will also enlarge and may eventually
cover up to half of the fruit. Fungi and bacteria may attack the
damaged tissue causing tissue discoloration

27. Blossom End Rot
• Anything that reduces the
plants ability to uptake
calcium can lead to the
development of this
disorder, with one of the
main reasons being the
availability of water.
Symptoms begin as a small,
water soaked light brown
spot at the blossom end of
the fruit

28. Tomato spotted wilt virus
Tomato spotted wilt virus (TSWV)
Symptoms
• Symptoms may vary widely
depending on variety and
environmental conditions;
generally leaves become
spotted and bronzed in
appearance; plant may droop
or wilt; fruit develop
concentric rings which are
light in color and become
necrotic
• Cause
• Virus
Characteristic ring spots on
pepper fruit

29. Tomato spotted wilt virus
Symptoms
• Symptoms may vary widely
depending on variety and
environmental conditions;
generally leaves become
spotted and bronzed in
appearance; plant may droop
or wilt; fruit develop
concentric rings which are
light in color and become
necrotic
• Cause
• Virus
Necorsis of pepper fruit caused
by TSWV

30. Tomato spotted wilt virus
TSWV is transmitted by thrips, which can only acquire
the virus as larvae and transmits it as an adult. The
initial symptom is chlorosis on leaves
In addition to chlorosis leaves may also become twisted and
distorted. The severity and appearance of symptoms will vary
depending on the cultivar, the age of the plant at the time of
infection, environmental conditions and the virus isolate

31. Tomato spotted wilt virus
Fruit may also be affected, developing chlorotic
or necrotic spots, ring spots or mosaics.

32. Tomato spotted wilt virus
Pepper plant infected with TSWV
Leaves of infected plants may also develop
chlorotic or necrotic ring spots