134 research outputs found

    Assessing the grapevine crop water stress indicator over the flowering-veraison phase and the potential yield lose rate in important European wine regions

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    In Europe, most of vineyards are managed under rainfed conditions, where water deficit has become increasingly an issue. The flowering-veraison phenophase represents an important period for vine response to water stress, which is known to depend on variety characteristics, soil and climate conditions. In this paper, we have carried out a retrospective analysis for important European wine regions over 1986-2015, with objectives to assess the mean Crop Water Stress Indicator (CWSI) during flowering-veraison phase, and potential Yield Lose Rate (YLR) due to seasonal cumulative water stress. Moreover, we also investigate if advanced flowering-veraison phase can lead to alleviated CWSI under recent-past conditions, thus contributing to reduced YLR. A process-based grapevine model is employed, which has been extensively calibrated for simulating both flowering and veraison stages using location-specific observations representing 10 different varieties. Subsequently, grid-based modelling is implemented with gridded climate and soil datasets and calibrated phenology parameters. The findings suggest wine regions with higher mean CWSI of flowering-veraison phase tend to have higher potential YLR. However, contrasting patterns are found between wine regions in France-Germany-Luxembourg and Italy Portugal-Spain. The former tends to have slight-to-moderate drought conditions (CWSI0.5) and substantial YLR (>40%). Wine regions prone to a high drought risk (CWSI>0.75) are also identified, which are concentrated in southern Mediterranean Europe. Advanced flowering-veraison phase over 1986-2015, could have benefited from more spring precipitation and cooler temperatures for wine regions of Italy-Portugal-Spain, leading to reduced mean CWSI and YLR. For those of France-Germany-Luxembourg, this can have reduced flowering-veraison precipitation, but prevalent reductions of YLR are also found, possibly due to shifted phase towards a cooler growing-season with reduced evaporative demands. Our study demonstrates flowering-verasion water deficit is critical for potential yield, which can have different impacts between Central and Southern European wine regions. This phase can be advanced under a warmer climate, thus having important implications for European rainfed vineyards. The overall outcome may provide new insights for appropriate viticultural management of seasonal water deficits under climate change.This study was funded by Clim4Vitis project-"Climate change impact mitigation for European viticulture: knowledge transfer for an integrated approach", funded by the European Union's Horizon 2020 Research and Innovation Programme, under grant agreement no. 810176; it was also supported by FCT-Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020. We acknowledge the data provisions from members of the PEP725 project, from IPHEN project and from the Consejo Regulador of Ribera de Duero and Rioja DOCa

    Use of a Sapindus mukorossi-extract to regulate fungal pathogens on vines – an alternative strategy for organic grape protection?

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    Ein wässriger Extrakt von Schalen der Indischen Waschnuss (Sapindus mukorossi) hat in Gewächshausversuchen an Blättern von Vitis vinifera (L.) eine gute Wirksamkeit gegenüber Guignardia bidwellii (Erreger der Schwarzfäule an Weinreben) und Plasmopara viticola (Erreger des Falschen Rebmehltaus) gezeigt. Diese Wirkung bestätigte sich bezüglich G. bidwellii grundsätzlich auch an Beeren im Freiland. Im Falle zeitnah vor der Inokulation durchgeführter Applikationen wurden hohe Wirkungsgrade im Bereich der beiden Vergleichswirkstoffe aus dem ökologischen Weinbau (Netzschwefel) bzw. integrierten Rebschutz (Metiram) erzielt (75 bis 90%). Die Wirkungsdauer ist jedoch begrenzt. Im Freilandversuch mit siebentägigem Applikationsintervall betrug der Wirkungsgrad des Waschnuss-Extraktes rund 50%. Entgegen den Ergebnissen aus dem Gewächshaus konnte ein Wirkungspotential gegenüber dem Falschen Rebmehltau im Freilandversuch – zumindest bei geringem Befallsdruck (Versuchsjahr 2008) – nicht nachgewiesen werden.In greenhouse experiments on leaves of Vitis vinifera (L.) a water-extract of shells of the Chinese Soapberry (Sapindus mukorossi) indicated an excellent efficacy against Guignardia bidwellii (causal agent of black rot) and Plasmopara viticola (causal agent of downy mildew). Regarding G. bidwellii, this effect was principally confirmed on clusters in the field. Here, when application takes place immediately prior to inoculation the observed efficiency (75 to 90%) was comparable to standard products applied in organic viticulture (Thiovit Jet®, a.i. sulphur) or integrated grape production (Polyram® WG, a.i. metiram). However, the duration of activity in the vineyard seems to be limited. In a field trial with a seven day application interval the efficacy of the water-extract of Sapindus mukorossi reached around 50%. The control of Plasmopara viticola in the field was even more difficult. Contrary to the results in the greenhouse, the potential of a water-extract of Sapindus mukorossi to control Plasmopara viticola was – at least in the growing period 2008 with prevailing low disease pressure – not evident

