Vanilla (Vanilla planifolia Ames) is an economically valuable spice crop that is widely cultivated in the tropics. Bacterial soft rot has occurred frequently in Hainan Province, China since vanilla was first cultivated in this region in the 1980s, usually with 15–30% incidence. Soft rot symptoms in vanilla plantations include the following: hygrophanous brown spots develop on the leaves and stems at early stages of infection; lesions spread quickly, and the tissues become soft and rotten, with brown lines at the edges; oozing white exudate is often produced under humid environmental conditions. The pathogen was previously identified as be Erwinia carotovora subsp. carotovora(Y. T. Wen 1992). However, we found that Dickeya dadantii (E. chrysanthemi) caused this disease in Wanning city (110.39′ N, 18.8′ E) and Qionghai city (110.46′ N, 19.25′ E). In September of 2013 and 2014, diseased samples were collected from vanilla fields of both cities and bacteria were isolated from diseased leaves and cultured on n...