Study of the effect of volatile metabolites of Trichoderma hamatum on the growth of phytopathogenic soilborne fungi.
Volatile compounds produced by T. hamatum were tested for their ability to suppress in vitro the growth of Alternaria citri, Bipolaris cynodontis [Cochliobolus cynodontis], B. sorokiniana [C. sativus], Curvularia brachyspora, C. lunata [Cochliobolus lunatus], Curvularia oryzae-sativae, Drechslera tritici-repentis [Pyrenophora tritici-repentis], Rhizoctonia solani, Sclerotinia minor and Sclerotium rolfsii [Corticium rolfsii]. The organisms were cultured in apparatus comprising 2 Erlenmeyer flasks joined together by their top parts. The variation of carbon dioxide, oxygen and ethylene in the internal system was determined using gas chromatography. Acetaldehyde and ethanol were not detected. Due to the respiratory metabolism of T. hamatum the carbon dioxide level progressively increased while the oxygen content decreased. Ethylene production was low and remained constant after 3 days. With the exception of C. oryzae-sativae and B. cynodontis, all other species showed changes in growth and development. It is suggested the inhibitory volatiles of T. hamatum could be a possible mechanism of biological control.