The viticulture sector has a significant part in the French agriculture and economy. As regards the cognac, an emblematic sector, it was leader of French exports of wine and spirits industry (sales of € 2.3 billion) in 2014 for the second year in a raw. Hennessy, the world cognac sales leader in the world, exports 97% of its products. This company, present in all continents, is also historically deeply rooted in the Charente vineyards. It now has 75,000 ha of grapevines that have to produce spirits of high quality. It thus requires vigorous plants and a few non-productive grapevines. The cognac sector and, more generally the wine and spirit sector, seems to be in a favourable position but is nevertheless endangered by many threats that induce profound changes, e.g. climate change and a major plant health crisis, the epidemic of grapevine trunk diseases (GTDs) that endangers the sustainability of the vineyard. Since the ban of the use of sodium arsenite in France in 2001, the only product registered against GTDs, crop losses and uprooting of grapevines increase regularly from year to year, over the last decade. At the present time, it is estimated that around 15% of the cognac vineyard is unproductive. GTDs have a negative impact on the whole French vineyard. For instance, for 2014, losses due to GTDs are huge: 13% of French vineyard is unproductive because of GTDs, it represents a billion euros in losses. This comes quite clearly in contradiction with the viticulture sector development prospects for the next years and those of Hennessy. Driven by its international dimension and fully assuming its leadership role in the viticulture sector, Hennessy has chosen to work on GTDs with UMR SAVE and to grant this research group with an allocation of 600,000 euros. The establishment of an Industrial Chair would enhance this partnership. Research results will benefit to the cognac wine growers partners and more widely to the French and international vineyards. From a general perspective, this project is designed to limit the development of GTD by using different levers: (i) the cropping practices (e.g. pruning, grafting) that affect the development of necrosis in the wood of the grapevines, a key point to address these diseases. Determining the influence of climate on GTDs will also be investigated, i.e. through irrigation. (ii) Necrosis in grapevine wood tissues are caused by pathogenic fungi, so determining the functions of the wood microbiota will help to get markers linked to the balance break of the microbial communities. This unbalance is linked to the pathogenic process and the subsequent development of wood necrosis. Biocontrol will also be used. Some microorganisms naturally colonizing the vineyards will be used in combination to biologically protect plants against GTDs. (iii) Results from the French GTDs Observatory indicated that grapevines varieties are more or less tolerant to GTDs. So, research on plant molecular polymorphisms associated with plant tolerance or not, seems to be an interesting research topic to determine tolerance markers for breeding. These complementary points will allow getting a global, systemic view on the development of GTDs at the vineyard. Short-management solutions (e.g. pruning systems, curettage) and medium term (e.g. genetic markers of tolerant plants, healthy cropping practices and "suppressive" microflora) will be proposed at the end of this project.

This project aims to develop an innovative method of biocontrol for the protection of the vineyard against cryptogamic diseases, and therefore to accelerate our independence from chemical pesticides. The objective is to transpose to the plot the concept of disinhibition of plant defence responses (demonstrated in controlled conditions) in order to increase the efficiency of protection induced by Plant Defence Inducers (PDIs). We have demonstrated in the laboratory and confirmed under controlled conditions that the enzymes type-2 Histone DeACetylases (HD2) negatively regulate the intensity of the immune responses of plants. The proposed strategy is therefore to combine disinhibition and activation of the immune responses. A natural molecule (of bacterial origin or from green chemistry), abundant, devoid of toxicity and inexpensive, has been identified as an efficient disinhibitor (declaration of invention DI-RV-21-0138). We have demonstrated in the laboratory and in the greenhouse, on herbaceous vine cuttings, that combining the disinhibition of plant defence responses with different PDIs (different chemical natures and modes of action) makes it possible to significantly increase the level of protection induced by these PDI applied alone against Plasmopara viticola, the downy mildew agent. Two PDIs with different modes of action (elicitor and potentiator), respectively marketed and under development by Cérience, will be used in phytoprotection trials against P. viticola on the experimental plot of UMR SAVE specifically dedicated to the evaluation of biocontrol products (BC2grape) and on the network of experimental plots of Cérience. They will be applied alone or in combination with the defence responses disinhibitor. The determination of the efficiency of protection (monitoring of P. viticola development), and of the potential impact of these treatments on grapevine physiology and berry ripening will be carried out over three years. Tests will also be