French Vineyards Research Articles

Flavescence Dorée-Derived Leaf Yellowing in Grapevine (Vitis vinifera L.) Is Associated to a General Repression of Isoprenoid Biosynthetic Pathways.

Flavescence dorée (FD), caused by the phytoplasma Candidatus Phytoplasma vitis, is a major threat to vineyard survival in different European grape-growing areas. It has been recorded in French vineyards since the mid-1950s, and rapidly spread to other countries. In Portugal, the phytoplasma was first detected in the DOC region of ‘Vinhos Verdes’ in 2006, and reached the central region of the country in 2009. The infection causes strong accumulation of carbohydrates and phenolics in the mesophyll cells and a simultaneous decrease of chlorophylls, events accompanied by a down regulation of genes and proteins involved in the dark and light-dependent reactions and stabilization of the photosystem II (PSII). In the present study, to better elucidate the basis of the leaf chlorosis in infected grapevine cv. Loureiro, we studied the isoprenoid transcript–metabolite correlation in leaves from healthy and FD-infected vines. Specifically, targeted metabolome revealed that twenty-one compounds (out of thirty-two), including chlorophylls, carotenoids, quinones and tocopherols, were reduced in response to FD-infection. Thereafter, and consistently with the biochemical data, qPCR analysis highlighted a severe FD-mediated repression in key genes involved in isoprenoid biosynthetic pathways. A more diverse set of changes, on the contrary, was observed in the case of ABA metabolism. Principal component analysis (PCA) of all identified metabolites clearly separated healthy from FD-infected vines, therefore confirming that the infection strongly alters the biosynthesis of grapevine isoprenoids; additionally, forty-four genes and metabolites were identified as the components mostly explaining the variance between healthy and infected samples. Finally, transcript–metabolite network correlation analyses were exploited to display the main hubs of the infection process, which highlighted a strong role of VvCHLG, VvVTE and VvZEP genes and the chlorophylls intermediates aminolevulunic acid and porphobilinogen in response to FD infection. Overall, results indicated that the FD infection impairs the synthesis of isoprenoids, through the repression of key genes involved in the biosynthesis of chlorophylls, carotenoids, quinones and tocopherols.

Spatial Patterns of Vineyard Abandonment and Related Land Use Transitions in Beaujolais (France): A Multiscale Approach

While the resilience of French vineyards is currently threatened, this paper focuses on the Beaujolais terroir, where the disappearance of vineyards has been qualitatively observed by local stakeholders. A targeted survey was led at three complementary scales. First, we provide an overview of the evolution of agricultural landscapes and practices for the whole Beaujolais area since 1990 from national statistical databases. It shows that the vineyard extent reached a maximum during the 1990s and that significant bifurcation occurred in 2000. Second, we document land use evolution in relation to vineyard abandonment at a more local scale. Three case studies (lower Ardières, Marverand, Merloux) exemplify the main local settings, and the land uses are described over time from an analysis that employed multitemporal photo interpretation. The results quantified the decrease in the vineyard surface extent since 1999: approximately 30% was lost in regular terroirs and 5% was lost in high added-value terroirs. Third, at a fine scale, we explained the precise location of the abandoned parcels regarding the site characteristics (e.g., incoming solar radiation, slope gradient, terroir quality). The results showed differences in evolution patterns between southern and northern Beaujolais. In northern Beaujolais, winegrowers tended to abandon vine parcels that were considered of lower quality; while, in southern Beaujolais, the winegrowers tended to abandon vine parcels in relation to the difficulty of maintenance (remote and steep parcels were preferentially abandoned) or in relation to suburbanization (parcels close to built-up areas were preferentially abandoned).

Integrating spatial variations in the vineyard to enhance quantitative trait locus (QTL) detection

French vineyards are often located on the least fertile lands, generally more heterogeneous than lands devoted to food crops. The detection of quantitative trait loci (QTLs) is all the more precise, as the number of genotypes studied is high, but increasing the size of experimental plots means taking the risk of exploring more spatial heterogeneity. Designing randomized blocks experiments is a classical way to overcome this difficulty. However, when several hundred genotypes are studied, this not only requires more land but is also time consuming. Another approach is to take into account the spatial heterogeneity when searching for QTLs. We performed QTL detection for variables corrected for spatial heterogeneity in the progeny of a 'Riesling' (RI) × 'Gewurztraminer' (GW) cross to evaluate the potential of such an approach. We show that mapping methods can improve QTL detection for grapevine water status (δ 13 C) and pruning weight. QTLs for vegetative indices measured with the portable fluorimeter Multiplex ® were, however, not better detected after taking into account the spatial heterogeneity. This study shows that QTL detection can be improved when correcting raw data for spatial heterogeneity.

