In vitro efficacy of bio-control agents and developing Integrated management strategies for Fusarial wilt disease of Marigold

Marigold is an annual flowering plant which is mainly affected by Fusarium wilt incited by Fusarium oxysporum f. sp. callistephi. In this study, use of saprophtically competitive bioagents like Trichoderma, Pseudomonas and Bacillus isolated from the rhizosphere were explored as an alternative to chemical fungicides. The efficacy of oil cake extracts and the combined effect of various management measures were explored. Among the 10 isolates, the suppression was higher with Trichoderma viride (Tvj), Pseudomonas fluorescens (Pf₃) and Bacillus subtilis (Bs₁₀) which effectively inhibited the growth of causal organism to an extent of 78.3, 56.0, 50.3%, respectively over control. Neem cake at 10% concentration recorded 50.6% reductions in mycelial growth. Among the systemic fungicides tested, the combination product carbendazim 12% + mancozeb 64% inhibited the fungal growth completely above 1000 ppm concentrations.