Dear David, Black Rot bacterial disease has been found in cabbages in Kapsaos. Look for V-shaped yellow lesions starting from leaf edges. Once infected, there is no cure - remove affected plants. Prevention: 1) Use treated seeds, 2) Rotate with non-cabbage crops for 3 years, 3) Disinfect tools between fields, 4) Control insect pests that spread bacteria. Next planting season, consider resistant varieties.