Prevention is the best bet. Read on to learn how to prevent bacterial leaf spot in turnips. Pseudomonas syringae pv. maculicola and Xanthomonas campestris pv. amoraciae Bacterial diseases of turnip leaves are very serious infections. There are no highly effective controls for them, and once they have infected a field, the diseases can quickly spread throughout a whole field and render the greens inedible. In addition to black rot of turnip, there are two types of bacteria that cause leaf spots: Pseudomonas syringae pv....