Field and Laboratory Performance of Some Commonly used Insecticides against Fall Armyworm of Maize

The experiment aimed to evaluate the efficacy of eight insecticidal treatments against fall armyworm (FAW) on a sweet corn variety of maize. FAW abundance was consistently highest in the untreated control plot, while the combination treatment of tetraniliprole + chlorpyrifos + cypermethrin + Celastrus angulatus (Vayego 20 SC + Nitro 505 EC + Bio-chamak 1% EW) achieved the lowest FAW abundance (4.7±0.9) at 7 days post-treatment. This treatment also resulted in the most favorable plant growth parameters, including the greatest plant height (121.7±0.3 cm), base diameter (2.0±0.1 cm), number of nodes (11.3±0.3), leaves per plant (11.0±0.6), leaf length (61.7±0.3 cm) and leaf width (8.3±0.3 cm). Additionally, it produced the longest cobs (18.7±0.1 cm), largest cob diameter (4.0±0.1 cm), heaviest cob weight (210.7±3.8 g), highest number of grains per cob (521.7±15.0) and the greatest yield (13.3 tons ha^-1). Laboratory bioassays revealed that tetraniliprole (Vayego 20 SC) exhibited the highest FAW larval mortality rates at 24, 48, and 72 h post-treatment (62.2±2.2, 74.4±7.2, and 82.2±9.7%, respectively). Among all treatments, tetraniliprole + chlorpyrifos + cypermethrin + Celastrus angulatus (Vayego 20 SC + Nitro 505 EC + Bio-chamak 1% EW) provided the highest benefit-cost ratio of 2.37, making it the most cost-effective solution for FAW management, making it a highly effective and economically viable option for sustainable pest management in maize cultivation.