Abstract
Since 1973, a new disease of maskmelon caused by Rhizopus sp. occured in Shizuoka prefecture. The fungus of Rhizopus disease attacks on fruits of maskmelon were arrived at a market. Rhizopus sp. isolates obtained with high frequency from affected fruits. The symptoms appeared on the peduncle of muskmelon fruits at the begining of the disease development. The symptom on peduncle are covered with black mycelia. Soon after, the disease fruits softened and rotted circularly at the peduncle. The fungus was similar to Rhizopus stolonifer because of the agreements in their morphological and pathogenical properties to the description by Inui and Zycha. From these results, the causal fungus was identified as Rhizopus stolonifer (Eherenberg Ex Fr.) Lind (syn. Rhizopus nigricans Ehr.).
