Efficacy of three plant oils against Sitophilus oryzae L. (Coleoptera: Curculionidae) on stored polished and local rice

Abstract

Oil extracts from three tropical plants, Annona muricata, Moringa oleifera and Senna alata commonly used medicinally in treating various ailments were tested in the laboratory under constant conditions at 30+2 °C and 60-65 % relative humidity for their ability to protect local and polished rice grains against Sitophilus oryzae, a major pest in storage. Doses at 0.0, 0.5 and 1.0 ml/100 g rice grains were separately applied for assessment of adult mortality in the laboratory for 3 days. Parameters assessed were single effect, combined effects and combined cumulative effects of plant oils on mortality of S. oryzae on local and polished rice. The experiment was laid out in a Completely Randomized Design (CRD) with each treatment replicated four times. The results showed that A. muricata at 1.0 ml and M. oleifera at 0.5 and 1.0 ml each recorded higher (p