In vitro and greenhouse evaluations of Trichoderma isolates for biological control of potato wilt disease (Fusarium solani)

The biological efficacy of Trichoderma species may differ due to variations in ecosystems. This study was conducted to assess the biocontrol efficacy of some native Trichoderma isolates against Fusarium solani, an important causal agent of potato wilt disease under laboratory and greenhouse conditions at Shahrood Agricultural Research Centre, Shahrood, Iran, during 2006–2007. Fourteen isolates were collected among which eight showed promising ability in inhibiting the growth of the pathogen through dual culture and production of volatile and non-volatile inhibitors but T. brevicompactum (T1), T. longibrachiatum (T5) and T. asperellum (T2) were almost better than other isolates in inhibiting the mycelial growth of the pathogen in comparison to control in the above three tests (p ≤ 0.01). Isolates performing mycoparasitism under in vitro condition were evaluated against the disease in pot culture under greenhouse condition. In all treatments in which Trichoderma isolates + F. solani were involved lower disease incidence was noticed in comparison to Fusarium-infested control (p ≤ 0.05). Best disease control was observed in potted plants treated with F. solani + T. longibrachiatum (T5) with 6.25% disease incidence in comparison to Fusarium-infested control, in which disease incidence was observed to be 75%. Interaction of T. brevicompactum (T1) and F. solani also indicated good control of the disease by 12.50% of disease incidence.