Brown pepper (Piper guineense) seed powder, used for culinary and medicinal purposes, was evaluated in the laboratory with a conventional storage chemical, actellic 2% dust (Pirimiphos-methyl), as standard, to protect stored cowpea against the cowpea bruchid, Callosobruchus maculatus. Four rates of the seed powder were used (2.5, 5.0 and 10.0 g/100 g seed with a control, 0.0 g) while actellic dust was applied at 1.0, 2.0, 3.0 g/100 g seed and 0.0 g/100 g seed as control. Data on percentage mortality, oviposition, adult emergence and seed damage were collected over a six-month period. Weevil perforation indexes (WPI) were estimated with the seed damage data. All data were analysed for variance at P≤0.05. Actellic dust at the lowest dose inflicted adult mortality (90 – 100%) in the first 48 h after treatment and prevented oviposition (95 – 100%) in the first five months of storage compared to the control. The highest rate of Piper guineense application caused mortality of up to 90.0% in 48 h, reduced oviposition (70 – 80%), decreased adult emergence (15.90 to 28.40 insects) as against the control (104.7 – 272.7 insects) and reduced seed damage by 80 % with a WPI of between 33.3 and 10.0 %. Proximate analysis and germination tests indicated that the treatment materials increased the moisture and crude fibre content, decreased crude protein content but had no significant effect on the viability of stored seeds. Organoleptic tests demonstrated that treatment materials had no significant negative effect on taste, odour, texture, appearance and overall acceptability of cooked cowpea seeds after six months of storage. It can be safely concluded that the powdered form of P. guineense seed at the highest doses (5.0 and 10.0 g) gave significant protection of cowpea seeds against the cowpea bruchid, which compared favourably with actellic dust when applied topically.
Study to evaluate the insecticidal efficacy of pyrethrum, Chrysanthemum cinerariifolium, relative to a synthetic insecticide (Cypermethrin 10 E. C) in the control of some field pests of groundnut was carried out at the Teaching and
The cowpea beetle, Callosobruchus maculatus Fab. is an economically important pest of stored grain and causes serious damage to stored peas. The application of pesticides has been the generic control measure due to its effectiveness, affordability and ease of application. However, due to the apparent health and environmental consequences with pesticides, stakeholders are advocating for an alternative management approach that has less social and environmental impact and is more sustainable. Consequently, this study examined the attraction of mated female to volatile blends collected from pods of cowpea plants (Borno-brown and black-eyed cultivars) at three developmental stages developing podsie; 15-17 days after anthesis (daa), fully developed pods (18-20 daa) and mature pods (> 20 daa). The beetles’ responses to the pods’ odour were determined using a two-arm olfactometer, and gas chromatography-mass spectrometry (GC-MS) was used to identify and quantify the volatile compounds collected from the pods. The results showed that female C. maculatus attraction increased with the pod’s age, and that the composition and abundance of volatile compounds varied between cowpea cultivars and the pod’s developmental stage. These findings form an important bases towards developing alternative approach for the management of bruchids.
Key words: volatile compounds, cowpea plants, GC-MS, pod’s developmental stage, days after anthesis
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.