A Trichoderma koningii seed treatment is effective before and after seed storage against Sclerotium rolfsii damping off of tomato

An isolate of Trichoderma koningii was used for treatment of tomato seeds with a suspension of 10(6) con/ml in dilute Tween-20 or sterile distilled water. Seeds were stored at 6 degreesC or 20 degreesC and periodically sampled in order to determine the efficacy of Trichoderma koningii as a biocontrol agent against Sclerotium rolfsii damping off in the greenhouse. Seed germination tested in water agar plate showed that T. koningii slightly delayed seed germination over control treatments. Length of storage had a significant effect on the survival of Trichoderma on seeds, which was more pronounced when seeds were stored at 20 degreesC rather than at 6 degreesC. The biocontrol ability of T. koningii, expressed as pre- and post-emergence damping off in artificially infested sterile potting compost, was affected by the length of storage. Storage temperature also excerted a significant (P=0.034) effect on final stand. After each storage period, Trichoderma-treated seed still gave significantly greater seedling counts of plants than uncoated control seed.