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Characterisations of thirty grapevine varieties (Vitis vinifera L.) from the experimental vineyard ‘Radmilovac’ were conducted using a large number of OIV descriptors and eight highly polymorphic microsatellite loci. The ampelographic description contained 45 features. Molecular characterisation of selected microsatellite loci was performed using capillary electrophoresis fragment analysis. Dendrograms based on ampelographic and genetic data resulted in three groups of varieties. Qualitative ampelographic characteristics tended to manifest significant differences. The most common deviation among varieties within the group was in the characteristic OIV 051 (colouration of the upper side of a young leaf). Genetic characterisation of SSR markers through analyses of a large number of varieties contributes to better organisation of grapevine collections and simpler identification of varieties, as well as data exchange. When identifying the varieties, the results of the DNA analysis should be combined with the ampelographic descriptors, in order to select grapevine varieties with desirable viticultural and oenological traits. Integration of the obtained genetic data with the ampelographic data is of utmost importance for accurate identification of the varieties and offers a significant means for the preservation and use of the varieties.

The present research focused on the characterisation of climate evolution in a typical Apulian region for table grape production under the protected geographical indication, “Uva di Puglia I.G.P.”Two thirty-year time window period (TW) were analysed: 1961-1990 and 1991-2020. Georeferenced maps for both TWs were produced to delimit homogeneous zones and to evaluate the climate variability within the investigated area by means of the two bioclimatic indices, Heliothermal Index (HI) and Winkler Index (WI). Spatial analysis of HI and WI was performed using the regression-kriging (RK) interpolation method and the Digital Elevation Model/DEM (10 x 10 m) as a prediction attribute.An increase in both the minimum and maximum temperatures was observed, and locations above 300 m a.s.l. shifted from HI+1 “temperate warm” to HI+2 “warm” according to the Geoviticulture Multicriteria Climatic Classification System. WI values similarly increased between the periods 1961–1990 and 1991–2020, shifting all the sites grouped in the Elevation Classes defined as being below 300 m a.s.l. from Region IV to Region V of the Winkler Classification.According to HI and WI, presumed maturity was calculated as being reached 9 to 15 (HI) and 12 to 28 days (WI) earlier in 1991–2020 than in 1961–1990, taking into account the heat requirements of cv. Italia table grape (representative of Apulian table grape production), were set at 2200 for both indices on the basis of literature data.Moreover, three table grape vineyards, located in the three main producing provinces of Apulia (Bari, Taranto and Barletta-Andria-Trani (BAT)), were considered for future scenarios analysis on the basis of two different Representative Concentration Pathways (RCPs), 4.5 and 8.5, and classified according to the Geoviticulture Multicriteria Climatic Classification System (MCC). Future scenarios scored WI values that exceeded the threshold of 2700 in the BAT and TA provinces in the 2061–2090 time window period for RCP 8.5. In contrast, RCP 4.5 led to a mitigating effect, which was not noticeable until 2040, with a consequent reclassification of the investigated areas on the basis of HI and Cool Night Index (CI).These findings suggest that in order to prevent or overcome heat stress, it will be necessary to implement strategies, such as vineyard relocation to unexplored elevations or latitudes and/or the exploitation of new table grape varieties able to fulfill the optimal maturity parameters, even when the duration of the phenological phases is shorter.

In table grapes (cv. Thomson Seedless), the antifungal activity against Botrytis cinerea was further analysed and compared between two high potential bacterial biological control agent (BCA) strains, Bacillus velezensis BUZ-14 and B. ginsengihumi S38. Two commercial biocontrol products (BPs), served as standards of comparison, Amylo-X® and Serenade Max®, also based on Bacillus BCA strains. The main mode of action quantified for all the strains was antibiosis due to hydrosoluble and volatile metabolites and their combinations. The BUZ-14 strain was the most active BCA strain, demonstrating significant disease reduction exceeding 60 % when used in the culture form grown in 863 medium, including living cells (LCs) and cell-free supernatant (CFS). Both BPs exhibited significantly reduced efficacy of their CFS fraction (< 10 %) compared with that of the two BCA strains, confirming their high antibiosis potential. The novel methodology allowed us to demonstrate the significant effect of the BCA culture medium on volatilome (VOC) antagonist efficacy. The S38 strain achieved the highest disease reduction (90 %) owing to the greatest production of VOCs in the richest MOLP (Medium Optimum Lipopetide Production) culture medium, whereas grape juice was the least favourable medium for VOC efficacy for both bacterial strains (BUZ14 and S38). The overall poor activity of living Bacillus cells in all the BCA and BPs tested is discussed based on the low capacity of the BCA strains to grow in the berry. Then, the presence of living cells is also discussed with the possibility that these cells are not required in field applications of such BCA strains in this genus. Moreover, different environmental suboptimal conditions, including temperature (22 and 27 °C) and relative humidity (RH) (100 and 85–95 %), were tested, and BUZ-14 exhibited the highest Botrytis reduction at both temperatures and RH values. However, no significant differences were observed between temperatures or RH values for the same BCA. Further studies in vineyard conditions and applications, such as biofumigation or active packaging, will be performed to confirm the new findings reported in this investigation.

‘Xinomavro’ (the second planted red Greek variety behind ‘Agiorgitiko’) generally produces wines that are light in colour but with increased astringency, possibly related to grape flavonoid amount and composition; although irrigation is accepted as an effective means to enhance grape phenolic maturity, its role has not yet been sufficiently studied in the case of Xinomavro. This study aimed to determine the effect of post-veraison irrigation on berry anthocyanin and proanthocyanidin amount and composition, of field-grown Xinomavro vines (Vitis vinifera L.), under the typical summer conditions of Northern Greece. In a 10-year-old Xinomavro vineyard, two post-veraison watering regimes were applied—irrigation starting 20 days after veraison (mid-ripening irrigation, MRI) and irrigation starting immediately after veraison was completed (after veraison irrigation, AVI)—alongside non irrigated vines (NI), and vines irrigated continuously from berry set through harvest (continuous irrigation, CI). Proanthocyanidin composition was determined in both skins and seeds by employing phloroglucinolysis followed by HPLC-UV and MS detection (high-performance liquid chromatographic with tandem mass spectrometric and ultraviolet absorbance detection), and the anthocyanin profile was identified only in the skin extracts by HPLC-UV (high-performance liquid chromatographic with ultraviolet absorbance detection). Post-veraison irrigation increased yield parameters and reduced anthocyanin levels and the proportion of their stable forms (acylated vs. non-acylated, tri-oxygenated and methoxylated on the B-ring vs. di-oxygenated and hydroxylated), compared to NI vines; however, these effects were more pronounced in the case of early post-veraison irrigation (AVI) than late-season irrigation (MRI). Irrigation also increased the mean Degree of Polymerization (mDP) and prodelphinidin percentage of skin tannins and decreased mDP of seed tannins. In the light of the necessity to control the accelerated ripening under the increasingly hotter and drier climatic conditions, late irrigation (MRI) might provide a solution to avoid excessive sugar levels and allow a slightly higher yield without significant reductions in berry phenolic content. The results suggest that the optimisation of the timing of irrigation could provide an effective adaptation strategy to climate change in Mediterranean viticultural areas.

