22 results on '"Traoré, Pierre Sibiry"'
Search Results
2. Seasonal forecasts in the Sahel region: the use of rainfall-based predictive variables
- Author
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Lodoun, Tiganadaba, Sanon, Moussa, Giannini, Alessandra, Traoré, Pierre Sibiry, Somé, Léopold, and Rasolodimby, Jeanne Millogo
- Published
- 2014
- Full Text
- View/download PDF
3. Climate change impact and variability on cereal productivity among smallholder farmers under future production systems in west Africa
- Author
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MacCarthy, Dilys Sefakor, Adam, Myriam, Freduah, Bright Salah, Fosu-Mensah, Benedicta Yayra, Ampim, Peter A. Y., Ly, Mouhamed, Traoré, Pierre Sibiry, Adiku, Samuel G.K., MacCarthy, Dilys Sefakor, Adam, Myriam, Freduah, Bright Salah, Fosu-Mensah, Benedicta Yayra, Ampim, Peter A. Y., Ly, Mouhamed, Traoré, Pierre Sibiry, and Adiku, Samuel G.K.
- Abstract
Agriculture in West Africa is constrained by several yield-limiting factors, such as poor soil fertility, erratic rainfall distributions and low input systems. Projected changes in climate, thus, pose a threat since crop production is mainly rain-fed. The impact of climate change and its variation on the productivity of cereals in smallholder settings under future production systems in Navrongo, Ghana and Nioro du Rip, Senegal was assessed in this study. Data on management practices obtained from household surveys and projected agricultural development pathways (through stakeholder engagements), soil data, weather data (historical: 1980–2009 and five General Circulation Models; mid-century time slice 2040–2069 for two Representative Concentration Pathways; 4.5 and 8.5) were used for the impact assessment, employing a crop simulation model. Ensemble maize yield changes under the sustainable agricultural development pathway (SDP) were −13 and −16%, while under the unsustainable development pathway (USDP), yield changes were −19 and −20% in Navrongo and Nioro du Rip, respectively. The impact on sorghum and millet were lower than that on maize. Variations in climate change impact among smallholders were high with relative standard deviations (RSD) of between 14% and 60% across the cereals with variability being higher under the USDP, except for millet. Agricultural production systems with higher intensification but with less emphasis on soil conservation (USDP) will be more negatively impacted by climate change compared to relatively sustainable ones (SDP).
- Published
- 2021
4. Potential impacts of agricultural intensification and climate change on the livelihoods of farmers in Nioro, Senegal, West Africa
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MacCarthy, Dilys Sefakor, Hathie, Ibrahima, Freduah, Bright Salah, Ly, Mouhamed, Adam, Myriam, Ly, Amoudou, Nenkam, Andrée, Traoré, Pierre Sibiry, Valdivia, Roberto, MacCarthy, Dilys Sefakor, Hathie, Ibrahima, Freduah, Bright Salah, Ly, Mouhamed, Adam, Myriam, Ly, Amoudou, Nenkam, Andrée, Traoré, Pierre Sibiry, and Valdivia, Roberto
- Published
- 2021
5. Ecogeographical distribution of wild, weedy and cultivated Sorghum bicolor (L.) Moench in Kenya: implications for conservation and crop-to-wild gene flow
- Author
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Mutegi, Evans, Sagnard, Fabrice, Muraya, Moses, Kanyenji, Ben, Rono, Bernard, Mwongera, Caroline, Marangu, Charles, Kamau, Joseph, Parzies, Heiko, de Villiers, Santie, Semagn, Kassa, Traoré, Pierre Sibiry, and Labuschagne, Maryke
- Published
- 2010
- Full Text
- View/download PDF
6. Which is more important to sorghum production systems in the Sudano-Sahelian zone of West Africa: Climate change or improved management practices?
- Author
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Adam, Myriam, MacCarthy, Dilys Sefakor, Traoré, Pierre Sibiry, Nenkam, Andrée, Freduah, Bright Salah, Ly, Mouhamed, Adiku, Samuel G.K., Adam, Myriam, MacCarthy, Dilys Sefakor, Traoré, Pierre Sibiry, Nenkam, Andrée, Freduah, Bright Salah, Ly, Mouhamed, and Adiku, Samuel G.K.
