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Stale seedbeds (or false seedbeds) aim to trigger weed seed germination during summer fallow in order to reduce the weed seed bank. This tillage operation must be shallow (less than 5 cm) and create a firm seedbed without clods. Field trials did not show any correlation between weed emergence during summer fallow and weed emergence in the following crop. Weed emergence observations underestimate the efficacy of stale seedbeds because they disregard seeds that germinate without emerging. Stale seedbed efficacy depends on soil moisture and seed dormancy level at the time of the operation. This technique must be combined with other techniques such as delaying the sowing of the following crop. This strategy was successful in simulations with the FLORSYS weed dynamics model. In an oilseed rape-winter wheatwinter barley rotation, stale seedbed the most reduced the weed infestation in the following crops if it was carried out in mid-August. Later operations risk to increase weed emergence after the sowing of the earliest winter crops.; Le faux semis consiste à faire germer des adventices pour les détruire ultérieurement avant le semis d’une culture. Cette opération doit être superficielle (moins de 5 cm) et générer un lit de semences bien affiné et rappuyé. Les essais ne montrent pas de lien entre les levées d’adventices observées pendant l’interculture et celles observées dans les cultures. Le comptage des levées ne prend pas en compte les semences germées qui meurent avant de lever. Par ailleurs, l'efficacité du faux-semis dépend énormément de l'humidité du sol et de la dormance de l'espèce adventice à la période où il est réalisé. L'effet du faux semis est donc partiel et variable, d’'où l'intérêt de le combiner avec d'autres techniques préventives, comme le décalage de la date de semis de la culture. Cette stratégie est confirmée par des simulations avec FLORSYS qui montrent que dans une rotation colza-blé-orge d’hiver, l’effet des faux semis sur la flore des cultures suivantes atteint son maximum pour des interventions de mi-août. Les opérations plus tardives risquent de faire lever les adventices après le semis de céréales les plus précoces.

International audience; Le développement des légumineuses dans la sole française, facteur dedurabilité, doit faire face à des contraintes de production qui peuventpénaliser leur rentabilité. Des avancées significatives, obtenues en poisd’hiver, devraient accélérer le progrès génétique et favoriser cette culture.

This study was designed to elucidate the biological variation in expression of many metabolites due to environment, genotype, or both, and to investigate the potential utility of metabolomics to supplement compositional analysis for the design of a new resilient cultivar of Brassica napus that can be steady in phytochemicals in different regions in France. Eight rapeseed varieties, grown in eight regions of France, were compared using a non-targeted metabolomics approach. The statistical analysis highlighted the distance and closeness between the samples in terms of both genotypes and geographical regions. A major environmental impact was observed on the polar metabolome, with different trends, depending on the varieties. Some varieties were very sensitive to the environment, while others were quite resilient. The identified secondary metabolites were mapped into the KEGG pathway database to reveal the most sensitive target proteins susceptible to environmental influences. A glucosyl-transferase encoded by the UGT84A1 gene involved in the biosynthesis of phenylpropanoid was identified. This protein could be rate limiting/promoting in this pathway depending on environmental conditions. The metabolomics approach used in this study demonstrated its efficiency to characterize the environmental influence on various cultivars of Brassica napus seeds and may help identify targets for crop improvement.

International audience; Analyse socio-économique des chaînes de valeur légumineuses en Europe: quels premiers enseignements? Tiana SMADJA (Terres Univia) Marie-Benoit MAGRINI (INRA) Frédéric Muel (Terres Inovia)

National audience

International audience; Rapeseed meal is a cheap and abundant raw material, particularly rich in phenolic compounds of biotechnological interest. In this study, we developed a two-step bioconversion process of naturally occurring sinapic acid (4-hydroxy-3,5-dimethoxycinnamic acid) from rapeseed meal into canolol by combining the complementary potentialities of two filamentous fungi, the micromycete Aspergillus niger and the basidiomycete Neolentinus lepideus. Canolol could display numerous industrial applications because of its high antioxidant, antimutagenic and anticarcinogenic properties. In the first step of the process, the use of the enzyme feruloyl esterase type-A (named AnFaeA) produced with the recombinant strain A. niger BRFM451 made it possible to release free sinapic acid from the raw meal by hydrolysing the conjugated forms of sinapic acid in the meal (mainly sinapine and glucopyranosyl sinapate). An amount of 39 nkat AnFaeA per gram of raw meal, at 55 °C and pH 5, led to the recovery of 6.6 to 7.4 mg of free sinapic acid per gram raw meal, which corresponded to a global hydrolysis yield of 68 to 76% and a 100% hydrolysis of sinapine. Then, the XAD2 adsorbent (a styrene and divinylbenzene copolymer resin), used at pH 4, enabled the efficient recovery of the released sinapic acid, and its concentration after elution with ethanol. In the second step, 3-day-old submerged cultures of the strain N.lepideus BRFM15 were supplied with the recovered sinapic acid as the substrate of bioconversion into canolol by a non-oxidative decarboxylation pathway. Canolol production reached 1.3 g/L with a molar yield of bioconversion of 80% and a productivity of 100 mg/L day. The same XAD2 resin, when used at pH 7, allowed the recovery and purification of canolol from the culture broth of N. lepideus. The two-step process used mild conditions compatible with green chemistry.

Background Understanding the effects of resistance QTL on pathogen development cycle is an important issue for the creation of QTL combination strategies to durably increase disease resistance in plants. The oomycete pathogen Aphanomyces euteiches, causing root rot disease, is one of the major factors limiting the pea crop in the main producing countries. No commercial resistant varieties are currently available in Europe. Resistance alleles at seven main QTL were recently identified and introgressed into pea agronomic lines, resulting in the creation of Near Isogenic Lines (NILs) at the QTL. This study aimed to determine the effect of main A. euteiches resistance QTL in NILs on different steps of the pathogen life cycle. Results NILs carrying resistance alleles at main QTL in susceptible genetic backgrounds were evaluated in a destructive test under controlled conditions. The development of root rot disease severity and pathogen DNA levels in the roots was measured during ten days after inoculation. Significant effects of several resistance alleles at the two major QTL Ae-Ps7.6 and Ae-Ps4.5 were observed on symptom appearance and root colonization by A. euteiches. Some resistance alleles at three other minor-effect QTL (Ae-Ps2.2, Ae-Ps3.1 and Ae-Ps5.1) significantly decreased root colonization. The combination of resistance alleles at two or three QTL including the major QTL Ae-Ps7.6 (Ae-Ps5.1/Ae-Ps7.6 or Ae-Ps2.2/Ae-Ps3.1/Ae-Ps7.6) had an increased effect on delaying symptom appearance and/or slowing down root colonization by A. euteiches and on plant resistance levels, compared to the effects of individual or no resistance alleles. Conclusions This study demonstrated the effects of single or multiple resistance QTL on delaying symptom appearance and/or slowing down colonization by A. euteiches in pea roots, using original plant material and a precise pathogen quantification method. Our findings suggest that single resistance QTL can act on multiple or specific steps of the disease development cycle and that their actions could be pyramided to increase partial resistance in future pea varieties. Further studies are needed to investigate QTL effects on different steps of the pathogen life cycle, as well as the efficiency and durability of pyramiding strategies using QTL which appear to act on the same stage of the pathogen cycle. Electronic supplementary material The online version of this article (doi:10.1186/s12870-016-0822-4) contains supplementary material, which is available to authorized users.