The aim of this study was to test the effect of pre-flowering leaf removal (PFD) on grape sanitary status, yield, source-sink balance and berry composition. A completely random block design experiment was conducted over four seasons in a commercial vineyard of the Tannat/SO4 combination located in the south of Uruguay (34° 35´30 S, 56° 15´23 O). The PFD treatment was compared with a commercial defoliation (CC) comprising partial leaf removal between the fruit set and cluster closure stages (four leaves from the first node), a traditional practice carried out by winegrowers. Both treatments received equal phytosanitary management during the study. The results were conditioned by seasonal meteorological conditions, particularly rainfall, temperature and evapotranspiration. The seasonal effect was significant for yield components, berry composition and source-sink balance. The PFD treatment resulted in the lowest yields in all four years and modified the primary and secondary composition of berries. It also showed a higher anthocyanin potential in 2016, 2017 and 2019, related to a higher percentage of exposed clusters, lower yield and/or higher leaf to fruit ratio. In 2017, environmental conditions were more favourable for the development of bunch rot, and lower values of incidence (3 %) were recorded for the PFD treatment compared to CC (22 %), due to greater exposure of bunches and less compact bunches. The PFD vines showed a steady reduction in dry matter production capacity, mainly explained by the steady reduction in yields. The Tannat variety showed a differential response to PFD depending on the weather during the growth cycle. Under humid climate conditions, pre-flowering defoliation proved to be effective for yield control, by reducing bunch rot incidence, and for improving some attributes in terms of grape composition. This work provides useful information for grape growers in humid regions on how to improve the sanitary status and quality of their production.

Starmerella bacillaris is a non-Saccharomyces yeast recently proposed for grape fermentation in association with Saccharomyces cerevisiae. Due to its high glycerol and moderate volatile acidity production this yeast can contribute to improving wine quality. Some strains have been demonstrated to exhibit antifungal activity against grey mould on grape, which is caused by Botrytis cinerea. The simultaneous presence of these traits in S. bacillaris is of great interest. Indeed, this yeast can be potentially used as a biocontrol agent in vineyards. Research on the ability of S. bacillaris to survive or, even to grow on the surface of grapes is a starting point in the evaluatation of its potential use in vineyards. The preliminary results of our study showed that when applied to the grape surface under laboratory condictions, inoculum sized S. bacillaris with antifungal activity developed and lasted for at least 6 days in high concentrations. In addition, it positively influenced the fermentation process by producing high concentrations of glycerol (average value 4.89 ± 0.47 g/L). Interestingly, a positive effect on wine quality was also observed when the inoculum size was 10 times higher or lower than the reference concentration. When sprayed on the vines in the vineyard and present on the grape skin surface after harvest, S. bacillaris cells can start alcoholic fermentation.

Pruned vine-shoots used as wine additives have proven to be a useful tool for improving and differentiating wines. This is because they accumulate substances from the plant itself, which later, as a result of the toasting process, express their greatest oenological potential. However, vine being one of the crops subject to the most phytosanitary treatments, including fungicides in particular, it can be assumed that their residues will accumulate in the vine-shoots and pass into the wine. The aim of this study was to determine the content in pruned vine-shoots of four of the main fungicides applied in the vineyard in Spain: trifloxystrobin, boscalid, kresoxim-methyl and penconazole. In order to do so, a HPLC-MS/MS method was developed, which showed high reliability given its adequate validation parameters. The method was linear for the concentration range studied, LOD was 0.003 mg/kg and LOQ was 0.01 mg/kg, which comply with the control criteria.The evolution of residues in vine-shoots complying with critical agricultural practices and good agricultural practices was monitored at 1, 3 and 6 months of storage after pruning and, in the latter case, after being subjected to a toasting process. The dissipation of all the residues was demonstrated to be affected by storage duration and toasting. It was confirmed that converting vine-shoots into oenological additives for wines will not pose a risk to the consumer if good agricultural practices are applied.

This review addresses the role of nitrogen (N) in vine balance and grape composition. It offers an integrative approach to managing grapevine N nutrition. Keeping in mind that N excess is just as detrimental to wine quality as N depletion, the control of grapevine N status, and ultimately must N composition, is critical for high-quality grape production. N fertilisation has been intensively used in the past century, despite plants absorbing only 30 to 40 % of applied N. By adapting plant material, soil management and vine balance to environmental conditions, it would be possible for grape growers to improve plant N use efficiency and minimise N input in the vineyard. Vineyard N management is a complex exercise involving a search for a balance between controlling vigour, optimising grape composition, regulating production costs and limiting pollution. The first part of this review describes grapevine N metabolism from root N uptake to vine development and grape ripening, including the formation of grape aroma compounds. The advantages and limits of methods available for measuring plant N status are addressed. The second part focuses on the parameters that influence grapevine N metabolism, distinguishing the impacts of environmental factors from those of vineyard management practices. Areas for further research are also identified.

Aim: To analyse unmanned aerial vehicle (UAV)-based imagery to assess canopy structural changes after the application of different canopy management practices in the vineyard.Methods and results: Four different canopy management practices: i–ii) leaf removal within the bunch zone (eastern side/both eastern and western sides), iii) bunch thinning and iv) shoot trimming were applied to grapevines at veraison, in a commercial Cabernet-Sauvignon vineyard in McLaren Vale, South Australia. UAV-based imagery captures were taken: i) before the canopy treatments, ii) after the treatments and iii) at harvest to assess the treatment outcomes. Canopy volume, projected canopy area and normalized difference vegetation index (NDVI) were derived from the analysis of RGB and multispectral imagery collected using the UAV. Plant area index (PAI) was calculated using the smartphone app VitiCanopy as a ground-based measurement for comparison with UAV-derived measurements. Results showed that all three types of UAV-based measurements detected changes in the canopy structure after the application of canopy management practices, except for the bunch thinning treatment. As expected, ground-based PAI was the only technique to effectively detect internal canopy structure changes caused by bunch thinning. Canopy volume and PAI were found to better detect variations in canopy structure compared to NDVI and projected canopy area. The latter were negatively affected by the interference of the trimmed shoots left on the ground.Conclusions: UAV-based tools can provide accurate assessments to some canopy management outcomes at the vineyard scale. Among different UAV-based measurements, canopy volume was more sensitive to changes in canopy structure, compared to NDVI and projected canopy area, and demonstrated a greater potential to assess the outcomes of a range of canopy management practices. Significance and impact of the study: Canopy management practices are widely applied to regulate canopy growth, improve grape quality and reduce disease pressure in the bunch zone. Being able to detect major changes in canopy structure, with some limitations when the practice affects the internal structure (i.e., bunch thinning), UAV-based imagery analysis can be used to measure the outcome of common canopy management practices and it can improve the efficiency of vineyard management.

