Ajustement structurel et effondrement des modèles idéologiques : Crise et renouveau de l'État africain

The crisis of the State preceded structural adjustment, the latter only exposing a pre-existing economic and financial crisis. As a result of this financial crisis, the State’s ambitions have fallen into discredit. Its leaders are less able to redistribute wealth and, as one problem leads to another, their political survival is threatened. The « revolt of the belly » has been carried over to the political playing-field thanks to favourable international circumstances which have forced states to accept multipartygovernment. From this viewpoint, the collapse of ideological models and the structural policies of adjustment are as much factors in the crisis of the African State as they are in its renewal

Epidémie de la panachure jaune du riz: une contrainte biotique majeure de la production rizicole dans les périmètres irrigués du Niger: Rice yellow mottle epidemic: a major biotic constraint of rice production in the irrigated perimeters of Niger Republic

La panachure jaune du riz, causée par le Rice Yellow Mottle Virus (RYMV), est présente au Niger depuis plus de trois décennies, avec des pertes importantes de récoltes. Une réévaluation de cette maladie sur les périmètres irrigués a été faite pour estimer son incidence et les pertes de récoltes qu’elle engendre. L’étude a consisté à: (i) surveiller l’épidémie dans quelques périmètres rizicoles sur deux campagnes, (ii) calculer les pertes de production en grains enregistrées et (ii) caractériser quelques isolats du virus. Elle a révélé que la maladie est toujours présente dans les périmètres irrigués du pays. Son incidence moyenne est de 5 à 30%, en saison sèche et en saison humide, elle varie entre 5 et 70%, avec des niveaux d’infestation variables d’un périmètre à l’autre. Les pertes moyennes de production en grains enregistrées en champ paysan sont variables selon les sites et oscillent entre 27,17% et 63,26% en saison humide où lesdites pertes ont été plus importantes. Ces résultats montrent que l’épidémie de la panachure jaune du riz est toujours très fréquente au Niger et constitue une contrainte majeure de la production rizicole, dominée par la prévalence d’isolats de contournement de la résistance e et l’utilisation presque exclusive de deux principales variétés de riz que sont IR1529-680-3-1 et Kogoni91-1. The rice yellow mottle due to Rice Yellow Mottle Virus (RYMV) is present in Niger Republic for more than three decades, with significant crop losses. A reassessment of this disease on irrigated areas has been made, to estimate its incidence and the crop losses it causes. The study consisted of: (i) monitoring the epidemic in a few rice-growing perimeters over two seasons, (ii) calculating the recorded grains production losses and (ii) characterizing some isolates of the virus. It revealed that the disease is still present in the country's rice irrigated perimeters. Its average incidence is 5-30% in the dry season and in the wet season it varies between 5 and 70%, with varying levels of infestation depending on the perimeter. Average grains production losses recorded in the producer’s field vary from site to site and range from 27.17% to 63.26% in the wet season when these losses were greater. These results show that the Rice yellow mottling epidemic is still very frequent in Niger Republic and constitutes a major constraint of rice production, dominated by the prevalence of Resistance Breaking isolates (RB) and the almost exclusive use of two main rice varieties which are IR1529-680-3-1 and Kogoni91-1

Assessment of the impact of crop management strategies on the yield of early-maturing maize varieties in the drylands of Niger Republic: Application of the DSSAT-CERES-Maize model

