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Most European vineyards are managed under rainfed conditions, where seasonal water deficit has become increasingly important. The flowering-veraison phenophase represents an important period for vine response to water stress, which is seldomly thoroughly evaluated. Therefore, we aim to quantify the flowering-veraison water stress levels using Crop Water Stress Indicator (CWSI) over 1986–2015 for important European wine regions and to assess the respective potential Yield Lose Rate (YLR). Additionally, we also investigate whether an advanced flowering-veraison phase may help to alleviate the water stress with improved yield. A process-based grapevine model STICS is employed, which has been extensively calibrated for flowering and veraison stages using observed data at 38 locations with 10 different grapevine varieties. Subsequently, the model is being implemented at the regional level, considering site-specific calibration results and gridded climate and soil datasets. The findings suggest wine regions with stronger flowering-veraison CWSI 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. An advanced flowering-veraison phase may have benefited from cooler temperatures and a higher fraction of spring precipitation in wine regions of Italy-Portugal-Spain, resulting in alleviated CWSI and moderate reductions of YLR. For those of France-Germany-Luxembourg, this can have reduced flowering-veraison precipitation, but prevalent alleviations of YLR are also found, possibly because of shifted phase towards a cooler growing season with reduced evaporative demands. Overall, such a retrospective analysis might provide new insights towards better management of seasonal water deficit for conventionally vulnerable Mediterranean wine regions, but also relatively cooler and wetter Central European regions. Acknowledgements: This study was funded by the 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.

The mismatch between the skills that employers seek and the skills that workers possess will increase substantially as demand for technically skilled workers accelerates. Skill mismatches disproportionately affect low-income workers and those within industries where relative demand growth for technical skills is strongest. As a result, much emphasis is placed on reskilling workers to ease transitions into new careers. However, utilization of training programs may be sub-optimal if workers are uncertain about the returns to their investment in training. While the U.S. spends billions of dollars annually on reskilling programs and unemployment insurance, there are few measures of program effectiveness that workers or government can use to guide training investment and ensure valuable reskilling outcomes. We demonstrate a causal machine learning method for estimating the value-added returns to training programs in Rhode Island, where enrollment increases future quarterly earnings by $605 on average, ranging from -$1,570 to $3,470 for individual programs. In a nationwide survey (N=2,014), workers prefer information on the value-added returns to earnings following training enrollment, establishing the importance of our estimates for guiding training decisions. For every 10% increase in expected earnings, workers are 17.4% more likely to express interest in training. State and local governments can provide this preferred information on value-added returns using our method and existing administrative data.

Key Insights●The COVID-19 public health emergency caused widespread economic shutdown. The resulting surge in unemployment and Unemployment Insurance benefits claims threatened to overwhelm the legacy systems state workforce agencies rely on to collect, process, and pay claims.●In the State of Rhode Island, we developed a scalable cloud solution to collect Pandemic Unemployment Assistance claims robustly and securely. These claims are part of a new program created under the CARES Act that extended Unemployment Insurance benefits to independent contractors and gig-economy workers not covered by traditional Unemployment Insurance programs.●Our new system was developed, tested, and deployed within ten days following the passage of the CARES Act, making Rhode Island the first state in the country to collect, validate, and pay Pandemic Unemployment Assistance claims. A cloud-enhanced interactive voice response system was deployed a week later to handle the corresponding surge in weekly certifications for continuing unemployment benefits. ●Cloud solutions can augment legacy systems by offloading processes that are more efficiently handled in modern scalable systems, reserving the limited resources of legacy systems for what they were originally designed for. This agile use of combined technologies allowed Rhode Island to deliver timely Pandemic Unemployment Assistance benefits with an estimated cost savings of $502 thousand (representing a 411% return on investment).

