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Maintaining optimal grape acidity at harvest is one of the most complicated challenges under climate change pressures, especially in early ripening cultivars. Warming trends are compressing vine phenology and fostering berry malic acid respiration. In this work, over four years, we evaluated yield components and fruit ripening in two local varieties in the Colli Piacentini, Ortrugo (ORT) and Barbesino (BRB). Our goal was to evaluate their ability to maintain satisfying acidity at harvest and understand the limits and features of the genetic control over organic acid degradation during ripening. The two varieties exhibited comparable yield and grape total soluble solids (TSS) accumulation dynamics, but BRB showed consistently higher acidity during the entire ripening process in any of the four years. BRB's higher acidity was linked to higher malic acid concentrations. ORT had earlier onset of malic acid degradation than BRB and lower maximum malic acid degradation rates. Malic acid degradation rates were lower in ORT also later in the season, until harvest. However, correlations built between malic acid degradation rates and instantaneous malic acid concentration revealed that BRB had a consistently lower malic acid loss for values of malate < 10 g/L. Our work demonstrates that there is a genetic control over the malic acid degradation rates exhibited at varying malic acid concentrations and higher acidity at harvest can be found in varieties exhibiting low malic acid degradation rates when malic acid is < 10 g/L. Post-veraison berry growth rates could interact with genotype effects. The analysis of the correlation can be used at different scales to identify cultivars retaining higher acidity at harvest.

Summer pruning encompasses a series of operations typically performed on the grapevine during the growing season. This review provides an update on the research conducted over the last 20 years on the modalities and strategies of main summer pruning operations, which include shoot positioning and thinning, shoot trimming, leaf removal, and cluster thinning, with a special focus on their adaptation to climate change occurring in Mediterranean areas. Three main novelties emerged from the survey. First, due to a common need to shelter clusters against overheating and sunburn-related damages, shoot thinning and leaf removal are practices that are now being applied in a much more cautious and conservative manner. Second, the meaning of summer pruning is evolving because operations are being used as precious tools to direct ripening toward a desired direction rather than being received passively. Third, some operations, such as leaf removal, have disclosed very high plasticity, which means that, depending on the timing and modalities of the intervention, yield can be either increased or decreased and ripening anticipated or postponed. In an era where economic and environmental sustainability have to find a good compromise, cluster thinning is increasingly being depicted as an extraordinary operation that should be left to occasional occurrences of overcropping. Moreover, summer pruning is a tool through which growers can, to an extent, exploit the potentialities offered by climate change. For instance, the crop-forcing technique, under the different configurations of single and double cropping within the same season, has been trialed promisingly in several regions and cultivars. The principle of forcing is to unlock the dormant bud during the first year by removing at least the young organs present on the shoot within a time window between the end of the flowering and pea-size stages. In particular, when it is applied in a double-cropping mode, the preliminary results r

This paper follows a first contribution on the long-term effects of variable rate nitrogen application on vegetative growth and leaf nutritional status of a small Barbera vineyard, where three vigor levels classified as low, medium, and high (L, M, H) were identified pretrial from normalized difference vegetation index (NDVI) values determined by remotely sensed imagery (5 megapixel resolution). Variable rate fertilization supplying no N (0 kg/ ha; C), standard rate (60 kg/ha; S), and variable rate application (VRA) of 60 or 120 kg/ha to H, M, and L over four consecutive seasons showed that variability among vigor levels was significantly reduced in years three and four, while mean effects related to fertilization strategy were not significant. In this companion paper, L vines were most balanced, suggesting a change in fertilization strategy to no N application in M and H areas, and for maintenance supply in L plots. However, significant vigor level × year interactions indicated that within-vigor variability for total yield and berry weight was considerably reduced, while concomitant seasonal accumulations of sugar and color in 2014 and 2015 were much less variable within dates across vigor levels, suggesting the efficacy of the VRA approach. While the main effects of fertilization supply were mostly non-significant, seasonal accumulation of total soluble solids and anthocyanins in 2014 and 2015 showed that plots receiving 60 kg N/ha had lower within-date values than C (no N), suggesting increasing sensitivity over years. However, the L vines had an almost negligible response to increased N supply, and most observed responses were primarily due to reduced vine capacity.

Chardonnay is a grape variety widely used to produce different white wine styles. In this work, a metabolomic approach based on ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-ESI/QTOF-MS) has been applied to clarify the entire phenolic composition of commercial Chardonnay wines. For this purpose, six wines from different viticultural regions were comprehensively profiled and the phenolic markers discriminating different samples were identified through orthogonal partial least squares discriminant analysis (OPLS-DA). Polyphenols were quantified according to their chemical class and subclass. The most abundant phenolic compounds detected in Chardonnay wines were campesteryl ferulate, caffeic acid and 4-hydroxybenzoic acid (on average 42.4, 5.7, and 5.6 mg/L, respectively). The averaged stilbenes’ content detected (as resveratrol equivalents) was 1.3 mg/L. Flavonoids (i.e., flavonols) were the main class of polyphenols contributing to discrimination of wines according to their geographical origin. Furthermore, the OPLS-DA approach provided an excellent discrimination when considering steel vs. barrel ageing process. These preliminary findings highlight that UHPLC-ESI/QTOF MS-based profiling appears to be a very promising approach in the comprehensive analysis of nutraceuticals, such as polyphenols, in white wine from different geographical origin.

Chardonnay is a grape variety widely used to produce different white wine styles. In this work, a metabolomic approach based on ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-ESI/QTOF-MS) has been applied to clarify the entire phenolic composition of commercial Chardonnay wines. For this purpose, six wines from different viticultural regions were comprehensively profiled and the phenolic markers discriminating different samples were identified through orthogonal partial least squares discriminant analysis (OPLS-DA). Polyphenols were quantified according to their chemical class and subclass. The most abundant phenolic compounds detected in Chardonnay wines were campesteryl ferulate, caffeic acid and 4-hydroxybenzoic acid (on average 42.4, 5.7, and 5.6 mg/L, respectively). The averaged stilbenes’ content detected (as resveratrol equivalents) was 1.3 mg/L. Flavonoids (i.e., flavonols) were the main class of polyphenols contributing to discrimination of wines according to their geographical origin. Furthermore, the OPLS-DA approach provided an excellent discrimination when considering steel vs. barrel ageing process. These preliminary findings highlight that UHPLC-ESI/QTOF MS-based profiling appears to be a very promising approach in the comprehensive analysis of nutraceuticals, such as polyphenols, in white wine from different geographical origin.

Variable rate application of vineyard inputs in field parcels characterized by different levels of vigor and/or yield is one of the most promising applications of precision agriculture. In a four-year study, we provided ground-truthing of three different vigor levels (L = low, M = medium, and H = high) derived pre-trial from Normalized Difference Vegetation Index (NDVI) values determined by remotely sensed imagery (5 m pixel resolution) in a small Barbera vineyard (0.64 ha). Each vigor level was subjected to three fertilization strategies (S) consisting of no N supply (C, 0 kg/ha), standard supply (S, 60 kg/ha), and variable-rate application (VRA) delivering 0, 60, and 120 kg/ha to H, M, and L vines, respectively. Post-trial effects were assessed by taking another NDVI satellite image at the same resolution and by adding proximal sensing performed with the MECS-VINE sensor yielding the estimation of a canopy index (CI). Ground-truthing was based on recording main vine growth parameters and leaf nutritional status. Results show that vine balance of L vines was optimal. Variability among vigor levels was significantly reduced in years 3 and 4, while mean effects related to fertilization strategy were not significant and very few S × V and S × Y interactions were found. However, when the ground-truthing assessment was compared with the CI index values, it was very clear that VRA was able to reduce variability among vigor levels (CV = 1.42%) versus standard fertilization at 60 kg/ha (8.20%).

