Overview
Clavibacter michiganensis subsp. michiganensis is a Gram-positive bacterium that causes bacterial canker and wilt of tomato. It is one of the most serious bacterial diseases of the crop worldwide, affecting both greenhouse and open-field production and capable of causing severe losses once established.
Symptoms
Infected plants show wilting — often on one side of a leaf or plant first — leaf-margin scorch, stem cankers and internal browning of the vascular tissue. On fruit it produces characteristic 'bird's-eye' spots with pale haloes.
How it spreads
The bacterium is mainly seed- and transplant-borne and spreads readily on hands, tools and through pruning and handling. Warm, humid conditions accelerate its development.
The control challenge
There is no effective curative chemical control for bacterial canker; management relies on clean seed, hygiene, exclusion and prevention. That absence of a curative tool makes targeted biological approaches a compelling area of study.
Bacterial canker of tomato is an additional target category within the scope of Exacta's platform. Bacteriophage approaches to seed- and foliar-borne bacteria are an area of research interest — described here as a development area, not a commercially available product.