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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.

Stomatal conductance is regulated by many factors such as air vapour pressure deficit (D), which can be the pivotal one affecting leaf gas exchange in species particularly sensitive to D such as C. avellana. The aim of this work was to evaluate stomatal sensibility to D and to determine correlations with hydraulics characteristics of leaves in three genotypes of C. avellana selected over centuries under different climatic conditions in the Italian peninsula. Among the three varieties Tonda Gentile delle Langhe (TGL), which was the one coming from northern Italy suffered the largest stomatal limitation at increasing levels of D in comparison with the other two cultivars [Tonda Romana (TR) and Tonda di Giffoni (TG), selected in central and southern Italy, respectively]. In all genotypes, photosynthesis decreased at high D although the reduction was mostly due to the rising of the temperature as suggested by the high values of sub-stomatal concentration of CO2. Concerning the hydraulic characteristics of the leaves, TG had considerable higher bulk elasticity compared with other two cultivars. These results contribute to explain the higher adaptability to different environments of TG and TR compared with TGL. Either the lower sensitivity to D of TG and TR and higher schlerophylly of TG might allow these cultivars to suffer less gas exchange limitations in hot and dry environments usually conducive to high D. Genotypic sensitivity to D represent one of the key factors to be considered in phenotyping protocols for D-sensitive species such as hazelnut.

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%).

Early leaf removal significantly alters the source-sink balance within grapevine shoots, leading to a reduction in fruit set. However, no research has previously examined the conditions controlling this process in terms of carbon allocation among major sink organs following defoliation. In this study, the impact of defoliation at bloom on the distribution dynamics of leaf assimilates among clusters and growing shoot apices was investigated on Vitis vinifera, cv. Pinot noir, grown in Michigan, a cool climate viticultural region. Three levels of defoliation: no leaves removed (LR-0); six leaves removed from six basal nodes (LR-6); andten leaves removedfromten basal nodes (LR-10), were imposedat full bloom. A13 C pulsing was performed 1 week after the treatment application to the defoliated shoots. Single leaf gas exchange (Pn), diurnal changes of the leaf net CO2 assimilation rate, carbon distribution, fruit-set, yield, and fruit composition were measured. Higher Pn was recorded in diurnal measurements of gas exchange in leaf removal (LR) treatments compared to LR-0. The shoot apex of LR-10 experienced the highest13 C allocation (%) after 3 and 7 days following the carbon pulsing. LR-10 had lower percentage of13 C allocated to clusters, which decreased fruit set by 60%, compared to the control, and enhanced the concentration of phenolic compounds in fruit. Alteration of carbon portioning among shoot sink organs indicated that an increasing severity of leaf removal significantly reduced fruit set, and was linearly correlated to shoot apex sink strength, which occurred at the expense of the cluster.

Frequency of extreme drought events are expected to increase due to climate change. Perennials are increasingly exposed to recurrent drought during their life span. The aim of the present work was to study the effect of recurrent droughts on the behavior of Vitis vinifera under water stress. Sangiovese and Montepulciano vines were exposed to severe drought stress for 4 years (WS-S). A dry-down experiment was carried out to compare their behavior with a set of vines kept at 90% field capacity during the whole seasons in the previous 4 years (WW-S). WS-S vines had higher transpiration and stomatal conductance than WW-S vines. Net photosynthesis was almost unaffected by the treatment. Stomatal conductance was higher at more negative Î ̈stemin WS-S vines than in control vines. Leaf petiole percentage loss of hydraulic conductance, measured during water stress, was higher in WS-S than in WW-S vines. Results indicate that previous water stress can lead to less conservative plant strategy toward water loss and decreased water use efficiency. This behavior seems to be coordinated with the different stomatal response to decreasing water potential that caused a reduction of xylem hydraulic safety margin in WS-S vines in comparison with WW-S vines.