International audience; Increasing temperatures due to climate change are leading to advances in grapevine phenology and sugar accumulation in grape berries. This study aims to (i) determine if a temperature-based model can predict the time to target sugar concentrations from 170 to 220 g/L for Vitis vinifera L., (ii) use the best model to characterise the time to the specified target sugar concentrations for a wide range of cultivars with statistical evaluation of each cultivar's parameterisation, and (iii) establish cultivar classifications based on these thermal times to the specified target sugar concentrations.The Day of the Year (DOY) to reach the specified target sugar concentrations (170, 180, 190, 200, 210 and 220 g/L) was determined from time series of sugar concentrations collected from research institutes, extension services and private companies. Models were fitted for the species Vitis vinifera L. The two best-fit models for the DOY to reach the target sugar concentrations were selected using the Akaike Criterion (AIC) (evaluates model complexity and goodness of fit within one criterion) and assessed for model efficiency (EF) and error of prediction (RMSE, root means squared error) followed by a sensitivity analysis and model validation. The models were then parameterised for individual cultivars.The best model across all target sugar concentrations was the non-linear best Sigmoid model "best SIG"’ model (parameters: start date (t0) = 86, d =−0.1294, e = 14.87). The best linear (Growing Degree Days) model was also selected which represents the model that required the least parameters and therefore the simplest in application for winegrowers. This model was termed the “Grapevine Sugar Ripeness” model (GSR) (parameters: base temperature (Tb) = 0 °C, start date (t0) = 91 or 1 April, Northern Hemisphere). Both models performed better than the Winkler and Huglin growing degree day models.Sixty-five cultivars were classified for the thermal time to one or more of the six sugar targets using these two models. Fifty percent of all combinations of cultivar and time to target sugar concentrations had EF values greater than 0.5 and RMSE values less than seven days. Confidence intervals were calculated for cultivars where there was sufficient data for the thermal time to target sugar concentrations. The classifications generated from both models provides the opportunity to implement either model to support cultivar choice in response to concerns of climate change and may provide cultivar solutions to issues of harvesting grapes at high sugar concentrations with resultant higher alcohol wines.

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.

Grape bunch rot caused by Botrytis cinerea is one of the major fungal diseases of grapevine (Vitis vinifera L.) worldwide. Besides crop cultural measures, botryticides are used on a regular basis for controlling bunch rot. To investigate the impact of (i) the time of application and (ii) the meteorological conditions on the efficacy of a single botryticide treatment per year (active ingredient: fenhexamid), field trials were conducted over a six year period (2011–2016) on the cultivars Riesling and Pinot gris. The median levels of efficacy compared to the untreated control at 100 days after growth stage BBCH 68 were 6.7%, 23.1%, 34.8%, 25.6%, 16.0%, 34.5% or 9.0% for Riesling and 13.9%, 16.5%, 23.7%, 9.8%, 6.6%, 9.3% or 14.1% for Pinot gris for applications at 0, 2, 4, 6, 8, 10 or 12 weeks after BBCH 68, respectively. Generally, the levels of efficacy as well as the delays of the epidemics caused by the fenhexamid treatment (i) were lower than those attainable by cultural measures and (ii) decreased with increasing temporal distance between BBCH 68 and the date of assessment as well as with the level of disease severity. Results indicate that in Riesling, fenhexamid treatments before bunch closure and shortly after veraison were most effective, whereas this was the case for Pinot gris only around bunch closure. The rather low overall efficacies suggest that a limited number of targeted botryticide applications may represent a facultative component in the complex bunch rot control strategy primarily based on efficient crop cultural measures. The delay of the epidemic induced by a single fenhexamid treatment was significantly affected by the annual meteorological conditions in the different stages of grape development even outside the application period suggesting that plant physiological factors also contribute to the overall effect.

Aims: The present analyses aimed at evaluating the performance of two models for estimating the overall effect of combining two or more measures (leaf removal, cluster division, late shoot topping, botryticide application, bioregulator application) for controlling grape bunch rot based on the efficacy of the individual measures.Methods and results: Field trials with the white Vitis vinifera cultivars Pinot gris and Riesling on the efficacy of three bunch rot control measures applied either alone or in combination were analyzed. Bunch rot disease severities prior to harvest were assessed and efficacies were calculated for each treatment. Observed efficacies of single measures were used to estimate the overall efficacies of all possible measure combinations. Calculated efficacies matched observed efficacies more accurately when assuming multiplicative interaction among the individual measures (R2 = 0.8574, p < 0.0001; average absolute deviation: 7.9%) than in case of assuming additive effects (R2 = 0.8280; average absolute deviation: 14.7%).Conclusions: The multiplicative approach assumes that each additional measure is affecting (in case of efficient measures: reducing) the disease severity level as the result of the additional treatments rather than compared to the disease severity level in the untreated control.Significance and impact of the study: The high goodness of fit as well as the observed low deviations between the estimated and the observed efficacies suggest that the multiplicative approach is appropriate for estimating the efficacy of combined viticultural measures in a complex practical bunch rot control strategy assembled of different modules.

