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The impact of access to agricultural advisory services on input use and farm performance: Evidence from Senegal
No full textInternational audiencePerformant agricultural advisory services (AAS) in Africa are crucial for improving the agricultural productivity and food security of the farm households. Yet, evidence‐based study on the impacts of AAS on farm performance are scarce, especially in West African countries. This study evaluates the impact of access to AAS on input use and farm performance in Senegal, employing the instrumental variable and control function approaches accounting for selection bias. The approaches are also employed to several sub‐samples to see if the impacts are heterogeneous across crop types and fertilizer use, and matching techniques are applied to test the robustness of the results. Results show that the highest positive impact of AAS is on yield, while the impacts on gross margin and improved seeds uptake are very modest. Access to AAS has no effect on fertilizer uptake. It also finds that AAS impacts positively cereal production and farmers using no fertilizer but has no effect on the legume and horticultural crop production and on farmers using fertilizer. Given the Senegalese government and donors have put a lot of effort into developing an efficient AAS system, a consideration of the identified weaknesses is required to improve its efficiency
Crop traits and production under drought
No full textInternational audienceDrought limits crop productivity and threatens global food security, with moderate drought stress — when crops grow at a reduced rate — commonly experienced. Increasing plant tolerance to moderate drought is a key target for adaptation and management, but efforts to understand and increase drought tolerance often focus on more extreme drought that causes complete crop failure and only consider crop genetics. In this Review, we discuss the influence of moderate drought on crop productivity and the role of physiological traits in drought tolerance and adaptation. Traits related to crop water use, water capture, water availability, transpiration efficiency and phenology impact drought adaptation, but their overall effect varies situationally. For example, early restrictions in transpiration, higher transpiration efficiency or altered tillering increase water availability during grain filling and can double yield in some drought scenarios. However, these same traits under less severe drought scenarios can also lead to yield penalties. To assess when and under what conditions traits will be beneficial, crop models are used to integrate the effects of genetics, the environment and management, estimating the expected yield responses under these combinations of scenarios and traits. More robust characterization of moderate drought tolerance and better integration between plant genetic information and modelling will enable the local selection of crop varieties suited to the expected drought scenarios
ROS responsive Aux/IAA multimerization modulates auxin responses
No full textAbstract Reactive oxygen species (ROS) function as key signals in plants to enable adaptation to environmental stresses. Plant roots respond to transient water stress by temporarily ceasing branching using the acclimative response xerobranching 1 . In this study, we report that a rapid ROS burst regulates Xerobranching by inducing multimerization of auxin repressor protein IAA3/SHY2. Mutations in specific cysteine residues in IAA3/SHY2 disrupt redox-mediated multimerization and interaction with co-repressor TPL, but not with auxin response partner ARF7 and auxin receptor TIR1. ROS-mediated oligomerization of IAA3/SHY2 is required for efficient ARF mediated target gene repression during Xerobranching and lateral root emergence. We demonstrate that AUX/IAA proteins vary in their redox mediated multimerization, revealing a new auxin response regulatory mechanism that directly connects ROS sensing to auxin signalling. Our study reveals how ROS, auxin and water stress intersect to shape acclimative responses in plant roots and maintain their phenotypic plasticity
A brief review on models for birds exposed to chemicals
No full textInternational audience"A Who's Who of pesticides is therefore of concern to us all. If we are going to live so intimately with these chemicals eating and drinking them, taking them into the very marrow of our bones-we had better know something about their nature and their power."-Rachel Carson, Silent Spring.In her day, Rachel Carson was right: plant protection products (PPP) like all the other chemical substances that humans increasingly release into the environment without further precaution, are among our worst enemies today. All compartments of the biosphere, air, soil and water, are potential reservoirs within which all species that live there are impaired. Birds are particularly concerned: PPP are recognized as a factor in the decline of their abundance and diversity predominantly in agricultural landscapes. Due to the restrictions on vertebrates testing, \textit{in silico} based approaches are an ideal choice alternative given input data are available. This is where the problem lies as we will illustrate in this paper. We performed an extensive literature search covering a long period of time, a wide diversity of bird species, a large range of chemical substances and as many model types as possible to encompass all our future need to improve environmental risk assessment of chemicals for birds. In the end, we show that poultry species exposed to pesticides are the most studied at the individual level with physiologically based toxicokinetic models. To go beyond, with more species, more chemical types, over several levels of biological organization, we show that observed data are crucially missing. As a consequence, improving existing models or developing new ones could be like climbing Everest if no additional data can be gathered, especially on chemical effects and toxicodynamic aspects
