This document summarizes several common diseases that affect peppers, including the causal pathogens, symptoms, and conditions required for disease development. Some of the major diseases discussed are anthracnose caused by Colletotrichum capsici, powdery mildew caused by Leveillula taurica, bacterial spot caused by Xanthomonas compestris pv. vesicatoria, and bacterial wilt caused by Ralstonia solani. Many of these diseases are spread through infected seeds, transplants, soil, debris or water and prefer warm, wet conditions. Several viruses are also discussed that are transmitted by various insect vectors like aphids, whiteflies or thrips.

1. DISEASES OF PEPPER
By
More D.R.

2. • ANTHARCNOSE
• POWDERY MILDEW
• CERCOSPORA LEAF SPOT
• DAMPING OFFAND ROOT ROT
• ALTERNARIA LEAF SPOT & BLIGHT
• DIE BACK
• SCLEROTINIA(WHITE MOLD)
• BACTERIAL SPOT
• BACTERIAL WILT
• CUCUMBER MOSAIC
• TOBAMOVIRUSES
• TOSPOVIRUSES
• LEAF CURL

3. ANTHRACNOSE
COLLETOTRICHUM CAPSICI
Symptoms
Fruit symptoms as water soaked spots later turn tan red or brown.
Spots on fruits

4. Conditions for disease development
• Opti.temp-20˚C to 24˚C
• Free moisture
• Fog and Dew
• Rain disseminates the pathogen spores
• Fungi can survive in seeds and persist in leaf or stem lesions in plant lesions

5. POWDERY MILDEW
Leveillula taurica
Symptoms
Powdery growth on leaves on both side

6. Conditions for disease development
• Air borne conidia from previous crops or weeds carried long distances from wind
• High relative humidity is not required
• Warm temp. and low light conditions

7. CERCOSPORA LEAF SPOT (FROGEYE)
Cercospora capsici
Symptoms

8. Conditions for disease development
• Can survive in infected plant debris for one yr.
• Wet, warm weather conditions
• Spores can spread by wind, air and irrigation water or mechanically by equipment
and people

9. DAMPING OFF AND ROOT ROT
Pythium.sp,Rhizoctonia soloni,Fusarium
Symptoms

10. Conditions for disease development
• Can survive for long in soil, plant debris and weeds
• High soil moisture
• Compaction
• Over crowding
• Poor ventilation
• Cool, dump and cloudy weather
• Water splashing moves infested soil from diseased to healthy plants

11. BACTERIAL SPOT
Xanthomonas compestris pv.vesicatoria
Symptoms

12. Conditions for disease development
• Infected seeds and transplants
• Can survive in crop debris, volunteer plants and in solanaceus weeds
• High relative humidity
• Heavy dew formation on leaves with warm weather
• Water splash
• Growth cracks of fruits, insect punctures and wounds

13. BACTERIAL WILT
Ralstonia solani
Symptoms

14. Conditions for disease development
• Soil borne
• Can survive for long periods in soil on roots and debris
• Infects roots through wounds caused by transplanting and cultivation
• High temp.
• High soil moisture
• Spread in irrigation water, diseased transplants and in soil

15. TOBAMOVIRUSES ( TMV,ToMV,PMMV) Mechanical transmition
Symptoms

16. Conditions for disease development
• Host range:200 plant sp. Including pepper,tomato,eggplant and tobacco
• Source of inoculum:infected plant parts,seed and debris
• Can spread through handling tools,trays,pots,stakes,clothing,pollination and pruning
and other cultural practices
• Can remain viable for several years in plant debris but generally loss there ability to
infect as debris composes

17. CUCUMBER MOSAIC
vector transmission
Symptoms

18. Conditions for disease development
• Host range:800 plant species
• Vector: Aphid
• Often remains in infected alternate host near agriculture area and transmitted to
pepper and egg plants when fav. condition occurs
• Also can mechanically transmit

19. Vector : Aphid (Myzus persicae)
• Travel from leaf to leaf and
plant to plant, as wingless
nymphs or winged or wingless
adults
• Causes spotting and chlorosis
• Leaf curling, distortion,
abscission of flowers
• Can be found on growing points
and underside of newer leaves
• Can travel for miles when
carried by winds

20. LEAF CURL
vector transmission
Symptoms

21. Conditions for disease development
• Vector:Whitefly
• Not mechanically transmitted
• Tomato plants can act as source for virus or vector near pepper area

22. VECTOR:WHITEFLY (Bemisia tabaci)
• Host:Over 500 plants including
weeds,vegetables,ornamentals and
agronomic crops
• Immature and adult flies colonize
underside of leaves
• Larval stage is sedentary
• Tiny adults fly short distances from leaf
to leaf and plant to plant
• Rain and cold weather reduce
populations
• Feed on phloem
• Cause stunting and defoliation

23. TOSPOVIRUS (vector transmission)
Symptoms

24. Conditions for disease development
• Presence of infected weeds or mature plants adjacent to fields
• Vector: Thrips
• Larvae acquire virus on short feeding periods
• Adult thrips transmits viruses
• Temp.above 22˚C accelerate hatching of eggs
• Not seed transmitted

25. VECTOR:THRIPS (Frankliniella fusca)
• Thrips reproduce without mating
• Larvae relatively inactive but tiny
adults are winged and mobile
• Adults live up to 20days
• Feed on developing flowers and
new leaves
• Egg deposition and feeding of
larvae causes scarring and
discoloration of in developing fruit
• Adults can transmit virus for the
remainder of their lives which can
live for 30 to 45 days

26. ALTERNARIA LEAF SPOT & BLIGHT
SYMPTOMS

27. Conditions for disease development
• High humidity
• Fungi overwinters in or on infected plant debris or in soil
• Splashing irrigation water
• Wounding predisposition on fruits

28. SOUTHERN BLIGHT(SCLEROTINIA WILT/WHITE MOLD):Sclerotium rolfisii
SYMPTOMS

29. Conditions for disease development
• Survive in soil & plant debris
• Long distance spread by airborne ascospores
• Short distance spread by contaminated soil & manure
• Irrigation water,infected plant debis,soil,surface water can spread
fungus from field to field
• Rainfall or irrigation followed by drought
• High humidity & warm temp.