International audience; AbstractThe drosophilid fly Drosophila suzukii is an invasive pest that has recently started threatening fruit production in Europe. In contrast to many other fruit flies, D. suzukii is able to lay eggs in ripening and mature fruits where larvae develop, rendering fruits unmarketable. This preference for ripening fruit requires pest control shortly before harvest, implying a high risk of residues on the fruit if synthetic insecticides are used. As the current management practices largely rely on chemical control, the need for alternative solutions has emerged. Here, we review the studies published up to now on the efficacy of natural compounds against D. suzukii. Several natural compounds were identified that act as repellents, contact or ingestion toxicants, fumigants, ovicides or oviposition deterrents. The most promising compounds of each group were (i) essential oils (EOs) such as the EO of thyme or its major ingredient thymol which repelled flies from fresh fruits for at least 24 h; (ii) Leptospermum ericoides and L. scoparium EOs, which expressed contact toxicity at a LD50

Aim: Grape (Vitis vinifera L.) phenology is mainly temperature-driven. Consequently, the shift in thermal conditions due to climate change is supposed to have a distinct influence on grape phenology, grape maturity and wine typicity. This study aims to investigate (i) the future phenological development, as well as (ii) the consequences on the temperature conditions in specific phenophases under the conditions of the Luxembourg grapegrowing region.Methods and Results: A budburst model and a phenological model were combined with an ensemble of ten regional climate change projections for Luxembourg. Analyses comparing four 30-year time spans (reference period: 1971-2000; present: 2001-2030; near future: 2031-2060; far future: 2061-2090) demonstrated that each of the 27 phenological stages according to BBCH code is projected to be reached significantly earlier than in the reference period. According to these projections, the length of phenophases at the early stages is not affected, whereas the ripening period length is significantly shortened. The air temperature increase in the ripening period (far future compared to reference period: + 4.6 °C to + 5.3 °C) is projected to be markedly higher than in the annual averages (+ 2.6 °C).Conclusions: Since (i) air temperatures are generally projected to increase in the future and (ii) the ripening period will take place earlier (usually in the warmer parts of the season), climate change is implicating a two-fold impact on air temperature increase in the ripening period.Significance and impact of the study: This two-fold impact potentially threatens the wine typicity of the traditional grapegrowing regions and therefore calls for specific adaptation strategies.

The aim of the present investigations was to simulate the annual risk of bunch rot (Botrytis cinerea) on Vitis vinifera L. cv. Riesling grapes based on three long-term (n = 3 × 7 = 21 cases) assessment data sets originating from three Central European grape-growing regions. Periods when meteorological parameters were significantly (p

International audience; The scope of the present work was the development of an ice cream containing substantial amount of phenolic compounds by substituting sucrose by a Muscat de Hamburg grape pulp and skin matter (GPSM)-enriched bulking agent at the level of 25 to 100% w/w. Sucrose replacement by GPSM reinforced the pseudoplastic and thixotropic character of the ice cream mixes imparting weak gel-like properties (G>G). Oscillatory thermo-mechanical analysis revealed the occurrence of a -relaxation peak at -17 to -12.8 degrees C, whilst a slight depression of the freezing point was observed. The increase in GPSM solids resulted in a significant increase in the instrumental hardness and overrun of ice cream samples, whilst it enhanced their meltdown resistance. Although GPSM boosted the nutritional value and flavour profile of the ice cream, when sucrose substitution exceeded 50%, undesirable sensory characteristics, such as coarse/grainy texture, bitterness and astringency, were detected.

Black rot on grapevine is a fungal disease caused by Phyllosticta ampelicida (syn. Guignardia bidwellii) affecting grape leaves as well as clusters. A novel black rot decision support system termed VitiMeteo Black rot was assembled based on existing sub-models and incorporated into the established VitiMeteo forecast and decision support platform. Based on local weather data and a 5-day weather forecast, VitiMeteo Black rot simulates the relative susceptibility of grape clusters, the occurrence and severity of infection events as well as the duration of incubation periods. Data sets obtained in extended international (14 case studies; eight monitoring locations; 11 cultivars; seven countries in Europe and North America) field monitoring campaigns in 2012 and 2013 were used to evaluate the model predictions of newly expressed symptoms on leaves. In the case of the Vitis vinifera cultivars, on average 26.3 disease assessments took place per season. On average, 9.9 predictions were classified as true positive, 8.0 as true negative, 5.2 as false positive and 3.2 as false negative. Model precision, sensitivity and accuracy were on average 64, 77 and 67 %. Potential reasons for false positive and false negative predictions are discussed. VitiMeteo Black rot is freely available for several locations in Germany, Luxembourg and Austria on the internet via the VitiMeteo platform and might be expanded to other regions in the future.