Most modern and traditional grape-growing regions are facing challenging times due to the unpredictability of weather conditions and warming trends. Innovative and sustainable tools such as seaweed-based biostimulants may play a key-role in the development of environment-friendly viticultural strategies to improve yields, biotic/abiotic stress tolerance and fruit and wine quality. A sprayable Ascophyllum nodosum extract was tested on grapevines cv. Sangiovese grown under Mediterranean conditions (central Italy) and on grapevines cv. Pinot Noir and Cabernet Franc within a cool-climate viticulture region (Michigan, USA). The product was sprayed on the canopies at label doses (1.5 kg/ha) five times during the season, starting two weeks before veraison. The seaweed extract did not affect leaf gas exchanges, yield or cluster and berry size, but hastened veraison, improved anthocyanins accumulation in all cultivars and increased phenolic content particularly in Sangiovese. Therefore, medium-late application of the seaweed extract can be a simple way to favour chromatic and chemical proprieties of grapes and wines. This is the first report of positive effects of Ascophylium nodosum extracts on the quality of cultivated wine grapes. The adoption of the technique can be particularly suitable to cool climate viticulture, especially as it pertains to short growing seasons and genotypes with a limited phenolic profile

Over decades, the concept of grape quality has evolved emphasizing its multidisciplinary nature and that the same "desired quality" might correspond to even strikingly different compositional patterns. The review takes a long journey throughout the multiple factors impinging on grape quality, not excluding also sections devoted to table grapes. It starts with a through survey on the genetic factors influencing grape quality focusing on diversity in different compositional traits (sugar, organic acid, pH, phenolics and aromas) relating to cultivars and clones. Then, most recent knowledge about the effects of soil characteristics, nutrients, light, temperature and water availability, as standalone factors or in interaction, on grape quality are summarized. The more applied section of the review introduces the very much debated yield-quality relationship that, over years, is being interpreted with more flexibility and with greater consensus for an "optimal yield range" that within a given context can anyway reach the desired quality. The impact of the main summer pruning operations (leaf removal, shoot and cluster thinning, shoot trimming) is reviewed and special care taken to highlight most recent contributions with adjusted summer pruning developed to either adapt to climate change issues or to induce specific composition patterns. Review ends with a quick survey on methods nowadays available for fast, non-destructive grape composition assessment.

Leaf removal is a grapevine canopy management technique widely used to modify the source–sink balance and/or microclimate around berry clusters to optimize fruit composition. In general, the removal of basal leaves before flowering reduces fruit set, hence achieving looser clusters, and improves grape composition since yield is generally curtailed more than proportionally to leaf area itself. Albeit responses to this practice seem quite consistent, overall vine performance is affected by genotype, environmental conditions, and severity of treatment. The physiological responses of grape varieties to defoliation practices have been widely investigated, and just recently a whole genome transcriptomic approach was exploited showing an extensive transcriptome rearrangement in berries defoliated before flowering. Nevertheless, the extent to which these transcriptomic reactions could be manifested by different genotypes and growing environments is entirely unexplored. To highlight general responses to defoliation vs. different locations, we analyzed the transcriptome of cv. Sangiovese berries sampled at four development stages from pre-flowering defoliated vines in two different geographical areas of Italy. We obtained and validated five markers of the early defoliation treatment in Sangiovese, an ATP-binding cassette transporter, an auxin response factor, a cinnamyl alcohol dehydrogenase, a flavonoid 3-O-glucosyltransferase and an indole-3-acetate beta-glucosyltransferase. Candidate molecular markers were also obtained in another three grapevine genotypes (Nero d’Avola, Ortrugo, and Ciliegiolo), subjected to the same level of selective pre-flowering defoliation (PFD) over two consecutive years in their different areas of cultivation. The flavonol synthase was identified as a marker in the pre-veraison phase, the jasmonate methyltransferase during the transition phase and the abscisic acid receptor PYL4 in the ripening phase. The characterization of transcriptome cha

Sangiovese vines mechanically spur-pruned during dormancy in February were manually finished either immediately or post budburst to test the potential of a ‘double-pruning’ approach to delay fruit sugar accumulation and limit yield. The treatments were applied in 2014, 2015, and 2016 at BBCH-0 as standard hand-finishing on dormant buds (SHF), and as late (LHF) and very late (VLHF) hand-finishing at BBCH-14 and BBCH-19, i.e., when the two apical shoots on the mechanically-shortened canes were ~10 and 20 cm long, respectively. While yield per vine was drastically reduced in the VLHF treatment (-43% versus SHF) due to high incidence of unsprouted (blind) nodes, lower shoot fruitfulness, and berries per cluster, yield reduction in LHF was -22% versus SHF due only to the incidence of unsprouted nodes. While the fruit ripening profile was not significantly modified in VLHF compared to SHF, in data pooled over three seasons, LHF delayed basic fruit composition at harvest, producing fruit with less total soluble solids, lower pH, and greater acidity, but more phenolics than SHF. Overall, LHF proved to be effective at reducing yield per vine to a level that did not require expensive cluster thinning. By reducing berry sugar accumulation, it has the potential to produce wines with lower alcohol and higher phenol content. Noteworthy too is its potential to delay harvest date or increase crop hanging time under specific vineyard conditions.

The aim of this research was to verify the possibility of limiting yield and delaying grape sugar accumulation with postponement of finishing winter pruning after bud break in vines mechanically pre-pruned in February. In 2014 and 2015, in a spur-pruned Sangiovese vineyard, the finishing winter pruning treatments were carried out at BBCH0 (buds still dormant), BBCH15 and BBCH55 (when the apical shoots on the canes retained on vines with mechanical pre-pruning treatment were 10 and 20 cm long, respectively). Contrary to BBCH55 treatment, where the yield was drastically reduced (-49%), the results show that this technique, simple and cheaper, applied at BBCH15 can be useful in all situations where are required: 1) contain vine yield; 2) delay the technological ripening and maintain higher titratable acidity; 3) improve the phenolic compounds in grape and wine; 4) delay the useful period of grape harvest in specific vineyards, as can be required when close to high acreage of the same grapevine cultivar or different cultivars with contemporaneous ripeness can be need to avoid early racking with lost of color, tannins and aromatic compounds.

