Evaluation of persistence, phytotoxicity, and biosafety of insecticide based on cajuput and patchouli oils

Abstract

An excellent plant-based insecticide formula is effective against insect pests and must be safe against target plants and natural enemies of the problems. The study aimed to evaluate the persistence of cajuput and patchouli oil formulations under sun exposure to Nilaparvata lugens, their phytotoxicity on rice seedlings, and safety against predators Sycanus annnulicornis. The feed residue method was employed to conduct the persistence test. Phytotoxicity testing was carried out by spraying rice seedlings with oil formulations. Biosafety testing against predators was carried out using the dry-film contact method. Exposure to both oil preparations (patchouli oil: 0.02, 5.25; and 10.49% and cajuput oil: 0.02; 4.87, and 9.74%) under the sun for up to five days was still effective in causing mortality of N. lugens. Both oil formulas did not cause phytotoxicity in rice seedlings. Cajuput oil (concentrations of 4.87 and 9.74%) and patchouli oil (concentrations of 5.25 and 10.49%) were safe against nontarget insects, namely S. annulicornis.