Field trials investigating the impact of removing flower debris (necrotic flower caps, filaments, anthers, aborted unfertilized ovaries, and aborted berries), which usually remain partly attached to grape clusters after bloom, on the epidemic of grape bunch rot caused by Botrytis cinerea were conducted in the white grapevine (Vitis vinifera L.) cv. Pinot gris (four experiments) and cv. Riesling (two experiments) in Luxembourg in the period of 2011 to 2014. Grape clusters remained untreated (control), or (i) flower debris was removed from the clusters (brush), or (ii) the clusters were treated with a botryticide (active ingredient fenhexamid; botryticide), or (iii) the clusters were brushed with a brush soaked in a botryticide suspension (botryticide-soaked brush) (all three treatments conducted at growth stage BBCH 73). On average of all six trials, bunch rot epidemics (day of the year reaching 5% disease severity) were significantly (p

Aims: The present investigation in a Luxembourgish vineyard aimed at evaluating the potential of multispectral, multi-angular UAS (unmanned aerial system) imagery to separate four soil management strategies, to predict physiological variables (chlorophyll, nitrogen, yield etc.) and to follow seasonal changes in grapevine physiology in relation to soil management.Methods and results: Multi-angular (nadir and 45° off-nadir) multispectral imageries (530-900 nm) were taken in the years 2011 and 2012. Image grey values and reflectance-derived vegetation indices were computed and canopy and vigour properties were monitored in the field. All four soil management strategies could be significantly discriminated (box-plots, linear discriminant analysis) and vegetation properties estimated (linear regression) in 2011. For 2012, global models predicted chlorophyll contents and nitrogen balance index values with a R²cv of 0.65 and 0.76, respectively.Conclusions: Soil management strategies strongly affect plant vigour and reflectance. Differences were best detectable by oblique visible/near-infrared (Vis/nIR) UAS data of illuminated canopies.Significance and impact of the study: UAS imaging is a flexible tool for applications in precision viticulture., info:eu-repo/semantics/published

Background Though the Expanded Disability Status Scale (EDSS) is commonly used to assess disability level in relapsing-remitting multiple sclerosis (RRMS), the criteria defining disability progression are used for patients with a wide range of baseline levels of disability in relatively short-term trials. As a result, not all EDSS changes carry the same weight in terms of future disability, and treatment benefits such as decreased risk of reaching particular disability milestones may not be reliably captured. The objectives of this analysis are to assess the probability of confirmed disability worsening to specific EDSS milestones (i.e., EDSS scores ≥3.0, ≥4.0, or ≥6.0) at 288 weeks in the Tysabri Observational Program (TOP) and to examine the impact of relapses occurring during natalizumab therapy in TOP patients who had received natalizumab for ≥24 months. Methods TOP is an ongoing, open-label, observational, prospective study of patients with RRMS in clinical practice. Enrolled patients were naive to natalizumab at treatment initiation or had received ≤3 doses at the time of enrollment. Intravenous natalizumab (300 mg) infusions were given every 4 weeks, and the EDSS was assessed at baseline and every 24 weeks during treatment. Results Of the 4161 patients enrolled in TOP with follow-up of at least 24 months, 3253 patients with available baseline EDSS scores had continued natalizumab treatment and 908 had discontinued (5.4% due to a reported lack of efficacy and 16.4% for other reasons) at the 24-month time point. Those who discontinued due to lack of efficacy had higher baseline EDSS scores (median 4.5 vs. 3.5), higher on-treatment relapse rates (0.82 vs. 0.23), and higher cumulative probabilities of EDSS worsening (16% vs. 9%) at 24 months than those completing therapy. Among 24-month completers, after approximately 5.5 years of natalizumab treatment, the cumulative probabilities of confirmed EDSS worsening by 1.0 and 2.0 points were 18.5% and 7.9%, respectively (24-week confirmation), and 13.5% and 5.3%, respectively (48-week confirmation). The risks of 24- and 48-week confirmed EDSS worsening were significantly higher in patients with on-treatment relapses than in those without relapses. An analysis of time to specific EDSS milestones showed that the probabilities of 48-week confirmed transition from EDSS scores of 0.0–2.0 to ≥3.0, 2.0–3.0 to ≥4.0, and 4.0–5.0 to ≥6.0 at week 288 in TOP were 11.1%, 11.8%, and 9.5%, respectively, with lower probabilities observed among patients without on-treatment relapses (8.1%, 8.4%, and 5.7%, respectively). Conclusions In TOP patients with a median (range) baseline EDSS score of 3.5 (0.0–9.5) who completed 24 months of natalizumab treatment, the rate of 48-week confirmed disability worsening events was below 15%; after approximately 5.5 years of natalizumab treatment, 86.5% and 94.7% of patients did not have EDSS score increases of ≥1.0 or ≥2.0 points, respectively. The presence of relapses was associated with higher rates of overall disability worsening. These results were confirmed by assessing transition to EDSS milestones. Lower rates of overall 48-week confirmed EDSS worsening and of transitioning from EDSS score 4.0–5.0 to ≥6.0 in the absence of relapses suggest that relapses remain a significant driver of disability worsening and that on-treatment relapses in natalizumab-treated patients are of prognostic importance.