The aim of this research was to verify the possibility of limiting yield and delaying grape sugar accumulation with postponement of finishing winter pruning after bud break in vines mechanically pre-pruned in February. In 2014 and 2015, in a spur-pruned Sangiovese vineyard, the finishing winter pruning treatments were carried out at BBCH0 (buds still dormant), BBCH15 and BBCH55 (when the apical shoots on the canes retained on vines with mechanical pre-pruning treatment were 10 and 20 cm long, respectively). Contrary to BBCH55 treatment, where the yield was drastically reduced (-49%), the results show that this technique, simple and cheaper, applied at BBCH15 can be useful in all situations where are required: 1) contain vine yield; 2) delay the technological ripening and maintain higher titratable acidity; 3) improve the phenolic compounds in grape and wine; 4) delay the useful period of grape harvest in specific vineyards, as can be required when close to high acreage of the same grapevine cultivar or different cultivars with contemporaneous ripeness can be need to avoid early racking with lost of color, tannins and aromatic compounds.

Vitigno storico dell'Oltrepò Pavese orientale prima della fillossera era la seconda varietà più diffusa in loco. In occasione della ricostruzione post-fillosserica durata dalla fine del secolo XIX ai primi decenni del 1900, l'Ughetta di Canneto, scarsamente produttiva e sensibile alle malattia, venne quasi del tutto abbandonata in tutto l'Oltrepò Pavese. Oggi è un vitigno recuperato e impiegato nella piattaforma ampelografica dei vini del territorio.

Testing of new rootstocks for drought tolerance targets traditionally rain-fed districts where supplemental irrigation is more frequently needed due to the pressures of global warming. A seasonal evaluation of gas exchange and water-use efficiency (WUE) of cv. Sangiovese grafted to the new drought-tolerant genotype M4 in a dry-down trial against the commercial SO4 stock is reported. The experiment was conducted in 2014 on twelve 2-year-old, non-fruiting potted Sangiovese grapevines grafted on M4 and SO4 stocks and assigned to SO4-WW (well-watered), SO4-WS (water-stressed), M4-WW and M4-WS treatments. Progressive water deficit was imposed by reducing water supply to 70, 50 and 30 % of whole-canopy demand derived from concurrent measurements of transpiration in WW. Unlike SO4, M4 showed slower stress progression, as highlighted by pre-dawn leaf water potential, and retained higher whole-canopy net CO2 exchange rates (NCER) and transpiration rates per unit of leaf area at all replenishment levels as well as exhibiting higher canopy WUE at both 50 and 30 % WW. Although single-leaf assessment was in partial disagreement with data recorded on the whole-canopy basis, robust data were acquired to confirm that the M4 stock performs better than SO4 at any water replenishment level in terms of higher NCER/leaf area and/or canopy WUE. Findings feed expectations that grafting Sangiovese to the M4 rootstock should result in a problem-solving tool for rain-fed areas subject to temporary summer drought.

Negli ultimi decenni si è affermata tra gli ope- ratori della filiera viti- vinicola la consapevo- lezza di come la varia- bilità pedoclimatica dei comprensori vitati pos- sa influenzare la qualità dei vini e di co- me l’esperienza del vignaiolo, esercita- ta attraverso la scrupolosa gestione si- to-specifica dei vigneti, contribuisca a una marcata identità territoriale delle produzioni (Zamboni et al., 2008; van Leeuwen, 2010). Di conseguenza, vasti areali sono stati sottoposti a zonazione per l’individuazione di aree accomunate dallo stesso potenziale vitivinicolo, capaci di dare origine a vini con caratteristiche sensoriali simili e facilmente riconoscibili (Fregoni et al., 2003). Le carte nutrizionali sono state messe a punto con l’intento di fornire al viticoltore gli elementi utili alla realizzazione del piano di concimazione per un determinato modello viticolo in uno specifico territorio (Fregoni, 2009). In estrema sintesi, il principio fondante di queste modalità operative concepisce la singola parcella come un’entità perlopiù omogenea inserita all’interno di un’unità territoriale.

The influence of pruning date on yield control and ripening rate of spur-pruned Sangiovese grapevines was investigated over two years (2013 and 2014). Winter pruning was applied on 1 or 4 Feb (mid dormancy); 1 or 5 March (late dormancy); 2 or 7 April (bud swell); 2 or 7 May (flowers closely pressed together); and 1 or 6 June (40 to 50% of flower caps fallen), respectively. Vine yield and fruit composition at harvest were not affected by shift­ing from the standard pruning dates of mid and late dormancy to the bud swell stage. In contrast, the number of inflorescences in compound buds was significantly reduced for vines pruned in early May. No inflorescences were retained on vines pruned at the beginning of June. Early May pruning reduced fruit set and berry weight and slowed fruit ripening compared to the other pruning dates. At harvest, must soluble solids and titratable acidity were 1.6 Brix lower and 1.8 g/L higher, respectively, for the May treatment compared to the standard pruning dates. The early May pruning dates also achieved higher total anthocyanins and phenolic concentrations than the standard pruning dates, indicating that this technique can potentially decouple the accumulation dynamics of these components. Further studies are needed to better calibrate winter pruning date for managing yield and berry maturation rate. © 2016 by the American Society for Enology and Viticulture.

Background and Aims: Accelerated berry sugar accumulation resulting in wines of excessive alcohol concentration, sub-optimal colour and atypical flavour has become increasingly frequent in warm growing districts, a trend induced by factors that include global warming. The application of a film-forming antitranspirant may be an effective way of reducing early sugar accumulation without affecting colour development. Methods and Results: An antitranspirant emulsion was applied in 2013 and in 2014 on field-grown cv. Barbera vines at pre-flowering (PF), pre-veraison (PV) and at both dates (PFPV), and compared with the unsprayed control. Post-treatment assessment included seasonal gas exchange, yield components, growth of berry organs and must composition. Although all treatments were effective in reducing gas exchange by as much as 46% compared with that of the control, berry growth was not affected. Conversely, whereas PF slightly modified the ripening pattern, PV and PFPV markedly delayed accumulation of sugar in the warm 2013 season (-2.4 and -3.7° Brix, respectively, vs control) without detriment to colour development because the onset of anthocyanins occurred at lower TSS. In the cooler, wet 2014 season, PV and PFPV were again able to delay sugar accumulation without affecting colour development. Conclusions: Pre-veraison application of the antitranspirant alone or in combination with a PF spray proved effective in slowing sugar accumulation while avoiding concurrent delay of colour development. Significance of the Study: The use of antitranspirants is a practical and flexible way of regulating the sugar:anthocyanin ratio under conditions of excessively fast ripening. © 2016 Australian Society of Viticulture and Oenology Inc.

Background: Grapevine (Vitis vinifera L.) is an economically important crop with a wide geographical distribution, reflecting its ability to grow successfully in a range of climates. However, many vineyards are located in regions with seasonal drought, and these are often predicted to be global climate change hotspots. Climate change affects the entire physiology of grapevine, with strong effects on yield, wine quality and typicity, making it difficult to produce berries of optimal enological quality and consistent stability over the forthcoming decades. Results: Here we investigated the reactions of two grapevine cultivars to water stress, the isohydric variety Montepulciano and the anisohydric variety Sangiovese, by examining physiological and molecular perturbations in the leaf and berry. A multidisciplinary approach was used to characterize the distinct stomatal behavior of the two cultivars and its impact on leaf and berry gene expression. Positive associations were found among the photosynthetic, physiological and transcriptional modifications, and candidate genes encoding master regulators of the water stress response were identified using an integrated approach based on the analysis of topological co-expression network properties. In particular, the genome-wide transcriptional study indicated that the isohydric behavior relies upon the following responses: i) faster transcriptome response after stress imposition; ii) faster abscisic acid-related gene modulation; iii) more rapid expression of heat shock protein (HSP) genes and iv) reversion of gene-expression profile at rewatering. Conversely, that reactive oxygen species (ROS)-scavenging enzymes, molecular chaperones and abiotic stress-related genes were induced earlier and more strongly in the anisohydric cultivar. Conclusions: Overall, the present work found original evidence of a molecular basis for the proposed classification between isohydric and anisohydric grapevine genotypes.