- Abstract
The productivity of smallholder farming systems is held back by poor soil fertility, low input levels and erratic rainfall distribution in the sorghum-based cropping systems of the Sudano-Sahelian zone of West Africa. We assessed the sensitivity of current agricultural practices to climate change and to improved management practices: (i) increased fertilizer application combined with increased plant populations and (ii) use of improved sorghum varieties. We applied the Decision Support Systems for Agro-Technological Transfer (DSSAT) Cropping Systems Model, and the Agricultural Production Systems sIMulator (APSIM), for a multiple-farm assessment (i.e. diverse types of management and soils) in Koutiala (Mali) and Navrongo (Ghana), which are representative sites for West African sorghum production systems. Baseline climate data from observed weather (1980–2009) and future climates from five Global Circulation Models (GCMs: 2040–2069) in two Representative Concentration Pathways (RCP 4.5 and 8.5) were used as inputs for crop models. In Navrongo, under current management, sorghum yields either decreased or increased compared to the baseline, depending on the crop models and the GCMs; changes in management options induced a yield increase of up to 256%. The addition of genetic improvement resulted in further yield increases (24%). In Koutiala, sorghum yield changes for future climates ranged from −38 to +8% assuming current management. Shifting to an improved cultivar had a marginal effect on grain yields, while increased fertilizer rates resulted in grain yield increases ranging of 20% and 153% for DSSAT and APSIM, respectively, assuming the current climate. We conclude that in the Sudano-Sahelian zone of West Africa sorghum, as it is cultivated today, appears moderately vulnerable to climate change, while doubling fertilizer inputs with an adjusted planting density, in the current climate, would more than double yields. However, by exploring farm diversity we establishe
- Published
- 2020
7. Sensitivity of maize yield in smallholder systems to climate scenarios in semi-arid regions of West Africa: Accounting for variability in farm management practices
- Author
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Freduah, Bright Salah, MacCarthy, Dilys Sefakor, Adam, Myriam, Ly, Mouhamed, Ruane, Alex C., Timpong-Jones, Eric C., Traoré, Pierre Sibiry, Boote, Kenneth J., Porter, Cheryl, Adiku, Samuel G.K., Freduah, Bright Salah, MacCarthy, Dilys Sefakor, Adam, Myriam, Ly, Mouhamed, Ruane, Alex C., Timpong-Jones, Eric C., Traoré, Pierre Sibiry, Boote, Kenneth J., Porter, Cheryl, and Adiku, Samuel G.K.
- Abstract
Climate change is estimated to exacerbate existing challenges faced by smallholder farmers in Sub-Sahara Africa. However, limited studies quantify the extent of variation in climate change impact under these systems at the local scale. The Decision Support System for Agro-technological Transfer (DSSAT) was used to quantify variation in climate change impacts on maize yield under current agricultural practices in semi-arid regions of Senegal (Nioro du Rip) and Ghana (Navrongo and Tamale). Multi-benchmark climate models (Mid-Century, 2040–2069 for two Representative Concentration Pathways, RCP4.5 and RCP8.5), and multiple soil and management information from agronomic surveys were used as input for DSSAT. The average impact of climate scenarios on grain yield among farms ranged between −9% and −39% across sites. Substantial variation in climate response exists across farms in the same farming zone with relative standard deviations from 8% to 117% at Nioro du Rip, 13% to 64% in Navrongo and 9% to 37% in Tamale across climate models. Variations in fertilizer application, planting dates and soil types explained the variation in the impact among farms. This study provides insight into the complexities of the impact of climate scenarios on maize yield and the need for better representation of heterogeneous farming systems for optimized outcomes in adaptation and resilience planning in smallholder systems.