Field trials investigating the impact of the timing of first shoot topping in a vertical shoot positioning (VSP) trellis system on (i) the cluster morphology, (ii) the canopy structure in the cluster-zone, and (iii) the progress of the bunch rot disease severity, were conducted in two white Vitis vinifera (Pinot gris, Riesling) cultivars in the years 2012 and 2013 in Luxembourg. The first shoot topping was carried out at seven different times from one week prior to beginning of flowering (BBCH 57) to four weeks after the end of flowering (BBCH 75–79) at approximately weekly intervals. Late first shoot topping reduced cluster compactness, delayed bunch rot epidemics, and thereby prolonged the potential ripening period compared to the standard treatment, in which the first shoot topping was performed one week postbloom. First shoot topping four weeks postbloom delayed the moment when 5% disease severity was reached up to eleven days and increased total soluble solids by 0.77 to 2.24 Brix compared to the standard treatment, with no significant impact on yield. Postponing the first shoot topping to the latest technically possible moment is recommended to improve grape architecture and health as well as to optimize grape maturity and potential wine quality under cool climate conditions. Late first shoot topping can be implemented in bunch rot control strategies without imposing additional costs and might support the reduction of pesticide use.

Phyllosticta ampelicida (teleomorph: Guignardia bidwellii) is the fungal plant pathogen that causes black rot on grapevine. It is able to infect all green, expanding grape tissues. Black rot poses a threat to both yield and wine quality; a severe attack can virtually cause a complete crop loss. The fungus is native to North America, and was spread to Europe at the end of the 19th century. With the beginning of the 21st century, an increasing importance of the disease was observed in several European winegrowing regions. Successful black rot control strategies combine sanitary measures, cultural techniques, growing cultivars with reduced susceptibility and the use of effective fungicides. Berries are most susceptible to infections between flowering and bunch closure and consequently, fungicide applications against black rot need to focus on this period. In this paper, forecast models and decision support systems that help to achieve satisfactory control with a minimum of fungicide input are presented. Black rot in grapevine was reported to be well controlled in field experiments by a broad range of fungicide classes including quinone outside inhibitors (98 ± 3% efficacy), demethylation inhibitors (98 ± 3% efficacy) and dithiocarbamates (92 ± 7% efficacy). Average efficacies of other fungicide classes tested so far ranged from 32 to 69%; meta data on the efficacy of fungicides in numerous field trials are given. At present, black rot causes major problems primarily if vineyard management and fungicide use were reduced or abandoned. Organically managed vineyards are highly affected. Hence, site and cultivar selection as well as cultural measures are of the highest importance especially in organic viticulture. Recent studies showed that some strains formerly classified as G. bidwellii in fact belong to a distinct species (P. parthenocissi). Black rot pathogens produce some phytotoxic secondary metabolites, such as phenguignardic acid, guignardic acid, alaguignardic acid and the guignardianones A, E and F, which could stimulate the development of new herbicides of natural origin.

Background and Aims Late frosts are a significant risk to grape production in frost-prone viticultural regions. Increasing air temperature because of climate change is likely to advance grape budburst and last frost events in spring. So far, it is unclear whether one trend will be more pronounced than the other, and hence, whether the risk of late frost damage will increase or decrease. The aim of this work was to investigate the future frost risk in the Luxembourgish winegrowing region by assessing the effect of simulated future climate conditions on the timing of budburst and last frost date. Methods and Results Late frost risk was assessed by combining: (i) a phenological model for budburst of the grapevine (DORMPHOT); and (ii) ensemble-based projections of future air temperature. Analyses indicated that increasing spring temperature will advance the timing of budburst and the date of the last frost. This advancement, however, will be more pronounced for last frost events than for budburst. Conclusions Modelled projections showed that the frequency of spring frost damage in the Luxembourgish winegrowing region will decrease, without completely excluding them for the near (2021–2050) or the far future (2069–2098). Significance of the Study The application of a combination of a phenological model for grape budburst and ensemble-based projections of future air temperature enables the assessment of the future late frost risk in a frost-prone viticulture region.