This study aims to evaluate the interest of using an under-vine cover crop as a sustainable management tool replacing herbicides or tillage to control weeds, evaluating its effects on yield and berry parameters in a semi-arid climate. The performance of Trifolium fragiferum as an under-vine cover crop was evaluated in 2018 and 2019 in a Merlot vineyard in Traibuenas (Navarra, Spain). This trial showed that the soil under the vines was covered by 80 % of the cover crop in August 2018 and 100 % in Aug 2019, with clover (T. fragiferum) comprising around 26 % and 70 % of the cover crop surface, respectively. The presence of the cover crop only reduced the number of shoots in the second year, although both years there was an increment in water stress. Neither yield, cluster weight nor berry weight were affected by the presence of the under-vine cover crop. Similarly, no changes in grape composition were observed. The use of T. fragiferum-like cover crops under the vine allows for better control of weeds, provided a good installation is achieved. In the first two years, this cover crop reduced vegetative growth and increased water deficit slightly. However, no changes in yield and grape composition were observed.In a context of herbicide suppression and search for sustainable management, under-vine clover cover crops constitute a viable alternative in semi-arid regions provided drip irrigation can be applied.

Currently, the greatest challenge for vine growers is to improve the yield and quality of grapes by minimizing costs and environmental impacts. This goal can be achieved through a better knowledge of vineyard spatial variability. Traditional platforms such as airborne, satellite and unmanned aerial vehicles (UAVs) solutions are useful investigation tools for vineyard site specific management. These remote sensing techniques are mainly exploited to get the Normalized Difference Vegetation Index (NDVI), which is useful for describing the morpho-vegetational characteristics of vineyards. This study was conducted in a vineyard in Tuscany (Italy) during the 2017, 2018 and 2019 seasons. Ground data were acquired to detect some agronomic variables such as yield (kg/vine), total soluble solids (TSS), and pruning weight (kg/vine). Remote sensed multispectral images acquired by UAV and Sentinel-2 (S2) satellite platform were used to assess the analysis of the vegetative variability. The UAV NDVI was extracted using both a mixed pixels approach (both vine and inter-row) and from pure canopy pixels. In addition to these UAV layers, the vine thickness was extracted. The aim of this study was to evaluate both classical Ordinary Least Square (OLS) and spatial statistical methods (Moran Index-MI and BILISA) to assess their performance in a multi-temporal comparison between satellite and ground data with UAV information. Good correlations were detected between S2 NDVI and UAV NDVI mixed pixels through both methods (R2 = 0.80 and MI = 0.75). Regarding ground data, UAV layers showed low and negative association with TSS (MI = - 0.34 was the lowest value) whereas better spatial autocorrelations with positive values were detected between UAV layers and both yield (MI ranged from 0.42 to 0.52) and pruning weight (MI ranged from 0.45 to 0.64). The spatial analysis made by MI and BILISA methodologies added more information to this study, clearly showing that both UAV and Sentinel-2 satellite allowed the vigour spatial variability within the vineyard to be detected correctly, overcoming the classical comparison methods by adding the spatial effect. MI and BILISA play a key role in identifying spatial patterns and could be successfully exploited by agricultural stakeholders.

Vineyard yield estimation is a fundamental aspect in precision viticulture that enables a better understanding of the inherent variability within a vineyard. Yield estimation conducted early in the growing season provides insightful information to ensure the best fruit quality for the maximum desired yield. Proximal sensing techniques provide non-destructive in situ data acquisition for yield estimation during the growing season. This study aimed to determine the ideal phenological stage for yield estimation using 2-dimensional (2-D) proximal sensing and computer vision techniques in a vertical shoot positioned (VSP) vineyard. To achieve this aim, multitemporal digital imagery was acquired weekly over a 12-week period, with a final acquisition two days prior to harvest. Preceding the multitemporal analysis for yield estimation, an unsupervised k-means clustering (KMC) algorithm was evaluated for image segmentation on the final dataset captured before harvest, yielding bunch-level segmentation accuracies as high as 0.942, with a corresponding F1-score of 0.948. The segmentation yielded a pixel area (cm2), which served as input to a cross-validation model for calculating bunch mass (g). The ‘calculated mass’ was linearly regressed against the ‘actual mass’, indicating the capability for estimating vineyard yield. Results of the multitemporal analysis showed that the final stage of berry ripening was the ideal phenological stage for yield estimation, achieving a global r2 of 0.790.

Aim: Shoot thinning is a common canopy management practice used to obtain a desired shoot density and to improve canopy microclimate. Since thinning is often carried out manually, the cost can be high. In this study the effect of severe shoot thinning (50 % of shoots removed) applied at EL 15 was investigated by comparing yield components, canopy size, berry and wine chemistry, and sensory attributes to a non-thinned control for the variety Semillon. The objective was to determine whether shoot thinning could change canopy architecture and lead to improved fruit and wine chemistry and sensory characteristics.Methods and results: The trial was carried out over four consecutive growing seasons (starting in 2014-15) in the Semillon block of the Coombe vineyard (Waite Campus, the University of Adelaide). Canopy architecture was monitored at key phenological stages in each season and yield components were assessed at harvest. The harvested fruit was used for chemical and sensory analysis of the berries. Wines were made and their chemistry and sensorial attributes assessed. Shoot thinning reduced the total leaf area in only two of the four seasons, but single shoot leaf area and cane weight were higher in shoot-thinned vines in all seasons. Shoot thinning did not reduce yield, despite a large reduction in bunch number, because of increased bunch weight. Shoot thinning did not change berry and wine chemistry. Similarly, little differences were observed in the sensory profile of berries and wines, and the assessors preferred the wines obtained from shoot thinned vines in the last season only.Conclusions: In this study, shoot thinning increased the leaf area per shoot and the cane weight, but yield and grape and wine chemistry were unaffected. The vine balance indices leaf area/yield and yield/pruning weight were also unaffected by the treatment, despite its intensity (50 % of shoots removed).Significance and impact of the study: The practice of shoot thinning when applied at EL stage 15 (8-9 leaves separated) was not effective as a technique to improve canopy microclimate and berry and wine chemistry for the white variety Semillon in a hot Australian climate. By not applying shoot thinning growers could potentially make significant savings without affecting yield or wine properties. Further research is needed to explore the effect and timing of shoot thinning on other varieties and in different environments.