- Published
- 2019
8. Estimating and understanding smallholder crop production variability from pixel to village levels thanks to satellite observation in Mali
- Author
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UCL - SST/ELI/ELIE - Environmental Sciences, UCL - Ingénierie biologique, agronomique et environnementale, Defourny, Pierre, Baret, Philippe, Bielders, Charles, Gérard, Bruno, Traoré, Pierre Sibiry, Delvaux, Bruno, Lambert, Marie-Julie, UCL - SST/ELI/ELIE - Environmental Sciences, UCL - Ingénierie biologique, agronomique et environnementale, Defourny, Pierre, Baret, Philippe, Bielders, Charles, Gérard, Bruno, Traoré, Pierre Sibiry, Delvaux, Bruno, and Lambert, Marie-Julie
- Abstract
In Sudano-Sahelian Africa, crop production is very variable across fields and years due to spatial rainfall heterogeneity, soil fertility constraints and agricultural practices. Crop production estimates are often available too late and at large administrative unit levels, preventing their use by the international community to support food security. This thesis aims to monitor local crop growing conditions and estimate crop production at village level. Unlike current agriculture monitoring systems, local crop growth variability was well depicted by moderate resolution imagery. This required an up-to-date cropland map successfully derived for the entire region thanks to a knowledge-based automated classification. Combining results from crop classification and yield estimation, production for four crops was accurately estimated at village level. This thesis also aims to better understand the smallholder crop production variability. We estimated the locally attainable yield gap at field, farm and village levels for four crops. Hierarchical analysis of farmer survey data highlighted the driving forces behind this yield gap, pinpointing inputs such as fertilization, farmer socio-economic conditions and farmer strategies. While most generic yield gap approaches assume that all farmers maximize their productivity, we showed that low income farmers put the emphasis on managing food shortage risks, while wealthier farmers allocate resources to manage the long-term fertility of their fields. These methodological developments are very promising to design, target and evaluate agriculture interventions according to the actual farmer’s needs., (AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 2018
- Published
- 2018
9. How does institutional embeddedness shape innovation platforms? A diagnostic study of three districts in the Upper West Region of Ghana
- Author
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Totin, Edmond, primary, Roncoli, Carla, additional, Traoré, Pierre Sibiry, additional, Somda, Jacques, additional, and Zougmoré, Robert, additional
- Published
- 2018
- Full Text
- View/download PDF
10. Climate change impacts on crop yield in Koutiala, Mali
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Adam, Myriam, Nenkam, A.M., Diancoumba, Madina, Akinseye, Folorunso M., Traoré, Pierre Sibiry, Traoré, Seydou B., Adiku, Samuel G.K., and MacCarthy, Dilys S.
- Subjects
U10 - Méthodes mathématiques et statistiques ,F01 - Culture des plantes ,P40 - Météorologie et climatologie - Abstract
An integrated modelling framework is used to simulate crop productivity for current and future climate scenarios. Two crop models, Decision Support Systems for Agro-Technological Transfer (DSSAT) and the Agricultural Productions Systems sIMulator (APSIM), were calibrated and evaluated for the study site in Koutiala, Mali, simulating yields of maize, millet, and peanut for 123 households. These crop models are fed by weather data from baseline climate (1980-2009) from observed weather and future climate (2040-2069) from 5 Global Circulation Models (GCMs) were used as inputs to crop models. The models' results differ according to the crop considered. For maize, there is a decrease of grain yield across all GCMs and crop models. For sorghum, there is a slight decrease across GCMs with DSSAT, but the grain yield remains constant on average with APSIM. For peanut and millet, the results are more optimistic and grain yield increases across all cases. These outputs will then be linked to the economical the Trade-Off Analysis-Minimum Data model (TOA-MD) to assess impacts on farmer livelihoods. Further, adaptation strategies (e.g. drought and heat tolerant cultivars) will be simulated to assess their potential impact for the future. (Texte intégral)
- Published
- 2016
11. Assessing the vulnerability of sorghum to changing climate conditions in West Africa semi-arid tropics. [P39]
- Author
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Akinseye, Folorunso M., Diancoumba, Madina, Myriam ADAM, Traoré, Pierre Sibiry, Agele, Samuel O., and Whitbread, Anthony M.
