Bacterial wilt of three Curcuma species, C-longa (turmeric), C-aromatica (wild turmeric) and C-zedoaria (zedoary) caused by Ralstonia solanacearum in Japan

A new bacterial disease was observed on three Curcuma species, C. longa (turmeric), C. aromatica (wild turmeric) and C. zedoaria (zedoary) in Okinawa Prefecture, Japan in January 2014. At harvest, leaves suddenly wilted, curled and yellowed, and the whole plant finally died. The wilted plants had rotted rhizomes with internal discoloration. Creamy-whitish bacteria were isolated from the rhizomes of each Curcuma species. These bacteria were identified as Ralstonia solanacearum race 4, biovar 4 and phylotype I based on bacteriological characteristics, pathogenicity tests and DNA-based analyses. The names bacterial wilt of turmeric, wild turmeric and zedoary are proposed for the diseases.