Biological control of Fusarium wilt of potato (Fusarium oxysporum f. sp. tuberosi) by Trichoderma isolates under field condition and their effect on yield

Application of trichoderma species is a harmless method of controlling soil borne plant diseases thus reducing hazardous pesticide use and environmental pollution. some trichoderma isolates with good inhibitory effect against fusarium oxysporum f. sp. tuberosi under laboratory and green house conditions were tested 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 of field study indicated that t. virens (t7) followed by t. asperellum (t2) were superior to others in reducing the disease. in comparison to control plots, yield was higher in all plots treated with trichoderma, but significantly higher yields were obtained from plots in which t. virens (t7) and t. asperellum (t2) were involved. it may be concluded that isolates of t. virens and t. asperellum have the required efficacy as biocontrol agents against fusarium wilt disease of potato and can be used as formulated biofungicides for reducing this disease.