- Subjects
F01 - Culture des plantes ,P40 - Météorologie et climatologie - Abstract
Rainfed agriculture would remain the dominant source of staple food production and the livelihood foundation of the majority of the rural populace in semi-arid West Africa. Prolonged dry spells during the growing season often lead to significant crop yield losses, a situation that is expected to be exacerbated by climate change. In this study, impacts of climate change on the sorghum production system in West Africa semi-arid tropics was analysed using the most accessible process-based crop models (DSSAT, APSIM and Samara) and simulated at six stations under rainfed conditions. The mid-century future climate predictions by 2069 indicate the productivity of grain sorghum would be diversely affected due to the differences in the GCMs projections in terms of temperature and rainfall. On the average, climate change is projected to reduce low photoperiod sensitivity genotype (CSM63E) grain yield to the tune of 13%, and by 7% for both medium photoperiod sensitivity genotype (CSM335) and high photoperiod genotype (IS15401) across the selected sites. Results also indicate that adaptation strategies like longer grain filling period and sowing date reduced the vulnerability on both the medium and high photoperiod sensitivity genotypes (CSM335 and IS15401) compared to low photoperiod sensitivity genotype (CSM63E). As obtained from the study, proper genotypic calibrations and evaluations of crop models could be used to explain the expected outcomes of future climate conditions on the diverse photoperiod sensitivity sorghum genotypes available across semi-arid area. Also, these results would serve as reliable tools towards the understanding of future climate change and adaptation options to be implemented, which could be shared among farmers and development partners interested in food security issues in West Africa semi-arid zone. (Texte intégral)
- Published
- 2015
12. Network of experiments to phenotype contrasted sorghum and to model its adaptability in West African environments. [P40]
- Author
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Myriam ADAM, Muller, Bertrand, Traoré, Pierre Sibiry, Folorunso, Akinseye, and Ndiaye, Malick
- Subjects
F30 - Génétique et amélioration des plantes - Abstract
Characterizing the environment, understanding farmers' requirements and evaluating crop responses to the environment is essential to choose which crop or even which variety is better adapted to the farming systems. Crop models can help to direct this choice. However, use of models requires excellent datasets to facilitate their calibration and validation. In West Africa, sorghum is traditionally the lead cereal and staple crop. A high diversity of sorghum varieties is farmed, but detailed data on these varieties in this specific environment is scarce. We aim at addressing this issue by setting up a network of experimentations in West Africa to characterize contrasted sorghum varieties and to assess their adaptability to different agroecological zones of West Africa. These varieties differ with respect to architecture (tall or small), uses (grain, biomass or dual purpose), composition (cellulose, lignin), and phenology adapted to different targeted regions in West Africa. To represent the diversity of the environment, three main sites in three major countries of the region have been chosen to test these ten varieties according to a rainfall gradient: (1) 700mm in Senegal, (2) 950mm in Mali and (3) 1150mm in Burkina Faso. The main crop traits characterized are phenology, number of leaves, plant height, leaf area index, organs biomass and grain yield, all essential data for good model calibration. The first results are (1) a comprehensible database of ten contrasted West African sorghum varieties, all tested in three major sites in West Africa, and (2) calibrated crop models (DSSAT, APSIM and SAMARA). These models will then be used to direct our choice of adapted cultivars to the right environment. Also, calibration of multiple models will enable to assess the uncertainty in the decision we take. (Texte intégral)
- Published
- 2015
13. Yield mapping for different crops in Sudano-Sahelian smallholder farming systems : results based on metric Worldview and decametric SPOT-5 Take5 time series
- Author
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UCL - SST/ELI/ELIE - Environmental Sciences, Blaes, Xavier, Lambert, Marie-Julie, Chomé, Guillaume, Traoré, Pierre Sibiry, de By, Rolf A., Defourny, Pierre, ESA Living Planet Symposium, UCL - SST/ELI/ELIE - Environmental Sciences, Blaes, Xavier, Lambert, Marie-Julie, Chomé, Guillaume, Traoré, Pierre Sibiry, de By, Rolf A., Defourny, Pierre, and ESA Living Planet Symposium
- Abstract
Efficient yield mapping in Sudano-Sahelian Africa, characterized by a very heterogeneous landscape, is crucial to help ensure food security and decrease smallholder farmers’ vulnerability. Thanks to an unprecedented in-situ data and HR and VHR remote sensing time series collected in the Koutiala district (in south-eastern Mali), the yield and some key factors of yield estimation were estimated. A crop-specific biomass map was derived with a mean absolute error of 20% using metric WorldView and 25% using decametric SPOT-5 TAKE5 image time series. The very high intra- and inter-field heterogeneity was captured efficiently. The presence of trees in the fields led to a general overestimation of yields, while the mixed pixels at the field borders introduced noise in the biomass predictions.
