Field Evaluation of Fungicides for Management of Leaf Blight of Tuberose Caused by Alternaria alternata

Abstract

Background: Tuberose (Polianthes tuberosa L.) is an economically important ornamental crop widely cultivated for its fragrant flowers. However, leaf blight caused by Alternaria alternata has emerged as a major constraint, leading to significant yield reduction under favourable environmental conditions. Aims: The present study aimed to evaluate the efficacy of selected fungicides in managing leaf blight of tuberose under field conditions. Place and Duration of Study: The experiment was conducted during Kharif 2024 and Rabi 2025 under farmers’ field conditions at Huskuru, Doddaballapura taluk, Karnataka. Methodology: Seven fungicides comprising contact, systemic, and combination products were evaluated in a randomized complete block design with three replications using cv. Arka Prajwal. Treatments were applied as foliar sprays at 15-day intervals starting from disease onset. Disease severity was assessed using a 0–5 scale, and percent disease index (PDI) and flower stalk yield (number m⁻²) were recorded. Results: All fungicides significantly reduced disease severity compared to the untreated control (73.46% PDI). Captan + hexaconazole (0.1%) was the most effective, recording the lowest mean PDI (25.05%) with maximum disease reduction (66.28%). This treatment also resulted in the highest flower stalk yield (31.01 m⁻²) and benefit–cost ratio (4.07). Conclusion: Captan + hexaconazole proved highly effective and economically viable for managing leaf blight of tuberose and can be recommended as part of integrated disease management strategies.