The (Non-)Disclosure of Energy Efficiency: The Case of Cooling Technologies across Africa
No full textInternational audienceThe adoption of air conditioning (AC) could grow exponentially across Africa under the joint effect of acute warming, sustained income growth and rapid urbanization. The implications for greenhouse gas emissions will crucially depend on the energy efficiency of the models adopted. Little is known, however, about how energy efficiency information is conveyed to consumers in these markets. To fill this gap, we gathered data on cooling appliances' characteristics from Africa's largest e-commerce platform, serving 13 countriess—Algeria, Cameroon, Côte d’Ivoire, Egypt, Ghana, Kenya, Morocco, Nigeria, Senegal, South Africa, Tanzania, Tunisia, and Uganda. We find that less than 10% of the AC models available on the marketplace (N=1,229) have information disclosed about their energy performance. Information disclosure appears to be highly idiosyncratic with weak strategic motives. This overall lack of information about energy efficiency represents an important challenge for enforcing energy performance standards and steering demand toward energy-efficient cooling appliances
L’alimentation des premiers agropasteurs du Néolithique : apport de l’étude des microrestes du tartre dentaire des individus de la Roussille (Auvergne)
No full textNational audienceThe Neolithic, a major episode in human history, is marked by the domestication of plant and animal species, the beginnings of agriculture, and significant demographic growth. The ANR WomenSOFar project (ANR-21-CE03-0008) aims to identify the status of women through how they move, eat, work, and care for the young. As part of this research project, an innovative and exploratory approach involving the analysis of micro-remains contained in dental calculus was carried out. The objectives were to test the interest of this still embryonic approach in France and to provide insights into the dietary habits of Neolithic communities in La Roussille (Vertaizon, Puy-de-Dôme), in addition to data from other paleoecological and bioarchaeological disciplines.The studied site, La Roussille, is located in Auvergne and has the particularity of being composed of a habitation area and a burial zone, dated to approximately 4600 to 4300 years BCE. Dental calculus samples from 7 individuals, including 2 males, 4 females, and 1 of unknown sex, were analyzed at the University College of Dublin, Ireland. Dental calculus samples were decalcified using the EDTA method before being studied under an optical microscope. Micro-remains were identified through publications and reference books. The main elements found were phytoliths, microscopic siliceous bodies produced by plants as a defense against attacks such as herbivory, as well as animal cells, micro-charcoal, pollen, and fungal spores. These initial results raise questions about the representativeness of the different types of elements identified in this matrix and the use of teeth as a tool.Le Néolithique, épisode majeur de l’histoire Humaine est marqué par la domestication des espèces végétales et animales, les débuts de l’agriculture et une croissance démographique significative. Le projet ANR WomenSOFar (21-CE03-0008) vise à identifier le statut des femmes à travers la façon dont elles se déplacent, se nourrissent, travaillent et prennent soin des jeunes. Dans le cadre de ce projet de recherche, une approche novatrice et exploratoire, consistant en l’analyse des micro-restes contenus dans le tartre dentaire, a été réalisée. Les objectifs étaient de tester l’intérêt de cette approche jusqu’à présent embryonnaire en France et de proposer des éléments de réponse au régime alimentaire des communautés néolithiques de La Roussille (Vertaizon, Puy-de-Dôme) en addition aux données d’autres disciplines paléoécologiques et archéobiologiques. Le site étudié, La Roussille, se situe en Auvergne et il présente la particularité d’être composé d’un habitat et d’un zone funéraire, datée d’environ 4600 à 4300 ans avant notre ère. Les échantillons de tartre dentaire de 7 individus, dont 2 hommes, 4 femmes, et 1 de sexe inconnu, ont été analysés (University College of Dublin, Irlande). Les échantillons de tartre dentaire ont été décalcifiés selon la méthode EDTA, avant d’être étudiés au microscope optique. Les microrestes ont été identifiés grâce à des publications et livres de référence. Les principaux éléments retrouvés étaient des phytolithes, corps microscopiques siliceux produits par les plantes en guise de défense contre des attaques telle que l’herbivorie, mais aussi des cellules animales, des microcharbons, des pollen ou encore des spores de champignon. Ces premiers résultats interrogent sur la représentativité des différents types d’éléments identifiés dans cette matrice et l’utilisation des dents en tant qu’outil
Comment mesurer la croissance des racines d'un arbre dans une forêt
No full textDescribing how to install a rhizotronComment mesurer la croissance des racines d'un arbre dans une forê