- Published
- 2016
14. Quantifying Fertilizer Application Response Variability with VHR Satellite NDVI Time Series in a Rainfed Smallholder Cropping System of Mali
- Author
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UCL - SST/ELI/ELIE - Environmental Sciences, Blaes, Xavier, Chomé, Guillaume, Lambert, Marie-Julie, Traoré, Pierre Sibiry, Schut, Antonius G.T., Defourny, Pierre, UCL - SST/ELI/ELIE - Environmental Sciences, Blaes, Xavier, Chomé, Guillaume, Lambert, Marie-Julie, Traoré, Pierre Sibiry, Schut, Antonius G.T., and Defourny, Pierre
- Abstract
Soil fertility in smallholder farming areas is known to vary strongly on multiple scales. This study measures the sensitivity of the recorded satellite signal to on-farm soil fertility treatments applied to five crop types, and quantifies this fertilization effect with respect to within-field variation, between-field variation and field position in the catena. Plant growth was assessed in 5–6 plots per field in 48 fields located in the Sudano-Sahelian agro-ecological zone of southeastern Mali. A unique series of Very High Resolution (VHR) satellite and Unmanned Aerial Vehicle (UAV) images were used to calculate the Normalized Difference Vegetation Index (NDVI). In this experiment, for half of the fields at least 50% of the NDVI variance within a field was due to fertilization. Moreover, the sensitivity of NDVI to fertilizer application was crop-dependent and varied through the season, with optima at the end of August for peanut and cotton and early October for sorghum and maize. The influence of fertilizer on NDVI was comparatively small at the landscape scale (up to 35% of total variation), relative to the influence of other components of variation such as field management and catena position. The NDVI response could only partially be benchmarked against a fertilization reference within the field. We conclude that comparisons of the spatial and temporal responses of NDVI, with respect to fertilization and crop management, requires a stratification of soil catena-related crop growth conditions at the landscape scale.
- Published
- 2016
15. Do participatory scenario exercises promote systems thinking and build consensus?
- Author
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Schmitt Olabisi, Laura, primary, Adebiyi, Jelili, additional, Traoré, Pierre Sibiry, additional, and Kakwera, Mayamiko Nathaniel, additional
- Published
- 2016
- Full Text
- View/download PDF
16. Network of experiments to phenotype contrasted sorghum and to model its adaptability in West African environments. [P40]
- Author
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Adam, Myriam, Muller, Bertrand, Traoré, Pierre Sibiry, Folorunso, Akinseye, Ndiaye, Malick, Adam, Myriam, Muller, Bertrand, Traoré, Pierre Sibiry, Folorunso, Akinseye, and Ndiaye, Malick
- Abstract
Characterizing the environment, understanding farmers' requirements and evaluating crop responses to the environment is essential to choose which crop or even which variety is better adapted to the farming systems. Crop models can help to direct this choice. However, use of models requires excellent datasets to facilitate their calibration and validation. In West Africa, sorghum is traditionally the lead cereal and staple crop. A high diversity of sorghum varieties is farmed, but detailed data on these varieties in this specific environment is scarce. We aim at addressing this issue by setting up a network of experimentations in West Africa to characterize contrasted sorghum varieties and to assess their adaptability to different agroecological zones of West Africa. These varieties differ with respect to architecture (tall or small), uses (grain, biomass or dual purpose), composition (cellulose, lignin), and phenology adapted to different targeted regions in West Africa. To represent the diversity of the environment, three main sites in three major countries of the region have been chosen to test these ten varieties according to a rainfall gradient: (1) 700mm in Senegal, (2) 950mm in Mali and (3) 1150mm in Burkina Faso. The main crop traits characterized are phenology, number of leaves, plant height, leaf area index, organs biomass and grain yield, all essential data for good model calibration. The first results are (1) a comprehensible database of ten contrasted West African sorghum varieties, all tested in three major sites in West Africa, and (2) calibrated crop models (DSSAT, APSIM and SAMARA). These models will then be used to direct our choice of adapted cultivars to the right environment. Also, calibration of multiple models will enable to assess the uncertainty in the decision we take. (Texte intégral)
- Published
- 2015
17. Prévision de l'aire de diffusion de variétés de sorgho au Mali
- Author
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Soumaré, Mamy, Vaksmann, Michel, Bazile, Didier, Traoré, Pierre Sibiry, Diakité, Cheick Hamala, and Kouressy, Mamoutou
