Field Evaluation of Fungicides for Management of Leaf Blight of Tuberose Caused by Alternaria alternata
B. Manjunath *
Department of Plant Pathology, College of Agriculture, GKVK, Bengaluru– 560 065, Karnataka, India.
Bhavana
Department of Plant Pathology, College of Agriculture, GKVK, Bengaluru– 560 065, Karnataka, India.
C. R. Jahir Basha
Department of Plant Pathology, College of Agriculture, GKVK, Bengaluru– 560 065, Karnataka, India.
G. S. Krishna Reddy
Agricultural Research Station, Nelamakanahalli, University of Agricultural Sciences, Bangalore, India.
A. B. Narayana Reddy
AICRP on Seed (Crops), National Seed Project, GKVK, Bengaluru – 560 065, Karnataka, India.
K. J. Sowmya
Department of Seed Science & Technology, College of Agriculture, GKVK, Bengaluru– 560 065, Karnataka, India.
*Author to whom correspondence should be addressed.
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.
Keywords: Alternaria alternata, tuberose, leaf blight, fungicides, field evaluation, disease management.