29 research outputs found

    Analyse de quelques aspects du système de production légumière et perception des producteurs de l’utilisation d’extraits botaniques dans la gestion des insectes ravageurs des cultures maraîchères au Sud du Togo

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    L’une des contraintes liée à la production maraîchère, est la pression exercée par les insectes ravageurs. Cette étude analyse quelques aspects du système de production légumière ainsi que la perception des   producteurs de l’utilisation d’extraits botaniques dans la gestion des  insectes ravageurs des cultures maraîchères. Elle a été réalisée à travers une enquête menée auprès de 217 maraîchers au Sud du Togo. L’analyse descriptive des données a révélé que plus d’hommes (72%) que de femmes (28%) pratiquent le maraîchage. Seul 33% a suivi une fois une formation en maraîchage. La contrainte majeure dans la production maraîchère est le problème de ravageurs et de maladies dont les principaux sont des insectes, des nématodes et des champignons. La lutte chimique constitue la principale méthode de lutte contre ces ravageurs. Néanmoins, les maraîchers connaissent des dangers induits par l’utilisation des pesticides de synthèse et sont au courant de l’utilisation des pesticides botaniques en maraîchage. Cependant, très peu les utilisent dans la gestion des ravageurs. Mais, ils sont disposés à utiliser les pesticides botaniques si ceux-ci sont disponibles, accessibles, efficaces et pas trop chers pour pallier les effets néfastes des pesticides de synthèse à la santé et à l’environnement.Mots clés : Maraîchage, perception des producteurs, extraits botaniques, Sud du Togo

    Selection of sites for the in situ conservation of four traditional leafy vegetables consumed in Benin

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    Acmella uliginosa, Ceratotheca sesamoides, Justicia tenella and Sesamum radiatum are four traditional leafy vegetables which are widely consumed in Benin. In order to document their origin, folk nomenclature, geographical distribution and ecology and to select adequate zones for in situ conservation of their genetic resources, 118 villages were randomly selected and surveyed throughout the country using a participatory research approach. All the species apart from Ceratotheca sesamoides were reported by farmers as introduced in Benin at different periods. The folk nomenclature comprising 93 different names is based on nine key criteria of variable frequencies according to the species. The geographical distribution maps revealed that the species under study are unequally distributed. Indeed, A. uliginosa is found exclusively in the northwest, J. tenella in the northeast and partially in the centre while S. radiatum and Ceratotheca sesamoides were found almost everywhere in Benin. Results from multivariate analysis combined with geographical distribution maps of the species and the soil and climate maps of Benin, leaded to the selection of the Northwest and of the Northeast regions as the appropriate conservation zones for the four species. Molecular analysis was recommended as it can help in describing genetic diversity and consequently in identifying additional sites for the widely spread species Sesamum radiatum and Ceratotheca sesamoides. Keywords: Folk nomenclature, biodiversity, geographical distribution, site selection, in situ conservation, Benin

    Mold Occurrence in Fresh Chilli Pepper (Capsicum spp.) Harvested Directly in the Field in Benin Republic

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    Introduction: The chilli pepper (Capsicum spp.), ranked among the world's leading spices or food additives, is now Benin'ssecond most-important vegetable crop after tomatoes. Unfortunately, chilli peppers are likely to be contaminated with mold which produces dangerous mycotoxins due to cultural practices, transport, and post-harvest storage. Objective: The purpose of this study is to isolate and identify the molds that contaminate chilli pepper varieties in open fields according to the cultivation methods used in the Republic of Benin. Materials and Methods: A total of 240 samples of three varieties of chilli peppers were taken directly from six districts of Benin. The molds were isolated and purified on a PDA (Potato Dextrose Agar) medium for identification. The identification focused on the morphological and cultural characteristics of isolated strains. Results: Nine (9) fungal genera from different taxonomic groups were detected. The genera that have been represented are Aspergillus (34%), Fusarium (21%), Penicillium (16%), Alternaria (7%), Cladosporium (7%), Mucor (7%), Scytalidium (4%), Trichophyton (3%), and Rhizopus(1%). Conclusion: The present study shows that chilli pepper is being contaminated in Benin. The genera Aspergillus, Fusarium, Penicillium, and Alternaria are respectively the main toxinogenic molds that contaminate peppers in the field. The mold control in chilli pepper against pathogenic agents became urgently required to reduce a consumer disease caused by chilli pepper in Benin

    Effect of high temperatures on sex ratio and differential expression analysis (RNA-seq) of sex-determining genes in <i>Oreochromis niloticus</i> from different river basins in Benin

