Competition between Phytophthora cinnamomi and Trichoderma spp. in autoclaved soil

Results from analyses of β-glucosidase (EC 3.2.1.21) and phosphatase (EC3.1.3.1; EC 3.1.3.2) activities indicated that presence of a Trichoderma isolate reduced development of Phytophthora cinnamomi. It was also observed that P. cinnamomi was more competitive in coinoculated cultures than in cultures where Trichoderma was added on day 3. Analysis of trehalase (EC 3.2.1.28) activity indicated that Trichoderma either utilized portions of the P. cinnamomi mycelium as substrate or the action of P. cinnamomi released additional nutrients not normally available to Trichoderma. The stronger Trichoderma isolate was T. harzianum.