Vine Response Research Articles

Assessing the influence of autumnal temperature fluctuations on cold hardiness in different grapevine cultivars: variations across vine age and bud positions.

The dynamic fluctuations in autumn temperatures, particularly the marked diurnal variations and the subsequent precipitous drops are key and a pivotal role in viticulture, as they critically influence the acclimation process of grapevines to cold, thereby directly impacting their survival and productivity in cold-climate regions. In this comprehensive study, we investigated the cold hardiness of four grapevine cultivars: 'Itasca', 'Frontenac', 'La Crescent', and 'Marquette', focusing on how these cultivars and their individual buds (1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, and 9th) respond to fluctuating weather and low temperatures typical of autumn [-1.1°C (30°F) -9.4°C (15°F) and -17.8°C (0°F)]. Our results illuminated the striking variability in cold hardiness that was manifest not only among the different cultivars but also within individual buds on the same vine, underscoring the critical influence of bud position on a vine for cold hardiness. 'Frontenac' showed greater cold hardiness at critical temperatures at which 10%, and 50% of the dormant buds were lethally affected by cold (LT10 and LT50) compared to 'Itasca' and 'La Crescent', with 'Marquette' exhibiting intermediate values. However, in cultivars such as 'Itasca' and 'Marquette', certain buds demonstrated a pronounced hardiness when faced with colder temperatures, while others exhibited a heightened sensitivity, thereby revealing a nuanced interplay between bud position and a vine's ability to withstand cold stress. Our study revealed a notable divergence from traditional viticulture understanding; apical buds demonstrated greater cold hardiness than basal buds and opened new paths for research into grapevine physiology. Our results also indicated a significant trend wherein older vines across all studied cultivars displayed enhanced cold hardiness, particularly pronounced at the critical LT50 and the critical temperature at which 90% of the dormant buds were lethally affected by cold (LT90) thresholds, in comparison to younger vines. Moreover, our findings shed light on the impact of autumn's diurnal temperature variations and the subsequent drop in temperatures on vine cold hardiness, thus highlighted the complex interplay between environmental temperature dynamics and dormant bud hardiness. In conclusion, our study showed that the cold damage observed in grapevines in North Dakota was not a result of extreme temperature fluctuations in the fall. This was confirmed by testing the vines after they had reached various threshold temperatures through differential thermal analysis (DTA) and optical differential nucleation and expansion analysis (ODNEAL) methodologies, particularly before the onset of severe pre-winter cold conditions. These comprehensive findings highlighted the complexity of the vine's response to climatic conditions and viticultural management, pointing to the need for specific strategies in vineyard management and cultivar selection to optimize bud hardiness and productivity in the face of various environmental challenges, especially in cold climate viticulture.

Physiological and Productive Responses of Two Vitis vinifera L. Cultivars across Three Sites in Central-South Italy

Grapevine adaptation to drought involves morphological, anatomical, and physiological modifications that could be viewed as a measure of drought avoidance. The main vine responses to drought consist of the regulation of carbon assimilation as a consequence of limited stomatal conductance, which is reflected in changes in plant water status. In this factorial study (2020–2021 growing seasons), two red cultivars, the local ‘Aglianico’, widely grown in Central-South Italy, and the international ‘Cabernet Sauvignon’, were used to evaluate how their interaction in three different environments can modify physiological adaptations and how yields and their qualitative traits can be modified. The lowest leaf water potential (−0.68 Mpa) for the two cultivars was registered in Molise, while the most stressed vine was found in Sicily for Aglianico (−1.86 MPa). At least in two of three locations, Molise and Campania, the detected stomatal conductance and the leaf water potential have shown that Cabernet Sauvignon can be classified as a near-isohydric cultivar, whereas Aglianico can be categorized as a near-anisohydric cultivar. The interactions between genotype x environment highlight different levels of adaptability between the two cultivars in different sites during each season. The data presented here contribute to a better understanding of the effects of genotype and environment interactions in progressive dry cultivation and how these interactions can modify the qualitative traits of grapes.

Secondary metabolites in grapevine: crosstalk of transcriptional, metabolic and hormonal signals controlling stress defence responses in berries and vegetative organs.

