Bioefficacy of Different Solvent Extracts of Sweet Flag, Acorus calamus (L.) Rhizome against Rice weevil, Sitophilus oryzae (L.) (Coleoptera: Dryophthoridae)

Abstract

The insecticidal activity of sweet flag (SF) (Acorus calamus L.) rhizome extracts against the rice weevil, Sitophilus oryzae (L.) on maize during storage is reported. Different solvent extracts were obtained by two extraction methods (soxhlet and mechanical shaker). The hexane extract obtained by both the methods showed cent per cent mortality at 0.1 per cent concentration on the 5th d after treatment (DAT). The maize seed remained protected against damage by the weevil upto 90 d at 0.09 and 0.1 per cent of hexane and ethyl acetate extracts respectively obtained by mechanical shaker extraction. The hexane extracts obtained by both the extraction methods were however, found to be superior. The phytochemical composition of the solvent extracts showed the presence of alkaloids, phenolic compounds, tannins, flavonoids, steroid, terpenoid, glycosides, carbohydrates and protein.