Investigation of the sensitivity of Plasmopara viticola to amisulbrom and ametoctradin in French vineyards using bioassays and molecular tools.

Complex III inhibitors are key compounds in the control of Plasmopara viticola. They are prone to the development of resistance, as demonstrated by the emergence of resistance to quinone-outside inhibitors. By using a combination of bioassays and molecular methods, we monitored sensitivity to amisulbrom and ametoctradin in P.viticola populations in French vineyards from 2012 to 2017. We found that the alternative oxidase (AOX)-related resistance mechanism was common in French P.viticola populations. Target-site resistance to ametoctradin was first detected in 2015 and is likely caused by a single point mutation in the cytochrome b gene, leading to the S34L substitution. The role of this substitution in resistance to ametoctradin was corroborated by another study using an experimental model. A molecular biology method has been developed to detect the mutant allele. To date, the frequency of this mutation is low in French P.viticola populations and it is often co-detected with the wild-type allele. Populations of P.viticola displaying evidence of AOX-related resistance were detected for every surveyed year, and their occurrence in French vineyards seems to be increasing over time. This resistance mechanism is currently threatening the efficacy of complex III inhibitors in the field. The low frequency of the S34L allele conferring resistance to ametoctradin, and the instability of resistant phenotypes in some populations, suggest that a fitness cost may be associated with the mutation. © 2019 Society of Chemical Industry.

Relative importance of environmental factors and farming practices in shaping weed communities structure and composition in French vineyards

Understanding the relative importance of spatial, temporal variables, environmental conditions and management practices as filters for weed assemblages is essential to promote biodiversity in agrosystems. In this study, we used a unique data set covering 46 vineyard plots in France (Champagne, Beaujolais and Languedoc winegrowing areas) with 883 flora surveys performed between 2006 and 2012. The three objectives of the present study were: (1) to characterize weed communities composition and structure (richness and abundance) in vineyards from three traditional winegrowing areas in France; (2) to evaluate the relative importance of spatial, temporal variables, environmental conditions and management practices on weed species composition and structure; (3) to determine whether or not weed composition and structure are affected by the same factors. The results of the study revealed that season (including timing of management practices) was the most important filter for weed communities in vineyards, opposing in each plot a spring community and a summer-autumn community. Furthermore, spatial variations between regions (latitude), soil types (pH) and inter-annual variations (2006 to 2012) were also seen to have a strong effect on species turnover. Farming practices explained an overall low variation in composition of weed communities but some species showed a high and consistent fit to contrasting practices. For example, herbicide applications (mostly glyphosate) promoted some species such as Malva sylvestris and Sorghum halepense whereas tillage in inter-rows selected typical annual weeds such as Cerastium glomeratum and Galium aparine. Farming practices had a much higher influence on species richness and abundance with equal effect of both herbicides and soil tillage for controlling weed species richness and abundance in inter-rows, but stronger effects of herbicides were observed on species abundance in the rows. Tillage along the rows and a combination of mowing and tillage along the inter-rows were associated to the highest level of weed richness and abundance. Our study suggests that grapevine growers have a limited ability to influence species composition (mostly determined by abiotic factors) but their choice of management can modulate the level of weed richness and abundance. Our results will contribute to guide farmers towards more integrated management practices, ensuring both an optimal management of the spontaneous vegetation in vineyards and allowing this vegetation to provide various ecosystem services.