Abiotic stresses, such as temperature, heat waves, water limitation, solar radiation and the increase in atmospheric CO2 concentration, significantly influence the accumulation of secondary metabolites in grapevine berries at different developmental stages, and in vegetative organs. Transcriptional reprogramming, miRNAs, epigenetic marks and hormonal crosstalk regulate the secondary metabolism of berries, mainly the accumulation of phenylpropanoids and of volatile organic compounds (VOCs). Currently, the biological mechanisms that control the plastic response of grapevine cultivars to environmental stress or that occur during berry ripening have been extensively studied in many worlds viticultural areas, in different cultivars and in vines grown under various agronomic managements. A novel frontier in the study of these mechanisms is the involvement of miRNAs whose target transcripts encode enzymes of the flavonoid biosynthetic pathway. Some miRNA-mediated regulatory cascades, post-transcriptionally control key MYB transcription factors, showing, for example, a role in influencing the anthocyanin accumulation in response to UV-B light during berry ripening. DNA methylation profiles partially affect the berry transcriptome plasticity of different grapevine cultivars, contributing to the modulation of berry qualitative traits. Numerous hormones (such as abscisic and jasmomic acids, strigolactones, gibberellins, auxins, cytokynins and ethylene) are involved in triggering the vine response to abiotic and biotic stress factors. Through specific signaling cascades, hormones mediate the accumulation of antioxidants that contribute to the quality of the berry and that intervene in the grapevine defense processes, highlighting that the grapevine response to stressors can be similar in different grapevine organs. The expression of genes responsible for hormone biosynthesis is largely modulated by stress conditions, thus resulting in the numeourous interactions between grapevine and the surrounding environment.

Evaluation of carbon balance and carbohydrate reserves from forced (Vitis vinifera L.) cv. Tempranillo vines.

Elevated temperatures during berry ripening have been shown to affect grape quality. The crop forcing technique (summer pruning that 'force' the vine to start a new cycle) has been shown to improve berry quality by delaying the harvest date. However, yield is typically reduced on forced vines, which is attributed to vine low carbon availability soon after forcing and likely incomplete inflorescence formation. The present study aims to estimate the carbon balance of forced vines and evaluate vine responses to changes in carbon patterns due to forcing. Three treatments were studied on Tempranillo cultivar: non-forced vines (Control), vines forced shortly after fruit set (CFearly) and vines forced one month later at the beginning of bunch closure (CFlate). Whole canopy net carbon exchange was modelled and validated using two whole canopy gas exchange chambers. In addition, non-structural carbohydrate reserves at budburst, forcing date and harvest, were analysed. Yield, yield components and vegetative growth were also evaluated. Harvest date was delayed by one and two months in the CFearly and CFlate, respectively, which increased must acidity. However, yield was lower in the forced treatments compared to the Control (49% lower for CFearly and 82% for CFlate). In the second year, at the time when CFearly and CFlate dormant buds were unlocked (forced budburst), forced vines had significantly lower non-structural carbohydrates than Control vines at budburst. Although the time elapsed from budburst to reach maximum net carbon exchange was longer for the Control treatment (80 days) than for the forced treatments (about 40 days), average daily net carbon exchange until harvest was comparable between Control (60.9 g CO2/vine/day) and CFearly (55.9 g CO2/vine/day), but not for CFlate (38.7 g CO2/vine/day). In addition, the time elapsed from budburst to harvest was shorter in forced treatments (about 124 days) than for the Control (172 days). As a result, the cumulative net carbon exchange until harvest was reduced by 35% (CFearly) and 55% (CFlate) in the forced treatments. However, no differences in carbon reserves at harvest were observed between treatments partly helped by the higher source:sink ratio observed in forced than Control vines.

Effects of cane- and spur-retained node numbers on the pre-flowering vegetative growth of cane-pruned Sauvignon blanc

