Field testing of <i>Carica papaya</i> and <i>Zanthoxylum zanthoxyloides</i> extracts against fall armyworm ( <i>Spodoptera frugiperda</i> ) on maize plants

Maize cultivation is an essential pillar of global agriculture and economic stability. It, however, faces threats from insect pests, among which fall armyworm is particularly devastating. Although, chemical insecticide is a main method of control, its effectiveness is hampered by resistance and adverse health impacts, necessitating other environmentally friendly alternatives. This study evaluated the efficacy of Carica papaya and Zanthoxylum zanthoxyloides extracts against fall armyworm infestation. This was done by testing C. papaya seed and Z. zanthoxyloides root extracts and a standard insecticide over two growing seasons. Data were collected on larval infestation, maize damage and yield. The findings revealed significant differences in infestation, with about 40% reduction in infestation and damage on treated plots. Infestation was higher in the minor season than the major season, and significantly differed for plant infestation (p = 0.026), leaf damage (p = 0.026), and tassel damage (p < 0.001), but not for prevalence (p = 0.218) and severity (p = 0.091). Cob damage differed between seasons (p < 0.001) and among treatments in the major season (p < 0.001), but not in the minor season (p > 0.05). Yield was 30% higher on treated plots compared to control plots. This study, therefore, demonstrated the efficacy of plant extracts against fall armyworms and as viable alternatives to chemical insecticides.