Emergence of boscalid-resistant strains of Erysiphe necator in French vineyards

The grapevine powdery mildew Erysiphe necator (E. necator) is an obligate pathogen. Powdery mildew-diseased vines show an important reduction in plant size, winter hardiness and grape yield. Even a low-level infection with powdery mildew was shown to taint wine and ultimately reduce wine quality. For many years, succinate dehydrogenase inhibitor (SDHI) fungicides, mainly the new generation active ingredients (AIs) boscalid, penthiopyrad and fluopyram, have been widely used to control powdery mildew in grapevines. The repeated use of fungicides (mainly boscalid) has resulted in the emergence of resistant microorganisms such as Botrytis cinerea (B. cinerea). However, boscalid resistance was never observed in E. necator. In this study, a large-scale survey of French grapevine field populations of E. necator revealed many field populations with low sensitivity to boscalid. Single spore strains originating from collected resistant populations showed Half maximal effective concentration (EC50) values greater than 100 mg L−1, and strains originating from boscalid sensitive populations showed EC50 values lower than 1 mg L−1. The complete nucleotide sequences of the EnSdhB succinate dehydrogenase of sensitive and resistant single spore strains revealed that H242R and H242Y substitutions in the EnSdhB succinate dehydrogenase subunit conferred E. necator resistance to boscalid. No cross-resistance of E. necator strains bearing H242R and H242Y substitutions in EnSdhB succinate dehydrogenase to fluxapyroxad and fluopyram was noticed. Therefore, our results highlight the emergence of resistance to boscalid activity in French vineyards and warrant the need of the implementation of risk assessment strategies to maintain effective grapevine protection against powdery mildew.

Landscape complexity perception and representation in a wine-growing region with the designation of origin in the Loire Valley (France): a cultural ecosystem service?

AbstractEcosystem services related to biodiversity, including cultural services, are essential for agricultural production such as viticulture. In agricultural landscapes, pesticides and mechanization threaten biodiversity, lead to landscape simplification and may reduce ecosystem services. On the other hand, consumers are more and more aware of environmental issues in food production. We investigated if landscape complexity, including soil management practices, was (i) appreciated by visitors and (ii) presented by winegrowers and tourism professionals in the French vineyards with the designation of geographical origin (DGO) ‘Coteaux du Layon’. Our goal was to determine if landscape complexity provides cultural ecosystem services such as aesthetics beneficial for the wine trade and the DGO region's attractiveness. We analyzed the iconographic content and the composition of landscape photographs on 50 websites to investigate if local winegrowers and tourism professionals associate biodiversity in the landscape and soil management practices with wine promotion. A questionnaire was realized to study the perception of local landscapes by interviewing 192 visitors of the region. The benefits of landscape complexity and soil management practices favoring biodiversity in viticulture were known and appreciated by many visitors, even if photographs of wine and traditional practices appeared to encourage wine purchasing. Local winegrowers’ representation of the DGO region only partially served these preferences; instead they mainly presented the wine-growing region by photographs focusing on wine bottles and vineyards. Consumer's preferences showed that complex landscapes could provide cultural ecosystem services that winegrowers are still less aware of. Therefore, complexity-targeted landscape planning including vegetation cover in soil management should be included in policy recommendations as agroecological measures for sustainable DGO production.

Tracking carbon footprint in French vineyards: A DEA performance assessment

Abstract In recent years, companies have become increasingly concerned about environmental performance and the impact of their activity on the environment. Although the growing interest in sustainability, life-cycle assessment and carbon footprint analysis in literature is observed, there is still a lack of studies proposing evaluation methods to assess the performance efficiency of companies under these new constraints. Our article furthers our knowledge in the field by providing an in-depth investigation of the operational performance of wine estates in the presence of composite indicators of carbon footprint. The calculated carbon footprint is related to vineyard practices with a major focus on pesticides, fertilizers and fuel use. We suggest in this article for the first time how to track the active ingredients in fertilizers and pesticides that contribute to carbon footprint. The methodology is based on an application of a classic radial model for an input-oriented minimization problem using data envelopment analysis. The proposed approach is applied to 38 wine producing companies in the Bordeaux region of France to estimate technical efficiency in the presence of carbon footprint. Research results show the percentage of carbon footprint contribution in average terms, from pesticides, fertilizers and fuel. Our results confirm that the carbon footprint effect in vineyards caused by the use of fuel is more than double the impact of pesticides and fertilizers. This strong vulnerability on fuel could do matter to factors guiding farmers' choice of vineyard practices. Additionally, clear improvement targets for the firms, which are inefficient in terms of labor force, net-fixed assets, and carbon footprint, are provided for enhancing their performance. We discuss managerial implications to be put in practice, and outline the suggestions for future studies.