Participatory modeling of past, current and future groundwater governance: An experiment in Aousja Ghar El Melh, Tunisia
No full textInternational audienceAnticipatory approaches are increasingly used to guide decision-making on environmental issues. A number of these approaches, particularly in the field of anticipatory governance, promote the participation of users in anticipatory thinking. Various tools are already used for this purpose. Nevertheless, most of these tools focus on the present and the future, rarely on the past. This article introduces a tool for the participatory modeling of past, current and future governance of groundwater in a territory. This tool was coupled with the Futures Triangle to foster dialog among the actors of Aousja Ghar El Melh territory in Tunisia. The tool allowed opening up dialog on what stakeholders in Aousja Ghar El Melh wanted to keep or change in past and current governance, and what future they envisioned for their territory. This article highlights the need for further methodological developments in order to be more dynamic and better integrate the three governance temporalities. Several avenues are discussed, including a dynamic presentation of the model and the use of role-playing games. This experiment also highlights the need not only to identify the different approaches to anticipatory governance at hand, but also to think ahead about how to articulate them, especially in an inter-disciplinary and multi-actor process
Development and validation of an occurrence-based healthy dietary diversity (ORCHID) score easy to operationalize in dietary prevention interventions in older adults: a French study
No full textInternational audienceHealthy diet and dietary diversity have been associated with healthy ageing. Several scores have been developed to assess dietary diversity or healthy diets in epidemiological studies, but they are not adapted to be used in the context of preventive nutrition interventions. This study aimed to develop an occurrence-based healthy dietary diversity (ORCHID) score easy to implement in the field and to validate it using dietary data from older participants in the latest French food consumption survey (INCA3). The ORCHID score was made of several components representing the consumption occurrences of twenty food groups, in line with French dietary guidelines. The score was then validated using dietary data (namely three 24-h recalls and a food propensity questionnaire) from 696 participants aged 60 years and over in the INCA3 survey. Score validity was evaluated by describing the association of the score with its components, as well as with energy intakes, solid energy density (SED) and the probability of adequate nutrient intakes (assessed by the PANDiet). Higher scores were associated with more points in healthy components such as 'fruits' and 'vegetables' (r = 0•51, and r = 0•54, respectively). The score was positively associated with the PANDiet (r = 0•43) and inversely associated with SED (r = −0•37), while no significant association was found with energy intakes. The ORCHID score was validated as a good proxy of the nutritional quality of French older adults' diets. It could therefore be a useful tool for both public health research and nutrition interventions
Mitochondrial variation in <i>Anopheles gambiae</i> and <i>An. coluzzii</i> : phylogeographic legacy and mito-nuclear associations with metabolic resistance to pathogens and insecticides
No full textInternational audienceMitochondrial DNA has been a popular marker in phylogeography, phylogeny, and molecular ecology, but its complex evolution is increasingly recognized. Here, we investigated mitochondrial DNA variation in Anopheles gambiae and Anopheles coluzzii, in relation to other species in the Anopheles gambiae complex, by assembling the mitogenomes of 1,219 mosquitoes across Africa. The mitochondrial DNA phylogeny of the Anopheles gambiae complex was consistent with previously reported highly reticulated evolutionary history, revealing important discordances with the species tree. The three most widespread species (An. gambiae, An. coluzzii, and Anopheles arabiensis), known for extensive historical introgression, could not be discriminated based on mitogenomes. Furthermore, a monophyletic clustering of the three saltwater-tolerant species (Anopheles merus, Anopheles melas, and Anopheles bwambae) in the Anopheles gambiae complex also suggested that introgression and possibly selection shaped mitochondrial DNA evolution. Mitochondrial DNA variation in An. gambiae and An. coluzzii across Africa revealed significant partitioning among populations and species. A peculiar mitochondrial DNA lineage found predominantly in An. coluzzii and in the hybrid taxon of the African “far-west” exhibited divergence comparable to the interspecies divergence in the Anopheles gambiae complex, with a geographic distribution matching closely An. coluzzii's geographic range. This phylogeographic relict of the An. coluzzii and An. gambiae split was associated with population and species structure, but not with the rare Wolbachia occurrence. The lineage was significantly associated with single nucleotide polymorphisms in the nuclear genome, particularly in genes associated with pathogen and insecticide resistance. These findings underline potential mitonuclear coevolution history and the role played by mitochondria in shaping metabolic responses to pathogens and insecticides in Anopheles