In established vineyards, node number retention at winter pruning is the first step to achieving and maintaining vine balance. Balanced vines exhibit timely and quasi-uniform 100 percent budburst. To understand how vine capacity and balance are expressed before flowering, mature Sauvignon blanc vines were pruned according to a 5 [total node numbers on canes: 10, 20, 30, 40, 50] x 3 [total node numbers on spurs: 1, 2, 3] factorial design in one site, and in two other sites according to a 5 [total node numbers on canes: 10, 20, 30, 40, 50] x 2 [total node numbers on spurs: 1, 2] factorial design. Two spurs of one, two or three nodes each were retained on either side of the vine. The number of canes laid down per vine was one, two, three and four canes each of 10 nodes for the 10-, 20-, 30- and 40-node treatments, and four canes averaging 12.5 nodes for the 50-node treatment. The budburst percentage was calculated on the whole vine, canes, and spurs. Blind nodes, count shoots, non-count shoots and double shoots were counted and mapped along canes and spurs. Many non-count shoots were measured on the vine head of 10-node vines (29.5 ± 3.0 shoots, p < 0.001), compared to 50-node vines (2.8 ± 1.9 shoots, p < 0.001). 50-node vines had an overall budburst of 100 %, despite having the highest number of blind nodes (7.6 ± 0.3 nodes, p < 0.001). These were mainly located at the canes’ proximal sections relative to the vine head and were likely caused by correlative inhibition and primary bud necrosis. Cane budburst provided a more accurate assessment of the vine response to node loading than vine budburst. The number of double shoots was not associated with the vine node load, as they appeared on both low-node and high-node vines. Three-node spurs developed more blind nodes than one-node and two-node spurs (p < 0.001). Based on the findings of this research, we recommend a composite metric (cane percent budburst, cane blind node count and head shoot count) to assess vine capacity and balance between budburst and flowering, and the practice of retaining one- or two-node spurs at cane pruning is also justified.

Influence of weather conditions and projected climate change scenarios on the suitability of Vitis vinifera cv. Carignan in Rioja DOCa, Spain

Grape development and its quality are highly dependent on soil and weather conditions. Under the progressive warming, which can affect the suitability of typical varieties grown in a given area, the knowledge of the vine response to changes in climate is essential to stablish strategies to maintain the viticulture sector. This research presents an analysis of phenology and grape composition of the Carignan cultivar, during a 13-year period, at two locations in Rioja DOCa. Based on the results obtained and the projected changes in climate under climate change scenarios (RC4.5 and RCP8.5), the response of this cultivar was evaluated. Differences in the phenological dates of up to 18, 29 and 40 days, for flowering, veraison and harvest, respectively, were observed between the warmest and the coolest years. An advance of up to 5, 8 and 11 days, respectively, for the mentioned stages, is projected under the RCP4.5 scenario by 2050, which could be near 1.5*times higher under the RCP8.5 scenario. These advances will be mainly driven by the temperatures recorded in the previous period. Grape acidity was mainly driven by water availability, in particular during ripening, which imply a slight projected reduction due to precipitation changes but not significant effect due to increasing temperatures. The phenolic composition could be positively affected by increasing temperatures and increasing water deficits, since this variety does not always reach a complete maturity at present. Thus, under the projected warming scenarios, the suitability of Carignan in Rioja DOCa was confirmed.

Trattamenti fogliari conArthrospira platensisin viticoltura: primi risultati da esperimenti in campo

Biostimulants are increasingly assuming a key role in viticulture, thanks to the well-known ability to influence the physiological behavior of plants, promoting the quality of the grapes and improving vine response to abiotic stress. Seaweed extracts are among the most used and studied biostimulants, while there are very few cyanobacterial-based biostimulants currently available on the market. This work had the purpose of investigating the effects of an extract ofArthrospira platensison eco-physiology, water potential, yield and quality of grapes inVitis viniferaExperiments were conducted in open field (seasons 2017 and 2018) in Tuscany, carrying out foliar treatments with theA. platensisextract 20 days and ten days before the expected harvest. Following the treatments, gas exchanges and water potential were monitored, and berry samples were collected to evaluate the technological and phenolic quality of the grapes. In general, the treatments only marginally influenced gas exchanges and water potential, with diversified results in relation to the seasonal climatic trend (2017 season, hot and drought; 2018 milder season), indicating a more conservative behavior of the treated vines compared to the control vines. In addition,A. platensisalways increased the berry weight, maintaining unchanged or improving the technological and phenolic quality of the grapes at harvest compared to the control. Although no univocal response to treatment emerges, the results globally suggest a positive impact of the leaf distribution ofA. platensison the eco-physiology and quanti-qualitative characteristics inV. viniferacandidating cyanobacteria for the formulation of new biostimulants.

