Abstract:
The present study was conducted to screened the secondary metabolite constituents and to evaluate
the repellent potential of selected medicinal plants against the C.maculatus infesting the stored seeds
of green gram under laboratory condition (30 ± 2°C and 70 ± 5%). Repellent potential of 1% Acorus
calamus L. rhizome powder, 1% Piper longum L. fruit powder, and 1% Aloe vera L. aqueous extract
were tested according to a free choice bioassay method. The plastic vial fixed at one end of the straw
was supplied with treated seeds and the other end supplied with untreated seeds. The hole in the
middle portion of each straw, 5 pairs of 1-2 days old C.maculatus introduced and covered with
adhesive tape. The experiment was laid out in a complete randomized design consisting of three
treatments with seven replications. The results revealed that almost all treatments had significant
(p<0.05) repellent potential against C.maculatus infesting green gram seeds. Among them, P.longum
powder treated seeds revealed higher mean repellent potential (81%) against the C.maculatus. A.vera
aqueous extract showed least mean repellency (18%) and their repellency rate was 5% after 5 hours
of introduction. Phytochemical screening of the aqueous extract of P.longum and A.calamus revealed
the presence alkaloids, flavonoids, steroid, triterpenoid, cardiac glycoside, saponin, and tannins
except phenols, and anthraquinones while A.vera showed the precence of alkaloid, phenol, and
cardiac glycoside. P.longum fruit powder possessed the highest repellent potential and will be more
effective in control and management of C.maculatus. However, further studies are necessary to
identify the biologically active components which are responsible for the repellent potential of these
selected medicinal plants.
Keywords: Repellent potential; Free choice bio assay; Callosobruchus maculatus; Piper longum;
Acorus calamus; Aloe vera.