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

Climate warming is causing an advance of the latest spring frosts and a consequent decrease of spring freeze risk during flowering. Cultivation areas of early blooming tree crops, such as almond, could be shifted pole-ward as consequence of global warming. On the other hand, warming winters and springs can cause an advance of the flowering period. The aim of the present work was to estimate which was the impact of climate change in the past six decades on the spring freeze damage risk during the almond blooming period in the Abruzzo region of Italy. According to our analysis a reduction of spring freeze risk due to the mitigation of springtime temperatures was counterbalanced by advanced almond blooming leaving the risk of spring freeze damage unchanged. These results suggest that the adaptation of almond phenology to changing climates could continue to limit the northward expansion of almond in Italy. Finally, these results may suggest that the loss of suitable areas due to loss of chilling units in the warmest climate areas cannot be compensated for by a pole-ward shift of almond plantings.

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.

Trunk shakers are among the most widespread machines for mechanical harvesting in intensive olive orchards (300–500 trees ha−1). Harvesting effectiveness is an important issue for this sort of machine because, due to the heterogeneity of the tree canopy structure, vibration transmission is uneven and some branches vibrate poorly. The aim of the present work was to determine if the removal of internal suckers before harvesting could improve vibration transmission and harvesting effectiveness. ‘Leccino’ and ‘Frantoio’ trees trained to free vase and planted in an intensive olive orchard (400 trees ha−1) were used in experiments carried out in 2012 and 2013 in two different orchards. Triaxial accelerometers, placed on tree trunk and on the main branches, were used to measure vibration transmitted to the canopy by two custom-built orbital and multidirectional trunk shakers. On average, harvesting effectiveness increased significantly from 83.4% to 95.6% as a consequence of sucker removal. Maximum acceleration transmitted to the trunk and branches increased by 33.1% and 46.6% respectively after internal sucker removal. These results suggest that internal suckers reduce vibration transmission through the canopy, affecting harvesting effectiveness. Furthermore, the larger the fruit retention force per fruit mass was, the larger was the effect of sucker removal on harvesting effectiveness. These results suggests that sucker removal prior to harvesting is advisable to improve harvesting effectiveness in open vase trees harvested by trunk shakers, in particular when mechanical harvesting is carried out at an early stage of fruit ripening.

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.

Intra-specific variability can be used as an important tool to contrast and mitigate the negative impacts of climate change. In particular, under Mediterranean climate conditions, drought stress is becoming a crucial issue for growers. Vine performance, taking into account vine yield and grape composition, is dependent on the vine capability of assimilating CO2 and fix it into carbohydrates throughout the whole season. Under water stress, stomatal regulation, that allow plants to prevent excessive water loss and tissue drying, limits leaf gas exchanges. Understanding the mechanisms regulating stomatal closure is crucial to determine the behaviour of genotypes under water stress. Two main mechanisms are accredited for controlling stomatal conductance under water stress: active mechanisms, based on the biosynthesis of hormonal signals, mainly abscisic acid (ABA), and passive mechanisms, mainly based on the variation of leaf turgor pressure as the plant water potential decreases during water stress. New research evidences pointed out that the capability of genotypes to close stomata at a given stem water potential threshold was correlated with its xylem vulnerability to cavitation. ABA accumulation in the leaf appears to be subsequent to stomata closure suggesting that, in vivo, stomatal conductance mainly rely to passive mechanism rather than to active ones. Hydraulic properties of each genotype appear to control their stomatal behavior under water stress consistently with the rising opinion that intraspecific variability of stomatal behavior cannot be discriminated into two different categories (isohydric and anisohydric) but should be represented as a continuum of genotypes with different levels of anisohydry. These results underline the need to learn more about the phenotype of grape cultivars. Growers will be able to use such information by planting more tolerant genotypes depending on the vineyard condition and to use different water potential thresholds for irri

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.

