Carrot spoiled by Erwinia carotovora (yellow) and yeast (gray). E. carotovora affects many other vegetables, including potatoes, cucumbers, onions, tomatoes, lettuce, and even some ornamental plants like iris. The crops are infected either in the field or in storage. Their tissues become soft and watery and then turn slimy and foul-smelling. Blackleg, aerial stem rot, and tuber soft rot are caused by two closely related bacteria, Erwinia carotovora subsp. atroseptica and Erwinia carotovora subsp. carotovora. The latter is very common and has an extensive host range, including most fleshy vegetables. It survives readily in soil and surface waters such as rivers, lakes, and even oceans. These bacteria are capable of multiplying and persisting in the root zones of many host and nonhost crop and weed species. In contrast, Erwinia carotovora subsp. atroseptica is associated mostly with potatoes. Enhanced SEM. Image width: 9.85 micrometers. Magnification: 10,150x if the image is printed 10 cm wide.