In-vitro screening of Trichoderma spp. against five species white-rot macromycetes was conducted. All fungal species were isolated from Sibolangit Conservation Forest, North Sumatera-Indonesia. Trichoderma spp. were screened and isolated from soil samples by dilution method followed by pour plate method.Macromycetes were isolated from fresh fruiting body. By dual culture technique, antagonism both of the fungi were measured based on colony growth and percentage inhibition between species both of the fungi and mixed culture two species Trichoderma and one species white-rot. Results showed that 5 species of Trichoderma spp. (TR01, TR03, TR04, TR05,TR06) and white-rot (Lepiotanaucina, Ganodermaapplanatum, Trametesversicolor, Coltriciacinnamomea, and Phaelusschweinitzii) were isolated. Antagonism between one species Trichoderma and white-rot indicates all Trichoderma spp. have varying ability to inhibit mycelia growth of the white-rot,and mean inhibition percentage of each Trichoderma against macromycetes is higher than that of mixed cultures. IsolateTR01, TR03 and TR05 have potential to inhibit the white-rot.Whereas, mixed cultures(TR03+TR05) showed the highest inhibition against L. naucina and G. applanatum. Among the white-rot, Phaelusweinitziiis the most resistant to Trichodermaand the lowest inhibition percentagenot only between Trichoderma species but in mixed cultures as well.