Manipulating or shifting annual grapevine growing cycle to offset limitations imposed by global warming is a must today, and delayed winter pruning is a tool to achieve it. However, no information is available about its physiological background, especially in relation to modifications in canopy phenology, demography and seasonal carbon budget. Mechanistic hypothesis underlying this work was that very late winter pruning (LWP) can achieve significant postponement of phenological stages so that ripening might occur in a cooler period and, concurrently, ripening potential can be improved due to higher efficiency and prolonged longevity of the canopy. Variability in the dynamics of the annual cycle was created in mature potted cv. Sangiovese grapevines subjected to either standard winter pruning (SWP) or late and very late winter pruning (LWP, VLWP) performed when apical shoots on the unpruned canes were at the stage of 2 and 7 unfolded leaves. Vegetative growth, phenology and canopy net CO2 exchange (NCER) were followed throughout the season. Despite LWP and VLWP induced a bud-burst delay of 17 and 31 days vs. SWP, the delay was fully offset at harvest for LWP and was reduced to 6 days in VLWP. LWP showed notably higher canopy efficiency as shorter time needed to reach maximum NCER/leaf area (22 days vs. 34 in SWP), highest maximum NCER/leaf area (+37% as compared to SWP) and higher NCER/leaf area rates from veraison to end of season. As a result, seasonal cumulated carbon in LWP was 17% higher than SWP. A negative functional relationship was also established between amount of leaf area removed at winter pruning and yield per vine and berry number per cluster. Although retarded winter pruning was not able to postpone late-season phenological stages under the warm conditions of this study, it showed a remarkable potential to limit yield while improving grape quality, thereby fostering the hypothesis that it could be used to replace time-consuming and costly cluster thin

Allo scopo di fornire una descrizione viticola ed enologica dell'Ughetta di Canneto coltivata in zone tradizionali dell'Oltrepò Pavese, tra il 2002 e il 2005 è stata condotta la caratterizzazione delle uve di ceppi rappresentativi delle varietà Ughetta di Canneto, Barbera e Croatina reperite in due vigneti diti nei Comuni di Canneto Pavese (Az. Quaquarini, cv. Ughetta di Canneto), Cigognola (Az. Chiappedi, cvs. Barbera e Croatina). Per quanto riguarda la caratterizzazione enologica sono state considerate a titolo esemplificativo le degustazioni (analisi sensoriali) dei vini prodotti nel 2007; anche in questo caso di è operato un raffronto del vino ottenuto dall'Ughetta di Canneto con vini prodotti da altri noti vitigni locali coltivati in azienda (Croatina e Uva rara). In tutti i casi, le viti sono allevate a Guyot semplice con una distanza di 2,4m tra i filati e variabile da 1,0 m (Azienda di Riccagioia, piante singole) e 1,6m (Azienda Chiappedi, piante biante) lungo la fila.

Testing of new rootstocks for drought tolerance targets traditionally rain-fed districts where supplemental irrigation is more frequently needed due to the pressures of global warming. A seasonal evaluation of whole-canopy gas exchange, water-use efficiency (WUEc), yield components and compositional traits of Vitis vinifera cv. Sangiovese grafted to the new drought-tolerant genotype M4 against the commercial SO4 stock is reported. The experiment was conducted in 2015 on twelve four-year-old, fruiting potted Sangiovese grapevines grafted on M4 and SO4 stocks and assigned to SO4-WW (well-watered), SO4-WS (water-stressed), M4-WW and M4-WS treatments. Water deficit was imposed pre-veraison by reducing water supply to 50% of whole-canopy demand derived from concurrent measurements of transpiration in WW and maintained until three weeks after veraison prior to full rewatering. While WUEc was unchanged in WS-SO4 as compared to WW-SO4, WUEc in WS-M4 increased by 22% vs. WW-M4 over the whole water deficit period and such gain was partially maintained upon rewatering. Higher WUEc in WS-M4 resulted from an ability to maintain canopy photosynthesis similar to WS-SO4 at a reduced water use. Although yield per vine was similarly reduced in the two WS treatments (about 1 kg less than WW), overall grape composition was improved in WS-M4 and worsened in WS-SO4 when compared to the WW controls. Total soluble solids (°Brix) rose by 11% in WS-M4 vs. the respective control, whereas in WS-S04 there was a slight decrease (−0.6 Brix). Most notably, anthocyanins accumulation was largely limited in vines grafted on SO4 (−45% vs. WW-SO4 when given on a concentration basis), while in M4-grafted plants berry pigmentation slightly improved vs. WW (+12.5%). Hypothesis is made that grafting onto different stocks can trigger differential gene regulation under water stress and high temperatures leading to different sensitivity in synthesis and/or degradation of already formed anthocyanins.

Since machine introduction in the early 1970s, much work has been expended to adapt pruners to vine trellis and physiological requirements, especially regarding the higher bud load their non-selective cuts leave compared to manual trimming. While units have successfully met the former requirement, efforts to meet the latter have been hampered by a broad range of variables depending on cultivar, machine type, environmental conditions and any manual follow-up. Several examples are instructive here. Winter hedge pruning usually delivers best results with low-to-medium basal node fruitfulness coupled with some hand finishing, two crucial factors for achieving the desired balance of crop yield and quality similar to hand pruning but at lower cost. Minimal pruning has by and large proved unsuccessful in European environments, although some of its good features like looser, less rot-susceptible clusters, earlier canopy filling, lower individual shoot vigor and higher vine capacity can be reproduced using a semi-minimal pruned hedge (SMPH) system to better control over-cropping while maintaining desired grape composition. For instance, the best option for winter mechanical pruning in Italian districts today is the single high-wire cordon managed to maintain upright canopy growth for fast and physiologically sound cutter-bar pruning with little or no manual follow-up. A more comprehensive outlook seems to presage robotics for "precision" pruning to deliver a bud load that is adjusted to vine vigor and desired crop level.

Viticulture is in great need of new rootstocks sharing features of scion growth control and tolerance to major biotic and abiotic stress factors. A two year study was carried out in pots to assess performances of the two new M1 and M3 rootstocks vs. those of the commercial rootstocks 1103P and 101-14. Potted vines of M1, M3, 1103P and 101-14 rootstocks were grown in a calcareous and non calcareous soil and for two consecutive seasons subjected to three N supply levels at 0, 2 and 4 g of N per pot. Vegetative growth, leaf gas exchange, leaf greenness index (GI) and leaf blade nutrition were assessed. M1 and 1103P were the least vigorous genotypes in terms of total pruning weight; M1 also manifested a stronger apical dominance. Both M rootstocks and 101-14 showed increased leaf WUE at both N supply levels which was due to ability to maintain, at increasing N supply, similar leaf assimilation rates while significantly reducing leaf transpiration. Common tendency of any rootstocks was that increasing N supply corresponded to lowered leaf concentration of K, P, Mg and B. M1 was able to combine a series of desirable features including lower vigor, strong apical dominance, higher WUE at increasing N supply and quite well balanced leaf nutritional pattern. In the present trial M3 did not have the expected devigorating effect.