International audience; In recent years, a growing number of studies have focused on the potential interest of urban green areas for supporting biodiversity. Private gardens, urban parks or green roofs may support relatively high densities of diverse wild bees. Knowledge is lacking regarding bee assemblages in Paris, the French capital, and one of the most densely populated part of France. In this context, we here provide a first assessment of the taxonomic and functional composition of bee assemblages in three urban parks in downtown Paris. Bees were sampled with a set of three coloured pan traps per park. Fifteen 24-hour sessions were performed from April to July 2011. We captured 425 specimens from 44 species representing five families and 11 genera. The assemblage was dominated by Halictidae (15 species representing 70.1% of total abundance), especially the eusocial species Lasioglossum morio that made 25.2% of total abundance. From a functional point of view, there were only two species of parasitic bees that made 1.2% of total abundance. Most non-parasitic species were polylectic and below-ground nesting. This study highlights the importance of preserving and managing urban parks and other green areas to promote the conservation of wild bees and ultimately the functionality of pollination service in urban ecosystems.

International audience; The determination of the nanocarrier fate in preclinical models is required before any translation from laboratory to clinical trials. Modern fluorescent imaging techniques have gained considerable advances becoming a powerful technology for non-invasive visualization in living subjects. Among them, Forster (fluorescence) resonance energy transfer (FRET) is a particular fluorescence imaging which involves energy transfer between 2 fluorophores in a distance-dependent manner. Considering this feature, the encapsulation of an acceptor/donor pair in lipid nanoparticles (LNEs: lipid nanoemulsions, LNCs: lipid nanocapsules) allowed the carrier integrity to be tracked. Accordingly, we used this FRET technique to evaluate the behavior of LNEs, conventional LNCs and newly designed stealth LNCs. After the development through a one-step (OS) PEGylation process of these stealth LNCs (OS LNCs), in vitro guest exchange dynamics and release kinetics were evaluated for both LNC formulations. We thereafter assessed in vivo biodistribution of all types of lipid nanoparticles. Results showed enhanced stability of encapsulation in OS LNCs in comparison to conventional LNCs. Additionally, the presence of the long PEG chains on the lipid nanoparticle surface altered the biodistribution pattern. Despite different release kinetic profiles, OS LNCs and LNEs showed extended blood circulation time associated with a good structure stability over several hours after intravenous injection.

International audience; Agricultural intensification, promoted by the Common Agricultural Policy over the past decades, led to important declines of biodiversity in European farmlands. In particular, the simplification of agricultural landscapes is known to affect insect pollinators, although paradoxically the yield of numerous crops depends on their survival. The Western honey bee (Apis mellifera) is one of the most important pollinators in farmlands. However, honey bee populations suffer high mortality rates, partly related to the loss of semi-natural habitats leading to a decrease in flower diversity and to periods of food shortage. While some studies assessed the link between semi-natural habitats and honey bee mortality at the colony level, it remains poorly investigated at the individual level. Individual worker bees play a critical role in the colony given that they can adjust their life history and foraging behavior to ensure sufficient intake of food according to colony needs. Therefore, assessing whether the loss of semi-natural habitats disturbs the lifespan and foraging behavior of individual honey bees could help to understand the mechanisms underlying colony mortality. To do so, we selected 14 sites along a landscape gradient of semi-natural habitats in a farmland system, in Western France. We monitored the life history of 1427 newly emerged worker honey bees in the study sites over periods of mass-flowering (April and July) or food shortage (May and June). We used the automatic RFID device (Radio Frequency IDentification) to track their lifespan, their flight activity and their allocation to foraging in the different landscapes. We found noticeable effects of semi-natural habitats on the lifespan and foraging behavior of individual honey bees that would help to understand how individual workers adapt their own life history traits to sustain food intake in landscapes with reduced flower availability. These results will be discussed with the general objective to provide recommendations of landscape management to safeguard insect pollinators in farmlands.

National audience

Frost is a major abiotic stress of winter type faba beans (Vica faba L.) and has adverse effects on crop yield. Climate change, far from reducing the incidence of frost events, is making these phenomena more and more common, severe, and prolonged. Despite the important interaction that the environment has in the tolerance of faba bean to frost, this trait seems to have good levels of heritability. Several QTLs for frost tolerance have already been reported, however, a more robust identification is needed to more precisely identify the genomic regions involved in faba bean tolerance to sub-zero temperatures. Several pea (Pisum sativum L.) and barrel medic (Medicago truncatula L.) frost tolerance QTLs appear to be conserved between these two species, furthering the hypothesis that the genetic control of frost tolerance in legume species might be more generally conserved. In this work, the QTL mapping in two faba bean recombinant inbred line (RIL) populations connected by a common winter-type parent has led to the identification of five genomic regions involved in the control of frost tolerance on linkage groups I, III, IV, and V. Among them, a major and robust QTL of great interest for marker-assisted selection was identified on the lower part of the long-arm of LGI. The synteny between the faba bean frost tolerance QTLs and those previously identified in other legume species such as barrel medic, pea or soybean highlighted at least partial conservation of the genetic control of frost tolerance among different faba bean genetic pools and legume species. Four novel RILs showing high and stable levels of tolerance and the ability to recover from freezing temperatures by accumulating frost tolerance QTLs are now available for breeding programs.