Viticulture is widely practiced in dry regions, where the grapevine is greatly exposed to water stress. Optimizing plant water use efficiency (WUE) without affecting crop yield, grape and wine quality is crucial to limiting use of water for irrigation and to significantly improving viticulture sustainability. This study examines the use in vineyards of particle film technology (engineered kaolin) and compares it to a film-forming antitranspirant (pinolene), traditionally used to limit leaf water loss, and to an untreated control. The trial was carried out under field conditions over three growing seasons, during which moderate to very severe plant water stress (down to -1.9 MPa) was measured through stem water potential. Leaf stomatal conductance (gs ) and photosynthesis rate (An ) were measured during the seasons and used to compute intrinsic WUE (WUEi, defined as An /gs ratio). Leaf temperature was also recorded and compared between treatments. Bunch quantity, bunch and berry weight, sugar accumulation, anthocyanin and flavonoid contents were measured. Finally, microvinifications were performed and resultant wines subjected to sensory evaluation.Results showed that the use of kaolin increased grapevine intrinsic WUE (+18% on average as compared to unsprayed vines) without affecting berry and bunch weight and quantity, or sugar level. Anthocyanin content increased (+35%) in kaolin treatment, and the wine was judged more attractive (p-value <0.05) and slightly more appreciated (p-value < 0.1) than control. Pinolene did not increase WUEi, limiting An more than gs; grapes with this treatment contained lower sugar and anthocyanin content than control, and the obtained wine was the least appreciated. This study demonstrates that particle film technology can improve vine WUEi and wine quality at the same time, while traditional antitranspirants were not as effective for these purposes. This positive effect can be used in interaction with other already-demonstrated

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

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

Lo studio è stato condotto - to nel biennio 2011-2012 in un vigneto sito nel comune di Magione (PG) e costituito da Sangiovese innestato sul portinnesto 3309 C, al - levato a cordone speronato e impiantato a 2,5 m × 0,8 m (5.000 ceppi/ha). Le tesi “defogliazione meccanica” e “controllo” sono state distribuite secondo un disegno a tre blocchi randomizzati lun - go sei filari adiacenti. La de - fogliazione è stata applicata in post-invaiatura, quando la concentrazione di zuccheri nel mosto era di ~17°Brix, utilizzando una defogliatrice Binger (Seilzug GmbH & Co., Germania) (Foto 1 e 2), che ha operato su entrambi i lati del filare, asportando le foglie inserite nella porzione mediana e apicale dei germogli lasciando inalterati 10-20 cm apicali. Durante la maturazione sono state monitorate le cinetiche di accumulo degli zuccheri, mentre alla raccolta sono state determinate la composizione dell’uva e la produzione unitaria. Alla vendemmia sono state eseguite microvinificazioni, prelevando 200 kg d’uva da ciascuna tesi, e sui vini ottenuti sono stati de - terminati i parametri di base. Durante il riposo invernale è stata determinata la concentrazione di zuccheri, amido e azoto totale in tralci e radici. I dati sono stati sottoposti ad ANOVA e le medie separate con il test Student-NewmanKeuls (P ¬ 0,05). Nel lavoro sono riportati i dati medi del biennio 2011/2012.

Over the last decade, the extent and severity of heat and light stress, often in combination with water scarcity, have caused extensive agricultural losses all over the world. There is consensus that the Vitis vinifera L. displays large variations in terms of tolerance to abiotic summer stresses, i.e. excessive temperature and radiation, water shortage in the soil and high leaf-to-air water vapour pressure deficit (VPD), both when considered alone or in combination. However, a quantification of the effects of such factors on source function and sink strength is crucial to avoid severe imbalances between vine growth and yield, to optimize the use of natural resources, especially water and light, and to develop appropriate management strategies. Therefore, this chapter will provide a brief overview about current knowledge on light and heat stresses with or without a concurrent water stress and how they mutually interact to modify physiology, growth patterns and productivity in the grapevine. Chapter complements this review by summarizing in particular the impact of light, water and heat in berry composition.

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

Over the last decade, the extent and severity of heat and light stress, often in combination with water scarcity, have caused extensive agricultural losses all over the world. There is consensus that the Vitis vinifera L. displays large variations in terms of tolerance to abiotic summer stresses, i.e. excessive temperature and radiation, water shortage in the soil and high leaf-to-air water vapour pressure deficit (VPD), both when considered alone or in combination. However, a quantification of the effects of such factors on source function and sink strength is crucial to avoid severe imbalances between vine growth and yield, to optimize the use of natural resources, especially water and light, and to develop appropriate management strategies. Therefore, this chapter will provide a brief overview about current knowledge on light and heat stresses with or without a concurrent water stress and how they mutually interact to modify physiology, growth patterns and productivity in the grapevine. Chapter complements this review by summarizing in particular the impact of light, water and heat in berry composition.