carried out to develop a solution allowing, from a unique application, a first action time of the disinhibitor and subsequent action time of the PDI. The “disinhibition strategy” we propose will initially be aimed at socio-economic partners who are developing PDIs-based biopesticide strategies. In the long term, the entire wine industry will be able to be offered increasingly effective biopesticide solutions, making it possible to greatly reduce the application of chemical fungicides or copper. The strategy developed in this project is in line with the objectives of the Ecophyto II+ plan to reduce the use of pharmaceutical products. It is based on the use of a natural molecule (disinhibitor), with no known toxicity and which significantly increases the activity of different PDIs. At the end of this project, we hope to be able to increase the efficiency of PDIs and generalize their use in the vineyard. This more effective biopesticide strategy at a lower cost will contribute to a more significant reduction in TFIs and will thus allow winegrowers using copper to limit/reduce inputs. This strategy is of interest both for the environmental impact (reduction of synthetic fungicides and copper) and societal (biocontrol products and application near areas occupied by the public, absence of residue). The consortium partners have established regular collaboration for several years and have acquired solid experience in the use of PDIs and/or the disinhibition strategy. Each partner has a perfect knowledge of the skills of the other two, allowing us to work efficiently. The complementary knowledge and skills of the partners will allow us to develop this project based on data obtained from the molecular level to the vine stock, from the laboratory to the cultivated plot.

Phytopathogenic fungi are among the dominant causal agents of crop diseases. In addition to direct losses related to yield reduction, some fungi produce mycotoxins harmful to humans and animals. In Europe, cereals and grapevine are the most concerned crops. The deoxynivalenol mycotoxin producer, Fusarium graminearum, and the ochratoxin A producer, Aspergillus carbonarius, are the most frequently found in cereal and grape crops, respectively. Although good cultural practices have been proposed to minimize the contamination of wheat with deoxynivalenol and of grape berries with ochratoxin, they are not sufficient to guarantee the compliance of harvests with the EU regulations. Combined with tillage, crop rotation and cultivar choice for wheat, the use of fungicide is a key factor in the integrated management strategies aiming at controlling mycotoxins. However, according to the growing commitment of European and National governments for limiting chemical inputs, biocontrol is a promising solution to be used instead of or in complement to chemical treatments. The French National Ecophyto plan claims to gradually reduce chemical treatments, hence stimulating the development and use of all novel practices including biocontrol. The future of agriculture will require the development of new environmental-friendly agronomical strategies guaranteeing the safety of food and feed. Among these strategies, the development of products issued from natural sources to protect crops against fungal pathogens and their mycotoxin production will contribute to decrease the use of chemical fungicides. In this context, the goal of StilDeTox is to characterize natural stilbenoid extracts (STEs) from vine by-products to be used in integrative fungal/mycotoxin control strategies. The project is organized in three tasks and will implement an integrated approach, from the production and screening of the STEs (task 1), the elucidation of the mechanisms of action (task 2) to the assessment of the in planta efficiency of formulated solutions and optimization of the production process (task 3). Environmental preoccupations will drive the project: identification of alternatives to chemical fungicides, zero-solvent extraction procedures, valorization of grapevine by-products. To achieve these objectives, StilDeTox associate three academic and one private partners selected for the diverse and complementary expertise and skills that they collectively bring into the project. The three academic partners are INRA, UR 1264 MycSA, which research programs focus on the understanding of the regulation of toxin biosynthesis by fungi, UR Oenology EA 4577, USC 1366 INRA, MIB which research programs target the isolation, characterization and evaluation of biological activities of phenolic compounds from grapevine/wine and, INRA, UMR 1065 SAVE specialized in developing integrated and sustainable protection strategies of the vine. The private partner is BioLaffort company which has expertise in plant product extraction and vegetal protection. The first innovation of StilDeTox lies in its guiding challenge using vine-production waste to address significant public health and economic issues. StilDeTox will develop innovative methodologies starting from the recycling of vine industry by-products using ecological technologies and ending with the proposition of biofungicide formulations. A second major innovation lies in the multidisciplinary and transdisciplinary approach that will be implemented. Basic studies and applied approaches will be combined, allowed by the complementarity of the expertise gathered in the project’s consortium.