Preventing lipid oxidation, especially with the polyunsaturated fat-based products, is a major concern in sectors as agri-food and cosmetic. Even though the efficiency of synthetic antioxidants has been recognized, both consumers and manufacturers are looking for more innovative, healthy and quality products while rejecting synthetic additives due to their concern about safety, along with their environmental impact issues. In this context, plant biomass, which have shown to be rich in compounds, have raised interest for the isolation of novel naturally occurring antioxidants. Among their myriad of molecules, bioactive peptides, which are biologically active sequence of amino acid residues of proteins, seem to be of a great interest. Therefore, the number of identified amino acids sequences of bioactive peptides from plant biomass with potential antioxidant action is progressively increasing. Thus, this review provides a description of 129 works that have been made to produce bioactive peptides (hydrolysate, fraction and/or isolate peptide) from 55 plant biomass, along with the procedure to examine their antioxidant capacity (until 2019 included). The protein name, the process, and the method to concentrate or isolate antioxidant bioactive peptides, along with their identification and/or specificity were described. Considering the complex, dynamic and multifactorial physico-chemical mechanisms of the lipid oxidation, an appropriate in-vitro methodology should be better performed to efficiently probe the antioxidant potential of bioactive peptides. Therefore, the results were discussed, and perspective for antioxidant applications of bioactive peptides from plant biomass was argued., Graphical abstract Image 1, Highlights • Exhaustive description of 129 works made to produce bioactive peptides from 55 plant biomass. • Controlled proteolysis can be used as a sustainable strategy to produce peptides. • Presentation of the important points to consider when estimating the antioxidant capacity of peptides. • Methodology should be improved to better probe the antioxidant potential of peptides.

Faba bean (Vicia faba L.) is a pulse crop of high nutritional value and high importance for sustainable agriculture and soil protection. With the objective of identifying gene-based SNPs, transcriptome sequencing was performed in order to reduce faba bean genome complexity. A set of 1,819 gene-based SNP markers polymorphic in three recombinant line populations was selected to enable the construction of a high-density consensus genetic map encompassing 1,728 markers well distributed in six linkage groups and spanning 1,547.71 cM with an average inter-marker distance of 0.89 cM. Orthology-based comparison of the faba bean consensus map with legume genome assemblies highlighted synteny patterns that partly reflected the phylogenetic relationships among species. Solid blocks of macrosynteny were observed between faba bean and the most closely-related sequenced legume species such as pea, barrel medic or chickpea. Numerous blocks could also be identified in more divergent species such as common bean or cowpea. The genetic tools developed in this work can be used in association mapping, genetic diversity, linkage disequilibrium or comparative genomics and provide a backbone for map-based cloning. This will make the identification of candidate genes of interest more efficient and will accelerate marker-assisted selection (MAS) and genomic-assisted breeding (GAB) in faba bean.

International audience; The invasive miteVarroa destructor is identified as the main biotic cause of European honey bee colony losses in many regions, leading to systematic treatments of colonies every year in order to prevent colonies from collapsing. However, some colonies have been reported to survive in the absence of treatment. The ability of honey bee colonies to survive varroa mite infestations has been associated with the development of Varroa Sensitive Hygiene (VSH) behavior. Colonies displaying VSH are able to detect the presence of varroa through the cap of developing brood cells and to remove the parasitized brood. To improve breeding programs for varroa resistance in apiculture, detailed knowledge of the mechanisms that enable bees to survive mite infestation and environmental conditions that can influence the expression and phenotyping of VSH behavior are needed. This study evaluated the influence of the genetic origin of the colony, the colony population dynamics, varroa density, and food supply on the ability of colonies to express the VSH trait. First, we found that varroa-selected colonies displayed lower varroa population growth rate. We also revealed that the genetic origin of the colonies and the month during which the test was performed had a significant impact on VSH behavior, with varroa-selected colonies showing higher VSH abilities than unselected colonies, and especially at the end of summer. Finally, we showed that sedentary varroa-selected colonies expressed higher VSH activity than colonies placed on lavender fields during active honey flow. Such findings are particularly important to standardize testing for varroa resistant colonies in different locations, a feature that is essential to ensure the success of breeding efforts.

Ce volume regroupe les textes issus du programme Casdar "Innovation et Partenariat" et "Recherche technologique" de 2016. Il a été réalisé sous l’égide du GIS Relance Agronomique.; International audience; Le projet Agro-éco-Syst’Nvisait à doter les conseillers agricoles, formateurs et enseignants de méthodes, outils et références leur permettant d’identifier et de concevoir des systèmes de culture à faibles pertes azotées vers l’environnement. A cette fin, une méthode de diagnostic des pertes d’azote vers l’eau (par lixiviation) et vers l’air (par volatilisation), utilisant l’outil Syst’N®, a été élaborée et formalisée. Elle a ensuite été utilisée pour évaluer et expliquer les performances azotées de plusieurs systèmes de culture dans des contextes pédoclimatiques variés.Quinze systèmes de culture ont ainsi été évalués et diagnostiqués. Leur analyse transversale a montré comment différentes combinaisons de pratiques dans un contexte donné conduisent à des performances variables en matière de pertes d’azote. Enfin, 21 cas-types ont été mis à disposition pour outiller les enseignants et conseillers sur le diagnostic des pertes d’azote, ressources mobilisables dans un éventail d’objectifs pédagogiques, de l’évaluation des pertes azotées à la reconception de systèmes de culture. Les systèmes simulés avec Syst’N®sont diffusés viala base de données Pertazote, mise à niveau au cours du projet

Empirical and process-based models are currently used to predict crop yield at field and regional levels. A mechanistic model named STICS (Multidisciplinary Simulator for Standard Crops) has been used to simulate soybean grain yield in several environments, including southern France. STICS simulates at a daily step the effects of climate, soil and management practices on plant growth, development and production. In spite of good performances to predict total aboveground biomass, poor results were obtained for final grain yield. In order to improve yield prediction, a surrogate model was developed from STICS dynamic simulations, feature selection techniques and regression learners. STICS was used to simulate functional variables at given growth stages and over selected phenological phases. The most representative variables were selected through feature selection techniques (filter, wrapper and embedded), and a subset of variables were used to train the regression learners Linear regression (LR), Support vector regression (SVR), Back propagation neural network (BPNN), Random forest (RF), Least Absolute Shrinkage and Selection Operator (LASSO) and M5 decision tree. The subset of variables selected by wrapper method combined with regression models SVR (R2 = 0. 7102; subset of variables = 6) and LR (R2 = 0. 6912; subset of variables = 14) provided the best results. SVR and LR models improved significantly the soybean yield predictions in southern France in comparison to STICS simulations (R2 = 0.040).