Common cumulative degree day models used to forecast grape growth stages often are only of local validity, restricted to a limited number of phenological stages, or do not take into consideration that the forcing effect of temperature is limited at higher temperatures. A new model was developed to simulate all 26 phenological stages (according to the BBCH scheme; Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) of Vitis vinifera L. Muller-Thurgau between budburst and harvest. Sixty time series of grape phenology from four European countries were used to set up and validate the model. Three cumulative degree day models (starting with budburst: BBCH 09) with one, two, or three optimized temperature threshold values were compared. The incorporation of an upper threshold temperature, above which a further increase of the temperature will not accelerate plant development, and of a heat threshold, above which a further increase of the temperature leads to a development deceleration, significantly improved the accuracy of the model compared to previous cumulative degree day approaches. The threshold triplet 5oC, 20oC, and 22oC for lower (base), upper, and heat threshold temperature, respectively, allowed the most precise forecast. In 70.5 or 95.8% of the cases, phenological stages were correctly predicted in 3 or 7 days (assuming daily mean temperatures of 20oC), respectively, around the predicted cumulative degree day. The model can be used for a range of applications in viticultural research and practical viticulture and could further be parameterized for other varieties.

Manual horizontal cluster division may constitute an efficient tool to optimize wine composition. To test this hypothesis and to determine the optimal timing of this viticultural practice, the impact of cluster division on cluster morphology, bunch rot disease severity, and harvest parameters such as yield and total soluble solids was examined on the white Vitis vinifera L. cultivars Pinot gris and Riesling in the Luxembourgish winegrowing region in 2010 and 2011. Treatments were applied at five different times between prebloom (BBCH 57) and veraison (BBCH 81). In both varieties, all postbloom cluster division treatments were able to loosen the cluster structure and reduce the bunch rot disease severity. The later cluster division took place, the more pronounced were the effects on cluster structure. The density index was a suitable measure of the cluster structure and the predisposition to bunch rot infestation. Cluster division resulted in yield reductions (up to 30%), which increased with time after flowering. Postbloom cluster division may help to optimize wine quality by improving grape maturity due to crop load reduction, reducing fungal contamination, and improving grape composition through the possibility of elongating the ripening period. Postbloom horizontal cluster division can be recommended as an efficient crop cultural tool for premium wine production under cool-climate conditions.

The duration of the incubation period of Guignardia bidwellii on leaves and clusters of Vitis vinifera strongly correlates to temperature. To describe this relationship mathematically, a new, cumulative degreeday- based model was developed. According to this model, first symptoms on leaves appear after reaching a threshold of 175 cumulative degree-days (calculated as the sum of average daily temperatures between 6 and 24°C starting on the day after the infection). On clusters, the duration of the incubation period is additionally affected by their respective developmental stages. For ‘Riesling’, the duration of the incubation period on clusters corresponds to the duration on leaves until reaching the phenological stage “berries beginning to touch“ but extends continuously with ongoing phenological development. Therefore, a correction factor recognizing cluster phenology was derived to calculate the cumulative degree-day thresholds for the occurrence of first symptoms on clusters after reaching “majority of berries touching”. Hence, this present model allows the estimation of fungal development and forecasts the appearance of new symptoms on leaves as well as on clusters, enabling growers to more precisely schedule curative as well as protective fungicide applications against grape black rot.

In the years 2006–2008, clusters of Vitis vinifera (cv. Riesling) were inoculated with a conidia suspension of Guignardia bidwellii, the causal agent of grape black rot, at weekly intervals from one week before until eight weeks after bloom. Berries’ susceptibility turned out to be strongly linked to the speed of the phenological development in the respective season. In view of this, a degree day-based model simulating the relative susceptibility as a function of the phenological development was established. Infections on inflorescences were already possible prior to bloom. The period of highest susceptibility for direct infection on berries lasted from fruit set to the beginning of bunch closure. Successful infections took place until the end of bunch closure. Ontogenic resistance occurred clearly before veraison. Consequently, control measures should focus on the period between directly prior to bloom and bunch closure. Thus, the time span of black rot control coincides with the period in which vineyards need to be protected against the two major grape pathogens, Erysiphe necator and Plasmopara viticola. Applications of fungicides aimed at powdery and downy mildew control, also effective against G. bidwellii (e.g. strobilurins, triazoles and dithiocarbamates), offer a simultaneous control strategy for these three fungal diseases.

