Pomegranate Bacterial Leaf Blight

Bacterial blight of pomegranate has assumed epidemic proportions (40-85% severity) in northern Karnataka (Bijapur, Bellary, Bagalkot) seriously threatening its cultivation.

Bacterial Blight

Symptoms:

1. Appearance of one to several small water soaked, dark colored irregular spots on leaves resulting in premature defoliation under severe cases.
2. The pathogen also infects stem and branches causing girdling and cracking symptoms.
3. Spots on fruits were dark brown irregular slightly raised with oily appearance, which split open with L-shaped cracks under severe cases.

Initial symptoms on leaves	Defoliation due to Bacterial Blight	Symptoms on flower
Symptoms on branches	V and Y shaped cracks on the spots	Cracking of fruit due to BLB

Causal organism: Xanthomonas axonopodies  pv.punicae

Disease cycle:

• Primary source of inoculum: Infected cuttings
• Secondary source of inoculum: Wind splashed rains

Epidemiology:

The increase in day temperature (38.6°C) and afternoon relative humidity of 30.4% along with cloudy weather and intermittent rainfall favored the disease initiation and further spread of the disease.