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    peer reviewedAbstract The high temperature sex reversal process leading to functional phenotypic masculinization during development has been widely described in Nile tilapia (Oreochromis niloticus) under laboratory or aquaculture conditions and in the wild. In this study, we selected five wild populations of O. niloticus from different river basins in Benin and produced twenty full-sib families of mixed-sex (XY and XX) by natural reproduction. Progenies were exposed to room temperature or high (36.5°C) temperatures between 10 and 30 days post-fertilization (dpf). In control groups, we observed sex ratios from 40 to 60% males as expected, except for 3 families from the Gobé region which showed a bias towards males. High temperature treatment significantly increased male rates in each family up to 88%. Transcriptome analysis was performed by RNA-sequencing (RNA-seq) on brains and gonads from control and treated batches of six families at 15 dpf and 40 dpf. Analysis of differentially expressed genes, differentially spliced genes, and correlations with sex reversal was performed. In 40 dpf gonads, genes involved in sex determination such as dmrt1, cyp11c1, amh, cyp19a1b, ara, and dax1 were upregulated. In 15 dpf brains, a negative correlation was found between the expression of cyp19a1b and the reversal rate, while at 40 dpf a negative correlation was found between the expression of foxl2, cyp11c1, and sf1 and positive correlation was found between dmrt1 expression and reversal rate. Ontology analysis of the genes affected by high temperatures revealed that male sex differentiation processes, primary male sexual characteristics, autophagy, and cilium organization were affected. Based on these results, we conclude that sex reversal by high temperature treatment leads to similar modifications of the transcriptomes in the gonads and brains in offspring of different natural populations of Nile tilapia, which thus may activate a common cascade of reactions inducing sex reversal in progenies

    Antibiorésistance Et Facteurs De Virulence Des Souches D’escherichia Coli Isolées Des Carcasses Bovines Du Bénin

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    The meat processing conditions expose it to several contaminations including the microbial. The present study was designed to assess the antibiotic resistance and toxin production by Escherichia coli strains isolated bovine carcasses collected in the slaughterhouse of Cotonou / Porto-Novo in Benin. Thus, a total of 240 samples was collected from 60 beef carcasses by the destructive method. The E. coli strains were identified by conventional microbiological and biochemical methods. The susceptibility of strains to 15 antibiotics was assessed by disc diffusion method on agar medium. The phenotypic identification of strains producing penicillinase and BSLE was performed respectively by the tubes acidimetric test and the double halo method. PCR was used to detect genes encoding the toxins and β-lactamases. The results showed that 57.92% of the samples were contaminated with E. coli, with highest rate recorded in the samples collected from arm. The susceptibility to 15 antibiotics tested has shown that all the isolated strains were multi-resistant with a high proportion to ceftriaxone (88.49%). the lowest resistance rate (~1%) was recorded with gentamicin. The E. coli strains producing β-lactamase carried multidrug resistance genes blaSHV (26.92%) and blaTEM (40.29%). To end, our data revealed the presence of EHEC pathovar (12.82%), responsible for the "traveler" disease. Thus, meat coming from slaughterhouses are therefore a potential source of food poisoning

    Applications and Action Mechanisms of Probiotic-Based Multi-Components

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    editorial reviewedProbiotic-based multi-component preparations refer to a mixture of bioactive agents, containing probiotics or postbiotics as main functional ingredients, and prebiotics, protectants, stabilizers, encapsulating agents, and other compounds as additional constituents.One Health approaches to support agroecological transformation of peri-urban farming1. No poverty2. Zero hunger3. Good health and well-being10. Reduced inequalities11. Sustainable cities and communities12. Responsible consumption and production13. Climate action17. Partnerships for the goal

    Minimal tillage and intermittent flooding farming systems show a potential reduction in the proliferation of Anopheles mosquito larvae in a rice field in Malanville, Northern Benin.