National audience; ARENA: Assessment of pest biocontrol in arable crops by naturally ocuring pest enemies: sampling network and tools to integrate this ecosystem service into integrated crop management Promoting pest biological control within agrosystems is a way to reduce the use of pesticides. The lack of quantification tools of this ecosystem service is a major obstacle to the changes in crop protection strategies. ARENA's ambition was to build methods to observe natural pest control directly on fields, provide tools to quantify and predict natural pest control potential. An important monitoring campaign of pests (slugs and aphids) and natural enemies monitoring took place in 171 fields (wheat, barley, corn, rape). On the basis of the monitoring carried out, tools for quantifying the regulation service were developed along three lines: (1) identification of agro-environmental contexts favourable to the expression of a high level of biological control, (2) development of a statistical model for the early evaluation of pest risk taking into account the level of local biological control and (3) development of an indicator of the potential for regulation by communities of beneficials in the field.; Favoriser le contrôle biologique des ravageurs dans les agrosystèmes est un levier pour réduire l’usage des produits phytosanitaires. Le manque d’outils de quantification de ce service écosystémique est un frein à sa prise en compte dans les stratégies de protection des plantes. Les objectifs du projet ARENA (Anticiper les REgulations Naturelles) étaient de proposer des méthodes d’observation des égulations naturelles en parcelles agricoles ainsi que le développement des outils de quantification et de prévisiondu potentiel de contrôle biologique. Une importante campagne de suivi de ravageurs (limaces et pucerons) et de leurs ennemis naturels a eu lieu sur 171 parcelles de grandes cultures (blé, orge, colza, maïs) pendant 3 ans (printemps et automne). Sur la base des suivis réalisés, des outils de quantification du service de régulation ont été développés suivant trois axes : (1) identification de contextes agroenvironnementaux favorables à l’expression d’un niveau élevé de contrôle biologique, (2) élaboration d’un modèle statistique pour l’évaluation précoce du risque ravageur prenant en compte le potentiel de régulation biologique et (3) élaboration d’un indicateur du potentiel de régulation par les communautés d’auxiliaires au champ.

An accurate estimation of crop yield under climate change scenarios is essential to quantify our ability to feed a growing population and develop agronomic adaptations to meet future food demand. A coordinated evaluation of yield simulations from process-based eco-physiological models for climate change impact assessment is still missing for soybean, the most widely grown grain legume and the main source of protein in our food chain. In this first soybean multi-model study, we used ten prominent models capable of simulating soybean yield under varying temperature and atmospheric CO2 concentration [CO2] to quantify the uncertainty in soybean yield simulations in response to these factors. Models were first parametrized with high quality measured data from five contrasting environments. We found considerable variability among models in simulated yield responses to increasing temperature and [CO2]. For example, under a + 3 °C temperature rise in our coolest location in Argentina, some models simulated that yield would reduce as much as 24%, while others simulated yield increases up to 29%. In our warmest location in Brazil, the models simulated a yield reduction ranging from a 38% decrease under + 3 °C temperature rise to no effect on yield. Similarly, when increasing [CO2] from 360 to 540 ppm, the models simulated a yield increase that ranged from 6% to 31%. Model calibration did not reduce variability across models but had an unexpected effect on modifying yield responses to temperature for some of the models. The high uncertainty in model responses indicates the limited applicability of individual models for climate change food projections. However, the ensemble mean of simulations across models was an effective tool to reduce the high uncertainty in soybean yield simulations associated with individual models and their parametrization. Ensemble, ensemble mean yield responses to temperature and [CO2] were similar to those reported from the literature. Our study is the first demonstration of the benefits achieved from using an ensemble of grain legume models for climate change food projections, and highlights that further soybean model development with experiments under elevated [CO2] and temperature is needed to reduce the uncertainty from the individual models. Made available in DSpace on 2022-02-25T18:00:30Z (GMT). No. of bitstreams: 1 AP-Soybean-models-2022.pdf: 10546770 bytes, checksum: 6995390284b79cf3d71d808e0570f1cc (MD5) Previous issue date: 2022

Plant breeding programs design new crop cultivars which, while developed for distinct populations of environments, are nevertheless grown over large areas during their time in the market. Over its cultivation area, the crop is exposed to highly diverse stress patterns caused by climatic uncertainty and multiple management options, which often leads to decreased expected crop performance.In this study, we aim is to assess how finer spatial management of genetic resources could reduce the yield variance explained by genotype × environment interactions in a set of cropping environments and ultimately improve the efficiency and stability of crop production. We used modeling and simulation to predict the crop performance resulting from the interaction between cultivar growth and development, climate and soil conditions, and management practices. We designed a computational experiment that evaluated the performance of a collection of commercial sunflower cultivars in a realistic population of cropping conditions in France, built from extensive agricultural surveys. Distinct farming locations sharing similar simulated abiotic stress patterns were clustered together to specify environment types. We then used optimization methods to search for cultivars × environments combinations leading to increased yield expectations.Results showed that a single cultivar choice adapted to the most frequent environment-type in the population is a robust strategy. However, the relevance of cultivar recommendations to specific locations was gradually increasing with the knowledge of pedo-climatic conditions. We argue that this approach while being operational on current genetic material could act synergistically with plant breeding as more diverse material could enable access to cultivars with distinctive traits, more adapted to specific conditions.Key messageCrop simulation helps to analyze environmental impacts on crops and provides year-independent context information. This information is of major importance when deciding which cultivar to choose at sowing time.

Ce travail d’expertise a été réalisé à la demande des Ministres en charge de l'Agriculture et la Transition Écologique et Solidaire.; La saisine vise à identifier des mesures de compensation écologique pour améliorer la protection et la conservation des insectes pollinisateurs en atténuant l’impact des épandages de produits phytosanitaires (herbicides et fongicides) pendant la floraison des cultures. L’application sur une culture attractive en floraison ou sur une zone de butinage d’un produit autorisé est réalisée dans les 2 heures qui précèdent le coucher du soleil et dans les 3 heures qui suivent le coucher du soleil. Elle reste sous réserve que ces molécules aient préalablement reçu une mention dérogatoire abeille relative à l‘arrêté du 28/11/2003, en vue de limiter les périodes de restriction d’épandage pendant lafloraison des cultures et hors présence d’abeilles. Cette période d’épandage peut être adaptée ou supprimée, notamment en vue de permettre des traitements le matin, sous réserve de la mise en place de mesures apportant des garanties équivalentes en matière d’exposition des abeilles et autres pollinisateurs. Ces mesures et les modalités de traitement associées qu’elles permettent seront définies après avis de l’Anses. Pour répondre à ces questions, un groupe d’experts a été constitué en prenant en compte les différents métiers et disciplines concernés dans la saisine : agronomie, cultures traitées, cultures et couverts mellifères, connaissance des abeilles domestiques et des pollinisateurs sauvages.

International audience; The decline of pollinators has been demonstrated scientifically and this phenomenon is widely recognized by both the general public and by stakeholders. Since pollinators face different threats that are all linked to human activities, there is a unique and unprecedented responsibility for people to conserve pollinators, requiring political action to counter the substantial worldwide risk of pollinator loss. As our perception of the situation is rapidly changing, as a result of the steady accumulation of international and national reports as well as new scientific findings, we propose here to provide an updated overview of pollinator conservation globally. We present the key messages and the proposed solutions found in international reports and assessments, how European countries have interpreted these solutions proposed in the context of existing international frameworks. Next, we analyze how scientific research is addressing the issue of pollinator conservation through different international, European and national programs. The analysis of the keywords used in published scientific articles also allows us to characterize how the scientific community has engaged with this issue over time. Finally, we focus on how France and Belgium have reacted to the observed decline of pollinators, and examine their national interpretations, conservation actions and research contributions.

