Title: Post harvest diseases of brinjal
1Post harvest diseases of brinjal
Anthracnose Colletotrichum melongenae
Fruit rot Phomopsis vexans
Fruit rot Alternaria solani
Fruit rot Pythium aphanidermatum
Fruit rot Phytophthora nicotianae var nicotianae
2Fruit rot - Phomopsis vexans
- First phase - blight on young seedlings
- Stem - girdled slightly above the soil line,
plant topples and dies - Stem lesion - dark brown, becoming grey in the
centre as pycnidia develops - Leaf - irregular brown spots
- Fruits soft, watery decays
- Finally black, mummified as pycnidia develop
abundantly over the surface
3- Fungus
- Pycnidia - with or without beak, brown to black
- Conidiophores - hyaline, simple or branched,
- Conidia - hyaline, one celled and subcylindrical
- Stylophores - filiform, curved, hyaline, septate
- Mode of spread and survival
- Seed borne
- Spread by rain splashes, implements and insects
- Survives in infected plant debris in soil
Conidia from pycnidium
4- Epidemiology
- Temp - 29oC (fungal growth)
- Storage rot of fruits is maximum at 25oC
- Management
- Seed treatment - hot water _at_ 50oC for 30 min
- Nursery - 0.2 difolatan or captan 0.2 _at_ weekly
interval - Field - Zineb 0.2
- Bordeaux mixture 0.8
5Fruit rot - Alternaria solani
- Small, concentric dark brown sunken spots
- Spots coalesces covers entire fruit
- Fungus
- Hyphae - septate, branched, light brown becoming
darker with age - Conidia - single, muriform, beaked and dark in
color - Source of infection - infected seeds and plant
debris - Pusa purple - moderately resistant
Alternaria solani conidia. Note the transverse
and vertical septa and the long "beak
6- Favourable conditions
- Temp - 25 to 30oC
- Sporulation abundant when rains are frequent
and heavy - Mode of survival and spread
- Conidia and mycelium in the soil and debris -
remain viable for gt 17 months - Conidia are windborne
- Control
- Spraying of zineb 0.2 or mancozeb 0.2
7Fruit rot - Pythium aphanidermatum
- Referred as cottony leak
- Decay begins at blossom end
- Purple colour of the skin bleaches and turns to
tan and wrinkling follows - Fleshy tissue becomes watery
- White cottony mycelium of the fungus covers the
surface - Fungus
- Mycelium - coenocytic, white and measures 2.8 -
7.5 µm in dia - Produce sporangia, zoospores, and oospores
- Oogonia - spherical, smooth walled, terminal on
lateral hyphae -
8- Mode of spread and survival
- Survival Through oospores present in the soil
- Spread Through irrigation water, implement
during cultural operations -
- Favourable conditions
- Excessive soil moisture
- High humidity
- Over crowding of seedling
- Control
- Remove affected plants and burn
- Avoid water logging condition
- Drench the soil with 1 Bordeaux mixture
- Fruits should not be allowed to touch the soil
- Do not store the infected fruits with healthy
fruits
9Fruit rot - Phytophthora nicotianae var nicotianae
- Fruits - Small, water soaked lesions
- Skin - discoloration, turns greyish brown, and
develop white cottony mycelium in humid weather - Rotten parts become depressed and develops
wrinkles - Rotting spread deep into the pulp and turns
brown, watery soft - Rapidly spreads during rainy season
10- Fungus
- Hyphae - 5 to 6 µm in dia
- Spherical hyphal swellings are common
- Zoosporangia - sub hyaline, oviod, pyriform borne
on short stalk - Control
- Removal and destruction of the affected fruits
- Spraying the crop with Difolatan (0.3) thrice at
an interval of 10 days effectively controls the
disease
A Sporangia. B Zoospore. CChlamydospore. D
Oospore.
11Anthracnose - Colletotrichum melongenae
- Sunken lesions on fruits vary in size
- Upto 1.3cm wide and may coalesce
- Tan colored ooze of fungal spores appear on
lesions - Fruit dries become black fruit drop
- Fungus
- Mycelium - septate, branched light pink to
brown - Acervuli - simple globose and dark brown
- Conidiophore - erect and hyaline
- Conidia - hyaline, one celled, oval or oblong
12- Mode of spread and survival
- Survives on crop debris as acervuli
- Spores dispersed by rain splash
- Epidemiology
- RH - 100
- Temp - 21 to29oC
- Control
- Field sanitation - destruction of infected plant
debris - Other host plant - S. torvum
- Harvesting of fruits before they over ripe
- Zineb or ferbam spray at 10 days interval