Integrated Pest and Disease Management (IPDM) Module for Major Insect Pest Thrips and Diseases of Onion (Allium cepa var. aggregatum)

Abstract

In the validation of IPDM module (Seed treatment with thiophanate methyl) @ 2.5 g kg-1 seed, soil application of Bacillus subtilis @ 1.25 kg ha-1 + Trichoderma asperellum @ 1.25 kg ha-1 + VAM fungi @ 12.5kg ha-1 + Azophos @ 4kg ha-1 + neem cake @ 250 kg ha-1 + blue sticky traps (20 traps per 0.4 ha at 30 cm height above the onion plant) + need based application of tebuconazole @ 1.5 mL l-1 for purple blotch disease management + need based application of (3.3% mefenoxam + 33.1% chlorothalonil SC 0.1 %) followed by 23.4% mandipropamid SC 0.1% for downy mildew management + fipronil 5% SC @ 1.0 mL l-1 for thrips) against thrips and major diseases of onion revealed significant reduction of purple blotch (10.7 PDI) downy mildew (6.1 PDI), twister blight (11.1 PDI) and thrips population (1.76 nos leaf -1) as against 25.0, 24.2,11.3 and 4.6 respectively in control. In the farmer's practice, the disease, severity, and thrips population recorded were 16.9 PDI, 8.7 PDI, 16.6 PDI, and 3.28 nos leaf -1, which emphasizes the effectiveness of the IPDM module. The reduction of the disease severity and thrips population over control in the IPDM module was 57.20%, 46.01%, 54.13 %, and 61.73 %, recording an economic return of 1:3.12. Hence, the validated IPDM module may be recommended to manage thrips, purple blotch, downy mildew and twister blight in onion to reduce the use of chemical pesticides