- Subjects
U10 - Informatique, mathématiques et statistiques ,F30 - Génétique et amélioration des plantes - Abstract
Suite aux sécheresses des années 1970 et 1980, d'importants moyens ont été déployés pour créer des variétés adaptées à des saisons des pluies plus courtes. La vulgarisation de ces variétés a connu peu de succès en raison de leur inadaptation à la variabilité interannuelle du climat et aux stratégies déployées par les paysan pour en tenir compte. Le climat soudano-sahélien est caractérisé par une saison des pluies monomodale dont le début et la fin sont extrêmement variables d'une année sur l'autre. L'analyse fréquentielle de la structure de la saison des pluies à l'aide d'un modèle de bilan hydrique permet de déterminer les dates de début et de fin de saison. Soixante dix postes pluviométriques répartis sur l'ensemble de la zone d'agriculture pluviale du Mali ont été utilisés. Le caractère photopériodique des variétés locales permet à la plante d'ajuster naturellement la durée de son cycle à la durée probable de la saison des pluies. Un modèle simplifié de développement des sorghos photopériodiques permet de prévoir la date de floraison de quelques variétés représentatives de la zone de culture pluviale. On considère qu'une variété est adaptée à un site si sa floraison se produit dans les 20 jours qui précèdent la date moyenne de fin de saison des pluies. Le couplage des deux modèles (bilan hydrique et développement des sorghos photopériodiques) au sein d'un système d'information géographique permet de délimiter pour chaque variété sa zone optimale d'adaptation.Les cartes obtenues représentent un outil de synthèse utile pour les agronomes qui désirent déterminer une zone possible de diffusion d'une variété. Ce résultat permet aussi aux sélectionneurs d'améliorer la définition de l'idéotype adapté et permet d'abandonner la notion de variétés à large adaptation géographique par la recherche d'adaptations à des niches écologique spécifiques.
- Published
- 2005
18. Seasonal forecasts in the Sahel region: the use of rainfall-based predictive variables
- Author
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Lodoun, Tiganadaba, primary, Sanon, Moussa, additional, Giannini, Alessandra, additional, Traoré, Pierre Sibiry, additional, Somé, Léopold, additional, and Rasolodimby, Jeanne Millogo, additional
- Published
- 2013
- Full Text
- View/download PDF
19. Coping with climate variability and change in research for development targeting West Africa: Need for paradigm changes
- Author
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Herrmann, Ludger, additional, Haussmann, Bettina Irmgard Gabriela, additional, van Mourik, Tom, additional, Traoré, Pierre Sibiry, additional, Oumarou, Hannatou Moussa, additional, Traoré, Kalifa, additional, Ouedraogo, Mahama, additional, and Naab, Jesse, additional
- Published
- 2013
- Full Text
- View/download PDF
20. Prévision de l'aire de diffusion des sorghos photopériodiques en Afrique de l'Ouest
- Author
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Soumaré, Mamy, Kouressy, Mamoutou, Vaksmann, Michel, Maikano, Ibrahim, Bazile, Didier, Traoré, Pierre Sibiry, Traoré, Seydou B., Dingkuhn, Michaël, Touré, Aboubacar, Vom Brocke, Kirsten, Some, Léopold, Barro-Kondombo, Clarisse Pulchérie, Soumaré, Mamy, Kouressy, Mamoutou, Vaksmann, Michel, Maikano, Ibrahim, Bazile, Didier, Traoré, Pierre Sibiry, Traoré, Seydou B., Dingkuhn, Michaël, Touré, Aboubacar, Vom Brocke, Kirsten, Some, Léopold, and Barro-Kondombo, Clarisse Pulchérie
- Abstract
Le photopériodisme des variétés locales de sorgho permet la synchronisation de la floraison avec la fin de la saison des pluies. La prise en compte de ce caractère par les programmes d'amélioration est très récente. L'intégration du photopériodisme dans un modèle de culture et l'utilisation d'un système d'information géographique (SIG) permettent d'identifier les zones optimales de culture des différents cultivars en combinant les caractéristiques variétales, l'incertitude climatique et les pratiques culturales des paysans. Une variété est considérée adaptée à une zone si elle fleurit dans les 20 jours qui précèdent la date moyenne de fin de saison. L'analyse prend en compte la grande incertitude sur les dates de semis qui peuvent s'étaler sur plus d'un mois à partir de l'installation des pluies. L'étude du comportement de 52 variétés locales et améliorées au Mali et au Burkina Faso montre que les variétés précoces possèdent une large adaptation géographique mais nécessitent de maîtriser la date de semis. Les variétés photopériodiques sont spécifiquement adaptées à une zone géographique mais tolèrent une large gamme de dates de semis, ce qui est un caractère primordial pour les paysans africains. Les cartes d'adaptation issues de ce travail peuvent aider les sélectionneurs à définir des idéotypes adaptés à la diversité des situations agroclimatiques d'Afrique soudano-sahélienne.