Strobilurin or triazole type fungicides have proven to be very effective in strategies to control grape black rot (causal agent: Guignardia bidwellii) due to their combined protective and curative activities. However, differences in their long-lasting protective capacity or in the limitation of the time frame for curative treatments have not yet been clearly described regarding this pathogen. To address these issues, trials with artificial inoculation were conducted using one representative of each group, pyraclostrobin and myclobutanil on leaves of potted vines as well as on berries of field grown vines. It could be demonstrated that pyraclostrobin possesses excellent pre-infection as well as post-infection activities on both, leaves and berries. Post-bloom, pyraclostrobin was able to completely inhibit infections on berries up to three weeks after application. Full curative control of developing black rot infections was achieved for up to 85% of the total incubation period. Myclobutanil turned out to be of limited protective activity. If applied the day prior to inoculation, the efficacy level reached around 90% but decreased continuously with increasing temporal distance between application and inoculation. However, curative applications of myclobutanil in the first half of the incubation period completely prevented symptom development on leaves as well as on berries. Due to their combined reach-back and forward activity to control black rot, both, pyraclostrobin as well as myclobutanil can be recommended in practical viticulture, especially in the most susceptible period between flowering and berries beginning to touch. Pyraclostrobin offers an exceptional protective and long-lasting curative potential, whereas myclobutanil is most effective in post-infection use.

INTRODUCTION – Common limits for phenotyping are costs in terms of equipment, specialized researchers, and time. Moreover, phenotyping requires specific methods in relation to the studied traits, and each method is generally designed to highlight very specific characteristics of the singular trait. Thus, the obtained results are not easily comparable between different institutions. However the data sharing is clearly the most powerful approach to limit the costs and efforts optimizing the obtained results in term of number of studied accessions. It should be stressed that funds are another great limit in research, especially in East countries, where the most interesting cultivar variability is preserved. 28 AIMS AND SCOPES – The main purpose of this work is the establishment of a phenotyping network able to produce comparable data among the Pan-European grapevine collections. MATERIALS AND METHODS – Two protocols were proposed: one for phenology and, the other, for enocarpological traits. Data were recorded in two consecutive vintages: 2012 and 2013. Concerning phenology, the extended BBCH scale (universal and flexible) was adapted to our objects by moving it into a chrono- phenological scale. Then, a cubic curve was selected for modelling the phenological courses. Thus, computing for each accession specific coefficients, it was possible to obtain the relative phenograms. Considering the different site climatic conditions, it was possible to spatialize the results, obtaining reference phenological maps. Concerning eno- carpological traits, the attention was focused on characteristics with a clear impact on the production quality, such as berry morphology (weight, diameters, number of seeds …) and composition (sugar, titratable acidity, anthocyanin and phenolic contents …). The protocol was organized to concatenate the data acquisition, with the objective to generate new derived variables. The methods were selected to be easily reproduced in all the involved collections, without the necessity of expensive facilities. RESULTS AND DISCUSSIONS – The first year of dataset was used to evaluate the methods. Two publications are already available confirming the protocols quality. Concerning phenology, both the variability between accessions grown into the same collection and the phenological shifts between the reference varieties cultivated in different areas were highlighted by the protocol. Matching climatic and phenological information of reference cultivars, phenophases maps were obtained. The performances obtained by the eno-carpological protocol were satisfactory both in a global point of view and in a singular collection evaluation. The project obtained an impressive participation, considering the volunteer contribution without any material funding to cover the work costs. Twenty-four institutions collaborate to the data collection. 1724 accessions were evaluated: 931 (583 in 2012 and 348 in 2013) for phenology and 793 (424 in 2012 and 369 in 2013) for eno-carpological descriptions. CONCLUSIONS AND POSSIBLE APPLICATIONS – The protocol sharing allows the data comparison among different grapevine collections. The possible future application for this dataset could be related to scientific studies of genetic associations. Moreover, the improved knowledge of minor and neglected cultivars could have a direct impact on the industrial production, giving information concerning new varieties for future introduction in viticultural areas.

Phenguignardic acid was recently described as a phytotoxic secondary metabolite from submerged cultures of the grape black rot fungus Guignardia bidwellii. Since the production rate of this natural product in submerged culture is very low, fermentation optimisation was carried out. The optimisation of cultivation conditions led to the identification of seven secondary metabolites, structurally related to guignardic acid, a known secondary metabolite from Guignardia species containing a dioxolanone moiety. All metabolites presented here have not been described to date and are presumably biosynthesised via deamination products of amino acids, such as phenylalanine, valine, tyrosine, and alanine. Four of the seven compounds showed phytotoxic activity. Based on the structures determined by NMR spectroscopy a preliminary structure activity relationship indicated a free carboxyl group as presumably required for the phytotoxic activity.

