Screening of Trichoderma species for virulence efficacy on seven most predominant phytopathogens

In vitro studies on the efficacy of Trichoderma species against phytopathogens revealed the antagonistic potential of eight different species of Trichoderma isolated from the rhizosphere soils of varied locations of Uttar Pradesh and were evaluated in vitro against the most widely occurring soil inhabiting plant pathogens viz., Fusarium oxysporum f. sp. ciceri, Alternaria solani, Phytopathora infestans, Pythium aphanidermatum, Sclerotium rolfsii, Bipolaris sorokiyana and, Rhizoctonia solani and identify the most potential and effective strains Trichoderma with high antagonistic activity. Eight species of Trichoderma highly inhibited the growth of the seven test phytopathogens by producing volatile compounds showing variability in antagonistic potential of different Trichoderma spp. against the different pathogens tested. The test antagonists grow faster than the pathogen and produced inhibition zones. These antagonistic interactions influence the incidence and severity of the disease caused by the pathogen. The present communication describes the impact of different Trichoderma spp. on growth inhibition of plant pathogens under in vitro conditions. The data revealed that Trichoderma reesei (Tr(CSAU) showed the maximum inhibition percentage of mycelial growth was recorded as against Scelerotium rolfsii (69.14%) followed by Bipolaris sorokiniana (80.33%), Alternaria brasiciae (83.3%), while, in case of remaining plant pathogens such as Pythium aphanidermatum, Fusarium oxysporum f. sp. ciceri, Trichoderma harzianum (Th.azad) were reduced the highest radial mycelium growth of Pythium aphanidermatum, Fusarium oxysporum f. sp. ciceri (85 and 80%) respectively. Apart from Trichoderma reesei and Trichoderma harzianum (Th.azad), Trichoderma viride (01PP) also inhibited the mycelial growth of Phytophthora infestans (80.83%) and Rhizoctonia solani (70.42%). Key words: Antagonism, Trichoderma, phytopathogens.