International audience; Farmers' use of fungicides and insecticides constitutes a major threat to biodiversity that is also endangering agriculture itself. Landscapes could be designed to take advantage of the dependencies of pests, pathogens and their natural enemies on elements of the landscape. Yet the complexity of the interactions makes it difficult to establish general rules. In our study, we sought to characterize the impact of the landscape on pest and pathogen prevalence, taking into account both crop and semi-natural areas. We drew on a nine-year national survey of 30 major pests and pathogens of arable crops, distributed throughout the latitudes of metropolitan France. We performed binomial LASSO generalized linear regressions on the pest and pathogen prevalence as a function of the landscape composition in a total of 39 880 field x year x pest observation series. We observed a strong disequilibrium between the number of pests or pathogens favored (15) and disadvantaged (2) by the area of their host crop in the landscape during the previous growing season. The impact of the host crop area during the ongoing growing season was different on pests than on pathogens: the density of most pathogens increased (11 of 17, and no decreases) while the density of a small majority of pests decreased (7 of 13, and four increases). We also found that woodlands, scrublands, hedgerows and grasslands did not have a consistent effect on the studied spectrum of pests and pathogens. Although overall the estimated effect of the landscape is small compared to the effect of the climate, a territorial coordination that generally favors crop diversity but excludes a crop at risk in a given year might prove useful in reducing pesticide use. Short abstract We sought to identify general rules characterizing the impact of the landscape on the prevalence of pests and pathogens of arable crops. We showed that the host crop area is consistently correlated with increased pressure of the pests and pathogens the following growing season. Correlations of pests and pathogens with host crop areas in the same year or with semi-natural components of the landscape (grasslands, hedgerows and forests) are less consistent and depend on the functional traits of the organisms involved.

Honey bee subspecies originate from specific geographic areas in Africa, Europe and the Middle East. The interest of beekeepers in specific phenotypes has led them to import subspecies to regions outside of their original range. The resulting admixture complicates population genetics analyses and population stratification can be a major problem for association studies. As a typical example, the case of the French population is studied here. We sequenced 870 haploid drones for SNP detection and identified nine genetic backgrounds in 629 samples. Five correspond to subspecies, two to isolated populations and two to human-mediated population management. We also highlight several large haplotype blocks, some of which coincide with the position of centromeres. The largest is 3.6 Mb long on chromosome 11, representing 1.6 % of the genome and has two major haplotypes, corresponding to the two dominant genetic backgrounds identified.

International audience

In France, areas cultivated with cereals-legumes mixtures have been steadily increasing for 10 years, mainly in organic farming systems. For this management, little advice is available for varietal choice and there is almost no specific varietal selection. Farmers based their varietal choice on the traits of cultivars grown in sole crop, cultivars that have been selected for the dominant sole crop system. In these conditions, we can wonder if the traits observed in monoculture are predictive of those observed in mixture. Our study focused on eleven varietal traits and performances of wheat and pea, in sole crop and in mixture. Our results show that only half of the traits measured in sole crop are predictive of the traits in mixture and that the other traits such as yield cannot be predicted correctly by the values in sole crop. Varietal advice for mixtures cannot therefore be based only on the known cultivars traits grown in sole crop. Specific assessments must then be carried out in mixture in order to 1) specify the varietal key traits necessary for the success of a mixture, according to the objectives targeted by the farmer, and 2) to develop, in the future, selection programs specific to mixtures.

International audience; The French government has supported as part of its "Investments for the Future" program a 9-year research project, PeaMUST, devoted to pea and to a lesser extent, faba bean improvement. Focusing on the main causes of yield irregularity that limit pea and faba bean cultivation, an integrated approach, including molecular exploitation of the pea genome sequence, was applied to identify and incorporate favorable alleles and allele combinations in prebreeding material.

In many cultivated crops, sources of resistance to diseases are sparse and rely on introgression from wild relatives. Agricultural crops often are allopolyploids resulting from interspecific crosses between related species, which are sources of diversity for resistance genes. This is the case for Brassica napus (oilseed rape, canola), an interspecific hybrid between Brassica rapa (turnip) and Brassica oleracea (cabbage). B. napus has a narrow genetic basis and few effective resistance genes against stem canker (blackleg) disease, caused by the fungus Leptosphaeria maculans, are currently available. B. rapa diversity has proven to be a valuable source of resistance (Rlm, LepR) genes, while B. oleracea genotypes were mostly considered susceptible. Here we identified a new resistance source in B. oleracea genotypes from America, potentially effective against French L. maculans isolates under both controlled and field conditions. Genetic analysis of fungal avirulence and subsequent cloning and validation identified a new avirulence gene termed AvrLm14 and suggested a typical gene‐for‐gene interaction between AvrLm14 and the postulated Rlm14 gene. AvrLm14 shares all the usual characteristics of L. maculans avirulence genes: it is hosted in a genomic region enriched in transposable elements and heterochromatin marks H3K9me3, its expression is repressed during vegetative growth but shows a strong overexpression 5–9 days following cotyledon infection, and it encodes a small secreted protein enriched in cysteine residues with few matches in databases. Similar to the previously cloned AvrLm10‐A, AvrLm14 contributes to reduce lesion size on susceptible cotyledons, pointing to a complex interplay between effectors promoting or reducing lesion development., Cloning of avirulence gene AvrLm14 in Leptosphaeria maculans allowed us to identify the first resistance gene to the fungus in Brassica oleracea; therefore B. oleracea diversity may be exploited to find novel resistance to the disease.

