POSTHARVEST DECAY OF CANTALOUPE CAUSED BY EPICOCCUM-NIGRUM

A decay causing red discoloration in cantaloupe fruit was observed in postharvest storage studies and on occasion has been involved in load rejection of melons grown in southeastern Oklahoma. Epicoccum nigrum was consistently isolated from areas showing the red discoloration. The fungus was also pathogenic on fruit of cucumber, tomato, apple, and pear. Comparison of the cantaloupe isolate of E. nigrum with isolates from Pennisetum flaccidum and Pisum sativum indicated that all were similar if not identical, based on host range and decay characteristics on the previously mentioned fruit. Light and scanning electron microscopy revealed that sporodochia and conidia were typical of E. nigrum. Radial growth was greatest on potato-dextrose agar at 20 C and limited at 1, 5, and 30 C. The fungus remained viable in screwcap culture tubes of soilless medium (potting mix) for 4 yr at about 20 C. A proposed common name for the disease is red rot.