Adventitious root formation in plant cuttings is influenced by many endogenous and environmental factors. Leaf photosynthesis during rooting of leafy cuttings in hard to root species can contribute to supply carbohydrates to the intensive metabolic processes related to adventious root formation. Light intensity during rooting is artificially kept low to decrease potential cutting desiccation, but can be limiting for photosynthetic activity. Furthermore, leafy cuttings collected from different part of the shoot can have a different ability to fuel adventitious root formation in cutting stem. The aim of this work was to determine the role of leaf photosynthesis on adventitious root formation in hazelnut (Corylus avellana L) (a hard-to-root specie) leafy cuttings and to investigate the possible influence of the shoot developmental stage on cutting rooting and survival in the post-rooting phase. Cutting rooting was closely related to carbohydrate content in cutting stems during the rooting process. Cutting carbohydrate status was positively influenced by leaf photosynthesis during rooting. Non-saturating light exposure of leafy cuttings can contribute to improve photosynthetic activity of leafy cuttings. Collection of cuttings from different part of the mother shoots influenced rooting percentage and this appear related to the different capability to concentrate soluble sugars in the cutting stem during rooting. Adventitious root formation depend on the carbohydrate accumulation at the base of the cutting. Mother shoot developmental stage and leaf photosynthesis appear pivotal factors for adventitious roots formation.

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

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.

Here, we describe a novel device for programming and replenishing water transpired by potted plants. To test the robustness of the system, vines were subjected to progressive water stress (WS), the severity of which was maintained in relation to transpiration (Tc) of well-watered (WW) plants. Throughout the 40-day experiment, water supply in the WS treatment was progressively lowered to 70, 50, and 30% of WW Tc prior to rewatering. During the same stages, mean Tc of WS plants was 74, 48, 28, and 93% that of WW plants. Linear relationships between vine transpiration and water supply during the 40-day experiment (R2 = 0.95 for WW and 0.94 for WS) confirmed the reliability of the system in providing a water supply that closely tracked measured transpiration. The emptying volume of the cylinder t ank was set at 265 m L and proved to be adequate for daily water losses, which ranged from ~300 to 2300 mL. In addition to relieving operators of laborious and time-consuming manual irrigation, the system provides the ability to adjust water supply to actual water use as measured concurrently in a grapevine-enclosure system and enables customization of the water supply according to the size and transpiration potential of each vine.

Grape berry composition mainly consists of primary and secondary metabolites. Both are sensitive to environment and viticultural management. As a consequence, climate change can affect berry composition and modify wine quality and typicity. Leaf removal techniques can impact berry composition by modulating the source-to-sink balance and, in turn, may mitigate some undesired effects due to climate change. The present study investigated the balance between technological maturity parameters such as sugars and organic acids, and phenolic maturity parameters such as anthocyanins in response to source-sink modulation. Sugar, organic acid, and anthocyanin profiles were compared under two contrasting carbon supply levels in berries of cv. Cabernet Sauvignon and Sangiovese collected at 9 and 14 developmental stages respectively. In addition, whole-canopy net carbon exchange rate was monitored for Sangiovese vines and a mathematic model was used to calculate the balance between carbon fixation and berry sugar accumulation. Carbon limitation affected neither berry size nor the concentration of organic acids at harvest. However, it significantly reduced the accumulation of sugars and total anthocyanins in both cultivars. Most interestingly, carbon limitation decreased total anthocyanin concentration by 84.3% as compared to the non source-limited control, whereas it decreased sugar concentration only by 27.1%. This suggests that carbon limitation led to a strong imbalance between sugars and anthocyanins. Moreover, carbon limitation affected anthocyanin profiles in a cultivar dependent manner. Mathematical analysis of carbon-balance indicated that berries used a higher proportion of fixed carbon for sugar accumulation under carbon limitation (76.9%) than under carbon sufficiency (48%). Thus, under carbon limitation, the grape berry can manage the metabolic fate of carbon in such a way that sugar accumulation is maintained at the expense of secondary metabolites.

