Present Status of Pomegranate Bacterial Blight and Its Management

Pomegranate (Punica granatum L.) regarded as a "Fruit of Paradise" is one among the major fruit crops of arid zones. The crop is mainly grown in Maharashtra, Karnataka, Andhra Pradesh and Tamil Nadu. In Karnataka, it is extensively cultivated in the northern districts viz., Bijapur, Bagalkot, Bellary and Koppal. It was a dollar earning and boom commercial fruit crop for farmers since 2002. From the year 2002, growers are in dire straits due to severe outbreak of bacterial blight caused by Xanthomonas axonopodis pv. punicae, which was once deemed as a minor important disease and became a serious threat for pomegranate production resulting in severe yield losses both in terms of quality and quantity. A survey report revealed 20-90% of disease severity in Bijapur and Bagalkot district. Similarly 71.14% severity was reported in Bellary district. Recent reports revealed the highest severity of trees was 74.80% in Bagalkot district and minimum severity (6.73%) in Bellary district. The disease is characterized by the appearance of one to several small water soaked, dark colored irregular spots on leaves resulting in premature defoliation under severe cases. The pathogen also infects stem and branches causing girdling and cracking symptoms. Spots on fruits were dark brown irregular slightly raised with oily appearance, which split open with L-shaped cracks under severe cases. Screening of different botanicals and bactericides by in vitro method revealed the superior efficacy of bactrinashak at 0.05% (20 mm inhibition zone) followed by streptocycline (0.05%). Garlic extract 5% was found the next best effective treatment. Field evaluation over the seasons showed that bactrinashak, streptocycline or bacterimycin at 0.05% concentration in combination with COC 0.25% were equally effective in reducing the disease severity. Integrated disease management practices like selection of disease free seedlings, use of organics, proper spacing, pruning time, method of pruning, sanitation, sufficient rest after harvest and use of antibiotics with copper fungicides have proven well in reducing the severity of bacterial blight of pomegranate. Since it is an airborne disease, a mass eradication program will be beneficial.