Ground-based proximal sensing of vineyard features is gaining interest due to its ability to serve in even quite small plots with the advantage of being conducted concurrently with normal vineyard practices (i.e., spraying, pruning or soil tilling) with no dependence upon weather conditions, external services or law-imposed limitations. The purpose of the present work was to test performance of the new terrestrial multi-sensor MECS-VINE® in terms of reliability and degree of correlation with several canopy growth and yield parameters in the grapevine. MECS-VINE®, once conveniently positioned in front of the tractor, can provide simultaneous assessment of growth features and microclimate of specific canopy sections of the two adjacent row sides. MECS-VINE® integrates a series of microclimate sensors (air relative humidity, air and surface temperature) with two (left and right) matrix-based optical RGB imaging sensors and a related algorithm, termed Canoyct). MECS-VINE® was run five times along the season in a mature cv. Barbera vineyard and a Canopy Index (CI, pure number varying from 0 to 1000), calculated through its built-in algorithm, validated vs. canopy structure parameters (i.e., leaf layer number, fractions of canopy gaps and interior leaves) derived from point quadrat analysis. Results showed that CI was highly correlated vs. any canopy parameter at any date, although the closest relationships were found for CI vs. fraction of canopy gaps (R2 = 0.97) and leaf layer number (R2 = 0.97) for data pooled over 24 test vines. While correlations against canopy light interception and total lateral leaf area were still unsatisfactory, a good correlation was found vs. cluster and berry weight (R2 = 0.76 and 0.71, respectively) suggesting a good potential also for yield estimates. Besides the quite satisfactory calibration provided, main improvements of MECS-VINE® usage versus other current equipment are: (i) MECS-VINE® delivers a segmented evaluation of the canopy up t

In this chapter, the conditions concerning the characteristics of viticulture and its products are described. In the first part, some methods to define the nutritional requirements of the vine in different situations are examined (grape varieties, areas of production), also thanks to the illustration of some emblematic case studies.The second part include the description of the main nutritional deficiencies (K, Mg, B, Fe) , reporting the photos of the symptoms and information about the causes, preventions and cure.

La potatura verde comprende una serie di operazioni condotte durante la stagione vegetativa volte a stabilire un equilibrio vegeto-produttivo ottimale, nonché a perseguire condizioni microclimatiche sfavorevoli agli insediamenti fungini e foriere di una buona qualità dell’uva. Molte di queste sono facilmente meccanizzabili, mentre i diradamenti dei germogli e dei grappoli, ancora forzatamente manuali, comportano un inevitabile aggravio dei tempi operativi. LA DEFOGLIAZIONE precoce e il diradamento dei grappoli influenzano le performance produttive e la composizione delle uve. Questi interventi di potatura verde possono essere utilizzati per accelerare l’accumulo zuccherino anticipando la vendemmia quando l’acidità del mosto è ancora su livelli ideali. Tale modulazione della maturazione può essere utile in tutti i vitigni bianchi destinati a vini frizzanti o spumanti che, in climi caldi, sono particolarmente esposti al rischio di non riuscire a mantenere acidità adeguate. Inoltre, a questo scopo, in condizioni ambientali che possono favorire marciumi e/o scottature del grappolo, la defogliazione precoce è preferibile.

Within-vineyard variability is known to deeply affect vine performance. Precision viticulture (PV) is a precious tool to describe and manage it through innovative variable rate technologies (VRT) that deliver a calibrated input according to the real vine need. Very few comparisons are still available between standard and VRT protocols. The present study aims to: i) describe within-field variability in a vineyard sited in the NW of Italy through a standard NDVI approach; ii) provide agronomical ground truthing on a two year basis (2012-2013) of the NDVI vigor levels; iii) evaluate mid-term effects of VRT-assisted N-supply. A multispectral image by remote sensing was taken on July 2010 (full canopy) on a mature, Guyot trained, cv. Barbera/ K5BB vineyard planted at 4167 vines/ha. Experimental layout was a vigor level x N-supply strategy factorial. Three vigor levels (low-LV, medium-MV and high-HV) were derived from the NDVI map, whereas the N strategy included traditional, VRA (VR application) and control. The N-supply (kg of N/ha) varied as it follows: control (0 kg/ha), traditional (60 kg/ha), VRT (0, 60 and 120 kg/ha in HV, MV and LV vigor blocks, respectively). In HV, pruning weight was higher than LV (895 vs. 485 g/vine), whereas berry and cluster weight and yield decreased from HV to LV (3 vs. 2.3 g, 291 vs. 181 g and 5.9 vs. 3.2 kg/vine, respectively). Cluster rot intensity varied according to compactness (12 vs. 57% and 17.5 vs. 23.5 g/cm in LV and HV, respectively). Total soluble solids, anthocyanins and phenols were higher in LV than HV (24.9 vs. 22 Brix, 1.56 vs. 0.89 g/kg and 2.66 vs. 1.74 g/kg), while malic acid was highest in HV (4.7 g/L). NDVI was closely correlated with pruning weigh, laterals growth, berry weight, cluster compactness and must pH. Vines from LV were most balanced and able to provide the best fruit quality in a context of long-aging red wine production. The VRA reduced N waste in HV while vines from LV blocks showed a low sensitivity to

Speciale Maturazione dell' uva - Si può ritardare la maturazione e contenere la produzione eseguendo la rifinitura manuale della potatura meccanica invernale a germogliamento avvenuto La risposta è positiva guardando i risultati preliminari. Va, tuttavia, verificato leffetto sulla differenziazione dei primordi fiorali delle gemme nellannata successiva.

In the present paper a series of WUE expressions, including the physiological and agronomical, were compared in potted cv. Sangiovese (Vitis vinifera L.) grapevines which were either well watered (WW) or subjected to progressive post-veraison water stress (WS) by supplying decreasing fractions (i.e. 70%, 50% and 30%) of daily canopy transpiration (Tc) concurrently recorded via a plant-enclosure gas exchange system. While single-leaf intrinsic water-use efficiency (WUEi) increased with water stress severity, seasonal whole-canopy WUE were similar at pre-stress, 70% Tc, and upon rewatering but dropped during severe water stress. WUE calculated as mass of dry weight stored in annual biomass (leaves, canes and clusters) per liter of water used, did not differ on a seasonal basis, whereas WW and WS showed similar grape composition despite the latter suffered a 25% yield reduction. Results confirm that whole-canopy WUE is a much better index than single-leaf based WUE parameter for extrapolation to agronomic WUE and actual grape composition. Under our specific case study, due to high reactivity of Sangiovese to early yellowing and shedding of basal leaves, it can be recommended that post-veraison water supply to Sangiovese vines should not be lower than 70% of daily vine water use

L'articolo esamina le prospettive legate alla meccanizzazione della potatura invernale della vite su forme d'allevamento con potatura lunga. Presentazione delle soluzioni in commercio per la stralciatura.