Photosynthetic performances and energy dissipation mechanisms were evaluated on the anisohydric cv. Sangiovese and on the isohydric cv. Montepulciano (Vitis vinifera L.) under conditions of multiple summer stresses. Potted vines of both cultivars were maintained at 90% and 40% of maximum water availability from fruit-set to veraison. One week before veraison, at predawn and midday, main gas-exchange and chlorophyll fluorescence parameters, chlorophyll content, xanthophyll pool and cycle and catalase activity were evaluated. Under water deficit and elevated irradiance and temperature, contrary to cv. Montepulciano and despite a significant leaf water potential decrease, Sangiovese's leaves kept their stomata more open and continued to assimilate CO2 while also showing higher water use efficiency. Under these environmental conditions, in comparison with the isohydric cv. Montepulciano, the protective mechanisms of energy dissipation exerted by the anisohydric cv. Sangiovese were: (i) higher stomatal conductance and thermoregulation linked to higher transpiration rate; (ii) greater ability at dissipating more efficiently the excess energy via the xanthophylls cycle activity (thermal dissipation) due to higher VAZ pool and greater increase of de-epoxidation activity.

Nel capitolo si focalizza l'attenzione sulla problematica relativa al global warming e alla intensità e distribuzione della piovosità annuale come eventi che hanno influenzato la viticoltura, costringendo i viticoltori, non abituati in precedenza a ricorrere ad interventi irrigui, ad affrontare questa nuova esigenza. Si pone l'attenzione sugli strumenti e tecniche a disposizione per far sì che l'apporto idrico si imponga come fattore di "qualità" in vigneto sfatando alcuni luoghi comuni che associano a qualsiasi apporto idrico esogeno il connotato di tecnica di forzatura.

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.

Di recente sono stati prodotti autorevoli aggiornamenti su tipologia, struttura e modalità di allevamento delle viti e gestione dei diversi sistemi. L'analisi affrontata nel capitolo si focalizza non sulla descrizione, ma sull'evoluzione dei sistemi di allevamento della vite e, soprattutto, su quei fattori che rendono questo elemento, definito in fase di progettazione dell'impianto, un protagonista primario di adattamento all'ambiente di coltura e, quindi, di efficienza dell'impianto.

Nel capitolo si affrontano tematiche relative alla scelta varietale considerando gli scenari imposti dal cambiamento climatico. Si pone attenzione ai vitigni tolleranti agli stress estivi, all'efficienza di uso dell'acqua, alla tolleranza alle fitopatie, alla scelta del portinnesto e all'adattamento alle condizioni pedoclimatiche.

Il cambiamento climatico in atto impone adattamenti delle tecniche colturali. In annate calde e siccitose meritano attenzione i fenomeni di eccessiva disidratazione degli acini con sintesi di aromi fortemente sbilanciati verso sentori tipici della sovra-maturazione, fino ad arrivare ai gravi danni delle scottature solari. Nel lungo periodo occorrerà prevedere una revisione della piattaforma ampelografica e allo stesso tempo, nell'immediato, occorrerà implementare strategie di difesa al fine di limitare i danni da eccessi termici e radiativi.

Nel capitolo si definiscono maturità tecnologica, maturità fenolica e maturità aromatica e si indicano le modalità di campionamento e i principali metodi per la loro determinazione, al fine di definire l'ottimale epoca di vendemmia in funzione della varietà e degli obiettivi enologici.

La vendemmia è certamente una delle pratiche colturali più delicate ed impegnative dell'intero percorso produttivo. Errori compiuti in questa fase, che richiede esperienza e tempestività, possono compromettere la qualità ed il valore commerciale del prodotto. La gestione della vendemmia comprende l'insieme di operazioni e di scelte che vanno dal distacco al trasferimento delle uve dal vigneto alla cantina e che hanno come obiettivi il mantenimento delle caratteristiche compositive e strutturali degli acini e l'assenza di contaminazioni. Oggi convivono modalità diverse con cui viene svolta la vendemmia: manuale, integrata e meccanica.

Nel capitolo si definisce l'equilibrio vegeto-produttivo e si identificano gli indici di equilibrio per l'analisi dell'efficienza del vigneto. Inoltre si forniscono le indicazioni per il mantenimento di tale efficienza tenendo in considerazione diversi aspetti, dalla sostituzione delle fallanze, al ringiovanimento del vigneto, alle potature per risanamento dal mal dell'esca o radicali per il contenimento del vigore.

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