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
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
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
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
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
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
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
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
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
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
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.
