Effets des modes de gestion des résidus du bananier et d’options de fumure minérale sur le rendement du maïs et les caractéristiques chimiques du sol dans un système de rotation bananier /maïs à l’Ouest du Burkina Faso

Au Burkina Faso, le recyclage des résidus de culture constitue un défi pour l’amélioration de la productivité des systèmes de production agricole. L’objectif de cette étude était d’évaluer les effets de la gestion des résidus du bananier (Musa acuminata C.) et de la fumure minérale sur les caractéristiques chimiques du sol et le rendement du maïs (Zea mays L.). Un essai en split-plot avec quatre répétitions comparant quatre modes de gestion des résidus du bananier et quatre options de fumure minérale a été conduit en culture pluviale et en culture irriguée. Les rendements grains du maïs ont augmenté de 24 à 66,2% avec le paillage et l’enfouissement de résidus par rapport au brûlage et au ramassage. Le pH, le carbone total, l’azote total et le potassium disponible du sol ont été améliorés par le paillage, l’enfouissement et le brûlage des résidus comparativement au ramassage. L’utilisation combinée des résidus et des engrais a permis un accroissement significatif des rendements. Cependant, elle a induit une baisse du pH et du potassium total du sol comparativement au témoin. L’étude a montré l’intérêt du paillage et de l’enfouissement des résidus du bananier combiné avec la fumure azotée pour améliorer les rendements de maïs. English title: The effects of banana tree residues managements and mineral fertilizers use options on soil chemical properties and maize yield in a banana tree / maize rotation system in western Burkina Faso In Burkina Faso, the recycling of crop residues for improving the productivity of cropping systems is still a challenge. The aim of this study was to evaluate the effects of the management of banana tree (Musa acuminata C.) residues and mineral fertilizers on both soil chemical characteristics and the yield of maize (Zea mays L.). A split-plot trial with four repetitions comparing four management types of banana tree residues (mulching, burying, burning and exporting) and four application options of mineral fertilizers was conducted in rain-fed and irrigated cropping systems. The results revealed that the maize grain yield increased by 24 to 66.2% with mulching and burying residues (green manure) compared to burning or exporting the banana tree residues. Soil pH, total carbon and nitrogen as well as available potassium were improved by the mulching, burying and burning compared to exporting the banana tree residues. The combined use of the residues and mineral fertilizers significantly improved the maize yield. However, it caused a decrease in the soil pH and total potassium compared to the control treatment. The study demonstrated that mulching and burying banana tree residues in combination with mineral fertilizer improves maize yield

Towards innovative solutions for monitoring precipitation in poorly instrumented regions: real-time system for collecting power levels of microwave links of mobile phone operators for rainfall quantification in Burkina Faso

Since the 1990s, mobile telecommunication networks have gradually become denser around the world. Nowadays, large parts of their backhaul network consist of commercial microwave links (CMLs). Since CML signals are attenuated by rainfall, the exploitation of records of this attenuation is an innovative and an inexpensive solution for precipitation monitoring purposes. Performance data from mobile operators’ networks are crucial for the implementation of this technology. Therefore, a real-time system for collecting and storing CML power levels from the mobile phone operator “Telecel Faso” in Burkina Faso has been implemented. This new acquisition system, which uses the Simple Network Management Protocol (SNMP), can simultaneously record the transmitted and received power levels from all the CMLs to which it has access, with a time resolution of one minute. Installed at “Laboratoire des Matériaux et Environnement de l’Université Joseph KI-ZERBO (Burkina Faso)”, this acquisition system is dynamic and has gradually grown from eight, in 2019, to more than 1000 radio links of Telecel Faso’s network in 2021. The system covers the capital Ouagadougou and the main cities of Burkina Faso (Bobo Dioulasso, Ouahigouya, Koudougou, and Kaya) as well as the axes connecting Ouagadougou to these citie

Influences of Storage Conditions, Cultivation and Culinary Practices, On the Antioxidant Capacity of Red Bulbs of Some Onion Varieties Grown in Burkina Faso

