Bacterial canker can infect tomato plants systemically, spreading through the plant’s water-conducting tissue, or remain as a more localized infection of leaves, stems and fruit. Infected plants may become stunted and wilt, sometimes on only one side. The vascular tissue inside the stem can turn brown and stems may eventually split and develop cankers. Fruit can develop characteristic “bird’s-eye” spots — small brown lesions surrounded by a pale halo.

The bacteria can arrive on infected seed or transplants and spread between plants in splashing water and on contaminated hands, tools and equipment. Pruning and other injuries provide particularly easy entry points.

How to Fix It

There is no cure for a tomato plant with a systemic bacterial canker infection. 

Remove badly affected plants, including the roots, and avoid handling healthy plants immediately afterward. 

Do not work among tomatoes while the foliage is wet, and disinfect pruning tools and other equipment that contacts infected plants.

Remove tomato debris after the season and control volunteer tomatoes and related weeds.

 Rotate away from tomatoes and other susceptible crops for at least two to three years. 

Start with disease-free seed and healthy transplants, since prevention is much more effective than trying to control bacterial canker after it becomes established.