Evaluation of Fungicides for Management of Maize Banded Leaf and Sheath Blight Disease Caused by Rhizoctonia solani f. sp. sasakii and Impact on Economics of Maize Cultivation

Abstract

Aims: To evaluate the in vitro and in vivo efficacy of selected fungicides against Banded Leaf and Sheath Blight (BLSB) of maize caused by Rhizoctonia solani, and identify the most effective fungicide for disease management and yield improvement. Place and Duration of Study: The study was conducted at Agricultural Research Station, Peddapuram (ANGRAU), Andhra Pradesh, India, over three consecutive kharif seasons from 2022 to 2024. Methodology: Seven fungicides were evaluated for their efficacy against Rhizoctonia solani f. sp. sasakii under in vitro conditions by poisoned food technique. Each fungicide was evaluated at three different concentrations. Field trial was laid out in Randomized Block Design (RBD) with three replications, treatments were imposed at 35 and 45 days after sowing. Data on disease severity and grain yield was recorded and analysed as per standard protocols. Results: Among the fungicides evaluated, combination fungicide formulations consistently outperformed individual fungicide formulations under both laboratory and field conditions. Foliar spray of azoxystrobin 11% + tebuconazole 18.3% @ 1.0 ml/l for 2 times during crop season at 35 and 45 DAS was most effective recording a pooled Percent Disease Index (PDI) of 15.1, grain yield of 6826 kg/ha, net returns of ₹79,615, and a benefit-cost ratio of 2.27. While individual fungicide formulations showed considerable efficacy, they were notably less effective than combination formulations. Conclusion: In the field trial for testing efficacy of seven fungicides against BLSB of maize, scheduled foliar spray of fungicide, azoxystrobin 11% + tebuconazole 18.3% @ 1.0 ml/l for 2 times i.e., at 35 and 45 DAS was effective resulting in a 65.2% reduction in banded leaf and sheath blight severity over untreated control. Fungicide combination formulations evaluated were superior in recording lower disease severity, improved productivity, higher net returns with superior B:C indicating a strong correlation between disease suppression and yields.