Control of fungal decay of apples and peaches by the biofumigant fungus Muscodor albus

The potential of the volatile-producing fungus Muscodor albus for controlling postharvest diseases of fresh fruit by biological fumigation was investigated. In vitro tests showed that M. albus volatiles inhibited and killed a wide range of storage pathogens belonging to species of Botrytis, Colletotrichum, Geotrichum, Monilinia, Penicillium and Rhizopus. Fumigation of apples for 7 days with culture of M. albus grown on autoclaved grain gave complete control of blue mold (Penicillium expansum) and gray mold (Botrytis cinerea) in wound-inoculated fruits. There was no direct contact between the fruit and the M. albus culture. Shorter fumigation times ranging between 24 and 72 h, applied immediately or 24 h after inoculation, also controlled blue mold and gray mold. In wound-inoculated peaches, 24-72 h fumigation with M. albus provided complete control of brown rot (Monulinia fructicola). The volatile profile of M. albus-colonized grain was measured by gas chromatograph connected to a flame ionization detector (GC-FID) and showed that 2-methyl-1-butanol and isobutyric acid were the major volatile compounds found in the headspace. Since M. albus is a sterile mycelium and does not require direct contact with the crops to be treated, it could be an attractive biological fumigant for controlling postharvest diseases. (C) 2003 Elsevier B.V. All rights reserved.