Trichoderma koningii and Trichoderma harzianum as destructive mycoparasites of Sclerotinia slerotiorum.

Three T. koningii (Tk 3, 5 and 12) and one T. harzianum (Th 9) strain isolated from S. sclerotiorum sclerotia were found to reduce the growth of the patogens by over 60% relative to that of the control. These strains also hyperparasited the sclerotia. All were also highly competitive when assessed in the saprophytic competitiveness test. Extra cellular enzyme production was not particularly correlated with antagonistic activity, Tk 12 and Th 9 produced some Beta-glucosidase and no endoglucanase. In contrast, Tk3, 5 and 12 produced large amounts of antibiotics, causing between 30% and 80% inhibition of growth of the pathogen. The interactions between T. harzianum strain and S. sclerotiorum appeared to be mycoparasitism, and results from the sclerotial survival tests showed they were also capable of destroying sclerotia