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

In Europe, most of vineyards are managed under rainfed conditions, where water deficit has become increasingly an issue. The flowering-veraison phenophase represents an important period for vine response to water stress, which is known to depend on variety characteristics, soil and climate conditions. In this paper, we have carried out a retrospective analysis for important European wine regions over 1986–2015, with objectives to assess the mean Crop Water Stress Indicator (CWSI) during flowering-veraison phase, and potential Yield Lose Rate (YLR) due to seasonal cumulative water stress. Moreover, we also investigate if advanced flowering-veraison phase can lead to alleviated CWSI under recent-past conditions, thus contributing to reduced YLR. A process-based grapevine model is employed, which has been extensively calibrated for simulating both flowering and veraison stages using location-specific observations representing 10 different varieties. Subsequently, grid-based modelling is implemented with gridded climate and soil datasets and calibrated phenology parameters. The findings suggest wine regions with higher mean CWSI of flowering-veraison phase tend to have higher potential YLR. However, contrasting patterns are found between wine regions in France-Germany-Luxembourg and Italy-Portugal-Spain. The former tends to have slight-to-moderate drought conditions (CWSI<0.5) along with a negligible-to-moderate YLR (<30%), whereas the latter is found to have severe-to-extreme drought (CWSI>0.5) and substantial YLR (>40%). Wine regions prone to a high drought risk (CWSI>0.75) are also identified, which are concentrated in southern Mediterranean Europe. Advanced flowering-veraison phase over 1986–2015, could have benefited from more spring precipitation and cooler temperatures for wine regions of Italy-Portugal-Spain, leading to reduced mean CWSI and YLR. For those of France-Germany-Luxembourg, this can have reduced flowering-veraison precipitation, but prevalent reductions of YLR are also found, possibly due to shifted phase towards a cooler growing-season with reduced evaporative demands. Our study demonstrates flowering-verasion water deficit is critical for potential yield, which can have different impacts between Central and Southern European wine regions. This phase can be advanced under a warmer climate, thus having important implications for European rainfed vineyards. The overall outcome may provide new insights for appropriate viticultural management of seasonal water deficits under climate change.

The Biological Significance of the Silver Vine Response in the Domestic Cat: Face and Head Rubbing against Silver Vine Allows Cats to Gain Chemical Defense against Mosquitoes

蚊は，人類の大敵である．蚊に吸血されると，かゆみが生じるだけでなく，生命を脅かすさまざまな伝染病，たとえば熱帯地域では，マラリアなどに感染する恐れもある．そこで人類は古くから植物からの抽出物を使って蚊を化学防御してきた．このような生存戦略をとった動物は，人類だけではない．たとえばオマキザルやハナジロハナグマなどの動物は柑橘類の果実の皮を身体に擦り付け，その忌避効果を利用していることが知られている(1)．つまりヒト以外の動物も進化の過程で病原体を媒介する蚊から身を守る化学防御術を身に着けてきたようである．本稿では，ネコでよく知られたマタタビ反応も実は蚊の攻撃から身を守る重要な行動であるという予想外の知見が得られたので(2)，この発見に至った経緯を紹介する．

Under-Vine Vegetation Mitigates the Impacts of Excessive Precipitation in Vineyards.

Excessive precipitation events have greatly increased in several grape growing regions due to human-caused climate change. These heavy downpours result in a myriad of problems in the vineyard including soil aggregate breakdown, soil runoff, nutrient leaching, excessive vine vegetative growth, and diseased fruit. The negative impacts of excessive precipitation events on vineyards are exacerbated by the maintenance of bare soil under the vines. Exposure of bare soil results in soil erosion and runoff which pollutes nearby watersheds; raindrops weaken and break apart soil aggregates, leading to increased soil erosivity and contributing to the formation of surface crusts. In addition to excessive precipitation events, some grape growing regions can be characterized by fertile soils. The availability of ample water and nutrients can lead to highly vigorous vines with shoot growth continuing through harvest. Long shoots and large leaves result in shaded fruit, a humid vine microclimate, and excessive cluster rot. In this review, we examined how either natural (i.e., resident) or seeded under-vine vegetation (UVV) can help mitigate many of the problems associated with excessive precipitation. Through providing vegetative coverage to reduce the force of raindrops, increasing soil organic matter and enhancing soil microbial diversity, UVV can reduce the soil degradation and off-site impacts caused by excessive precipitation events. Through competition for soil resources, UVV can reduce excessive vegetative growth of vines and decrease cluster rot incidence and severity, although grapevine response to UVV can be highly variable. We discussed recent advances in understanding below and aboveground vine response and acclimation to UVV and presented current evidence of factors influencing the impact of UVV on vine growth and productivity to assist practitioners in making informed decisions and maximize the ecosystem services provided by UVV.