Background and aims: Seasonal differences in vine yield need to be managed to ensure appropriate fruit composition at harvest. Differences in yield are the result of changes in vine management (e.g., the number of nodes retained after harvest) and weather conditions (in particular, temperature) at key vine development stages. Early yield prediction enables growers to manage vines to achieve target yields and prepare the required infrastructure for the harvest.Methods and results: Bunch mass data was collected during the 2016/17, 2017/18 and 2018/19 seasons from a commercial vineyard on the Wairau Plains, Marlborough, New Zealand (41o2’23”S; 173o51’15”E). A Bayesian growth model, assuming a double sigmoidal curve, was used to predict the yield at the end of each season. The accuracy of the prediction was investigated using the Monte-Carlo simulation for yield prediction at various growth stages assuming different prior information.Conclusion: The results show that the model is sensitive to prior assumption and that having a non-informative prior may be more beneficial than having an informative prior based on one unusual year.

International audience; The wine industry must face many challenges because of climate change. One of them is the increase in temperatures and droughts events. These changes sometimes lead to yield losses and can also impact the quality of the wine produced (e.g., increased alcohol content). The management of available water is also a sensitive issue as water requirements for vineyard irrigation are quickly increasing in the south of France. In this context, there is a need for a decision tool that can help evaluate the vine water status through the entire growth season at a large scale. To address this issue, we have previously developed a model (see Laroche-Pinel et al. 2021a) which predicts the vine Stem Water Potential (Ψstem) using Sentinel-2 (S2) images. This model was developed based on a field campaign over three years. The present study now aims to investigate the feedback of winegrowers on the outputs of our model. Therefore, it was applied on the plots of five wine estates that do not belong to the set used in the initial paper. The qualitative results show interesting spatial and temporal consistency in accordance with winegrower knowledge, irrigation data, and weather forecast. The predicted Ψstemhighlights spatial variability in vine fields where a water source emerges and reflects the differences between vine fields with a drip or sparkling irrigation or without an irrigation system. The predicted Ψstem also clearly reacts to a peak in temperature. According to their feedback, three of the five winegrowers would be glad to use this service in the years to come.

International audience; Microorganisms associated with plants are determinant for their fitness, but also in the case of vine grapes, for the quality and quantity of the wine. Plant microbiota is, however highly variable in space despite deterministic recruitment from the soil reservoir. Therefore, understanding the drivers that shape this microbiota is a key issue. Most studies that have analysed microorganisms associated with vines have been conducted at large scales (e.g., over 100 km) and have analysed the bulk soil and the rhizosphere. In this study, we focused on the root-microbiota endosphere, the most intimate fraction of microorganisms associated with plants. We sampled vine roots in 37 fields distributed throughout a vineyard to investigate drivers shaping the grapevine microbiota at the alpha-(i.e., within-field) and gamma-(i.e., between-field) diversity scales. We demonstrated that vine endospheric microbiota differed according to both the edaphic and plant-specific parameters including cultivar type and age. This work supports the idea of an existing microbial terroir occurring within a domain and offers a new perspective for winemakers to include the microbial terroir in their management practices.

The grapevine vegetative cycle, which is morphologically described by its phenological stages, is strongly determined by weather conditions. Phenological models are widely applied in viticulture and are based on the assumption that air temperature is the preponderant environmental factor which determines vine development. In this study, phenological development models (PDMs) were calibrated and validated to simulate several intermediate stages between budbreak and veraison for cv. Touriga Nacional (TN) and cv. Encruzado (EN) winegrape varieties, which are widely grown in the Dao Wine Region, Portugal. These are thermal models, with which the daily sum of the rate of forcing (R) was calculated using a sigmoid function. For this purpose, a high-quality and comprehensive dataset was used which combines phenology data and weather station data in several vineyard sites spread over the region. The model showed an overall high performance (global RMSE of 5.4 days for EN and 5.0 days for TN), although it depended on the phenological stage and variety. The RMSE ranged from 3.2 to 6.2 for TN, and from 3.9 to 6.8 for EN. For both varieties and in all phenological stages, the RMSE was significantly lower than the standard deviation of the phenological observations. For TN, the model efficiency was greater than 0.71 for all phenological stages. In future studies, these models will be combined with specific models that simulate the evolution of winegrape berry quality indicators commonly used for harvest decision support. The relatively low complexity of the selected PDMs enables their use as a crop management and decision support tool. To our knowledge, no previous studies have been carried out on either of these two varieties and their intermediate phenological timings. The present study is an illustration of conceivable model development under diverse environmental conditions, thus allowing similar approaches to be adopted in other wine regions on a worldwide scale. info:eu-repo/semantics/publishedVersion

The variability of grapevine phenological stages under climate change has been studied in many winegrowing regions, with many reporting an advancement of the major phenological stages, particularly flowering, veraison and harvest. This study aimed to compare these regional patterns to integrate our understanding of grapevine responses. Average daily January–March (JFM) mean temperatures were correlated with day of year budburst (DBUD) and average daily springtime March–May (MAM) maximum temperatures were correlated with day of year flowering (DFLO), day of year veraison (DVER) and day of year harvest (DHAR) for 17 vineyards and showed an advancement of the associated phenological stage with increased temperature for each index. There were significant differences between vineyard groups for the rate of advancement of DBUD, DVER and DHAR which suggests that the response of phenological stage to temperature is not linear and varies between cultivars. Only the interval between DBUD and DFLO showed a significant shortening as related to MAMMax, suggesting that the advancement of grape maturity as related to increasing springtime maximum temperature is largely due to the shortening of the DBUD to DFLO interval.

Proximal sensing is used in vineyards to precisely monitor and manage spatial and temporal variability while reducing laborious and repetitive measurements. Soil electrical conductivity (EC) and canopy vegetation indexes are two frequently assessed variables with off-the-shelf sensors. In this study, the ecophysiological variability of a commercial vineyard comprising three varieties in three blocks, Cabernet-Sauvignon (CS), Cabernet franc (CF), and Petit Verdot (PV), was investigated. Random sampling was used to continuously assess spatial variability in plant physiology and berry composition. Soil EC and NDVI were also continuously monitored throughout the season. There was a noticeable spatial pattern in the normalised differential vegetation index (NDVI) in the vineyard and soil EC. The spatial pattern of NDVI can be partially elucidated by the season-long stem water potential (Ψstem), which was lowest in the CS block. However, leaf photosynthesis did not match this spatial pattern. The spatial distribution of NDVI and soil EC did not satisfactorily explain the spatial variations in yield components and berry chemistry. Principal component analyses (PCA) were performed resulting in a clear discrimination of each of the three cultivars. Soil EC showed a significant relationship with Ψstem integrals, total skin anthocyanins and tri- to di-hydroxylated flavonoids. In each cultivar block, soil EC showed some capability to be related to plant water status, and NDVI showed a relationship with yield. Overall, this study provided evidence of the spatial variability of grapevine physiology in a commercial vineyard with three cultivars. Also, it showed that the cultivar effect and uniform crop level management can diminish the efficiency of proximal sensing, thus weakening the relationship of soil and canopy indexes with plant physiology and berry chemistry. Nonetheless, our study showed that it is possible to apply temporal proximal sensing methods when assessing plant water status, primary metabolism, yield and berry secondary metabolism, which give an indication of the possibility of managing the spatial variability of both plant physiology and berry chemistry.