The risk of tardive frost damage in French vineyards in a changing climate

Tardive frosts, i.e. frost events occurring after grapevine budburst, are a significant risk for viticultural practices, which have recently caused substantial yield losses over different winegrowing regions of France, e.g. in 2016 and 2017. So far, it is unclear whether the frequency of late frosts events is destined to increase or decrease under future climatic conditions. Here, we assess the risk of tardive frosts for the French vineyards throughout the 21st century by analyzing temperature projections from eight climate models and their statistical regional downscaling. Our approach consists in comparing the statistical occurrences of the last frost (day of the year) and the characteristic budburst date for nine grapevine varieties as simulated by three different phenological models. Climate models qualitatively agree in projecting a gradual increase in temperature all over the France, which generally produces both an earlier characteristic last frost day and an earlier characteristic budburst date. However, the latter notably depends on the specific phenological model, implying a large uncertainty in assessing the risk exposure. Overall, we identified Alsace, Burgundy and Champagne as the most vulnerable regions, where the probability of tardive frost is projected to significantly increase throughout the 21st century for two out of three phenological models. The third phenological model produces opposite results, but the comparison between simulated budburst dates and observed records over the last 60 years suggests its lower reliability. Nevertheless, for a more trustworthy risk assessment, the validity of the budburst models should be accurately tested also for warmer climate conditions, in order to narrow down the associated large uncertainty.

Strain effect on extracellular laccase activities fromBotrytis cinerea

Background and Aims Laccase enzymes produced by Botrytis cinerea are involved in the oxidation of phenolic substances during the development of grey mould, which causes significant economic losses. The aim of this work was to study the structural and activity characteristics of the laccase enzymes secreted by three B. cinerea strains that are involved in the development of grey mould. Methods and Results Laccase enzymes obtained from three B. cinerea strains [one reference strain (B05.10) and two strains obtained from two French vineyards (VA612 and RM344)] were characterised. Analysis by LC-QTOF-MS revealed that the three strains contained a mixture of Laccase-2-BcLCC2 and Laccase-3-BcLCC7. The structural characteristics of the laccases from the three strains, such as molecular weight and glycosylation degree, were identical. Nevertheless, their catalytic activities were significantly different. Conclusions Differences in catalytic activities could be due either to possible differences in the relative amount of Laccase-2-BcLCC2 and Laccase-3-BcLCC7 produced by each strain or to differences in the glycosidic fraction of the enzymes. Significance of the Study The severity of the infection caused by B. cinerea may be not only related to the infection level but also to the strain involved.

First Report of Lasiodiplodia viticola, Spencermartinsia viticola and Diplodia intermedia Associated With Vitis vinifera Grapevine Decline in French Vineyards

First Report of <i>Lasiodiplodia viticola</i>, <i>Spencermartinsia viticola</i> and <i>Diplodia intermedia</i> Associated With <i>Vitis vinifera</i> Grapevine Decline in French Vineyards

Life traits of four Botryosphaeriaceae species and molecular responses of different grapevine cultivars or hybrids

Botryosphaeriaceae is a fungal family comprising many species involved in botryosphaeria dieback, a worldwide grapevine trunk disease. Currently, the interactions between Botryosphaeriaceae species and various grapevine cultivars are poorly understood and little data is available. This study investigated various life traits of five isolates belonging to four species of Botryosphaeriaceae found in French vineyards (Diplodia mutila, Diplodia seriata, Lasiodiplodia viticola and Neofusicoccum parvum). The two species N. parvum and L. viticola exhibited the highest optimal growth temperature and the best growth rates. They were also responsible for the most extensive necrosis and cankers in three Vitis vinifera cultivars (Cabernet Sauvignon, Merlot and Ugni‐Blanc) that differed in susceptibility to botryosphaeria dieback, and in two genotypes resistant to downy and powdery mildew (RV4 and RV5). Identification of the extracellular toxins produced by isolates in culture media showed that the N. parvum isolate had a different metabolite profile from the others, producing terremutin and salicylic acid derivatives, which are known to be compounds associated with virulence. In a second step, life traits were associated with nondestructive monitoring of gene expression involved in the defence mechanisms of five grapevine cultivars and genotypes after inoculation of wood cuttings with Botryosphaeriaceae. The transcript analyses were carried out at different times and were associated with principal component analysis (PCA). Each cultivar presented a specific transcript signature and several transcripts were correlated either with the size of necrosis/cankers or with symptom reduction, thus offering useful markers for breeding or estimating the defence status of plants.

