Primary and secondary metabolite compounds in cowpea seeds resistant to the cowpea bruchid [Callosobruchus maculatus (F.)] in postharvest storage

2021 ◽  
Vol 93 ◽  
pp. 101858
Author(s):  
Akovognon Dieudonné Kpoviessi ◽  
Symphorien Agbahoungba ◽  
Eric E. Agoyi ◽  
Ephraim Nuwamanya ◽  
Achille E. Assogbadjo ◽  
...  
Keyword(s):  
Secondary Metabolite ◽  
Callosobruchus Maculatus ◽  
Postharvest Storage ◽  
Cowpea Seeds ◽  
Cowpea Bruchid

scholarly journals Efficacy of Piper guineense Schumach. seed powder in the control of Callosobruchus maculatus (Fabricius, 1775) (Coleoptera: Chrysomelidae: Bruchinae) and on the nutritional and organoleptic characteristics of stored cowpea Vigna unguiculata (L.) Walp.

2018 ◽  
Vol 87 (2) ◽  
pp. 119-140
Author(s):  
Frank O. Ojiako ◽  
Adeyinka A. Adesiyun ◽  
Gabriel O. Ihejirika ◽  
Sunday A. Dialoke
Keyword(s):  
Callosobruchus Maculatus ◽  
Adult Emergence ◽  
Adult Mortality ◽  
Proximate Analysis ◽  
Crude Fibre ◽  
Piper Guineense ◽  
Seed Damage ◽  
Cowpea Seeds ◽  
Organoleptic Characteristics ◽  
Cowpea Bruchid

Abstract 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.

scholarly journals Perforation index assessment of cowpea seeds against cowpea bruchid, Callosobruchus maculatus (Fabricius) [Coleoptera: Chrysomelidae], infestation using Piper guineense

2020 ◽  
Vol 81 (1) ◽  
Author(s):  
Kayode David Ileke ◽  
Jacobs Mobolade Adesina ◽  
Luke Chinaru Nwosu ◽  
Abimbola Olagunju
Keyword(s):  
Callosobruchus Maculatus ◽  
Adult Emergence ◽  
Adult Mortality ◽  
Contact Toxicity ◽  
Toxicity Assay ◽  
Piper Guineense ◽  
Cowpea Seeds ◽  
Leaf Powder ◽  
Human Use ◽  
Seed Extracts

Abstract Background Powders and extracts of Piper guineense seeds and leaves were assessed for insecticidal activities against Callosobruchus maculatus in the laboratory at temperature and relative humidity of 29.6 °C and 75.9%, respectively. Bioactive compounds in P. guineense leaves and seeds were also investigated. The powders were tested at rates 1.0, 2.0 and 4.0 g/20 g cowpea seeds while extracts were tested at 1.0, 2.0 and 3.0%. Results Results of contact toxicity assay of the seed powder caused 100% adult mortality at 96 h post-treatment period whereas leaf powder evoked 90% adult mortality within the same period at concentration of 1.0 g/20 g cowpea seeds. Low adult emergence was observed on cowpea seeds treated with 1 g of seed powder with percentage adult emergence of 10.0% and inhibition rate (IR) of 97.5%. Beetle Perforation Index (BPI) obtained from treated cowpea seeds was significantly different (P < 0.05) from BPI of untreated seeds. Extracts of P. guineense seed were more toxic than seed powder. Piper guineense seed extract caused 87.5% adult mortality of C. maculatus while leaf extract caused 70.0% adult mortality within 24 h of infestation at concentration of 1%. Progeny development of C. maculatus was completely inhibited in cowpea treated with 2% and 3% leaf and seed extracts of P. guineense. β-Pinene was the most abundant active compound in P. guineense seed (55.6%) and leaf (48.4%). β-Phellandrene occurred 38.2% in seeds while Ocimene had the least value of 0.2% in seed and 0.5% in leaf. Conclusion The study showed that P. guineense seed powder and extracts were more effective than leaf powder and extract. Utilization of plant products as alternative to synthetic insecticides in protecting cowpea seeds against C. maculatus should be encouraged for enhanced food safety and security. Piper guineense is used as spice and medicine and interestingly safe for human use.

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