Evaluation of some plant powders against Khapra beetle (Trogoderma granarium Everts) (Coleoptera: Dermestidae) on stored groundnut

Abstract

Studies were conducted at the Agronomy laboratory of Michael Okpara University of Agriculture, Umudike, Nigeria in 2013. Plastic vials containing 1.5 g powder each of Curcuma longa L. (Turmeric) rhizomes, Zingiber officinale Rosc. (Ginger) rhizomes, Allium sativum L. (Garlic) bulb, Ficus exasperata P. Beauv (sand paper leaf) leaves, Garcinia kola Heckel (Bitter kola) seeds and 0.5 ml petroleum ether extract of Z. officinale were evaluated for their efficacy against Trogoderma granarium Everts (Khapra beetle) in stored groundnut. The experiment was laid in Completely Randomized Design (CRD) with four replicates. Adult mortality, progeny emergence, percentage grain damage, percentage weight loss and germination percentage were assessed. The results obtained from adult mortality counts revealed that all the botanicals exhibited significant (P < 0.05) protection of groundnut seeds from T. granarium infestation compared with the control, which recorded 10.6% mortality. A. sativum recorded the highest percentage of mortality of 96.2% at 49 days after treatment. Progeny emergence and weight loss was reduced in the treated seeds. Significantly (P < 0.05) higher germination percentage was recorded in the various botanicals when compared with the control, which recorded 10%. The botanicals which are readily available and cheap can be used as alternative to synthetic insecticides for the control of T. granarium in stored groundnut.

Keywords: Botanicals, efficacy, groundnut, Trogoderma granarium.