PHYTOCHEMICAL SCREENING AND EVALUATION OF THE BIOCONTROL ACTIVITY OF SELECTED LEAF EXTRACTS AGAINST THE RICE WEEVIL, SITOPHILUS ORYZAE

Abstract

Plants are considered to be the richest source of highly renewable natural insecticides. Specifically, botanical extracts provide an interesting alternative to synthetic pesticides and are safe and compatible. In the current study, isopropyl alcohol extracts of Nerium oleander and Datura stramonium leaves were tested for its efficacy in inducing mortality of rice weevil Sitophilus oryzae. The mortality percentage was tested at concentrations of 2%, 4%, 6%, 8% and 10%.The results were subjected to statistical analysis (Mean ± SD). Further, phytochemical analysis of the leaf extracts were carried out using standard protocols. Results of the biocontrol activity revealed that mortality rate increased with increasing concentration. Among the two leaf extracts, Datura stramonium leaf extracts exhibited maximum biocontrol activity. Datura stramonium leaf extracts when tested for the phytochemical revealed the presence of Alkaloids, Tannins, Steroids, Saponnins and Cardiac glycosides. It may be concluded on the basis of the result of present study that isopropyl alcohol extracts of plants have toxic effects with significant insecticidal effects.