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Carbon and nutrient fluxes in oil palm sustainable agro-system: Interfacing tree to molecular scales
No full textCarbon and nutrient balance are essential components of yield determinism in oil palm agrosystems and as such is crucial to optimize cropping practices and monitor fertilisation for sustainable production. Carbon balance at the plantation scale has received much attention, in particular carbon sequestration in global change context and crop modelling. My work provided new estimates of roots biomass, respiration loss (autotrophic and heterotrophic at tree scale) net and gross primary production (NPP and GPP) from planting to adult stage. My work further considered spatial variability inherited from cropping practices and temperature increase (global warming) in Indonesia (North Sumatra) and North Benin. In both countries, I have demonstrated that efficient recycling of fronds (dead leaves) is a key for agrosystem sustainability. I also have undertaken crop modelling (carried out as in studies from Wageningen) to look for new estimates of NP (net photosynthesis) and maximal stomatal conductance in potential ecological conditions (i.e. North Sumatra with no water deficit), coupled with phenology to predict (with two determinist models, SIMPALM and PHENOPALM) carbon allocation to fruits. In order to understand further mechanisms controlling C allocation I took advantage of natural isotope 13C abundance use to follow photosynthetic products (soluble sugars, starch) from leaves to fruits and identify C reserve pools. A metabolic model at tree scale was built from this study to estimate allocation fluxes. Because it is well-known that potassium (K) is essential for phloem transport and thus sugar circulation, I then explored links between carbon metabolism and K availability with metabolomics, and analyses of yield and leaf K content and the relationship between them. This work has shown that K can circulate quickly within the tree, supporting sucrose transport from leaves to fruits, while surprisingly, glucose is a major sugar that declines along with starch when yield increases. This new direction work has also shown that metabolomics signatures reflecting the K status of trees and can be used to improve a precious tool for fertilizer management the foliar diagnosis. This represents a potential tool for monitoring trees, i.e., improve agronomical diagnosis and guidance for K fertilisation
L'Analyse du Cycle de Vie (ACV) pour l'éditeur QUAE - Des perspectives stratégiques pour les métiers de l'édition scientifique, basées sur la méthode d'évaluation multicritère des impacts environnementaux des produits et des services
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Action collective et prévention des crises sanitaires : une contextualisation empirique et méthodologique sur les maladies zoonotiques liées aux moustiques au Cameroun
No full textTrente ans d'évolution des importations agri-alimentaires vers la Guadeloupe : 1995-2023
No full textEngaging marginalized communities in multi-level transformative innovation policy: The case of the Just Transition Fund
No full textTo address grand challenges like climate change, transformative innovation policies (TIPs) are emerging as a framework for societal prosperity. Implemented through various instruments, TIPs may operate in a multi-level governance (MLG) context whereby policies originate at a supra-national level and are directed to national, regional, and local tiers. TIPs also emphasize inclusivity and engagement with marginalized communities. However, practical insights on these aspects for TIPs are limited. This paper therefore investigates how TIP instruments are channeled from a supra-national context to a local one to engage with marginalized communities. Taking Belgium as the setting for our paper, we focus on the European Green Deal as a TIP and the Just Transition Fund as the instrument. Finding a series of barriers that prevent engagement, we identify the key role of inter-organizational relationships (coordination, cooperation, collaboration), especially related to the initial vertical coordination of a TIP instrument. If vertical coordination does not extend to the local level, engagement with marginalized communities is difficult. Opening horizontal relationships to include a broader set of actors in decision-making processes is also important. Consequently, we unpack these barriers and build upon both the TIP and just transition literature by applying the participatory governance school of thought
Evaluation du potentiel germinatif de semences fourragères tropicales et de leur semis en association
No full textDealing with sugarcane pests and diseases in the context of regenerative agriculture: Report on the XIII ISSCT pathology workshop
No full textThe XIII ISSCT Pathology Workshop was held together with the XI Entomology Workshop from 25 to 27 November 2024 in Salta, Argentina, followed by a two-day field trip to north western Argentina. The workshop focused on dealing with sugarcane diseases in the context of regenerative agriculture. The 77 workshop attendees were from 12 countries: Argentina, Australia, Brazil, Colombia, Cote d'Ivoire, Cuba, France, Papua New Guinea, Réunion Island, South Africa, USA and Zimbabwe. The pathology section consisted of 20 oral and 22 poster presentations. A range of themes was covered during the workshop, from an update on the new version of A guide to sugarcane diseases to IPM that included breeding for resistance, tissue- culture plant production for nurseries, new diagnostic tools that included nanopore technology, NIRS and other tools, and increasing the accuracy and sensitivity of diagnostic assays. Pathogen diversity, transmission and evolution, and plant damage including cell structure and impact on yield were also discussed. The most cited diseases were ratoon stunt, leaf scald, red stripe, rust, smut, yellow leaf, and mosaic
Impact of wheat-legume mix intercrops on wheat epidemics by modelling
No full textContext : Intercropping is a promising strategy for integrated disease management and agroecological transition, although experimental and modelling studies are scarce. Objectives : This study aims to understand and quantify the impact of non-host species choice and nitrogen (N) fertilization on disease epidemics in the context of intercropping. Methods : We collected existing experimental data on LAI based on a literature survey of non-diseased wheat intercropped with different non-host legume species (pea and faba bean) and N fertilization treatments. Based on a foliar epidemic model for intercropping, we simulated epidemics directly on these experimental data of LAI. The model is parameterized for two wheat fungal diseases: Septoria tritici blotch, a rain-borne disease, and wheat leaf rust, an air-borne disease. Results : Our results indicate that intercropping can decrease disease intensity and improve protectiveness for both diseases. Effect depends however on species choice as pea intercropped with wheat leads to lower disease intensity and better intercropping protectiveness compared with faba bean, whereas N fertilization increased disease intensity. We also found that crop indicators describing wheat leaf area index (LAI) can predict disease intensity, whereas indicators describing companion LAI can better predict intercropping protectiveness. Conclusions : Intercropping can significantly reduce fungal epidemics on wheat, and intercropping management practices can be optimized for effective disease management in wheat-legume intercrops. The dilution effect is more related to disease intensity, while the barrier effect is more related to intercropping protectiveness. Implications : These findings pave the way for identifying field indicators to predict epidemics. However, this study also stressed the critical lack of experimental data on disease in intercropping