Soil management in semi-arid vineyards: Combined effects of organic mulching and no-tillage under different water regimes

Optimizing water use in vineyards is crucial for ensuring the sustainability of viticulture in semi-arid regions, and this may be achieved by minimizing direct water evaporation from the soil through the use of mulching. In this context, the current study aimed at assessing the combined effects of the vine-row application of an organic mulch (vine prunings) and no-tillage under two water regimes on soil properties, plant water and nutritional status, yield and must composition of grapevine (Vitis vinifera L.) cv. Bobal grown under semi-arid conditions. For this purpose, a field experiment in a split-plot design was carried out for three years (2016–2018) in a mature Bobal vineyard located in Eastern Spain. Two soil management strategies (tillage and organic mulching with no-tillage) were assessed under two water regimes (rainfed and deficit drip irrigation) with four replications per combination. Vine responses were determined by measuring midday stem water potential, leaf nutrient concentrations, pruning weight, yield components and grape composition. Soil properties were assessed at the end of the experiment. Mulching and no-tillage positively affected vine water status under both water regimes, resulting in reductions in grape phenolic composition. Interactive effects of both water regime and soil management on water use efficiency were found. Regardless of soil management practice, irrigation increased yield and pruning weight when compared to rainfed conditions. Soil management had slight effects on vine nutritional status. At the end of the experiment, soil compaction increased and infiltration decreased as a consequence of mulching and no-tillage. Organic mulch and no-tillage improved vine water status, however, considering the final soil surface compaction and low water infiltration rate, longer-term studies are necessary to assess the sustainability of combining both practices.

Vegetative development of vine rootstock cultivars in brazilian cerrado conditions

In the State of Goiás, studies related to the vine's responses to the region's edaphoclimaticconditions are scarce. Therefore, the objective of this work was to evaluate the growth of three vine rootstock cultivars, IAC 572 'Jales', IAC313 'Tropical' and IAC766 'Campinas', in the region of Goiânia, GO, after drastic pruning for uniformity. To evaluate the growth of rootstocks, the experiment was carried out in random blocks, in a double factorial scheme (3x7), with five replications, each repetition formed by a plant. The first factor consisted of three rootstocks: IAC313 ‘Tropical’, IAC572 ‘Jales’ and IAC766 ‘Campinas’. The plants were evaluated after 45 days after a drastic uniformization pruning, totaling seven evaluations (45, 60, 75, 90, 105, 120, 135 days after pruning), this being the second factor. The diameter of the main branch at the height of grafting (80 cm) and length of the main branch were evaluated. With the data on the diameter and length of the main branch, the absolute growth rate in diameter and length was calculated.The IAC572 'Jales' rootstock cultivar has greater vigor for branch growth, being 69% and 47.3% longer in length, and 49.8% and 18.8% longer in diameter than the IACrootstock. IAC 313 'Tropical' 'and' IAC766 'Campinas', respectively. The IAC766 ‘Campinas’ rootstock cultivar, although it has low vigor in branch growth, presents satisfactory development.

Molecular basis of rootstock-related tolerance to water deficit in Vitis vinifera L. cv. Sangiovese: A physiological and metabolomic combined approach

The rootstock M4 (V. vinifera × V. berlandieri) × V. berlandieri cv. Resseguier n.1) is a recent selection reported to confer improved drought tolerance to grafted V. vinifera scions, a very desired feature in the era of global warming. Therefore, a short-term study was performed on a batch of 12 potted cv. Sangiovese vines grafted either on M4 or on the drought susceptible SO4 rootstock. Ecophysiological assessments as whole canopy net CO2 exchange rate (NCER), transpiration (Tc), and pre-dawn leaf water potential (Ψpd) and UHPLC-ESI/QTOF-MS metabolomics were then used to investigate the different vine responses during water limiting conditions. Water stress was induced by applying 50 % of estimated daily water use from days of year 184–208.M4 was able to deliver similar CO2, at a significantly reduced water use, compared to SO4 grafting. In turn, this resulted in enhanced canopy water use efficiency (NCER/Tc ratio) quantified as +15.1 % during water stress and +21.7 % at re-watering. Untargeted metabolomics showed a similar modulation of brassinosteroids and ABA between the two rootstocks, whereas the up accumulation of cytokinins and gibberellins under drought was peculiar of M4 grafted vines. The increase in gibberellins, together with a concurrent down accumulation of chlorophyll precursors and catabolites and an up accumulation of folates in M4 rootstock suggests that the capacity of limiting reactive-oxygen-species and redox imbalance under drought stress was improved. Finally, distinctive osmolyte accumulation patterns could be observed, with SO4 investing more on proline and glycine-betaine content and M4 primarily showing polyols accumulation.