Several recent papers have shown that in grapevine (Vitis vinifera L.), interpretation of responses to drought can differ depending upon the parameter chosen to express water use efficiency (WUE). In the present paper, a series of WUE expressions, including physiological and agronomical, were compared in potted grapevines (Vitis vinifera L. cv. Sangiovese) that were either well-watered (WW) or subjected to progressive drought before veraison (WS) by supplying decreasing fractions (i.e. 70%, 50% and 30% of daily vine transpiration (Trd) determined gravimetrically before vines were fully rewatered. Although single-leaf intrinsic and instantaneous WUE increased with water stress severity, seasonal and whole-canopy WUE were similar to that before stress, at 70% Trd and upon rewatering, but dropped during severe water stress. WUE calculated as mass of DW stored in annual biomass (leaves, canes and bunches) per litre of water used did not differ on a seasonal basis, whereas WS plants showed lower must soluble solids at harvest, and unchanged colour and phenolic concentration in spite of smaller berries with higher relative skin growth. Results confirm that whole-canopy WUE is a much better index than any single-leaf based WUE parameter for extrapolation to agronomic WUE and actual grape composition. In our specific case study, it can be recommended that water supply to drought-stressed Sangiovese grapevines before veraison should not be lower than 70% of daily vine water use.

The increasing interest by the wine market in sparkling white wines challenges how the desired grape composition can be achieved under the pressure of global warming. The aim of the present study was to assess the viability of summer pruning as a tool to pilot ripening towards desired compositional patterns. Methods and Results: Ortrugo was subjected to basal leaf removal applied either at pre-flowering (ELR) or in lag-phase (LLR) and to bunch thinning (BT; removal of 50% of crop at lag-phase) in comparison with untreated control (C). Treatments induced large variation in bunch mass (30% less in ELR vs BT), yield per vine (37 and 21% less in BT and ELR vs C) and total soluble solids at harvest (BT scored 2.9°Brix higher than that of C). Conversely, given the same harvest date, all practices failed to maintain titratable acidity (TA) at the threshold of 6.5g/L. Conclusions: The data suggest that crop regulation achieved in the high yielding Ortrugo, through either BT or ELR, increases sugar accumulation rate so that concurrent optimal TA level (≅6.5g/L) can be easily achieved by slightly anticipating harvest date. Under conditions of thermal or light stress, or weather conducive to bunch rot, preference should be given to ELR. Significance of the Study: Suitable summer pruning techniques might be used as flexible and powerful tools to direct ripening towards the desired crop composition.

La produzione vitivinicola è regolata dalle caratteristiche del sito prescelto e si avvantaggia dell'attività dell'uomo che, operando le più idonee scelte colturali, ne modifica il naturale comportamento fisiologico. Le complesse relazioni che si instaurano fra ambiente fisico, genotipo e tecniche di gestione determinano l'agrosistema viticolo e concorrono alla definizione della qualità e dell'originalità delle produzioni vitivinicole. L'essenza della "viticoltura di territorio" si concretizza nella tradizione locale e si avvale delle nozioni che la ricerca e la tecnologia hanno reso disponibili nel corso degli anni. Partendo dal presupposto che il clima regola sia la qualità che la distribuzione geografica della coltivazione della vite, occorre scegliere la migliore combinazione fra vitigno e portinnesto che più si adatta al sito prescelto, caratterizzato da singolari condizioni termiche, idriche, luminose e pedologiche.

Si rivedono i principi che regolano gli interventi di gestione della chioma come la potatura (corta, lunga, tempi e modlaità di esecuzione), gli interventi in verde (cimatura, defogliazione, scacchiatura, sfemminellatura, diradamento e spollonatura) anche in riferimento all'adattamento delle tecniche al global warming.

Si è studiata l'adattabilità di nuovi portinnesti della vite a condizioni di differente disponibilità di azoto nel mezzo e verificato il loro effetto sulla nutrizione azotata di Vitis vinifera

E'stata studiata l'adattabilità di nuovi portinnesti della vite della serie M a condizioni di differente disponibilità di potassio nel mezzo e verificato il loro effetto sulla nutrizione minerale, in particolare potassico-magnesiaca, di Vitis vinifera

E'stata studiata l'adattabilità di nuovi portinnesti della vite della serie M a condizioni di differente disponibilità di potassio nel mezzo e verificato il loro effetto sulla nutrizione minerale, in particolare potassico-magnesiaca, di Vitis vinifera

Si è studiata l'adattabilità di nuovi portinnesti della vite a condizioni di differente disponibilità di azoto nel mezzo e verificato il loro effetto sulla nutrizione azotata di Vitis vinifera

Amid growing concerns over global warming and available management strategies for reducing cluster temperature to prevent overheating and sunburn damage, there is increasing interest in sprawling, non-positioned canopies as an alternative to traditional vertically-positioned ones. However, management of sprawling canopies needs adjustments so that a mostly erect growth pattern is maintained during the season. A three-year study (2009–2011) was carried out to investigate the performance of 15-yr-old Pinot noir grapevines trained to a single high-wire trellis (SHW) subjected to pre-bloom shoot trimming to retain seven (T7) or eleven (T11) main stem leaves. Results showed significant year x treatment interactions: with a low crop and weather conducive to post-trimming lateral re-growth in 2010, trimmed vines had higher leaf area, soluble solids concentration, pH, total anthocyanins and cluster rot incidence than control vines, whereas in 2009 and 2011 the overall must compositional pattern was reversed due to sub-optimal leaf-to-fruit ratios in the trimmed plots. The effects linked to this necessary operation are very much dependent upon unpredictable weather occurring after shoot trimming and, hence, the milder trimming severity (T11) may more successfully balance the need of inducing a still mostly erect canopy while retaining more vine leaves to buffer any weak lateral formation after trimming. The paper provides new and useful knowledge for improved canopy management in trellises having free shoot growth due to absence of foliage wires.

Ten clones of V. vinifera L. 'Cabernet Sauvignon' from different origins (Italy, clone R5; Chile, clone ISV117; California, clones VCR8 and ISV2; France, clones 191, 341, 338, 169, 685; Argentina, clone ISV105), grafted on V. Berlandieri × V. riparia SO4 rootstock, were grown in pots to compare vegetative, productive (bud fertility, grape yield, mean cluster and berry weight) and qualitative (soluble solids, pH, titratable acidity, tartaric acid, anthocyanins, polyphenols, stilbenes) parameters. The clones showed similar yields but different cluster and berry weights. Differences in phenolic and technological maturity were observed.

