| Root rot and stem rot | Macrophomina phaseolina |
| Bacterial wilt | Pseudomonas solanacearum |
1. ROOT ROT and STEM ROT – Macrophomina phaseolina
Symptoms
The fungus attacks the stem at the nodal region, causing shredding of the bark. In mature plants, necrotic lesions on the leaves appear at the apex and along their margins. Pycnidia are formed on the infected roots and stem
Pycnidial stage – Macrophomina phaseolina
Sclerotial stage – Rhizoctonia bataticola
Mode of Spread and Survival
The pathogen is Soil borne and seed borne, survives as Sclerotia in soil
Epidemiology
Prolonged drought followed by irrigation encourage the disease
Management
- Crop rotation with non-host crops
- Field sanitation
- Use disease free seeds
- Soil drenching with 0.1 % carbendazim
2. BACTERIAL WILT – Pseudomonas solanacearum
Symptoms
Affected plants become stunted and chlorotic. The leaves of diseased plants fall off and root system is poorly developed
Mode of Spread and Survival
The bacterium spreads through wind splashed rains and survives in infected plant debris
Management
- Field sanitation
- Crop rotation
- Running of irrigation water from diseased field to other field should be prevented