Red onion bulb is a vegetable containing micronutrients with antioxidant properties. However, certain factors can have an impact on the content of these compounds. The present research evaluate the effects of parameters such as cultural practices, storage conditions and culinary practices, on the antioxidants content of red onion bulb of some varieties grown in Burkina Faso. The identification of the factors was carried out through field surveys, and their effects on the antioxidants content were assessed and appreciated through especially specific related bibliographic and laboratory test data. The results showed that84.78% of farmers use chemical fertilizers and all of them use chemical pesticides on onion crop. They don’t use premises or equipment suitable for storage. About dishes,7.61% of cooks, peel, cut and wash onion bulb before steam cooking, boiling water cooking or oil frying them at high temperature during 30 minutes to 3 hours. Some cooks use to braise onion bulb scales as ingredients for different dishes such as barbecue. Only 02,72% of cooks grind the onion bulbs with a pestle, before using the crushed as such on barbecue, or slow cooking it in different sauces. Research results show that these culinary practices contribute declining significantly the final intake of antioxidant for the consumer's body

Solar energy powered decentralized smart-grid for sustainable energy supply in low-income countries: analysis considering climate change influences in Togo

A smart and decentralized electrical system, powered by grid-connected renewable energy (RE) with a reliable storage system, has the potential to change the future socio-economic dynamics. Climate change may, however, affect the potential of RE and its related technologies. This study investigated the impact of climate change on photovoltaic cells’ temperature response and energy potential under two CO2 emission scenarios, RCP2.6 and 8.5, for the near future (2024–2040) and mid-century (2041–2065) in Togo. An integrated Regional Climate Model version 4 (RegCM4) from the CORDEX-CORE initiative datasets has been used as input. The latter platform recorded various weather variables, such as solar irradiance, air temperature, wind speed and direction, and relative humidity. Results showed that PV cells’ temperature would likely rise over all five regions in the country and may trigger a decline in the PV potential under RCP2.6 and 8.5. However, the magnitude of the induced change, caused by the changing climate, depended on two major factors: (1) the PV technology and (2) geographical position. Results also revealed that these dissimilarities were more pronounced under RCP8.5 with the amorphous technology. It was further found that, nationally, the average cell temperature would have risen by 1 °C and 1.82 °C under RCP2.6 and 8.5, in that order, during the 2024–2065 period for a-Si technology. Finally, the PV potential would likely decrease, on average, by 0.23% for RCP2.6 and 0.4% for RCP8.5 for a-Si technology

Influence of Agro-Ecological Areas on the Antioxidant Capacity of Onion Varieties Grown in Burkina Faso

Colored onion bulb is an important source of antioxidants. Some ecological factors can significantly influence the content and quality of these substances. The aim of the present study is to determine the antioxidant and total polyphenol content of fresh bulbs of five (05) varieties of onion (Galmi Violet, Damani Violet, Prema, Safari and a Local variety-LV) grown in Burkina Faso, and to evaluate also the influence of agro-ecological parameters on the antioxidant content of the most cultivated variety (Galmi violet) of them. Samples of onion bulb for analysis were collected in the six agro-ecological areas of Burkina Faso under the same cultivation conditions. Antioxidant activities were evaluated using the method of Ferric Reducing Antioxidant Power. The evaluation of the total polyphenol contents was carried out using the Folin-Ciocalteu method. The results showed that antioxidant activities for the 5 varieties tested vary between 0.125 ± 0.001 and 0.149 ± 0.004 mg TE / g, and total polyphenol contents from 0.172 ± 0.011 to 0.272 ± 0.003 mg EAG/g. Results on the assessment of the effect of ecology on the antioxidant content of Galmi violet variety revealed significant variations in antioxidant content from 0.144 ± 0.002 to 0.155 ± 0.001 mg TE / g, and total polyphenols from 0.208 ± 0.014 to 0.292 ± 0.012 mg EAG / g depending on the ecological cultivation area

Évaluation de la teneur en vitamine A et de l’indice de peroxyde des huiles végétales couramment vendues dans les marchés au Burkina Faso

