In vitro evaluation of various bioagents and phytoextracts against stem rot (Sclerotium rolfsii) in Aster plant

Aster Stem rot, caused by the soil-borne fungus Sclerotium rolfsii, poses a significant threat to the cultivation of aster plants (Aster spp.). This study aimed to evaluate the efficacy of various bioagents and phytoextracts in controlling this disease under in-vitro conditions. Bioagents such as Trichoderma viride, T. harzianum, T. hamatum, T. koningii and T. virens with one bacterial bioagent, Pseudomonas fluorescens were tested for their antagonistic activity against Sclerotium rolfsii. Additionally, phytoextracts fromDrumstick leaf, Neem leaf, Tulsi leaf, Garlic clove, Custard Apple leaf, Ghaneri leaf were assessed for their antifungal properties. The results indicated that both Trichoderma viride (5.5cm) which was significantly superior over all other bioagents inhibited the growth ofSclerotium rolfsii, reducing mycelial expansion and sclerotia formation. Similarly, the radial mycelial growth of the test pathogen ranged from 0.8 (garlic) to 8.1 cm (drumstick). It was maximum in drumstick (8.1 cm) which is significantly superior followed by custard apple (6.4 cm), neem (5.3 cm), ghaneri (3.5cm) demonstrated strong antifungal activity, effectively suppressing the pathogen. These findings suggest that integrating bioagents and phytoextracts into disease management programs could offer a sustainable and ecofriendly alternative to chemical fungicides. Future research should focus on field trials to validate these in-vitro findings and explore the potential synergistic effects of combining different bioagents and phytoextracts. This study contributes to the development of integrated disease management strategies for stem rot in aster plants, promoting healthier and more resilient crops.