A breeding programme by intra-specific crossing was set up in 1989, in the experimental Station "Riccagioia" (Lombardia region, north-west Italy), with the aim of getting new varieties mainly for white sparkling wine. V. vinifera L. 'Riesling italico' was used as the female parent, while cv. 'Pinot noir' and cv. 'Chardonnay' were used as males, resulting in two progenies (designated RPN and RCH). 900 and 400 seedlings were obtained from RPN and RCH crossings respectively, and a low-pressure field selection was performed, choosing 50 individuals out of the 1,300, by utilizing as screening criteria vegetative habit, phenology, ripening and health aspects. The selected seedlings were grafted on SO4 rootstock, and the productivity and qualitative grape parameters of the field-grown vines were checked over a 4-year-period (2002- 2005) by multifactorial analysis of variance (MANOVA) and SNK (Student Newman Keuls). DNA fingerprinting (by microsatellite) of the progenies and the parent varieties was performed as well, confirming the parentage. Grapes were vinified at harvest, and the wines were evaluated according to sensory analysis, by processing the main descriptors by the non parametric Friedman test. According to the above mentioned parameters, three new varieties were selected, as follows: RCH10 and RPN33 (both white berry) and RPN26 (red berry), due to a good canopy (RCH10), high acidity and sugar and very low cluster and berry weight (RPN26). RCH10 and RPN33 are interesting for sparkling wine because of the white color, the wider sensorial profile and the highest pleasure indices, as compared to the parents (cv. 'Riesling italico' and cv. 'Pinot noir'). RPN 26 has an unexpected later ripening and a wine color intensity much higher than 'Pinot noir', being suitable for the production of red wines; according to the high-pressure selection tightly connected with the objectives of this breeding program, this genotype would have been excluded in the first step of the sel

Understanding how water use efficiency (WUE) changes under drought is crucial for interpreting adaptive responses of species and cultivars to such abiotic stress. Several recent papers have concluded that in grapevine these responses and the guidelines stemming therefrom can differ, depending upon the parameter chosen to express WUE. In the present paper a complete set of WUE expressions, including the physiological and agronomical, were compared in potted, fruiting cv. Montepulciano (Vitis vinifera L.) grapevines which were either well watered (WW) or subjected to progressive pre-veraison drought (WS) by supplying decreasing fractions (i.e. 70%, 50% and 30% of daily vine transpiration, Tg) determined gravimetrically before vines were fully rewatered. While single-leaf intrinsic water-use efficiency (WUEi) increased with water stress severity, seasonal and diurnal whole-canopy WUE were similar at pre-stress, 70% Tg, and upon rewatering but dropped in WS during severe water stress. Agronomic WUE calculated as mass of dry weight stored in annual biomass (leaves, canes and bunches) per L of water used, was also lower in WS, whereas WS had similar must composition with WW despite a 37% reduction in the yield per vine. Results warn that whole-canopy WUE is a much better index than any single-leaf based WUE parameter for extrapolation to agronomic WUE and actual grape composition. Under our specific case study, it can be recommended that, to avoid significant profit loss, water supply to drought stressed Montepulciano at pre-veraison should not be lower than 70% of daily vine water use.

A multichamber whole-canopy gas exchange system coupled with an automatic pot weighing device was tested for continuous 24 hr recording over 50 days in a trial comparing cv. Sangiovese vines subjected to progressive reduction of total transpiration water supply to well-watered vines. The system ran smoothly under regular maintenance for the entire period and gravimetric vine water loss was highly correlated with chamber-derived vine transpiration (r = 0.95) for data pooled over treatments. Seasonal and diurnal whole-canopy net CO2 exchange rate (NCER) and transpiration (Tc) showed that supplying 50% and 30% of daily gravimetric vine water loss (Tg) consistently corresponded to a NCER more than proportionally limited as compared to Tc, hence leading to lower canopy water-use efficiency (WUE) expressed as NCER/Tc ratio. Conversely, canopy WUE did not differ between treatments at 70% Tg restitution and rewatering. Similarly, during the most limiting water supply periods, the WUE difference between treatments was greatly reduced during cloudy days with lower vapor pressure deficit and higher diffuse-to-direct light intensity ratio. Data sets taken over different time frames on whole-canopy WUE provide a scenario different from that which might derive from traditional single-leaf assessment, reporting in almost all cases that intrinsic WUE increases under stress and suggests that the methodology used can mask or alter conclusions about adaptive response of grapevine cultivars to water stress. © 2014 by the American Society for Enology and Viticulture. All rights reserved.

One of the main objectives of wine grape growers in several viticultural areas throughout history has been the achievement of full ripening, i.e. maximum soluble solids concentration in the absence of apparent berry shrinkage. Recently, this target is somewhat losing its appeal since an increasing number of consumers from both domestic and foreign markets prefer lighter wines characterized by moderate alcohol content. The above scenario needs to be added of another actor, i.e. the global warming and its effects on vine growth and berry composition which can be summarized as it follows: (i) onset of flowering and veraison phenological stages occurs earlier; (ii) grape ripening is generally accelerated as per increment of sugar accumulation into the berries which, in turn, leads to higher alcohol content in the wine; (iii) faster depletion of organic acids in the juice and more rapid increase of pH values which, as a consequence, triggers high microbiological instability of the must during pre-fermentation; (iv) due to excessive heat summations and poor thermal excursion the overall aroma profile can result untypical shifting towards overripe; (v) uncoupling of technological (more accelerated) and phenolic (more delayed) ripening with negative effects on grape and wine aroma and flavor, especially in red grape varieties; (vi) higher frequency of berry withering up to sun burn damage. In the medium-to-long term these factors likely will affect the geographical distribution of viticulture and will require new breeding programs for selecting more adapted roostocks and scions, whereas in the short term, new management techniques able to mitigate these negative impacts are urgently needed. In this review, several tools including varietal and clonal choice, possible diversification of wines produced, suitable training system and rootstocks, traditional and innovative management techniques able to regulate a too much accelerated and/or unbalanced grape ripening process, will

A dynamic crop growth model based on availability of a minimal set of weather data and elemental vineyard and plant characteristics is described and its accuracy at predicting phenology, leaf area development, light interception and pending yield evaluated. Outputs calibration based on field measurements was carried out over 2011-2012 on hedgerow trained cv. Barbera (Vitis vinifera L.) vines having either low-density (LD, ≅10 shoots per m of row) or high density (HD, ≅ 60 shoots per mof row) canopies. Model validation was then carried out based on a five year (2003-2007) independent dataset characterized by a wide inter-annual variability of meteorological conditions. During calibration, MAE, CRM and R2 values evinced high-to-very high model accuracy at predicting phenology, leaf area development, total light interception and pending yield for any year×treatment combination. The validation procedure showed that, despite large inter-annual weather variability, final yield was very accurately predicted (R2=0.96 in LD and R2=0.94 in HD), whereas precision at simulating final total leaf area was higher in HD (R2=0.92) than in LD (R2=0.63). Due to its flexibility the model can also be easily applied to the analysis of long time series of meteorological data coming from weather stations where only daily maximum and minimum temperature and daily precipitation are available and it can also be run in a forecast mode. Moreover, the broad range of released outputs renders the model an ideal tool to be used in decision support system applications which typically rely on real time or forecast estimation of vine development parameters.