La carence en vitamine A constitue un problème de santé publique dans les pays en développement et affecte en particulier les jeunes enfants et les femmes en âge de procréer. Le but de cette étude était d'évaluer l’application de la politique nationale en matière de production et d’importation, des huiles végétales raffinées, d’enrichissement obligatoire en vitamine A au Burkina Faso, à travers la détermination de la teneur en vitamine A et de l'indice de peroxyde des huiles végétales vendues sur le marché. Cette étude transversale a été menée dans cinq villes sélectionnées selon la densité de la population. Cinquante-neuf échantillons d’huile ont été achetés dans ces villes pour évaluer la teneur en vitamine A, l'indice de peroxyde et leur conformité aux normes nationales et internationales. Dans l'ensemble, 76,27% des huiles n'étaient pas suffisamment enrichies en vitamine A. Pour l'indice de peroxyde, 3,39% des huiles n'étaient pas conformes. Globalement, 77,97% des huiles n'étaient pas conformes pour ces deux paramètres. Au regard de ces résultats il est nécessaire d’intensifier la lutte contre la mise à la consommation des huiles non enrichies en vitamine A au Burkina Faso. English title: valuation of the vitamin A content and the peroxide value of vegetable oils commonly sold in markets in Burkina Faso Vitamin A deficiency is a public health problem in developing countries and particularly affects young children and women of childbearing age. The aim of this study was to assess the implementation of the national policy on the production and importation of refined vegetable oils and mandatory vitamin A fortification in Burkina Faso, through the determination of the vitamin A content and peroxide value of vegetable oils sold on the market. A cross-sectional study was conducted in five cities selected according to population density. Fifty-nine oil samples were purchased in these cities to assess vitamin A content, peroxide value and compliance with national and Codex standards. Overall, 76.17% of the oils were not adequately fortified with vitamin A. For the peroxide value, 3.39% of the oils did not comply. Overall, 77.97% of the oils did not comply for these two parameters. In view of these results, it is necessary to intensify the fight against the consumption of oils not enriched in vitamin A in Burkina Faso

Le Statut des Populations d’Ongulés de Taille Moyenne en 2010, Ranch de Gibier de Nazinga, Burkina Faso (Afrique de l’Ouest)

The present study consists of analyzing the raw data collected from the annual line-transect foot count of medium-sized ungulates, carried out at the Nazinga Game Ranch (NGR), Burkina Faso (Western Africa), in both 2001 and 2010. The annual census focused on the seven main medium-sized ungulates, namely (in alphabetical order), the Bushbuck (Tragelaphus scriptus), the Common Warthog (Phacochoerus africanus), the Defassa Waterbuck (Kobus ellipsiprymnus), the Grimm’s Duiker (Sylvicapra grimmia), the Oribi (Ourebia ourebi), the Roan Antelope (Hippotragus equinus) and the Western Hartebeest (Alcelaphus buselaphus). The census also focused on illegal anthropogenic activities. The wildlife populations were quantitatively analyzed through an estimation of their absolute density via the distance sampling method and through their evolution over the last decade using two relative density indexes, namely the Kilometric Abundance Index (KAI) and a spatial distribution index. These indexes were also used to measure the evolution of illegal activities over the same period. Both the wildlife observations and the anthropogenic observations were mapped using the Kernel method. Following an increasing trend in their population between 2001 and 2010, both the Roan Antelope and the Western Hartebeest reached an estimated density of 4.7 individuals per km², while the Defassa Waterbuck reached 2.4 individuals per km². Following an inverse trend over the same period, the Bushbuck, the Grimm’s Duiker and the Oribi reached an estimated density of 0.4 individuals per km². As for the Common Warthog, its estimated density of 2.5 individuals per km² seemed to remain unchanged during that decade. A comparison between wildlife observations and anthropogenic observations reveals a high decrease in animal densities in the north, east and west peripheral borders of the NGR and a flagrant extension of the proportion of the ranch being subjected to illegal activities (poaching, cattle herding, etc.)