Effects of regulated deficit irrigation on the growth and berry composition of Cabernet Sauvignon in Ningxia

The adoption of water-saving irrigation strategies is required particularly for wine grape variety, which has been widely cultivated in arid and semiarid areas. To assess vine response to regulated deficit irrigation (RDI), the grape growth and berry composition under five treatments that irrigated at a certain percentage of the crop evapotranspiration (ETc) were evaluated over a 3-year period in a vineyard with the grape variety of Cabernet Sauvignon. The results indicated that RDI had a significant effect on the grape berry size and yield. The largest berry size (12.20 mm) was obtained under the T50 in 2014, while the smallest berry size (9.83 mm) one was obtained under the CK treatments in the same season. The highest individual yield occurred in the T50 treatment, with an average of 1.99 kg, followed by the T25-50 treatment. However, both weights were significantly larger than that of the CK treatment. Compared with the T50 treatments, the individual grape vine yield in the T50-25 treatments were slightly less by 16.9% for 2013, 15.3% for 2014 and 18.1% for 2015. Compared to control (CK) treatment, the soluble solid and reducing sugar contents decreased, the total acid content increased, and the sugar/acid ratio basically showed a downward trend. The treatment irrigated at 50% ETc until veraison and 25% thereafter (T50-25) increased the phenolic compound content in grape skins. The treatment received only rain water during the grape growing season (CK) and the one irrigated at 25% of the ETc crop evapotranspiration (T25) caused defoliation and negatively affected the yields and grape composition during all 3 years. Therefore, the RDI not only inhibited the vine vegetative growth but also improved the fruit quality. In terms of productivity and grape composition, the Cabernet Sauvignon grape variety was most sensitive to water stress post-veraison. Over the comprehensive consideration of yield, water-use efficiency and berry composition, the T50-25 treatment was the most efficient irrigation strategy in this area. Keywords: regulated deficit irrigation, Cabernet Sauvignon, arid area, grape composition DOI: 10.25165/j.ijabe.20191206.5206 Citation: Wang R, Yan P K, Sun Q, Su B F, Zhang J X. Effects of regulated deficit irrigation on the growth and berry composition of Cabernet Sauvignon in Ningxia. Int J Agric & Biol Eng, 2019; 12(6): 102–109.

Variability in grape composition and phenology of 'Tempranillo' in zones located at different elevations and with differences in the climatic conditions

The objective of this research was to analyse the variability on phenology and berry composition of 'Tempranillo' among different elevations and different climatic conditions. The study was conducted on 'Tempranillo' vineyards located in Rioja DOCa at elevations between 367 and 650 m a.s.l. Phenology and the evolution of berry composition during ripening, related to pH, total acidity, malic acid, total anthocyanins, total polyphenols index, colour intensity and sugar content were analysed for the period 2008-2018 at each elevation. The weather conditions recorded during the period of study were evaluated. The results indicate that, on average, differences between the analysed elevations of up to 21 days existed in the dates in which the maturity was reached, being the differences higher in the years with extreme conditions (very wet or dry and very hot or cool). The comparative analysis among elevations and in years with differences in temperature and in precipitation allowed knowing the differences in the vine response under different climatic conditions. From this analysis some conclusions may be extracted that may be useful for police makers to define new planting areas in which less imbalanced situations may occur under warm conditions.

