Symptoms
- Small, circular reddish-brown spots with concentric rings on leaves
- Dark brown lesions on petioles, stem and capsules
- Blighting of leaves and defoliation
- Splitting of capsules and shrivelled seeds
Identification of pathogen
- Conidiophore : Occasionally in groups
- Conidia : Obclavate and light olive in colour in chains
Favourable Conditions
High atmospheric humidity (85-90%) and low temperature (16-20ºC).
Mode of Spread and Survival
- Survive on Jatropha pandurifoliaand Bridelia hamiltoniana.
- Primary spread: Externally and internally seed borne.
- Secondary spread: Wind-borne conidia.
Management
- Remove the reservoir host periodically
- Avoid closer spacing.
- Spray mancozeb at 1000 g/ha.
|
|