Bioactivity-guided isolation led to the identification of phenguignardic acid (2), a new phytotoxic secondary metabolite from submerged cultures of grape black rot fungus, Guignardia bidwellii. The compound is structurally related to guignardic acid (1), a dioxolanone moiety-containing metabolite isolated previously from Guignardia species. However, in contrast to guignardic acid, which is presumably synthesized from deamination products of valine and phenylalanine, the biochemical precursor for the biosynthesis of the new phytotoxin appears to be exclusively phenylalanine. Guignardic acid was also found in extracts of cultures from Guignardia bidwellii. The phytotoxic activities of both compounds were assessed in plant assays using either detached vine leaves or intact plants. Antimicrobial and cytotoxic activities of phenguignardic acid were determined.

Dense grape clusters have a high predisposition to bunch rot. An elongation of cluster stems could result in a loosening of the cluster structure. To achieve such an elongation, gibberellic acid (GA3; 10 ppm) was applied to Sauvignon blanc either when three, five, seven, nine, 11 or 13 leaves were unfolded or at full bloom in the 2010 season. In the present season, all applications led to stem elongation, a reduction of cluster compactness as well as a reduction of bunch rot severity. The density index proved to be an efficient tool to describe the predisposition of grape clusters to bunch rot. Best success was achieved if the application took place when seven leaves were unfolded. In the subsequent season (2011; the year following the year of application), the number of inflorescences per shoot, the length of the clusters, as well as the yield were considerably reduced, especially in the treatments with promising positive effects on the cluster structure and disease severity. Hence, the present study shows the loosening potential as well as the risk of pre-bloom gibberellic acid applications. Due to the observed negative resultant effects, the pre-bloom application of GA3 at the present concentration (10 ppm) cannot yet be recommended for practical use in Sauvignon blanc.

In the framework of the COST Action FA1003 – ‘GRAPENET: East-West Collaboration for Grapevine Diversity Exploration and Mobilization of Adaptive Traits for Breeding’ – common phenotyping methods have been proposed to characterize germplasm accessions. The protocols aimed at the description of traits of interest for the cultivars exploitation. In particular, phenological and eno- carpological methods were selected. This paper will focus on the phenological records. The extended BBCH scale was selected and adapted to our scope. Methodological details, including agrometeorological data process are presented together with an overview of the first year results. Phenograms were obtained for each observed accession. Replications among the collections and in different years will be necessary to better define the cultivars characteristics. In 2012, the phenological protocol was applied by 20 institutions spread in 16 countries (Azerbaijan, Chech Republic, Croatia, Cyprus, Georgia, Germany, Greece, Hungary, Italy, Latvia, Luxembourg, Moldova, Portugal, Spain, Switzerland, Ukraine). 562 accessions were monitored. The large application of the protocol underlines the determination to collaborate among the European research institutions involved in grapevine germplasm evaluation.

Present investigations aimed at developing a unified cumulative degree day based model approach allowing for (i) a precise simulation of grapevine phenological development of a broad range of cultivars and (ii) a classification of the cultivar specific relative precocity of different cultivars at different stages of grape development. Based on a long-term (7-year) data set of high-resolution phenological observations for 11 cool climate cultivars originating from Remich/Luxembourg, the unified phenological model (UniPhen) was developed using a cumulative degree day approach with three temperature thresholds (lower threshold: 10 °C; upper threshold: 20 °C; heat threshold: 30 °C). The average normalized standard deviation of UniPhen over all stages and cultivars was 5.26 corresponding to 5.26 days at 15 °C. In the cross-validated model, on average 53% of the observations were located in a range of ± 3 days and 82% in a range of ±7 days (assuming daily mean temperatures of 15 °C) around the predicted date. The sequence of the cultivar-specific relative precocity was not stable over the different stages of phenological development. The model approach (i) enables a precise simulation of all 31 BBCH stages between beginning of the bud swell (01) and berries being ripe for harvest (89) for 11 cultivars grown in the climatic conditions of the Luxembourgish grapegrowing region and (ii) is open to being extended to other grape cultivars and re-calibrated under deviant climatic conditions. Due to their instability, a classification of the cultivars’ relative precocity is only reasonable if it relates to a specific phenological stage. UniPhen represents a precise high-resolution phenological model approach and might be applied as a bioclimatic indicator describing the suitability of a location/region for the cultivation of specific cultivars.