Abstract

Powders prepared from parts of four indigenous botanical plants in Nigeria (Curcuma longaL. rhizomes, Dennettia tripetala Baker F. fruits, Piper guineense, Schum and Thonn, seedsand Zingiber officinale Rosc. rhizomes) were evaluated for insecticidal activity against rice weevil Sitophilus oryzae (L.) in the laboratory. The experiment was carried out in a completely randomized design (CRD) with four replications. A control treatment was set up. The result obtained showed that the use of powders from the selected indigenous botanical plants increased adult mortality and suppressed the adult emergence of the rice weevils. P.guineense and D. tripetala recorded the highest mean mortality of 18.8 and 16.5 respectively at 35 days after treatment (DAT) when compared with other treatments. Applying P. guineense seed powder, the number of adults that emerged (3.25) was significantly (P<0.05) lower in the rice seed treated and also performed best in terms of percentage weight loss when compared with the control. These results suggest that the plants are suitable for possible exploitation in protecting stored rice from damage by storage insects.

Key words: Sitophilus oryzae, rice, plant products, control.