Bio-intensive and Chemical Management Strategies for Leaf Blight in Maize (Zea mays L.)

Abstract

Leaf blight is an important constraint to maize production in the rainfed farming systems of Vizianagaram district, Andhra Pradesh. This study compared farmer's practice, conventional chemical management and an integrated bio-intensive management module through on-farm trials conducted during the Kharif seasons of 2024 and 2025 in Badangi mandal. The conventional module involved Mancozeb seed treatment and foliar application, whereas the integrated module combined seed treatment with Trichoderma viride at 6 g/kg seed and foliar application of azoxystrobin 11% + tebuconazole 18.3% SC at 1 ml/L water. Disease levels, grain yields and economic returns were assessed across three participating farms in 2024 and four in 2025. The integrated module recorded mean leaf blight indices of 1.50% in 2024 and 1.03% in 2025, compared with 3.17% and 3.25%, respectively, under conventional chemical management. The corresponding reported grain yields were 6,125 and 6,006 kg/ha, representing increases of 32.78% and 33.82% over farmer's practice. The integrated treatment also recorded the highest net returns in each season, at ₹78,985/ha in 2024 and ₹77,152/ha in 2025. These findings indicate that the combined management package was associated with lower reported leaf blight levels, higher grain yields and improved net returns under the evaluated on-farm conditions. Further validation is needed before wider recommendations can be made.