C18- Analyse phytochimique et évaluation de l’activité larvicide contre le vecteur de la dengue (Aedes aegypti) d’extraits de feuilles de Calotropis procera R. br (Apocynaceae) en vue de leur utilisation comme bio-insecticide

La résistance des moustiques aux insecticides chimiques conventionnels demeure une préoccupation majeure pour les programmes de lutte anti-vectorielle. Les recherches s’orientent actuellement vers l’utilisation d’alternatives naturelles, les bio insecticides. L’activité insecticide de certaines plantes comme le Calotropis procera (Ait.) R.br (Apocynaceae) pourrait avoir un grand intérêt dans ce domaine. Dans cette étude, nous avons effectués un criblage des extraits de feuilles de C. procera (aqueux, hydro- éthanolique, méthanolique et éthanolique) par HPTLC, puis mesurer leur teneur en stérol, triterpène et en cardénolides. Nous avons étudié également l’activité larvicide des extraits aqueux et hydro- éthanolique contre le vecteur de la dengue Aedes aegypti selon la méthodologie décrite par l’OMS. Le profil chimique des différents extraits montre la présence de flavonoïdes, tanins, stérols et triterpènes, coumarines, alcaloïdes et cardénolides. La plus grande activité larvicide a été obtenue avec l’extrait hydro-éthanolique provenant de feuilles récoltées en saison sèche dans la localité de Kombissiri (partie Centre Sud du Burkina) avec une DL50 de (1,58 mg/ml ± 1,51 ; 1,66 mg/ml) Les résultats obtenus indiquent que l’extrait hydro-éthanolique de C. procera pourrait servir à la formulation d’un bio-insecticide écologique et peu coûteux pour lutter contre les larves d'Aedes aegypti.

Ressources génétiques des mils en Afrique de l’Ouest

Le mil constitue, avec le sorgho, la base de l’alimentation d’une part importante des populations indiennes et africaines. Au Niger, deuxième pays producteur en Afrique, cette culture représente les trois quarts de la production céréalière et occupe plus de la moitié des terres cultivées. C’est en Afrique de l’Ouest que se situent les zones d’origine et de diversification des mils cultivés (Penniselum glaucum subsp. glaucum) et l’on peut encore y trouver des populations de la forme sauvage (P. glaucum subsp. monodii). Mieux conserver, évaluer et valoriser ces ressources génétiques, tels sont les enjeux exposés lors de l’atelier « Ressources génétiques des mils et plantes associées en Afrique de l’Ouest » organisé à Niamey en 2002. L’IRD et ses partenaires y ont présenté une synthèse des résultats de recherches pluridisciplinaires (génétique, agronomie, anthropologie) sur le rôle des pratiques paysannes dans la dynamique de la diversité génétique des mils sauvages et cultivés au Niger. Cet atelier a également permis de confronter les expériences et conclusions d’autres équipes et a contribué à la réflexion sur les stratégies de conservation (in et ex situ) et de valorisation des ressources génétiques des mils et de quelques autres plantes cultivées dans les agrosystèmes sahéliens.Pearl millet is, along with sorghum, the staple food for a large part of Indian and African populations. In Niger, the second producing country in Africa, this crop accounts for three quarters of the cereals production and more than half of cultivated land. Regions of origin and diversification of pearl millet (Pennisetum glaucum subsp. glaucum) are located in West Africa, where wild millet populations (P. glaucum subsp. monodii) can still be found. A better conservation, evaluation and valorisation of this diversity is therefore an important challenge, that was adressed during a workshop on genetic resources of pearl millet and associated crops in West Africa, held in Niamey in 2002. IRD and its partners presented there a synthesis of their multidisciplinary research (genetics, agronomy, anthropology) on the role of farmers' practices in the dynamics of genetic diversity of wild and cultivated millets in Niger. The workshop allowed exchanges and comparisons of experience and conclusions of other teams and contributed to the debate on strategies of conservation (in and ex situ) and utilisation of genetic resources of pearl millet and other crops in Sahelian agrosystems.© IRD Éditions, 200