Regional-scale analysis of arbuscular mycorrhizal fungi: the case of Burgundy vineyards

&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Aim&lt;/strong&gt;: To improve knowledge of arbuscular fungal communities for a sustainable management in vineyards.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Methods and results&lt;/strong&gt;: In 16 plots across Burgundy under contrasted soil properties and agricultural practices, we assessed arbuscular mycorrhizal fungal (AMF) diversity in vine roots, using pyrosequencing of ribosomal Internal Transcribed Spacers (ITS). AMF sequences could be retrieved from all plots across Burgundy, both in organic and in conventional vineyards with high chemical inputs. Sequences from the survey were almost exclusively affiliated to molecular taxa in the Glomerales, including six “core species” found in all plots, corresponding to 77% of all sequences, suggesting a relatively low species diversity in vine roots. A large part of the molecular taxa had no close similarity to previously-reported sequences.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Conclusion&lt;/strong&gt;: AMF diversity observed in vine roots was relatively low and a significant proportion of molecular taxa shared between the sites. Nevertheless, some differences in the AMF community composition were observed between the plots.&lt;/p&gt;&lt;strong&gt;Significance and impact of the study&lt;/strong&gt;: This is the first large-scale study of AMF diversity in French vineyards using high-throughput sequencing, which will contribute to a better understanding of ecology of these fungi in vine roots, thus providing essential knowledge for future applications in sustainable agriculture in vineyards

Stealing to Survive? Crime and Income Shocks in Nineteenth Century France

Using local administrative data from 1826 to 1936, we document the evolution of crime rates in nineteenth century France and we estimate the impact of a negative income shock on crime. Our identification strategy exploits the phylloxera crisis. Between 1863 and 1890, phylloxera destroyed about 40% of French vineyards. We use the geographical variation in the timing of this shock to identify its impact on property and violent crime rates, as well as minor offences. Our estimates suggest that the phylloxera crisis caused a substantial increase in property crime rates and a significant decrease in violent crimes.

Bugs, Tariffs and Colonies: The Political Economy of the Wine Trade 186001970

The 1860–1970 period is a particularly interesting period to study wine trade because of dramatic changes in the wine markets and trade over the course of a century. The dramatic changes in trade flows were caused by both “nature” and “men”. Mediterranean wine trade represented around 90% of global wine trade and France was the world’s leading exporter. The arrival of Phylloxera devastated French vineyards and stimulated Spanish and Italian wine exports. When French wine production recovered, French winegrowers pressured their government to intervene, resulting in high tariffs on Spanish and Italian wines and Greek raisins. The protectionist trade regime contributed to the bankruptcy of Greece and to the substitution of wine trade from Spain and Italy to France’s North African colonies. When Algeria, Morocco and Tunisia became independent, France imposed high wine tariffs, effectively killing their wine exports. The decline of the wine industry in North Africa coincided with the trade and policy integration of the South European wine exporters in the EEC — the predecessor of the EU.

LLHistoire se rrppte: Why the Liberalization of the EU Vineyard Planting Rights Regime May Require Another French Revolution (And Why the US and French Constitutions May Have Looked Very Different Without Weak Planting Rights Enforcement)

In 2008, the EU voted to liberalize its system of planting rights which has strictly regulated vine plantings in the EU. However, after an intense lobbying campaign the liberalization of the planting right system was overturned in 2013 and new regulations created an even more restrictive system. European wine associations complained about the detrimental effects of the new regulations. There is a precedent in history. In 1726, the French political philosopher and landowner Montesquieu complained to the French King about the prohibition on planting new vines. Montesquieu was not successful in his demands to remove the planting rights. Old and recent history suggests that political forces against liberalization of planting rights are very strong. Only the French Revolution in 1789 led to a fundamental liberalization of planting rights. The period of the 19th century was sustained by the combination of the French Revolution’s liberal ideology, the thirst for wine of Napoleon’s armies and diseases that wiped out most of the French vineyards. That said, in the past and the present, enforcement of planting rights is a major problem. In fact, despite the official restrictions, Montesquieu managed to plant his vines, allowing him to become a successful wine producer and merchant and to travel and to spend time thinking, discussing and ultimately writing up his ideas which influenced much of the Western world’s constitutions.

First Report of Grapevine redglobe virus (GRGV) in Grapevine in France.