    A Review of the Potential Climate Change Impacts and Adaptation Options for European Viticulture

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    Viticulture and winemaking are important socioeconomic sectors in many European regions. Climate plays a vital role in the terroir of a given wine region, as it strongly controls canopy microclimate, vine growth, vine physiology, yield, and berry composition, which together determine wine attributes and typicity. New challenges are, however, predicted to arise from climate change, as grapevine cultivation is deeply dependent on weather and climate conditions. Changes in viticultural suitability over the last decades, for viticulture in general or the use of specific varieties, have already been reported for many wine regions. Despite spatially heterogeneous impacts, climate change is anticipated to exacerbate these recent trends on suitability for wine production. These shifts may reshape the geographical distribution of wine regions, while wine typicity may also be threatened in most cases. Changing climates will thereby urge for the implementation of timely, suitable, and cost-effective adaptation strategies, which should also be thoroughly planned and tuned to local conditions for an effective risk reduction. Although the potential of the different adaptation options is not yet fully investigated, deserving further research activities, their adoption will be of utmost relevance to maintain the socioeconomic and environmental sustainability of the highly valued viticulture and winemaking sector in Europe.This study was funded by Clim4Vitis project—“Climate change impact mitigation for European viticulture: knowledge transfer for an integrated approach”, funded by the European Union’s Horizon 2020 Research and Innovation Programme, under grant agreement no. 810176; it was also supported by FCT—Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020

    Phenological Model Intercomparison for Estimating Grapevine Budbreak Date (Vitis vinifera L.) in Europe

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    Budbreak date in grapevine is strictly dependent on temperature, and the correct simulation of its occurrence is of great interest since it may have major consequences on the final yield and quality. In this study, we evaluated the reliability for budbreak simulation of two modeling approaches, the chilling-forcing (CF), which describes the entire dormancy period (endo- and eco-dormancy) and the forcing approach (F), which only describes the eco-dormancy. For this, we selected six phenological models that apply CF and F in different ways, which were tested on budbreak simulation of eight grapevine varieties cultivated at different latitudes in Europe. Although none of the compared models showed a clear supremacy over the others, models based on CF showed a generally higher estimation accuracy than F where fixed starting dates were adopted. In the latter models, the accurate simulation of budbreak was dependent on the selection of the starting date for forcing accumulation that changes according to the latitude, whereas CF models were independent. Indeed, distinct thermal requirements were found for the grapevine varieties cultivated in Northern and Southern Europe. This implies the need to improve modeling of the dormancy period to avoid under- or over-estimations of budbreak date under different environmental conditions.This research was funded by the European Union’s Horizon 2020 Research and Innovation Programme, under the Clim4Vitis project: “Climate change impact mitigation for European viticulture: knowledge transfer for an integrated approach”, grant agreement no. 810176. It was also supported by FCT-Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020 and the French National Research Agency (ANR) in the frame of the Investments for the Future Program, within the cluster of excellence COTE (ANR-10-LABX-45)
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