Bacterial leaf blight (BLB) is caused by the bacterium Pseudomonas syringae p.v. aptata and can affect both leaves and bulbs.

 

Identification

Dark greasy leaf lesions, often with lighter brown areas and centres, commonly occur on leaf margins where bacteria have accumulated. Seed borne infection can cause seedling blight.

 

Bacterial leaf blight

 

Importance

Commonly occurs in fodder beet crops. Severe infection reduces green leaf area and bulb dry weight. 

 

Spread

Primary infection often arises from seed-borne inoculum or via volunteer host plants and crops. Water splash, stock and machinery spread the disease. Bacteria can also survive on crop debris.

 

Management

Always sow seed from a reputable source. Avoid excessive foliage wetness and follow good crop rotation practices.