OBJECTIVES: The direct assessment of ileal samples of amino acid (AA) digestibility is invasive in humans. A less invasive but indirect method, namely « dual tracer » was recently developed. It relies on the plasma isotopic enrichment ratio of two labeled protein, a reference protein or alternately AAs labeled with (13)C and the test protein labeled with (15)N. This recent method has not yet been challenged against direct measurement of ileal digestibility. METHODS: Seven healthy volunteers were intubated with naso-ileal tube. Every 30min for 4h, they ingested sunflower biscuits containing a total of 25g of (15)N intrinsically labeled sunflower protein isolate. They also ingested 60g chocolate containing a total of 400mg of a mix of (13)C algal individual AAs. Ileal contents were collected continuously for 8h following the first meal and plasma was sampled every 30min for 4h and hourly between 4 and 8h. (15)N and (13)C indispensable amino acid (IAA) ileal digestibility were determined by measuring (15)N and (13)C enrichment in AAs by GC-C-IRMS and AA content by UHPLC in ileal effluent. Plasma and meal (15)N and (13)C IAA enrichment were measured by GC-C-IRMS. Isotopic (15)N/(13)C ratio were determined using area under the curve value for each isotope. RESULTS: Using direct ileal sampling, average IAA ileal digestibility was: (i) 88.5 ± 5.0% for sunflower isolate ((15)N) with values ranged from 85.8 ± 5.1% for threonine to 91.1 ± 5.8% for methionine, and (ii) 97.6 ± 1.7% for free AAs (13C) with values ranged from 95.9 ± 2.3% for lysine to 98.8 ± 0.8% for phenylalanine. With the “dual tracer” method, digestibility of isoleucine, leucine, threonine and valine was significantly lower than with ileal determination (from 7.9% for threonine to 24.3% for leucine), Methionine and phenylalanine values were aberrant (over 100%) For lysine, the difference between the two methods was not statistically different (4.7%, p = 0.49). CONCLUSIONS: With our methodological conditions, the “dual tracer” method provides physiological values for most IAA except methionine and phenylalanine. However, values were low compared to ileal digestibility (about 10%) and interindividual variability was high. This less invasive method is promising but requires methodological improvements. FUNDING SOURCES: French Research National Agency (ANR), financial support of SOFIPROTEOL under the FASO Project PRODIAL.

International audience

International audience

Early Access; International audience; The control of stem canker disease of Brassica napus (rapeseed), caused by the fungus Leptosphaeria maculans is largely based on plant genetic resistance: single-gene specific resistance (Rlm genes) or quantitative, polygenic, adult-stage resistance. Our working hypothesis was that quantitative resistance partly obeys the gene-for-gene model, with resistance genes "recognizing" fungal effectors expressed during late systemic colonization. Five LmSTEE (stem-expressed effector) genes were selected and placed under the control of the AvrLm4-7 promoter, an effector gene highly expressed at the cotyledon stage of infection, for miniaturized cotyledon inoculation test screening of a gene pool of 204 rapeseed genotypes. We identified a rapeseed genotype, 'Yudal', expressing hypersensitive response to LmSTEE98. The LmSTEE98-RlmSTEE98 interaction was further validated by inactivation of the LmSTEE98 gene with a CRISPR-Cas9 approach. Isolates with mutated versions of LmSTEE98 induced more severe stem symptoms than the wild-type isolate in 'Yudal'. This single-gene resistance was mapped in a 0.6 cM interval of the 'Darmor_bzh' x 'Yudal' genetic map. One typical gene-for-gene interaction contributes partly to quantitative resistance when L. maculans colonizes the stems of rapeseed. With numerous other effectors specific to stem colonization, our study provides a new route for resistance gene discovery, elucidation of quantitative resistance mechanisms, and selection for durable resistance.This article is protected by copyright. All rights reserved.

Soybean (Glycine max (L.) Merr.) may contribute to the agro-ecological transition of cropping systems in Europe, but its productivity is severely affected by summer drought. New drought-avoidance cropping strategies, such as early sowing, require cultivars with high early plant growth under suboptimal conditions. This study aims at phenotyping early-stage root and shoot traits of 10 cultivars commonly grown in Europe. Cultivars were grown in minirhizotrons under two soil moisture status in controlled conditions. Root and shoot traits were evaluated at 10 days after sowing. Field early growth of two cultivars was also analyzed under early and conventional sowing dates. A significant intraspecific variability (p &lt, 0.05) was found for most investigated shoot and root morpho-physiological traits regardless of the soil moisture status under controlled conditions. However, no significant difference among cultivars (p &gt, 0.05) was found in terms of root architectural traits that were mainly affected by water stress. Total root length was positively correlated with shoot length and shoot dry matter (p &lt, 0.05). Under field conditions, the differences between cultivars were expressed by the canopy cover at emergence, which determines the subsequent canopy cover dynamics. The significant early growth difference among cultivars was not related to the maturity group. Cultivars characterized by high root depth and length, high root density and narrow root angle could be considered as good candidates to cope with water stress via better soil exploration. New agronomic strategies mobilizing the diversity of cultivars could thus be tested to improve soybean water use efficiency in response to climate change.

International audience

International audience; The growing gap between new evidence of pesticide toxicity in honeybees and conventional toxicological assays recommended by regulatory test guidelines emphasizes the need to complement current lethal endpoints with sublethal endpoints. In this context, behavioral and reproductive performances have received growing interest since the 2000s, likely due to their ecological relevance and/or the emergence of new technologies.We review the biological interests and methodological measurements of these predominantly studied endpoints and discuss their possible use in the pesticide risk assessment procedure based on their standardization level, simplicity and ecological relevance. It appears that homing flights and reproduction have great potential for pesticide risk assessment, mainly due to their ecological relevance. If exploratory research studies in ecotoxicology have paved the way toward a better understanding of pesticide toxicity in honeybees, the next objective will then be to translate the most relevant behavioral and reproductive endpoints into regulatory test methods. This will require more comparative studies and improving their ecological relevance. This latter goal may be facilitated by the use of population dynamics models for scaling up the consequences of adverse behavioral and reproductive effects from individuals to colonies.

International audience; A major path helping agriculture achieve the dual challenges of production and environmental preservation, consists of transitioning from the current, external input-based, conventional farming systems to a biodiversity-based agricultural system that rely more on ecosystem services. One lever of this transition consists of diversifying agri-food systems using practices such as rotation extension, intercropping (IC), multiple cropping or multi-services cover crops (MSCC) implementation. Here, we investigated to what extent the combination of diversification practices could contribute to the enhancement of the sustainability of current conventional cropping systems through an ex ante evaluation.We compared the sustainability performances of five diversified (DIV) cropping systems from five major arable crop production regions of France to their local less diversified reference (REF) systems by calculating various criteria and implementing a multi-criteria decision aid model. 76 criteria assessing the three dimensions of sustainability were calculated (10, 17 and 49 criteria for the economic, social and environmental dimensions respectively).Our analysis showed that the combination of diversification practices could improve the environmental performances while maintaining a priori economic and social performances at satisfactory levels according to the local expert working group. The DIV systems always had lower greenhouse gas (GHG) emissions compared to their REF systems and often improved air and water quality and above- and belowground biodiversity. However, diversification may also cause drawbacks for some indicators, as negative impacts were observed from, gross margin, NO3 lixiviation, NH3 volatilization or pesticide use, in some cases. Our analysis also suggested that the effect of a combination of diversification practices on an indicator can be either positive or negative according to the pedo-climatic context, the level of performance of the reference and compromises in the management of diversification practices in response to local objectives of performance.