Aluminium plays a central role in soil acidity, which is one of the main constraints on grape production in humid, northern temperate viticultural regions. To decrease the acidity of vineyard soil, it is usually amended with alkaline materials that provide conjugate bases to weak acids (liming). However, one practical consideration is the danger of overliming, which has potential implications in terms of yield reduction and decreased bioavailability of several mineral nutrients. The main aim of this study was to evaluate the effects of overliming using dolomitic lime on grapevines growing on acid soil. The effects on the topsoil fertility parameters (0–30 cm), petiole and berry nutrient levels, berry weight and must quality properties were studied in a vineyard planted with Vitis vinifera L. cv. Mencía for three years (2014–2016). Data analysis performed using a mixed model that took into account both random effects (year of sampling) and fixed effects (liming treatments) showed that overliming decreased the manganese content in both leaf and berry tissues. Until now, nothing was known about the effects of overliming on both vine nutritional status and harvest quality properties, thus this study fills an important knowledge gap.

This study aimed to investigate the possible existence of reproducible aromatic red wine styles, focusing on fresh fruit aromas and mature fruit aromas (i.e., with dark, jammy fruit characteristics) and taking into account both vintage and vineyard.The study was performed on Australian Shiraz and Cabernet‑Sauvignon from three different meso-climate areas and two consecutive vintages. Sequential harvests were carried out based on the plateau of the physiological indicator berry sugar accumulation (mg/berry) in order to obtain fresh fruit and mature fruit wine sensory profiles. There was a predictable aromatic sequence during grape ripening at each of these two distinct maturity stages regardless of grape genotype (variety) and environment (vineyard and vintage). The post-plateau period of berry sugar accumulation was found to be crucial for the evolution of wine aromatic profiles. During this period, wine aromatic and phenolic maturity were uncoupled from technological maturity (i.e., berry sugar concentration). Dimethyl sulfide was found to be the most relevant wine aromatic marker for differentiating the fresh fruit and mature fruit stages irrespective of the variety. Specific cultivar markers with potential sensory contribution were also identified; for example, (Z)‐3‐hexenol, a possible contributor to the aromatic freshness of Shiraz wines from the fresh fruit stage. The evolution of terpenoids appeared to be separate from the dynamics of berry ripening post plateau of fruit sugar accumulation. On the other hand, ester composition was significantly altered during the same ripening period in Shiraz and Cabernet‑Sauvignon wines with a marked grape genotype effect. The results showed that yeast metabolism was also affected by berry ripening evolution from the plateau of berry sugar accumulation onwards.

This study aimed to validate the use of UAV-based point cloud analysis to detect canopy decline severity and its spatial distribution in vineyards.A new approach to assess canopy decline, caused by Eutypa dieback-like symptoms, using unmanned aerial vehicle (UAV) remote sensing was compared with ground visual assessment in the vineyard. Canopy point cloud captured by UAV-based imagery during the growing season was analysed by a customized program to determine canopy decline severity and spatial distribution in a symptomatic Shiraz vineyard in Eden Valley, South Australia. Experienced assessors performed a ground visual assessment in the vineyard at E-L stage 15. k-means clustering was used to detect reduced canopy volume due to Eutypa dieback-like symptoms. Results from point cloud analysis showed that 12.5 % of the total canopy length in the vineyard had Eutypa dieback symptoms while the ground visual assessment detected 11.4 %. Confusion matrix results showed an accuracy of 87.4 % and a kappa coefficient of 0.43 compared with ground visual assessments. Additionally, automatic analysis of the point cloud was quicker than the ground visual assessment and generated precise geographic coordinates of the symptomatic canopy sections. Point cloud analysis can detect Eutypa dieback-like symptoms and its spatial distribution with 87.4 % accuracy, compared with the ground assessment. Similar to ground visual assessment, E-L stage 15 appears to be a suitable stage to apply point cloud analysis to make Eutypa dieback-like symptom assessments. Grapevine canopy decline, caused by various factors such as Eutypa dieback and inadequate management, can cause yield reduction and threaten vineyard longevity. Compared with tedious ground visual assessments, point cloud analysis can accelerate the assessment of canopy decline in vineyards and help with the planning of remedial practices using precise geographic coordinates of the affected sections.

The aim of the study was to identify the ecological indicators that facilitate predictive analysis and to search for patterns in local geographical information to identify risks and opportunities in viticulture. The study focused on environmental factors that significantly affect the ripeness of the Gewürztraminer grape variety cultivated near Tramin, a village in northern Italy. In particular, the reliability of the new Solar Radiation Identity (SRI) topoclimate classification method was tested, along with its predictive capability in terms of the biosynthetic activity of the vine and the quality of its grapes. The SRI index characterises each vineyard in a precise and comparable way and helps to understand the way in which the topoclimate acts as an important abiotic stress factor for vines. A direct relationship between grape must sugar content and the SRI topoclimate index was observed. Our findings indicate an increase in sugar content of approximately 0.8 °KMW for every 10 points of the SRI index. Thus, a novel prediction model of grape ripening based on an SRI curve analysis is proposed. The correct application of the SRI index could be useful for discriminating and predicting geographical charactersitics of a given area strongly connected to ecological diversity and wine quality. It could support decision making in viticulture in terms of, for example, correctly matching vineyard and grape varieties, reducing wine vulnerability and production risk and predicting optimal ripeness and harvesting days. The use of the SRI prediction curve could help in adopting a more sustainable approach to agriculture and in finding new methods for adapting to climate change, such as by improving the match between the cultivars’ phenological status, vineyard location and growing season average temperature.

This work seeks to synthesise the knowledge on the use of cover crops in vineyards in the last 20 years, emphasising on the one hand, soil characteristics such as nutrition, organic carbon, structure or erosion and, on the other hand, environmental factors such as soil and biodiversity in vineyards, and gas emissions.A systematic review was made using Scopus-index journals for the past 20 years (1999 - 2018). The selection was independently done by two researchers, selecting a total of 272 published papers related to cover crops in the vineyard. Each article was categorised according to its theme and metadata were created, considering all relevant information from an agro-ecological point of view.The use of cover crops has a positive effect on the vineyard by increasing soil organic carbon (SOC), improving water infiltration and aggregate stability, and reducing erosion and greenhouse gases emission to the atmosphere. Furthermore, there is an increase in biodiversity, both in soil and the vineyard. Finally, cover crops do not constitute as a rule a major competition for nutrients to the vines except for nitrogen when grass covers are used. Contrarily, legume cover crops generally increase N in the soil, although its availability for plants is not immediate.This review constitutes an objective tool to help growers when considering the use of cover crops in vineyards that, based in a systematic review, provides relevant information depending on the characteristics of the growing condition of the vineyard.

