AN IN VITRO ANTAGONISTIC EFFECT OF Trichoderma spp. AGAINST Fusarium oxysporum f.sp. lycopersici

Abstract

The experiment was conducted in the Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, India. Diseased tomato stems and roots showing symptoms of Fusarium wilt were collected from the Research and Training plots of the Department. The pathogen isolated was identified as Fusarium oxysporum f.sp. lycopersici. Nine native Trichoderma strains were isolated from healthy tomato rhizosphere soils from three different locations of Allahabad; viz Naini, Sangam and Prayagraj. Six isolates were found to be strains of Trichoderma harzianum (SP-4, Th-6, Th-3, Th-5, RTM-16 and EPI-5) while the three were of Trichoderma viride (SP-1, KI-9, SP-3). They were examined in the laboratory for the control of pathogen Fusarium oxysporum. The results revealed that all Trichoderma spp. isolates were found to effectively inhibit the mycelial growth of the pathogen compared to control. However, significant differences between the species and strains were found (P<0.005). The isolates SP-1, SP-3 and Th-6 showed significant inhibition of mycelial growth of the pathogen. In this study, while both Trichoderma strains had a considerable antagonistic effect on the tested pathogen, SP-3 and SP-1 were respectively found to be more successful having the higher percent inhibition of 97.68% and 92.83% at 7 days after incubation. It shows that the strong repressive effect of T. viride isolates (SP-3 and SP-1) can be applied in biological control of Fusarium oxsporum.