The objective of this study is to isolation and agonistic test ability of Trichoderma spp. againts Sclerotium rolfsii Sacc. cause of wilting on pepper plants and has been conducted in Pathogenicity Laboratory Faculty of Agriculture Unpatti. The study use 5 treatment of isolate Trichoderma spp. (Tc3, Tc4, Tc5, Tc6 and Tc7) with 3 replications so that there are 15 experimental units. The results showed that the five isolates Trichoderma spp. has an antagonistic power to S. rolfsii with an average percentage of inhibition of S. rolfsii of 26,01%. Percentage of inhibition bolth of isolate ware not significantly different at 95% level test results between treatment. Average percentage inhibition of S. rolfsii by Trichoderma spp. each treatment was Tc6 = 27,31%, Tc3 = 26,63%, Tc5 = 26,05%, Tc7 = 25,69% and Tc4 = 24,37%.
Keywords: antagonism, Trichoderma spp., Sclerotium rolfsii