The isometric virus Grapevine redglobe virus (GRGV), was first described on grapevine cv. Red Globe in southern Italy in 2000 (3) and later in Greece and California. GRGV belongs to the genus Maculavirus in the family Tymoviridae. These viruses are thought to be disseminated through propagation and grafting, as no vectors or seed transmission are known to date. A partial sequence (2,006 nucleotides [nt]) encompassing the 3' end of the replicase, the coat protein, and P17 genes, was obtained in 2003 (1). GRGV infections are apparently symptomless (2). In 2014, GRGV was identified by Illumina sequencing of total RNAs extracted from a Vitis vinifera cv. Cabernet franc (CF) vine grafted onto Gravesac in a vineyard of the Bordeaux region in France. This Cabernet franc plant displayed fanleaf-like degeneration symptoms associated with Tomato black ring virus (TBRV) infection. It had been collected in 2010 and maintained since in a greenhouse. The partial contigs assembled from the Illumina reads (552 and 430 nt, both in the putative replicase gene, KM491303 and KM491304) showed 85.9 and 86.3% nt identity with the partial sequence of a GRGV Italian isolate (AF521577), respectively. Total RNA extracts from leaves of 18 plants of cv. Cabernet franc from the same plot, collected in 2014, were analyzed by RT-PCR using specific primers RG-CF-F1 (5'-GAATTCGCTGTCGGCCACTC-3') and RG-CF-R1 (5'-AGTGAGAGGAGAGATTCCATC-3') designed on the basis of the alignment of the partial sequences of GRGV-CF and the Italian isolate (AF521577). Fifteen (83%) of the plants gave strong positive amplification for GRGV. Given the mixed viral infection status of these vines, it was not possible to associate a specific symptomatology with the presence of GRGV. Two RT-PCR amplicons were directly sequenced and showed 91.5 and 91.7% identities, respectively, with the reference GRGV-CF sequence. To our knowledge, this is the first report of GRGV in France. Further studies will be necessary to determine the prevalence of GRGV in the French vineyards and varieties, including rootstocks, and its possible threat to the grapevine industry. Studies are also needed to assess the pathogenicity of GRGV. Similarly to its close relative, Grapevine fleck virus, does it induce latent or semi-latent infections in Vitis vinifera and rootstock hybrids, influencing vigor, rooting ability, and graft compatibility?

Microsatellite markers for population studies of the ascomycete Phyllosticta ampelicida , the pathogen causing grape black rot

Grape black rot, caused by the homothallic ascomycete Phyllosticta ampelicida , is a disease originating from North America and is widespread in Europe. To investigate population structure and epidemics of this pathogen, we developed 11 microsatellite markers. A multiplex PCR assay was used to amplify genomic DNA from environmental samples including mummified berries and foliar lesions, and from fungal cultures. Environmental samples were collected from five countries (Switzerland, France, Germany, Luxembourg and the USA), and consisted of 64 different genotypes. Five additional genotypes were identified from pure cultures isolated in Switzerland and Germany. The allele rarefaction approach indicated that French vineyards in the region of Bordeaux displayed the greatest mean allelic richness, probably related to the fact that France is the country where the disease was first reported outside North America, in 1885. Our results also suggest the absence of links between the species/cultivar of Vitis hosts and the infecting P. ampelicida genotypes. This is the first report of development of microsatellite markers and their deployment for population studies of P. ampelicida .

Field evaluation of an expertise-based formal decision system for fungicide management of grapevine downy and powdery mildews.

In France, viticulture accounts for 20% of the phytochemicals sprayed in agriculture, and 80% of grapevine pesticides target powdery and downy mildews. European policies promote pesticide use reduction, and new methods for low-input disease management are needed for viticulture. Here, we present the assessment, in France, of Mildium, a new decision support system for the management of grapevine mildews. A 4 year assessment trial of Mildium has been conducted in a network of 83 plots distributed across the French vineyards. In most vineyards, Mildium has proved to be successful at protecting the crop while reducing by 30-50% the number of treatments required when compared with grower practices. The design of Mildium results from the formalisation of a common management of both powdery and downy mildews and eventually leads to a significant fungicide reduction at the plot scale. It could encourage stakeholders to design customised farm-scale and low-chemical-input decision support methods.

Between the approved and the actual dose. A diagnosis of pesticide overdosing in French vineyards

In this article, we explore the factors leading winegrowers to apply pesticide doses exceeding the official recommendations. Our approach is founded on an original methodology that determines practices of overdosing by matching four databases in 2006: the Farm Accountancy Data Network (FADN); the cropping practices survey (PK) in the winegrowing sector; the e-phy database operated by the French Ministry of Agriculture and Food, which identifies authorised doses per input; and climatic data measured by the Meteo France meteorological office. Our sample, which contains 105 vineyards throughout France, reveals that 50% of these winegrowers never overdose, while 24% systematically apply excessive doses of pesticides. The latter group benefits from a comfortable financial situation, but suffers from an unfavourable climate.