Among the different agronomic levers mobilised in organic farming (OF), the choice of variety is animportant factor in the design of arable farming systems. The ECoVAB project examined how to describeand evaluate a variety suitable for use in organic farming. The results confirm that the evaluation ofspecific traits is expected. This concerns especially the ability to compete with weeds (or companion cropfor intercropping), useful for all species, of interest beyond OF for agro-ecological transition. The workhas also shown that there is a continuum of varietal assessment between organic and conventionalfarming (CF), which varies according to the species, the criteria considered, the genotypes assessed andthe test conditions (intercropping, level of use of inputs, varied pedoclimates). It is therefore not necessaryto duplicate the networks in OF and CF, but rather to make them work together, with modalities in bothmanagement. Beyond the trials to be fostered, it appears that coordination between actors in the seedand development sectors is essential to optimise the orientation of varietal assessment, the disseminationof references and the production of high-quality seeds.; Parmi les différents leviers agronomiques mobilisés en agriculture biologique (AB), l’entrée variétale est un facteur important dans la conception des systèmes de grandes cultures. Le projet ECoVAB s’est interrogé sur comment décrire et évaluer une variété adaptée à une utilisation en AB. Les résultats confirment que l’évaluation de caractères spécifiques est attendue pour les variétés destinées à l’AB. Il s’agit en particulier de la compétitivité vis-à-vis des adventices (ou d’une plante compagne en cas d’association de cultures), pour toutes les espèces, d’intérêt au-delà de l’AB dans le cadre de la transition agroécologique. Les travaux ont montré par ailleurs qu’il existe un continuum de l’évaluation variétaleentre agricultures biologiques (AB) et agricultures conventionnelles (AC), variable selon les espèces, les critères considérés, les génotypes testés et les conditions d’essais (cultures associées, niveau d’utilisation d’intrants, pédoclimats variés). Aussi, il n’est pas nécessaire de doubler les réseaux en AB et en AC, mais plutôt les faire fonctionner ensemble, avec des modalités en AB et en AC, chacun pouvant mobiliser des résultats issus de l’autre. Au-delà des essais à développer, il apparait que la coordination entre acteurs des filières des semences et du développement est essentielle pour optimiser l’orientation de l’évaluation variétale, la diffusion des références et la production de semences de qualité

International audience; Ozone can react with fatty species such as vegetable oils to form oxidized compounds with interesting antibacterial activity. The iodine and peroxide indexes of these ozonated products are two crucial antibacterial characteristics. Currently, these two parameters are determined by chemical methods, which is disadvantageous because it requires long handling time, sample destruction and the use of toxic products. Spectroscopic analyses coupled with chemometric evaluations have already shown their usefulness for characterizing virgin oils via rapid, chemical-free methods. In addition, infrared spectroscopy is widely used to characterize ozonated compounds. The present study evaluates the possibility of coupling infrared spectroscopy with chemical analyses of ozonated compounds. We subjected 187 fat samples of varying compositions to different ozonation conditions to determine their chemical parameters. We analyzed the samples by infrared spectroscopy and modeled the results by combining chemical data with spectral analysis. The model results are quantified by the coefficient of determination R-2, the root-mean-square error, and the residual predictive deviation (RPD). The model produces RPDs greater than 3.5 for the mid-infrared spectral range, which means that they may be used to estimate indexes. In addition, with RPDs between 2 and 3, partial least squares near-infrared models demonstrate a capacity for rough screening of ozonated fats.

International audience; Le soja (Glycine max (L.) Merr.) possède de nombreux atouts pour contribuer à la transition agroécologique des systèmes de culture en Europe, cependant sa production est fortement impactée par la sécheresse estivale. Les caractéristiques du système racinaire, y compris en phase précoce, apparaissent essentielles pour augmenter et stabiliser le rendement sous climat actuel et futur (Battisti et al., 2017). Cette étude vise à phénotyper les traits racinaires pour une gamme de variétés de référence au sein d’un continuum phénotypage-modélisation-conception de nouveaux idéotypes (Schoving et al., 2020).

International audience; The autonomy for Protein-Rich resources of poultry feed in France is around 40%, due in particular to massive imports of soybean meals, which are economically and nutritionally competitive. The study ofnew French Protein-Rich Feedstuffs (FPRF) within the framework of VOCALIM has shown that technological processes make it possible to better exploit fiber-rich resources (rapeseed and sunflower meals), without affecting the performance or health of the animals. The genetic selection of animals could be a lever to further improve the valuation of these resources. Simulations up to 2023 showed a gain of 17 protein autonomy points in broilers production and a reduction in food costs of 2.8% thanks to these FPRF. Their use allows, according to the scenarios studied, to gain in protein efficiency and to reduce overall environmental impacts.; L’autonomie protéique de l’alimentation des volailles est en France d’environ 40%, en raison notamment d’importations massives de tourteau de soja, très concurrentiel sur le plan économique et nutritionnel. L’étude de nouvelles Matières Premières Riches en Protéines françaises (MPRP) dans le cadre du projet VOCALIM a permis de montrer que des procédés technologiques permettent de mieux valoriser des ressources riches en fibres (tourteaux de colza et tournesol), sans altérer les performances ou la santé des animaux. La sélection génétique des animaux pourrait être un levier pour encore améliorer la valorisation de ces ressources. Des simulations à l’horizon 2023 montrent un gain de 17 points d’autonomie protéique dans la filière poulet de chair et une réduction du coût alimentaire de 2,8% grâce à ces MPRP. Leur utilisation permet, selon les scénarios étudiés, de gagner en efficience protéique et de réduire globalement tous les impacts environnementaux.

• Crop diversification is a dynamic pathway towards sustainable agrifood systems. • Technological and institutional barriers restrict uptake of crop diversification. • More coordination and cooperation among agrifood system stakeholders is required. • The European Crop Diversification Cluster calls for multiactor networks. European cropping systems are often characterized by short rotations or even monocropping, leading to environmental issues such as soil degradation, water eutrophication, and air pollution including greenhouse gas emissions, that contribute to climate change and biodiversity loss. The use of diversification practices (i.e., intercropping, multiple cropping including cover cropping and rotation extension), may help enhance agrobiodiversity and deliver ecosystem services while developing new value chains. Despite its benefits, crop diversification is hindered by various technical, organizational, and institutional barriers along value chains (input industries, farms, trading and processing industries, retailers, and consumers) and within sociotechnical systems (policy, research, education, regulation and advisory). Six EU-funded research projects have joined forces to boost crop diversification by creating the European Crop Diversification Cluster (CDC). This Cluster aggregates research, innovation, commercial and citizen-focused partnerships to identify and remove barriers across the agrifood system and thus enables the uptake of diversification measures by all European value-chain stakeholders. The CDC will produce a typology of barriers, develop tools to accompany actors in their transition, harmonize the use of multicriteria assessment indicators, prepare policy recommendations and pave the way for a long-term network on crop diversification.