Cost effective and environmentally friendly strategies in plant nutrition are prime considerations for sustainable viticulture in the face of ever-increasing stress factors throughout the world. Therefore, the present study aimed to investigate the effects of applying different types of organic and inorganic material [control (C; no application), basaltic pumice (P), commercial dry compost (DC), pruning residue:farm manure mixture (1:2, v:v) compost (PR+FM), straw:farm manure mixture (1:2, v:v) compost (S+FM), pumice:dry compost (P+DC), pumice+straw:farm manure compost (P+(S+FM)) and pumice+pruning residue:farm manure compost (P+(PR+FM))] to ‘Black Magic’ grapevines on their agronomic and nutrient acquisition during two consecutive years: 2017 and 2018.The highest yield (6172 g/vine and 7874 g/vine) and cluster weight (411.4 g and 463.2 g) were obtained for the application of S+FM in both years. In terms of berry weight, the highest value was obtained for P+(PR+FM) in 2017, although no significant difference was found between treatments in 2018. PR+FM slightly accelerated berry ripening. The differences between macro and micro element contents of the leaves were statistically significant. The leaf mineral values obtained from pumice were generally higher whether it was applied alone or in combination with other materials. N, P, Ca, Fe and Mn concentrations were sufficient for all applications, while K, Mg and Zn values were within the limits of deficiency. Regarding CO2 production, P+(PR+FM) application in 2017 and S+FM application in 2018 gave the highest values. The effect of organic materials used on microbial biomass-C in soil was higher for S+FM in 2017 and for S+FM and P+DC in 2018 than the other treatments. The application of P+(PR+FM) in 2017 and PR+FM in 2018 had the highest efficiency in terms of dehydrogenase enzyme activity. Urease and phosphatase enzyme values showed a higher activity for P+(PR+FM) in 2017 and P+DC in 2018 than for the other treatments.In this study, we found that applications of organic and inorganic material generally provided good improvement in terms of the agronomic and nutritional properties examined. In order to be able to provide recommendations for appropriate material, it would be useful to evaluate the accumulated effects of the treatments in further research.

Terroir is about the link between wine and its origin. It has long been understood by sensory evaluation that the taste of wine from a given variety can be related to its origins. Specific organoleptic characteristics of wine are influenced by environmental factors such as soil and climate. By deconstructing the effect of measurable soil and climate parameters on grape and wine aroma compounds, the terroir effect on wine typicity can be better understood. Climate influences on vine development and grape ripening are mainly associated with temperature, radiation and rainfall, while soil influences are primarily associated with water availability and nitrogen supply. Significant advances have been made over recent years in understanding wine aromas and their molecular basis and influences of climate and soil on a wide range of molecules responsible for wine aroma expression. This article aims to review these recent research advances to obtain a more comprehensive understanding of how terroir influences wine typicity. The effect of terroir on wine quality and typicity is sometimes considered intangible and difficult to explain on a scientific basis. By combining agronomic, analytical and sensory approaches, however, this review shows that the terroir effect is mediated by measurable factors that can easily be monitored in the vineyard. Assessment of the results compiled by this review allows the suggestion that terroir expression at specific sites might be maximized by choosing appropriate plant material in relation to soil and climate, by acting on manageable parameters like vine water and nitrogen status, or by implementing canopy management to modify microclimate in the bunch zone.

Vine genetics, fruit maturity, region and vineyard are perceived as factors that strongly influence Pinot noir grape and wine composition. Our study aims to understand the relationship between grape (and ultimately wine) composition and the physical appearance and performance characteristics of a vine (i.e. vine ideotype). Our experimental approach controlled these variables by studying within-block differences in vine performance across multiple seasons and vineyards. Grapes were sourced at commercial harvest from 20 single vines from 12 vineyard sites in three Pinot noir growing regions (Central Otago, Martinborough and Marlborough) of New Zealand.Across three vintages yields ranged from 0.1 kg to 6.3 kg per metre, but there was no general relationship between yield and berry soluble solids. On a vine by vine basis normalised yields did not correlate among seasons. Berry extract colour measures were, on average, three-fold higher in 2019 than in 2018.Principal Component Analysis has indicated that vintage dominated berry composition effects that might otherwise be associated with yield per vine, region and vineyard. The extent of the variation in performance of the same vines between seasons largely excludes factors that are stable between seasons as primary causes. Changes in management of the same vine from year to year appeared the most likely contributors to variation. We have derived highly significant negative linear relationships between vine yield class and the frequency of vines that were within a benchmark specification established for icon vines, providing evidence of the quality risk associated with higher yield. The results also indicate that a proportion of vines meet the benchmark specification at higher yields. From results to date we can further our research confident in the knowledge that factors such as vine yield, region or vineyard are, in themselves, unlikely to be the principal drivers of major differences in Pinot noir grape and wine composition.

In several production areas, dessert (sweet) and reinforced wines are made after a more or less intense dehydration of harvested grapes. The dehydration process depends on several factors, including the size, morphology and anatomy of the berries, all genetically defined traits that can be affected by vineyard management and microclimate conditions. At harvest, berry outer surface and skin ultrastructural features of cvs Aleatico, Sagrantino, Sangiovese and Trebbiano berries were investigated in a frozen-hydrated state using cryo‑scanning electron microscopy (Cryo‑SEM). The berries were subjected to postharvest dehydration at 23 °C for twelve days and the differences in weight loss were determined. In terms of weight loss rate, Aleatico and Trebbiano were the fastest and the slowest respectively. Therefore, the ultrastructural changes of berry skin of these two varieties were also investigated at the end of the dehydration process. At harvest, the structure of the epicuticular waxes on the skin outer surface differed between berries of different cultivars. The thickness of the cuticle, epidermis and hypodermis was also found to be significantly different, with Trebbiano berries having the thickest skin. At the end of the dehydration process all the measured parameters decreased, in particular Aleatico epicuticular wax, hypodermis and cuticle thickness, as well as the hypodermis cell wall and the mesocarp parenchyma cell area. The high weight loss rate recorded for Aleatico can be partly explained by the thickness of the berry skin at harvest, which was significantly thinner than that of Trebbiano, as well as by other skin-related morphological and histological factors possibly affecting permeability.

