International Journal of Horticulture, 2017, Vol.7, No.9, 64-75
64
Research Article Open Access
Biotoxicity of Different Parts of
Anacardium occidentale
(Linn.) against
Callosobruchus maculatus
(F.) Infestation on Stored Cowpea Seeds
Obembe O.M.
1
, Ogungbite O.C.
1,2
1 Department of plant Science and Biotechnology, Ekiti State University, Ado-Ekiti, Nigeria
2 Department of Biology, Federal University of Technology, Akure, Ondo State, Nigeria
Corresponding email
International Journal of Horticulture, 2017, Vol. 7, No. 9 doi
Received: 06 Mar., 2017
Accepted: 10 Mar., 2017
Published: 15 Apr., 2017
Copyright
©2017 Obembe et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Obembe O.M., and Ogungbite O.C., 2017, Biotoxicity of different parts of
Anacardium occidentale
(Linn.) against
Callosobruchus maculatus
(F.) infestation
on stored cowpea seeds, 7(9): 64-75 (doi
Abstract
Biotoxicity of different parts of
Anacardium occidentale
extracted with different methods were tested against
Callosobruchus maculatus
infesting cowpea seed. The nut, stem bark, root bark and leaf of the plant were pulverized to fine powder. The
extracts were made by soaking the powders in ethanol, hot and cold water and concentrations of 1, 2, 3 and 4% were made. The mortality
of the insect was observed at 24, 48, 72 and 96 h post treatment. The oviposition and adult emergence of the beetle as well as the damage
and weight loss of the seeds were recorded. All the extracts recorded high beetle mortality but only nut ethanolic extract achieved 100%
mortality. Probit analysis showed that only little concentration of the extracts was required to achieve high mortality of the insect. The
extracts significantly reduced the oviposition of the insect while the nut extracts of the plant prevented the emergence of the beetle and
damage and weight loss of the seeds. Regression analysis showed that there was great correlation between adult mortality and
oviposition as well as between adult emergence and weight loss. The extracts of the plant had proven insecticidal and can therefore be
introduced to management system of the insect.
Keywords
Biotoxicity;
Callosobruchus maculatus
;
Anarcadium occidentale
; Ethanolic extract; Correlation; Lethal dosage
1 Introduction
Botanicals of different species have been noted for their insecticidal efficacy. Many of them are believed to
contain myriads of chemicals that are insecticidal in nature (Zibaee, 2011). The management of insect pests based
on the use of plant extracts and powders have long been made known as potential substitute to synthetic chemical
insecticides because they are believed to have lesser or no effect on human and environmental health (Isman et al.,
2011). Many of these botanicals have antifeedant and growth reducing effect on insects while many of them have
been proven to have toxic effect on the survival of the insects and their ability to oviposite (Berenbaum and
Zangerl, 1996; Isman, 2006; Zibaee, 2011; Akinneye and Ogungbite, 2013).
Before the discovery of many nowadays popular synthetic chemical insecticides, botanical powder and extracts
have been reported of being used extensively by farmers to protect their farm produce (Isman, 2006; Martins et al.,
2012; Forim et al., 2012).
Capsicum annum
dust for example has been used extensively by ancient farmers to
protect their cowpea (Oni, 2014). Thacker (2002) and Isman (2006) traced back the use of botanicals and their
derivatives as crop protectant to ancient China, Egypt, Greece and India before they were being downgraded by
many synthetic chemical insecticides in the early 1930s. However, many adverse effects associated with these
chemical insecticides have made the government of many developed countries of the world to ban their use (2006).
Therefore, this has created a chance for botanical insecticides to gain back their first position in the global world
insecticide market.
Different factors have been reported to be responsible for the effects of botanical powders and extracts against
insects. Oni et al. (2015) reported the different drying methods as a key factor in effectiveness of botanicals. Also,
the period of harvest of botanicals and their age have been reported to have considerable effect on their
effectiveness as insecticide Doughari (2012). Furthermore, different parts of botanicals have been reported to have
