1Plant Protection Department, Shahrood Agricultural Research Center, P. O. Box: No. 36155-313, Shahrood, Iran.
2Department of seed and plant improvement, Shahrood Agricultural Research Center, Shahrood, Iran, P. O. Box No: 36155-313.
Application of Trichoderma species is a harmless method in controlling soil borne plant diseases thus reducing hazardous pesticide use and environmental pollution. Some Trichoderma isolates performing proper inhibitory effect against Fusarium oxysporum f. sp. tuberosi under laboratory and green house conditions were screened against wilt disease of potato caused by this pathogen under field condition in Shahrood Agricultural Research Center, Iran, during 2009-2010. Results of two years field studies indicated that T. virens (T7) followed by T. asperellum (T2) were superior to others in reducing the disease in comparison to infested control. In comparison to Fusarium infested plots, yield was higher in all plots treated with Trichoderma, but highest yields were obtained from plots in which T.virens (T7) and T. asperellum (T2) were involved respectively. It might be stated that isolates of T. virens and T. asperellum are among the effective biocontrol agents against Fusarium wilt disease of potato and can be used as formulated biofungicides in reducing this disease.