- Published
- 2008
21. Adaptation des sorghos du Mali à la variabilité climatique
- Author
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Kouressy, Mamoutou, Traoré, Seydou B., Vaksmann, Michel, Grum, Mikkel, Maikano, Ibrahim, Soumaré, Mamy, Traoré, Pierre Sibiry, Bazile, Didier, Dingkuhn, Michaël, Sidibé, Amadou, Kouressy, Mamoutou, Traoré, Seydou B., Vaksmann, Michel, Grum, Mikkel, Maikano, Ibrahim, Soumaré, Mamy, Traoré, Pierre Sibiry, Bazile, Didier, Dingkuhn, Michaël, and Sidibé, Amadou
- Abstract
Il est couramment admis que la sécheresse en Afrique de l'Ouest a entraîné l'adoption par les paysans de variétés de sorgho plus précoces que les cultivars traditionnels. Pour mesurer l'évolution récente du cycle des sorghos du Mali, nous avons étudié la phénologie de deux collections de variétés locales prospectées à 20 ans d'intervalle en 1978 et en 2000. Les dates de début et de fin de saison des pluies ont été calculées pour tous les villages échantillonnés. La sensibilité des cultivars à la photopériode a été mesurée à l'aide d'un essai comportant deux dates de semis. Un modèle permet d'étudier l'adaptation des variétés au climat en tenant compte de la latitude et du régime des pluies de leurs zones d'origines. Le déficit pluviométrique n'a pas entraîné un raccourcissement important des cycles végétatifs. En 20 ans, le cycle moyen des cultivars locaux s'est raccourci de 5 jours. Pour des latitudes inférieures à 14° N, la grande majorité des cultivars sont photopériodiques, la floraison des variétés se produit dans les 20 jours qui précèdent la date moyenne de fin de la saison des pluies. Ce caractère permet d'optimiser l'alimentation en eau des cultures et d'éviter de nombreuses contraintes biotiques. Pour des latitudes supérieures ou égales à 14° N, la floraison moyenne coïncide avec la fin de saison. On note la présence simultanée de variétés tardives et précoces. Dans ces régions, la culture du sorgho dépend moins de la pluviométrie car les systèmes traditionnels valorisent des situations diversifiées et les reports d'eau sur les toposéquences. Cette diversité des cycles contribue à sécuriser la production agricole en zone aride. Ce travail permet de guider les programmes de sélection dans la définition d'idéotypes spécifiquement adaptés à la gamme d'environnements climatiques rencontrés dans la région.
- Published
- 2008
22. Changes in seasonal descriptors of precipitation in Burkina Faso associated with late 20th century drought and recovery in West Africa
- Author
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Lodoun, Tiganadaba, primary, Giannini, Alessandra, additional, Traoré, Pierre Sibiry, additional, Somé, Léopold, additional, Sanon, Moussa, additional, Vaksmann, Michel, additional, and Rasolodimby, Jeanne Millogo, additional
- Published
- 2013
- Full Text
- View/download PDF
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