PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Aims: To assess the in vitro fungitoxic and antagonistic potential of systemic fungicides, contact/combi-product fungicides, fungal and bacterial biocontrol agents, and organic amendments against Sclerotium rolfsii, the causal agent associated with stem rot of chilli.

Study Design: Completely Randomised Design (CRD).

Place and Duration of Study: Department of Plant Pathology, College of Agriculture, Latur, Maharashtra, India; 2025–2026.

Methodology: The pathogen was isolated from symptomatic chilli collar/root tissues and identified morphologically on Potato Dextrose Agar (PDA). Seven systemic fungicides (500 and 1000 ppm), seven contact/combi-product fungicides (2000 and 2500 ppm), and seven organic amendments (5% and 10%) were evaluated using the poisoned-food technique. Seven biocontrol agents were screened using a dual-culture assay. Each experiment was conducted in a CRD with three replications.

Results: Propiconazole 25% EC, Tebuconazole 25.9% EC, and Hexaconazole 5% SC produced 100.00% inhibition at both systemic-fungicide concentrations. Six of the seven contact/combi-product fungicides produced 100.00% inhibition at 2000 and 2500 ppm; copper oxychloride was less effective. Among the bioagents, Trichoderma harzianum produced the greatest inhibition (66.22%; colony diameter 30.40 mm), followed by Aspergillus niger (65.52%; 31.03 mm). Groundnut and cotton seed cake extracts produced 100.00% inhibition at 10%, with average inhibitions of 92.27% and 89.46%, respectively.

Conclusion: The assays identified several treatments with strong in vitro activity against S. rolfsii. These treatments are candidates for subsequent compatibility, greenhouse, phytotoxicity, and field efficacy studies before being recommended as components of integrated disease management.