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    BACKGROUND: Irrigation systems have been identified as one of the factors promoting malaria disease around agricultural farms in sub-Saharan Africa. However, if improved water management strategy is adopted during rice cultivation, it may help to reduce malaria cases among human population living around rice fields. This study aimed to assess the impact of the different irrigation practices on malaria transmission, as well as to evaluate the water management system that will best mitigate malaria transmission in Malanville, Benin. METHODS: Knowledge, Attitude and Practice (KAP) study was conducted on 104 households staying on and around the rice fields in Malanville. The study focused on the frequency of mosquito bites and preventive measures against malaria as well as soil preparation and rice planting methods. Mosquito larvae density was assessed in different water management system: continuous flooding (CF) or intermittent flooding (IF), deep tillage (DT) or minimal tillage (MT) and normal levelling (NL) or abnormal levelling (AL) in an experimental hut set-up. Larvae were collected using dipping methods and their density was determined. RESULTS: Three tillage systems, which include the use of tiller, plow and hoe, were identified on the rice field. Continuous flooding was the only irrigation system used by farmers. Retrospective data from Malanville Health Centre revealed higher malaria cases during rice production season, which was also confirmed by field participants. The density of Anopheles larvae was reduced by 80.8%, 30.8% and 40.7% (P = 0.000) during transplanting, tillering and maturation periods, respectively with intermittent flooding compared to continuous flooding. In addition, a clear reduction of larva density was observed with both intermittent flooding systems applied to minimal tillage (MT + IF + NL) and intermittent flooding applied to deep tillage (DT + IF + AL), showing that intermittent flooding could reduce the abundance of malaria vector in rice fields. CONCLUSION: Recommending intermittent flooding technology for rice cultivation may not only be useful for water management but could also be an intentional strategy to control mosquitoes vector-borne diseases around rice farms

    Composition Chimique Et Influence De Différents Tweens Sur Le Pouvoir Antimicrobien Des Huiles Essentielles De Ocimum Gratissimum, Ocimum Basilicum, Laurus Nobilis Et Melaleuca Quinquenervia

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    This study aimed firstly to determine the chemical composition, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of essential oils extracted from Ocimum gratissimum, Ocimum basilicum, Laurus nobilis and Melaleuca quinquenervia collected from Benin (West Africa) on five oral microorganisms (Micrococcus luteus ATCC 10240, Staphylococcus aureus ATCC 29213, Proteus mirabilis ATCC 24974, Pseudomonas aeruginosa ATCC 27853 and Candida albicans IP 4872), and secondly to assess the influence of different tweens on antimicrobial potential of four oils against previous microorganisms. Using Clevenger apparatus, oil extraction was performed by steam distillation and the chemical compositions was determined by chromatography. The antimicrobial activity of different oils was evaluated according to microdilution method using ELISA microplates. From this study, Tween 60 proved best to others tweens (20, 40 and 80) by ensuring proper dispersion and distribution of oils. With tween 60, O. brasilicum essential oil proved the most effective of the four oils with the lowest MIC (0.078 mg/ml) and CMB (0.078 mg/ml) and is effective on all oral germs tested. Chemical screening of these species revealed the presence of several compounds among which thymol (30.62%), para-cymene (25.25%) and gamma-terpinolene (24.24%) (O. gratissimum); methyl-chavicol (85.92%) (O. basilicum); eugenol (42.50%), myrcene (28.09%) (L. nobilis) and beta-ocimene (29.62%), alphapinene (12.11%) and viridiflorol (11.85%) (M. quinquenervia)

    The Rapid Degradation of Lambda-Cyhalothrin Makes Treated Vegetables Relatively Safe for Consumption.

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    Lambda-cyhalothrin (λ-cyhalothrin) is the most commonly used pyrethroid insecticide for vegetable farming in Benin. This insecticide is misused and overused by farmers, and hence may pose health hazards to consumers. We monitored λ-cyhalothrin residues in lettuce and cabbage from farms at the market gates in Cotonou and Parakou using high performance liquid chromatography (HPLC) analysis techniques. These residues were also monitored on samples directly from farms (on-farm sampling) for 14 days post-treatment. Potential factors such as photolysis and hydrolysis involved in λ-cyhalothrin degradation were also screened. Results revealed that the level of λ-cyhalothrin residue concentrations in lettuce from Houeyiho decreased from 4.2 mg/kg on Day 1 to about 0.2 mg/kg on Day 7. On Day 9, analyzed lettuces were all λ-cyhalothrin free. In contrast, even 14 days after treatment of cabbage from Bawera (Parakou), we still recorded the presence of λ-cyhalothrin residues in analyzed samples. For samples from market gates, λ-cyhalothrin residues were found in lettuce from two markets out of the nine surveyed in Cotonou. Interestingly, none of these contaminated samples had residues above the maximum residue limit for lettuce (MRL = 0.5 mg/kg). Similarly, in Parakou, samples from all five surveyed vegetable markets were contaminated with λ-cyhalothrin residues at concentrations below the MRL for cabbage (MRL = 0.2 mg/kg). We conclude that λ-cyhalothrin residues in lettuce and cabbage from farms and markets in Parakou and Cotonou are within the MRL, and hence are relatively safe for consumption
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