L’Ortrugo (Vitis vinifera L.) è un vitigno autoctono piacentino a bacca bianca che, di recente, ha ridestato un notevole interesse tra i viticoltori grazie alla facile collocazione commerciale del vino che se ne produce, particolarmente apprezzato dai consumatori locali. Tuttavia, l’Ortrugo è indubbiamente una varietà difficile da coltivare poiché facilmente soggetta ad eccesso di produzione e caratterizzata da grappoli compatti che, specie in annate con marcata piovosità pre-vendemmiale, aggravano la sensibilità nei confronti dei marciumi fungini. Inoltre, gli effetti del cambio climatico sulla viticoltura hanno accentuato ulteriormente, e talvolta in maniera preoccupante, la degradazione degli acidi organici durante la maturazione imponendo vendemmie spesso troppo anticipate e associate a una perdita di tipicità del vino. La ricerca, condotta nel triennio 2011-2013, si è proposta di: a) definire la relazione esistente tra carico produttivo e composizione dell’uva; b) migliorare la morfologia del grappolo e della bacca ponendo a confronto le seguenti tesi: diradamento dei grappoli in pre-invaiatura (DIR), defogliazione basale in pre-fioritura (DF) e in pre-invaiatura (DI) e, infine, un testimone non trattato (T). Le foglie principali e le eventuali femminelle sviluppatesi dai primi sei nodi basali del germoglio sono state eliminate mentre il diradamento è stato applicato asportando il 50% dei grappoli.

According to the importance of nitrogen nutrition and the enviroment on the quantitative and qualitative grapevine production, an experiment was conduced, from 2008 to 2011, in a Cabernet Sauvignon vinyard in Oltrepò Pavese (north-west Italy), to check the nutritional effect of different nitrogen formulations in reference to the quality of grapes produced (used products: calcium cyanamide, ammonium nitrate and Nitrophoska gold was tested for 60 kg/ha of N, in comparison with a control). The application of fertilizer was divided in randomized block design and it was used the multifactorial ANOVA (with sources of variation: fertilization, different position in the field and year, and their interactions) to measure also the importance (sum of squares) of each source of variation. The main variables measured: leaf mineral composition (limbe and petioles), presence of chlorophill (SPAD) weight of berry and grapes per vine, sugars, acids and anthocyanins in the must. The main factors that have affected the vegetation and the production of the vines are estimated in the climate (by the year factor) and in soil (by the block factor). The fertilizers, that among them have not shown any substantial difference, has showed a significant increase of nitrogen concentrationi in leaves (veraison) and a significant reduction of sugar, anthocyanins and tartaric acid/malic acid.

In questa ultima decade, lo studio della “variabilità” vegeto-produttiva esistente nel vigneto ha assunto connotati fortemente innovativi e, per certi aspetti, dirompenti grazie alle tecniche di “agricoltura di precisione” basate sull’acquisizione di immagini aeree (da satellite o da velivoli radiocomandati) che, dopo essere state sottoposte a procedure di orto-rettifica e ri-campionamento, restituiscono mappe di vigore che, a loro volta, presentano una segmentazione in “classi di vigore” (solitamente da 2 a 10) definite dall’indice NDVI (Normalized Difference Vegetation Index). Lo scopo di questa review è duplice; in primo luogo valutare criticamente in che misura nozioni classiche e ben consolidate di fisiologia possono interfacciarsi con le tecniche di viticoltura di precisione (VT) e, in seconda battuta, vagliare la valenza fisiologica di tecniche colturali a “rateo variabile” anch’esse figlie dell’approccio VT. Il lavoro discute il grado di correlazione tra valori di NDVI e parametri di “vigoria” e di funzionalità della chioma ponendo in guardia da un uso generalizzato di indici di vigoria appetibili poiché di facile rilevazione (es. peso di potatura) e, soprattutto, dal significato fisiologico dell’aggettivazione “alta vigoria” che, a seconda delle condizioni del sito in cui si opera, può di fatto corrispondere ad una vigoria in realtà oggettivamente modesta. Il secondo filone del lavoro è dedicato ai rapporti tra fisiologia e tecnologie di intervento basate sull’intelligente principio del “rateo variabile” (RV), ovvero della immissione nel sistema di input in quantità variabile e quindi “personalizzata” in funzione delle esigenze evidenziate dalle mappe di vigore. Le operazioni a rateo variabile prese in esame sono concimazione, defogliazione e vendemmia e, specie per le prime due, viene segnalata l’esigenza, laddove si voglia operare un confronto corretto tra “rateo” e “tradizionale” di predisporre piani sperimentali che non si limitino a valutare come cambi

Background and Aims: Postveraison limitation of canopy photosynthesis delays grape berry ripening and reduces sugar accumulation, thus lowering the alcohol content of the subsequent wines. This study was designed to evaluate whether similar results could be obtained by defoliation apical to the bunch zone using a leaf-plucking machine when berry sugar content was approximately 16-17°Brix. Methods and Results: In 2011 and 2012, defoliation treatments were applied postveraison to cv. Sangiovese vines (D) on either side of each row using a mechanical leaf remover, and these D vines were compared to a nondefoliated control (C). The machine removed 35% of the leaves on the vine and created a 50-cm vertical window without leaves above the bunch area, but retained a few leaves at the canopy apex (about 0.50m2/vine). In both years, leaf removal reduced the rate of berry sugar accumulation and led to a 1.2 lower harvest °Brix and consequently, a lower wine alcohol (-0.6%) content in D relative to that of C vines. In 2012, sugar content of D vines, monitored in a group of vines that was not harvested, had recovered to that of C vines 2 weeks after harvest. The concentration of total phenolic compounds in the grapes, the chemical and chromatic characteristics of the wines and the replenishment of soluble sugars, starch and total nitrogen in the canes and roots were similar in the D and C vines. Conclusion: To achieve an effective delay in sugar accumulation in the berries, leaves should be removed at 16-17°Brix, and at least 30-35% of vine leaf area should be removed. Significance of the Study: Mechanical removal of leaves postveraison above the bunch zone of Sangiovese can be an easy and economically viable technique for delaying sugar accumulation in the berries and for limiting the alcohol content of wines with no negative impact on desirable composition of either berries or wines.

Background and Aims: Global warming is inducing a general earliness in the onset of grapevine phenological stages including ripening, a phenomenon that occurs often in the hottest seasons and which leads to unbalanced wines. Our aim was to assess the physiological basis of late leaf removal applied above the bunch area as a tool for delaying ripening. Methods and Results: Potted cv. Sangiovese grapevines were subjected to leaf removal treatments applied preveraison (DEF-I) and postveraison (DEF-II) by pulling out six to seven primary leaves and laterals, if any, above the bunch zone; untouched vines served as the control. Whole-canopy net CO2 gas exchange was monitored seasonally from 9 days before DEF-I to 35 days after DEF-II. Concurrently, single-leaf gas exchange was assessed, and at harvest yield components, grape composition and the leaf-to-fruit ratio were determined. The seasonal carbon/yield ratio did not differ between treatments because of the high capacity for photosynthetic compensation shown by the DEF treatments and quantified as about a 35% higher net CO2 gas exchange per unit of leaf area per day. While ripening was temporarily retarded in both DEF treatments, with sugar content being lower and titratable acidity higher, a week later both treatments had fully or partially recovered; phenolic ripening was unaffected at either harvest date. Conclusions: Defoliation above the bunch zone applied at lag-phase and postveraison (average 12°Brix) was effective in temporarily delaying technological ripeness without affecting colour and phenolics. This result depended upon the high compensation capacity for photosynthesis shown by vines in both treatments. Significance of the Study: The data provide a preliminary yet robust physiological background for targeting better field application of the technique.