Purple Spot of Aloe (Aloe arborescens Mill.) Caused by Fusarium phyllophilum Nirenberg et O'Donnell (New Disease)

A new disease causing purple spots on leaves of candelabra aloe (Aloe arborescens Mill.) was found in Tahara-cho and Irako, Atsumi Peninsula, Aichi Pref. in October 1993. A species of Fusarium was isolated from lesions of many infected plants. This fungus was found to be pathogenic on A. arborescens by inoculation of wounded and intact leaves. The fungus was identified as Fusarium phyllophilum Nirenberg et O'Donnell on the basis of cultural and morphological characteristics. The disease was also observed at every location examined in Boso, Miura, Kii, Osumi, and Satsuma Peninsulas, where the climate is similar to that in Atsumi Peninsula. Four additional isolates from Jogashima Island were also identified as F. phyllophilum. This is the first report of the disease on A. arborescens in Japan.