In vitro interactions between Cylindrocladium floridanum and species of Trichoderma

Isolates of Trichoderma harzianum, T. viride, T. koningii, T. polysporum, T. hamatum, and one isolate of T. virens were assessed for their ability to inhibit Cylindrocladium floridanum under laboratory conditions. When the pathogen and Trichoderma species were inoculated simultaneously, the ability of the Trichoderma to inhibit microsclerotium formation by C. floridamum was determined to be strain and isolate dependent. Greater differentiation of the inhibitory abilities of Trichoderma was evident if the pathogen was allowed to become established on the substrate prior to inoculation with Trichoderma. The most inhibitory Trichoderma isolates produce 6-n-pentyl-2H-pyran-2-one in culture, which inhibits the mycelial growth and microsclerotium production of C. floridamum. C. floridanum was found to produce a substance inhibitory to the mycelial growth of Trichoderma.