Aim: Wine quality is influenced by the nitrogen nutrition of grapevines in the vineyard. A deficiency of this nutrient will affect grape quality, decrease yeast available nitrogen (YAN) and influence alcoholic fermentation. Chasselas wines from nitrogen-deficient grapes (YAN < 140 mg N/L) are systematically more astringent and bitter and less fruity than those from grapes with higher YAN content (Spring et al., 2014). The aim of this study was to identify chemical markers in wine linked to nitrogen deficiencies in the vineyard.Methods and results: Wine samples produced from grapes growing in nitrogen-deficient vineyards with nitrogen treatment (HN) and without it (LN) were used over four consecutive years (2006–2009). They were all analysed at the same time (2012) with electronic-nose, GC-MS and UHPLC-TOFMS techniques. A metabolomics approach was used for a comprehensive survey of volatile and nonvolatile compounds in order to identify markers related to nitrogen nutrition. Volatile markers with alcohol and ester functions and nitrogen-containing compounds were found and tentatively identified by GC-MS. Additionally, 16 nonvolatile markers were putatively identified by UHPLC-TOFMS, including compounds from diverse chemical classes, namely, amino acids, vitamins, hormones, organic acids, phenolic compounds and polysaccharides.Conclusion: The nitrogen nutrition of grapevines has a clear but complex effect on the chemical composition of wine. Several markers were tentatively identified and their role in wine composition discussed according to the actual knowledge reported in the literature.Significance of the study: This study is an important starting point for selecting the most relevant chemical markers in wine, and for determining whether organoleptic problems are related to nitrogen nutrition deficiency in the vineyard and changes in vineyard management are needed.

Aims: The aim of the present study was to analyse the impact of different water regimes on the physiological and agronomical behavior of an aromatic white grapevine (cv. Arvine) by means of various levels of irrigation. The consequences of the plant water status were evaluated by carrying out a chemical (aromatic precursors) and sensorial analysis of the resulting wines.Methods and results: Adult vines of Vitis vinifera L. cv. Arvine grafted onto 5BB were subjected to different water regimes (various levels of irrigation) during the growing season. Physiological indicators were used to monitor the plant water status [pre-dawn leaf (ΨPD) and stem (ΨSTEM) water potentials and carbon isotope composition (d13C) in the must]. Gas exchange (net photosynthesis AN and transpiration E), stomatal conductance (gs), yield parameters, berry composition at harvest, analysis of potential grape aromatic properties (glycosyl-glucose G-G, precursor 3-mercaptohexanol P 3-MH) and the sensorial quality of wines were analysed over a period of 8 consecutive years (2009-2016) in the Agroscope experimental vineyard in Leytron under the relatively dry conditions of the Rhône valley in Wallis, Switzerland.In the non-irrigated vines, the progressively increasing water deficit observed over the season reduced the leaf gas exchange (AN and E) and gs. The intrinsic water use efficiency (WUEi, A/gs) increased over the season and was greater in the vines that had suffered water restriction than in the irrigated vines. The rise in WUEi was correlated with an increase in d13C in the must sugars at harvest. A decrease in plant vigor was observed in the water stressed vines over multiple years. Moderate to high water stress during fruit ripening lowered the contents of total and malic acidity in the musts and the content of yeast available nitrogen (YAN). On the other hand, contents in sugar and the aromatic precursor (P-3MH) in berries were not influenced by the vine water status. The G-G values for berries increased with rising water stress in the non-irrigated vines. The wines from the plants subjected to water stress and to yeast available nitrogen deficiency (non-irrigated vines during hot and dry seasons) had a less distinctive typicity, and developed a lower aromatic expression with a more bitter taste, than the wines from the non-stressed plants. Overall, and compared with the stressed vines, the organoleptic characteristics and quality of Arvine wines from vines which had not undergone restrictions in water and nitrogen during the growing season were appreciated more.Conclusions: The vine’s physiological behavior (leaf gas exchange, plant vigor) and agronomic parameters (yield, berry composition), together with the quality of white aromatic Arvine wines, were strongly influenced by vine water regimes during the growing season.Significance and impact of the study: Vine water status and must nitrogen contents are key factors in grape composition and in the sensorial quality of resulting aromatic white wines.

Terroir factors and vineyard practices largely determine canopy and root system functioning. In this study, changes in soil conditions, multi-level (vertical, horizontal) light interception (quantitative, photographic, schematic, 3D modelled), leaf water potential and photosynthetic activity were measured during the grape ripening period on NS, EW, NE-SW, and NW-SE orientated (Southern Hemisphere) vertically trellised Shiraz grapevine canopies. It was hypothesised that the spatial radiation interception angle and radiation distribution of differently orientated and vertically trained grapevine rows would affect soil conditions and vine physiological activity. Soil water content showed an increase and soil temperature a decreasing gradient with soil depth. In the afternoon, soil layers of EW orientated rows reached their highest temperature. This, along with measured photosynthetic active radiation received by canopies, complimented the diurnally-captured photographic, constructed and 3D modelled images (also schematically) of canopy and soil exposure patterns. The top, bottom and outside of NS canopies mainly received radiation from directly above, from the E and the W; during midday, high radiation was only received from above. The EW rows received the highest radiation component from above and from the N. The NE-SW rows received high levels of radiation from above, from the SE until 10:00, and from the NW from 13:00. A similar profile can be described for NW-SE rows, but with high radiation received from the NE up to 13:00 and from the SW from 16:00. Overall, lowest leaf water potential occurred for NE-SW canopies, followed by those orientated NW-SE, NS and EW. Photosynthetic activity reflected the positive radiation impact of the sun azimuth during the grape ripening period; best overall performance seemed to occur for E and N exposed canopy sides. This was largely driven by the responsiveness of the secondary leaves to radiation. Photosynthetic output decreased from apical to basal canopy zones with low, erratic values in the light-limited canopy centre. The NS and EW orientated canopies generally showed the highest average photosynthesis, while it was lower for the sides facing S, SE and SW. The results provide a better understanding of the physiological functioning of horizontal and vertical leaf layers in differently orientated grapevine canopies, as affected by climatic conditions. The study contributes to the longstanding challenges of capturing the complexity of parallel microclimatic and physiological output of grapevine canopies under open field conditions. The results can be directly applied to the selection of vineyard practices and seasonal management to ensure the attainment of yield, grape composition and wine quality objectives.

