In recent years, lenticel rot of potato tubers, caused by the bacterium Erwinia carotovora subsp. carotovora, has become an economically important postharvest disease for Kern County growers. Disease symptoms are sunken and rotted tissue surrounding tuber lenticels, which develop after harvest and packing. In the field, the bacterium also causes Erwinia early dying, characterized by wilt and progressive necrosis of leaves, eventually resulting in potato plant death. This study confirms Erwinia carotovora subsp. carotovora as the causal agent of both problems in Kern County and establishes the link between the field and postharvest diseases. Control of both diseases is difficult and relies on the integration of cultural methods, from preplant seed-piece handling to postharvest processing.