Evaluation of soil- based non chemical formulations against fall armyworm, Spodoptera frugiperda (J.E.Smith) on maize in Manipur condition

Abstract

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is an invasive lepidopteran pest of global significance, posing severe threats to maize production due to its rapid reproduction, wide host range, and adaptability to diverse environmental conditions. Conventional chemical control remains the dominant management approach but is increasingly constrained by resistance development, ecological concerns, and potential health risks. The present study aimed to evaluate the efficacy of selected non-chemical insecticidal formulations mixed with soil for its management under field conditions during the kharif season of 2023-24 at the College of Agriculture, Central Agricultural University, Imphal. Among the treatments, T₄ (soil + Bacillus thuringiensis var. kurstaki @ 50 mL/kg soil) recorded the lowest leaf damage (4.27, 2.07, and 2.00), minimum percent plant infestation (29.33%, 20.33%, and 10.00%), and lowest larval population (0.13, 0.10, and 0.07 larvae per ten plants) at 7, 14, and 21 DAT, respectively. All treatments performed significantly better than the untreated control, with T₄ (soil + Bacillus thuringiensis var. kurstaki) recording the lowest cob damage (1.11) and the highest grain yield (86.36 q/ha) with an increase of 34.92 q/ha over control. Overall, soil application of Bacillus thuringiensis var. kurstaki can be considered a promising eco-friendly option for managing S. frugiperda in maize.