Post-budbreak pruning changes intra-spur phenology dynamics, vine productivity and berry ripening parameters in Vitis vinifera L. cv. ‘Pinot Noir’

Late pruning is an emerging cultural technique aimed at deferring ripening kinetics and reducing the negative effects of warming trends on grape maturity. It relies on the inhibition of basal nodes and on the postponement of the progression of phenological stages. As a consequence, late pruning is capable of maintaining at harvest a moderate sugar concentration and an adequate acidity level in grapes. This work was intended to deepen the effects of late pruning, focusing on the intra-vine phenology variability and progression as well as on the interactions existing between the changes in vine balance and the ripening time shift.Two experiments were conducted over two consecutive years in different vineyards located in Abruzzo (central Italy), comparing late pruning (LP) applied when unpruned canes had shoots with two/three leaves already unfolded (phenological stage BBCH 12/13) with standard winter pruning executed at dormancy (WP).LP shifted phenology and led to a significant variability in the development stages detected on shoots arising from the different nodes of the spurs, whereas in WP vines shoots arising from count-nodes developed in synchrony. LP successfully delayed ripening, but the outputs of the two experiments were different: LP postponed sugars accumulation and the decrease of acidity in both experiments (-2° Brix and +2.5 g/L at harvest, as an average of the two experiments) though the yield was negatively affected only in the first experiment (-47% as compared to WP).Late spur-pruning confirmed its efficacy in spreading grapes maturity and maintaining higher acidity along with a reduced sugar concentration. The delaying effect seems to be quite independent from the seasonal vine balance given as leaf area-to-fruit ratio.The study provided further clarification of the physiological bases underlying vine response to delayed winter pruning and indicated robustness of its effects regardless environmental conditions and degree of vine balance.

Effects of an Ascophyllum nodosum (L.) Le Jol. extract on grapevine yield and berry composition of a Merlot vineyard

Few publications in the scientific literature document effects of seaweed extracts on winegrape varieties. A 2-year field experiment was conducted to evaluate effects of foliar applications of an Ascophyllum nodosum (L.) Le Jol. extract on vine yield components, canopy chlorophyll content, berry composition and phenolic indices. The split plot experiment allowed for the investigation of extract effects with and without in-season N fertilization in a Merlot vineyard in 2015 and 2016. Great differences in vine productivity and berry composition between years were attributed to hail damage in 2015. Vines were not affected by N supply in any single year other than a decline of some berry quality parameters in 2016. Effects of seaweed extract application were evident in the absence of hail damage in 2016. The greatest vine responses were obtained with 1% extract concentration under in-season N supply by a 26% increase in yield, 35% increase in the number of berries and 21% increase in anthocyanin extractability of berry skins. These beneficial effects came about without a negative impact on other parameters of berry composition or phenolic indices and, in part, appear to be caused by direct effects on berry physiology and grapevine nitrogen status. The lower extract concentration (0.2%) also increased number of berries and anthocyanin extractability, but these were accompanied by a reduction of berry phenols and an increase of seed tannins. The results demonstrate the potential of this extract to increase production and improve wine quality in red winegrape vineyards.

Effects of regulated deficit irrigation on the growth and berry composition of Cabernet Sauvignon in Ningxia

The adoption of water-saving irrigation strategies is required particularly for wine grape variety, which has been widely cultivated in arid and semiarid areas. To assess vine response to regulated deficit irrigation (RDI), the grape growth and berry composition under five treatments that irrigated at a certain percentage of the crop evapotranspiration (ETc) were evaluated over a 3-year period in a vineyard with the grape variety of Cabernet Sauvignon. The results indicated that RDI had a significant effect on the grape berry size and yield. The largest berry size (12.20 mm) was obtained under the T50 in 2014, while the smallest berry size (9.83 mm) one was obtained under the CK treatments in the same season. The highest individual yield occurred in the T50 treatment, with an average of 1.99 kg, followed by the T25-50 treatment. However, both weights were significantly larger than that of the CK treatment. Compared with the T50 treatments, the individual grape vine yield in the T50-25 treatments were slightly less by 16.9% for 2013, 15.3% for 2014 and 18.1% for 2015. Compared to control (CK) treatment, the soluble solid and reducing sugar contents decreased, the total acid content increased, and the sugar/acid ratio basically showed a downward trend. The treatment irrigated at 50% ETc until veraison and 25% thereafter (T50-25) increased the phenolic compound content in grape skins. The treatment received only rain water during the grape growing season (CK) and the one irrigated at 25% of the ETc crop evapotranspiration (T25) caused defoliation and negatively affected the yields and grape composition during all 3 years. Therefore, the RDI not only inhibited the vine vegetative growth but also improved the fruit quality. In terms of productivity and grape composition, the Cabernet Sauvignon grape variety was most sensitive to water stress post-veraison. Over the comprehensive consideration of yield, water-use efficiency and berry composition, the T50-25 treatment was the most efficient irrigation strategy in this area. Keywords: regulated deficit irrigation, Cabernet Sauvignon, arid area, grape composition DOI: 10.25165/j.ijabe.20191206.5206 Citation: Wang R, Yan P K, Sun Q, Su B F, Zhang J X. Effects of regulated deficit irrigation on the growth and berry composition of Cabernet Sauvignon in Ningxia. Int J Agric & Biol Eng, 2019; 12(6): 102–109.