Maize is increasingly becoming important in Niger for use as food and feed. Production is however, faced with several abiotic and biotic constraints. Researchers have developed early-maturing maize varieties that are tolerant to drought, the parasitic weed Striga hermonthica and diseases that fit into the short growing production environment. The evaluation and deployment of these varieties would, however, involve costly and time-consuming field trials across the maize production zones of the country. The CERES-Maize model was applied to assess the performance of two early-maturing maize varieties under varying planting windows and nitrogen application in three agroecological zones of the country. The model was calibrated with datasets collected from field trials conducted under optimal conditions (supplementary irrigation and full nutrient supply) at three locations in northern Nigeria. The model was validated with independent data set obtained from field trials conducted in 2020 and 2021 at 4 locations in the Republic of Niger under rainfed conditions. For each variety the treatments were five nitrogen (N) rates (0, 30, 60, 90 and 120 kg ha−1). The results from model calibration and validation revealed that the model accurately reproduced the observed value for days to flowering, physiological maturity, aboveground dry biomass and grain yield with low nRMSE (0.4–12.7%) and high d-index (0.70–0.99) for both varieties. The long-term simulation results (1985–2020) showed that the maize performance was dependent on location, planting window and nitrogen rates. The variety 2014 TZE-Y yielded higher than Brico in all locations for all treatments because it takes longer to mature and accumulate higher dry matter and have higher number of kernels. Simulated yields were generally higher in the Sudan savanna agroecological zone than in the other zones because of higher rainfall and higher clay content of the soil in this zone. The response to N application was influenced by planting window in each agroecological zone. With the exception of two sites, grain yield declined with planting beyond July 14 (PW3) and response to N was not significant beyond this date in the Sudan savanna agroecological zone. Grain yield declined with planting beyond July 7 in the Sahel and Sudan Sahel agroecological zones. There was no further response to N beyond 30 and 60 kg N ha−1 when planting is delayed beyond July 7 in the Sahel and Sahel-Sudan agroecological zones, respectively

Les sociétés rurales face aux changements climatiques et environnementaux en Afrique de l’Ouest

L’avenir de l'Afrique de l'Ouest dépend de la capacité de son agriculture à assurer la sécurité alimentaire de sa population, qui devrait doubler en vingt ans, tout en faisant face aux risques nouveaux engendrés par le réchauffement climatique. En effet, les modifications de température et de précipitations déjà à l’oeuvre, et qui devraient s’amplifier, auront dans un futur proche des répercussions importantes sur la production agricole et sur les ressources en eau de cette partie du continent africain. L’adaptation des sociétés rurales aux risques climatiques est une des clés pour relever ce nouveau défi. Pour mieux en connaître le potentiel, les processus et les barrières, cet ouvrage analyse les évolutions récentes et en cours du climat et de l’environnement, et étudie comment les sociétés rurales les perçoivent et les intègrent : quels sont les impacts de ces changements, quelles vulnérabilités mais aussi quelles nouvelles opportunités entraînent-ils ? Comment les populations s’y adaptent-elles, et quelles innovations mettent-elles en oeuvre, alors que les effets induits par le climat interagissent avec les changements sociaux, politiques, économiques et techniques en cours sur le continent ? En associant des chercheurs français et africains (climatologues, agronomes, hydrologues, écologues, démographes, géographes, anthropologues, sociologues…) dans une approche interdisciplinaire, cet ouvrage apporte une contribution précieuse pour mieux anticiper les risques climatiques et évaluer les capacités des sociétés africaines à y faire face

Rural societies in the face of climatic and environmental changes in West Africa

The future of West Africa depends on the capacity of its agriculture to ensure the food security of the population, which should double in the next 20 years, while facing up to the new risks resulting from climate warming. Indeed, the changes in temperature and precipitations already operating and that should become more marked will have serious effects on agricultural production and water resources in this part of Africa in the near future. One of the keys to meeting this new challenge is the adaptation of rural societies to climate risks. To gain better knowledge of the potential, processes and barriers, this book analyses recent and ongoing trends in the climate and the environment and examines how rural societies perceive and integrate them: what are the impacts of these changes, what vulnerabilities are there but also what new opportunities do they bring? How do the populations adapt and what innovations do they implement—while the climate-induced effects interact with the social, political, economic and technical changes that are in motion in Africa? By associating French and African scientists (climatologists, agronomists, hydrologists, ecologists, demographers, geographers, anthropologists, sociologists and others) in a multidisciplinary approach, the book makes a valuable contribution to better anticipation of climatic risks and the evaluation of African societies to stand up to them

Correction: Experimental Treatment with Favipiravir for Ebola Virus Disease (the JIKI Trial): A Historically Controlled, Single-Arm Proof-of-Concept Trial in Guinea.

[This corrects the article DOI: 10.1371/journal.pmed.1001967.]