International audience; Invasive species events related to globalization are increasing, resulting in parasitic outbreaks. Understanding of host defense mechanisms is needed to predict and mitigate against the consequences of parasite invasion. Using the honey bee Apis mellifera and the mite Varroa destructor, as a host–parasite model, we provide a comprehensive study of a mechanism of parasite detection that triggers a behavioral defense associated with social immunity. Six Varroa-parasitization-specific (VPS) compounds are identified that trigger Varroa-sensitive hygiene (VSH, bees’ key defense against Varroa sp.), enable the selective recognition of a parasitized brood and induce responses that mimic intrinsic VSH activity in bee colonies. We also show that individuals engaged in VSH exhibit a unique ability to discriminate VPS compounds from healthy brood signals. These findings enhance our understanding of a critical mechanism of host defense against parasites, and have the potential to apply the integration of pest management in the beekeeping sector.

International audience

International audience; Food legumes are crucial for all agriculture-related societal challenges, including climate change mitigation, agrobiodiversity conservation, sustainable agriculture, food security and human health. The transition to plant-based diets, largely based on food legumes, could present major opportunities for adaptation and mitigation, generating significant co-benefits for human health. The characterization, maintenance and exploitation of food-legume genetic resources, to date largely unexploited, form the core development of both sustainable agriculture and a healthy food system. INCREASE will implement, on chickpea (Cicer arietinum), common bean (Phaseolus vulgaris), lentil (Lens culinaris) and lupin (Lupinus albus and L. mutabilis), a new approach to conserve, manage and characterize genetic resources. Intelligent Collections, consisting of nested core collections composed of single-seed descent-purified accessions (i.e., inbred lines), will be developed, exploiting germplasm available both from genebanks and on-farm and subjected to different levels of genotypic and phenotypic characterization. Phenotyping and gene discovery activities will meet, via a participatory approach, the needs of various actors, including breeders, scientists, farmers and agri-food and non-food industries, exploiting also the power of massive metabolomics and transcriptomics and of artificial intelligence and smart tools. Moreover, INCREASE will test, with a citizen science experiment, an innovative system of conservation and use of genetic resources based on a decentralized approach for data management and dynamic conservation. By promoting the use of food legumes, improving their quality, adaptation and yield and boosting the competitiveness of the agriculture and food sector, the INCREASE strategy will have a major impact on economy and society and represents a case study of integrative and participatory approaches towards conservation and exploitation of crop genetic resources.

International audience; Maintaining seed yield under low N inputs is a major issue for breeding, which requires thoroughly exploiting the genetic diversity of processes related to Nitrogen Use Efficiency (NUE). However, dynamic analysis of processes underlying genotypic variations in NUE in response to N availability from sowing to harvest are scarce, particularly at the whole-plant scale. This study aimed to dynamically decipher the contributions of Nitrogen Uptake Efficiency (NUpE) and Nitrogen Utilization Efficiency (NUtE) to NUE and to identify traits underlying NUpE genetic variability throughout the growth cycle of rapeseed. Three experiments were conducted under field-like conditions to evaluate seven genotypes under two N conditions. We developed NUE_DM (ratio of total plant biomass to the amount of N available) as a new proxy of NUE at harvest, valid to discriminate genotypes from the end of inflorescence emergence, and N conditions as early as the beginning of stem elongation. During autumn growth, NUpE explained up to 100% of variations in NUE_DM, validating the major role of NUpE in NUE shaping. During this period, under low N conditions, up to 53% of the plant nitrogen was absorbed and NUpE genetic variability resulted not from differences in Specific N Uptake but in fine-root growth. NUtE mainly contributed to NUE_DM genotypic variation during the reproductive phase under high-N conditions, but NUpE contribution still accounted for 50–75% after flowering. Our study highlights for the first time NUpE and fine-root growth as important processes to optimize NUE, which opens new prospects for breeding.

International audience; The Syppre action (ARVALIS, ITB, Terres Inovia) aims to support the development of innovativecropping systems that meet a triple performance objective: economic, environmental and social. For the"experimentation" component of the action, several ex ante evaluations of cropping systems have beencarried out, using tools adapted to each stage. Within the framework of the ANR CoSAC, a newevaluation method has been developed based on the DEXiPM® model, to support the development ofthe systems being tested. Links have been created between this model from the Pure project and theSYSTERRE® and FLORSYS tools for weed indicators. The article shows the interest of mobilizing exante evaluation in experimentation for a multi-criteria vision of the cropping systems studied. It highlightsthe interest of cross-referencing several tools and models whose choice depends on the degree ofmaturity of the trials and the sustainability criteria to be reinforced.; L’action Syppre ‘construire ensemble les systèmes de culture de demain’ (ARVALIS, ITB, Terres Inovia)a pour objectif d’accompagner la mise au point de systèmes de grande culture innovants répondant àun objectif de triple performance : économique, environnementale et sociale. Pour le volet« expérimentation » de l’action, plusieurs évaluations ex ante des systèmes de culture ont été réaliséesen amont du test terrain, mobilisant une gamme restreinte d‘outils adaptés à chaque étape –SYSTERRE®, AMG et OdERA. Dans le cadre de l’ANR CoSAC, une nouvelle méthode d’évaluation aété mise au point – DEXiPM®-Syppre, permettant d’accompagner la mise au point des systèmes encours d’essai. Des liens ont été créés entre DEXiPM®, modèle issu du projet européen Pure, l’outilSYSTERRE® et le modèle FLORSYS pour les indicateurs relatifs aux adventices. L’article montrel’intérêt de mobiliser l’évaluation ex ante en expérimentation pour une vision multicritère des systèmesde culture étudiés. Il illustre l’avantage de croiser plusieurs outils et modèles dont le choix dépend dudegré de maturité des essais et des critères de durabilité à renforcer.

Forecasting sunflower grain yield a few weeks before crop harvesting is of strategic interest for cooperatives that collect and store grains. With such information, they can optimize their logistics and thus reduce the financial and environmental costs of grain storage. To provide these predictions, data assimilation approaches involving the crop model SUNFLO are used. The methods are based on the re-estimation of soil conditions and on the sequential update of crop model states using an ensemble Kalman filter. They combine the simulation of the crop model and time series of leaf area index (LAI) derived from remote sensors and extracted over 281 fields near Toulouse, France. A sensitivity analysis is used to identify the most relevant model inputs to consider into the data assimilation process. Results show that data assimilation leads to statistically significant better predictions than the simulation alone (from an RMSE of 9.88 q·ha−1 to an RMSE 7.49 q·ha−1). Significant improvement is achieved by relying on smoothed LAI rather than raw LAI. Nevertheless, there is still an over estimation of the grain yield that can be partially explained by the limiting factors observed on the fields and the forecast yield still need improvements to meet the required applications’ accuracy.