Aim: The major focus of this research was to explain the so-called terroir effects that impact grapevine yield components, berry composition, and wine varietal character. To elucidate potential contributors to the terroir effect, vine water status [midday leaf water potential (ψ)] was chosen as a major determinant. The hypothesis of this component of the study was that consistent leaf ψ zones could be identified within vineyard sites and that vine water status would play a major role in vine performance and yield components. Soil texture was anticipated to play a role indirectly through its water-holding capacity.Methods and materials: To test this hypothesis, ten Riesling vineyards representative of each Vintners Quality Alliance of Ontario sub-appellation were selected within the Niagara Peninsula. These vineyards were delineated using global positioning systems and 75–80 sentinel vines were geo-referenced within a sampling grid for data collection. During the 2005–2007 growing seasons, leaf ψ measurements were collected bi-weekly from a subset of these sentinel vines. Data were collected on soil texture and composition, soil water content (SWC), vine performance and yield components. These variables were mapped using geographical information systems software and relationships between them were elucidated.Results: Vineyards were variable in terms of soil texture, composition, nutrition, and moisture. However, in general, few consistent relationships with soil composition variables were found. As hypothesized, consistent leaf ψ zones were identified within vineyards in all three vintages. Some geospatial patterns and relationships were spatially and temporally stable within vineyards. In many cases, spatial distribution of leaf ψ was temporally stable within vineyards despite different weather conditions during each growing season. Spatial trends within vineyards for SWC and leaf ψ were temporally stable over the 3-year period for eight vineyards. Generally, spatial relationships between leaf ψ, SWC, vine size, berry weight and yield were also temporally stable. Some inconsistencies in spatial distribution of variables were attributable to winter injury.Conclusions: Many viticultural variables such as leaf ψ, vine size, berry weight, and yield were spatially variable and, as hypothesized, consistent leaf ψ zones were identified within vineyards in three distinct vintages. Many geospatial patterns and relationships were determined and were temporally stable, and this temporal stability in these variables occurred despite different growing seasons. The strongest relationships were those concerning leaf ψ, SWC, vine size, and berry weight. No consistent relationships were found concerning soil composition. The most consistent soil variables that impacted vine performance and yield components were physical properties, particularly texture.Significance and impact of the study: Soil had some indirect effects, but leaf ψ was more likely a major contributor to the terroir effect, as it had a major impact on vine size, berry weight and yield in many vineyards across multiple vintages. Temporal stability is required for many practical geomatic applications to be initiated in vineyards, but it is also of importance to future research endeavors for this project as well as others.

Aim: The aim of this study was to investigate the effects of integrated (INT), organic (ORG) and biodynamic (BD) management systems with similar C- and N-inputs on soil microbiology in a viticultural long-term field trial.Methods and results: Within the systems comparison, soil samples were taken 10 years after conversion, throughout the growing season. To gather information about microbial community structure, the activity of five soil enzymes was measured, and phospholipid fatty acids (PLFA) and neutral lipids fatty acids (NLFA) profiles were analysed accompanied by comprehensive soil analysis. pH associated with BD was significantly higher compared to INT soil. Copper and N-min values in INT were significantly lower compared to the organic systems. BD and ORG were characterised by a higher b-D-glucosidase and urease activity and a higher abundance of fungi and bacteria. INT had larger quantities of mycorrhizae indicator NLFAs.Significance and impact: Results from this study contribute to a better understanding of the microbial community structure and nutrient cycling under organic and biodynamic viticulture.

International audience; Background and aims: In most viticultural areas of the world, Vitis vinifera grapevines require grafting onto phylloxera-tolerant rootstocks of American origin. The species most commonly used in rootstock creation are Vitis berlandieri, V. riparia and V. rupestris. Rootstocks not only provide tolerance to phylloxera but also ensure the supply of water and mineral nutrients to the scion. The aim of the study was to investigate the extent to which rootstocks with different genetic backgrounds modify the mineral composition of the petioles of the scion.Methods and results: Vitis vinifera cv. Cabernet-Sauvignon grapevines were grafted onto rootstocks of 13 different genotypes and planted in a vineyard in three blocks. Petiolar concentrations of 13 mineral elements at veraison (berry softening) were determined. The genetic background of the rootstock had significant effects on the mineral composition of the petioles. Use of rootstocks with a genetic background including at least one Vitis riparia parent decreased the concentration of phosphorus and magnesium and increased the concentration of sulphur in the petioles of Cabernet-Sauvignon.Conclusion: Rootstocks with a Vitis riparia genetic background confer low petiolar concentrations of phosphorus and magnesium, and conversely, high petiolar concentration of sulphur.Significance of the study: The kind of rootstock onto which a grapevine has been grafted is known to influence the nutrient content of the scion. The results of the study show a significant relation between the genetic background of a rootstock and its ability to modify concentrations of phosphorus, magnesium and sulphur in the petioles of the scion under field conditions.

Aim: The aim of the study was to explicitly develop a methodology of delineation of natural Protected Designation of Origins (PDO) terroir regions for Austria, where PDO viticulture regions reflect natural conditions only in a formal manner.Methods and results: There is increasing competition in the wine market from globalized trends, where the European Union (EU) and non-EU wine producers have adopted different market strategies to promote their wines and gain larger market share. The EU has therefore established protective agricultural product categories such as PDO and Protected Geographical Indication (PGI) based on the terroir concept which contrasts with USA strategies. Here, we first collected and derived as many as possible relevant physical geographical data for a total of 66,673 officially registered vineyard areas in Burgenland (Austria). Next, we applied factor analysis to these data with the aim to shrink their size and reduce their dimensionality. For each vineyard plot was derived a factor score which was used for performing k-means clustering. The best count of clusters, k-parameter, was estimated using five internal validity indices. Five homogenous management zones were created as a result of clustering. Correctness and accuracy of the clustering was evaluated by multidimensional discriminant analysis. The final zones were compared to current Districtus Austriae Controllatus (DAC) of Burgenland.Conclusion: It was found by the comparison of DAC regions of Burgenland and our drafted zones that some of the DAC regions do not respect natural terroir zones, while these regions were created as PDO regions which should respect their natural terroir.Significance and impact of the study: The presented methodology can be applied all over Austria and, with some modifications caused by different input data, to each EU member country where it is necessary to revise PDO regions’ borders.

Industry concerns in Australia about the impacts of climate change have, to date, focused on the effects of warming, particularly shorter maturation periods. The effects of elevated CO2 concentration (eCO2) on C3 plant physiology have been extensively studied and suggest that eCO2 impacts on viticulture could affect grapevine shoot growth, fruit production and fruit composition. We previously used open top chambers (OTC) with an active heating system to study the effects of elevated air temperature (eTemp) on mature grapevines in the field. This system was augmented with the ability to elevate atmospheric CO2 and established in a mature Shiraz vineyard in a factorial combination of eTemp and eCO2. Three seasons of observations on the eTemp only treatment corroborated our previous study; all aspects of phenology were advanced, but leaf function was largely unaffected. In contrast, the effects of eCO2 on phenology were small in the first season, but increased over the subsequent two seasons. Interactive effects of the treatments on gas exchange were observed; photosynthesis rates were significantly higher in the eCO2+eTemp treatment, compared to eCO2 alone, suggesting that the likely future climate will have a larger impact on viticulture than might be predicted from experiments examining only one of these factors.