Black Rot of Brassica Crops

Black rot (Xanthomonas campestris pv. campestris, Xcc) is uncommon but can be a devastating bacterial disease in South Dakota. Typically, South Dakota’s climate is not conducive to development of this disease, but when periods of hot and wet weather are sustained, it can lead to rapid and widespread crop loss. Black rot can develop at any stage of growth, though it is more commonly seen either in the spring on new transplants or late summer following several days of high humidity and temperatures. When the environment is less suitable, progression and spread of this disease will slow, though symptoms will rapidly worsen when conditions are suitable again.