ABSTRACT: Reduction of pesticide use in crops is now becoming an urgent concern, and implementation of biological control are issues to achieve this goal. Biological control against insect pests is now used in many crops as a control strategy replacing in most cases the use of insecticides. It can be achieved either by releasing of natural enemies, or by biodiversity conservation. Farmers are more and more aware of the important role that natural enemies may play on the control of crop pests. However, the absence of any actual quantification of the potential influence of natural enemies on grape-moths and aphids population dynamics (the most damaging pests in grape and cereal crops respectively) reduced until now the inclusion of natural enemies activity in management decisions. The present project PARADe focus on biodiversity conservation scoping on efficient parasitoids that occurs in these major crops, cereals and grapes. It involves two important INRA research units, two French Agronomy high schools (Agrocampus West and Bordeaux National School of Agricultural Sciences), two technical national structures (ARVALIS and French Vine and Vine Institute), two ‘extension services (Chambres d’Agriculture) and two important grape producer cooperatives. Originally, the two agrosystems are considered together in developing decision tools based on identical philosophy: assessing the occurrence of such parasitoids in the two crops and developing decision support tools to assist farmers in the development of agroecological pest management strategies. We thus want to predict the risk of reaching the threshold currently indicated to farmers to trigger insecticide treatment, based on the level of infestation of the plot and the rate of parasitism at the beginning of population development. These objectives will be based on the use of recently identified molecular tools able to detect with a fine accuracy, the occurrence of parasitoids in the two main pests of cereals (aphids) and grapes (grape-moths). These molecular tools will be used early in season to evaluate the damage on next insect generations and then to assist the decision ‘treating or not treating’. Non-academic and academic partners of this project will work closely to the process of model development and transfer to final users: technical papers, presentations and training sessions to growers and to cooperatives and structural adjustment of the teaching and pedagogical practices in order to integrate this innovation into academic training.

The deployment of plant genetic resistances to pathogens is essential to limit the use of pesticides in agriculture. The deployment of such varieties one by one on large surfaces leads to the adaptation of pathogen populations, making them ineffective. Mobilizing intraspecific diversity by combining different varieties would make it possible to constrain this adaptation through the existence of antagonistic host-pathogen interactions. Based on this concept, the COMBINE project aims to define new strategies for the deployment of resistance combinations in order to find the best compromise between efficiency, durability and technical- and cost-effectiveness. We propose a global multidisciplinary approach combining biology (epidemiology and evolutionary biology), modeling and socio-economics. Several pathosystems with different biological features, causing diseases on different crops (wheat, grapevine, pepper, banana, rice) will be studied via three complementary tasks. In the first task, we will study the impact on the dynamics and evolution of pathogen populations of the combination of resistances in varietal mixtures, using experimental or existing on-farm situations, in order to understand whether antagonistic interactions are at play and their impact on the evolution of pathogen populations. In the second task, we will analyze the socio-economic constraints and levers that impacts the farmers' strategies for diversification. In the third task, a generic model based on the existence of antagonistic interactions will be improved and parameterized for a diversity of pathogens, in order to simulate a wide range of strategies on several pathosystems, and to derive optimal deployment strategies of plant resistances at different spatial scales that solve the durability / efficiency / technical- and cost-effectiveness trade-off. The consortium, which has been active for a year, brings together teams at the forefront of the disciplines concerned. COMBINE will provide new insights and generic tools for the sustainable use of genetic resistances in a pesticide-free agriculture.