Optimizing Legume-Based Intercropping Systems for Enhanced Pest Suppression, of Kharif Maize (Zea mays L.)

Legume-based intercropping may reduce insect pest pressure in maize, but the comparative performance of selected legumes and marigold under common field conditions requires evaluation. A field experiment was conducted during the kharif seasons of 2024 and 2025 at Bhopal, Madhya Pradesh, India, to examine the influence of ten cropping systems on fall armyworm (Spodoptera frugiperda), stem borer and aphids. Treatments were arranged in a randomised complete block design with three replications, including sole maize, maize–legume combinations and maize + cowpea + marigold. Pest observations were recorded from tagged maize plants and analysed using analysis of variance. In the pooled results, maize + cowpea + marigold (T10) had the lowest fall armyworm larval population (0.95 larvae per plant), plant infestation (12.8%), leaf damage (8.9%), Davis leaf damage score (1.7), whorl infestation (11.2%) and ear infestation (5.5%). The same treatment recorded the lowest stem borer dead heart incidence (4.0%), stem tunnelling (5.5%), stem borer larval population (0.45 larvae per plant), aphid population (11.2 aphids per plant) and aphid abundance (4.4 aphids per leaf). Sole maize consistently recorded the highest pest pressure, whereas maize + cowpea (1:1) was generally the next most effective treatment. The findings indicate that combining cowpea and marigold with maize may contribute to managing these insect pests under the field conditions evaluated.