Effects of regulated deficit irrigation on the growth and berry composition of Cabernet Sauvignon in Ningxia

The adoption of water-saving irrigation strategies is required particularly for wine grape variety, which has been widely cultivated in arid and semiarid areas. To assess vine response to regulated deficit irrigation (RDI), the grape growth and berry composition under five treatments that irrigated at a certain percentage of the crop evapotranspiration (ETc) were evaluated over a 3-year period in a vineyard with the grape variety of Cabernet Sauvignon. The results indicated that RDI had a significant effect on the grape berry size and yield. The largest berry size (12.20 mm) was obtained under the T50 in 2014, while the smallest berry size (9.83 mm) one was obtained under the CK treatments in the same season. The highest individual yield occurred in the T50 treatment, with an average of 1.99 kg, followed by the T25-50 treatment. However, both weights were significantly larger than that of the CK treatment. Compared with the T50 treatments, the individual grape vine yield in the T50-25 treatments were slightly less by 16.9% for 2013, 15.3% for 2014 and 18.1% for 2015. Compared to control (CK) treatment, the soluble solid and reducing sugar contents decreased, the total acid content increased, and the sugar/acid ratio basically showed a downward trend. The treatment irrigated at 50% ETc until veraison and 25% thereafter (T50-25) increased the phenolic compound content in grape skins. The treatment received only rain water during the grape growing season (CK) and the one irrigated at 25% of the ETc crop evapotranspiration (T25) caused defoliation and negatively affected the yields and grape composition during all 3 years. Therefore, the RDI not only inhibited the vine vegetative growth but also improved the fruit quality. In terms of productivity and grape composition, the Cabernet Sauvignon grape variety was most sensitive to water stress post-veraison. Over the comprehensive consideration of yield, water-use efficiency and berry composition, the T50-25 treatment was the most efficient irrigation strategy in this area. Keywords: regulated deficit irrigation, Cabernet Sauvignon, arid area, grape composition DOI: 10.25165/j.ijabe.20191206.5206 Citation: Wang R, Yan P K, Sun Q, Su B F, Zhang J X. Effects of regulated deficit irrigation on the growth and berry composition of Cabernet Sauvignon in Ningxia. Int J Agric & Biol Eng, 2019; 12(6): 102–109.

Variability of Tempranillo grape composition in the Rioja DOCa (Spain) related to soil and climatic characteristics.

Soil and climate are terroir elements that condition vine response. This research was intended to evaluate the variability of grape composition of the Vitis vinifera L. cv. Tempranillo in the Qualified Designation of Origin Rioja (DOCa) (Spain) in La Rioja (Spain), and its relationships with soil and climate characteristics. The relationships between grape composition (sugar content, acidity, phenolic compounds, and berry weight) and climate characteristics were analyzed for the period 2008-2017 in 20 plots scattered throughout Rioja Alta and Rioja Baja, using multiple-regression analysis. The spatial variability of grape composition and the effect of soil properties were evaluated using cluster analysis. Despite the high variability in climate characteristics from year to year, it was possible to define the soil and plot characteristics that affect grape composition at ripening. Acidity and anthocyanin concentrations were affected by temperature and by precipitation recorded in different time periods throughout the growing cycle. The increase in temperature in earlier stages reduced the total acidity and increased the total polyphenols, while an increase in temperature during the ripening period produced a decrease in total acidity, malic acid, and anthocyanin concentration, and a lower ratio between anthocyanins and sugars. The plots located in soils with higher soil water availability presented higher acidity and lower anthocyanin concentrations. © 2018 Society of Chemical Industry.