This study evaluated the insecticidal potential of aqueous extracts of Aegle marmelos against brown planthopper (Nilaparvata lugens) and yellow rice stem borer (Scirpophaga incertulas), as well as their effects on rice growth under controlled laboratory–greenhouse conditions in Bojonegoro, Indonesia, from March 2020 to February 2021. Fruit pulp, fruit peel, and leaf extracts were applied at concentrations of 20%, 40%, and 60%, with synthetic insecticide and untreated controls included for comparison. Separate experimental units were used for each target pest species. Mortality observations indicated that higher extract concentrations generally produced greater insecticidal activity. The 60% peel extract treatment produced the highest mortality against yellow rice stem borer, whereas fruit pulp extracts at 40% and 60% showed mortality values comparable to the synthetic insecticide treatment against brown planthopper. Several plant growth parameters, including tiller number, plant height, leaf color, and damage intensity, also tended to improve following extract application. However, some measured variables were not statistically significant, indicating considerable variability among replicates. The findings suggest that Aegle marmelos extracts possess potential as botanical insecticides for rice pest management, particularly against yellow rice stem borer. Further studies under broader greenhouse and field conditions are recommended to confirm efficacy, optimize formulation stability, and evaluate long-term effects on rice productivity and pest suppression. These results indicate that Aegle marmelos extracts may contribute to environmentally friendly pest management strategies by reducing dependence on synthetic insecticides while maintaining rice growth performance. Nevertheless, additional phytochemical characterization and toxicological evaluation are necessary before large-scale application can be recommended confidently.
Devi Majid (Sat,) studied this question.