The impact of temperature on 'Pinot Noir' berry and wine quality in a steeply sloping cool climate vineyard in South Australia

The degree and time of canopy trimming can alter phenology, rates of increase or decrease in berry components during grape ripening, and may influence yield and its components. The objective of this study was to investigate the extent to which reducing canopy size, by mechanical trimming post-flowering, changed Vitis vinifera L. 'Pinot noir' fruit yield and composition. Vines were mechanically trimmed to three different canopy heights at fruitset: 1000 mm (100 % canopy height), 600 mm (60 % canopy height relative to the control treatment) and 300 mm (30 % canopy height relative to the control treatment). Total soluble solids concentration and content, titratable acidity, pH and fresh berry mass were measured throughout ripening, and yield and leaf area were measured at harvest. Reduced canopy size via trimming to 30 and 60 % of the control treatment height slowed total soluble solids accumulation and in some cases increased titratable acidity and increased pH. The total soluble solids-titratable acidity ratio was therefore reduced throughout ripening by these trimming treatments relative to the full canopy height. Trimming to reduce canopy size had two effects on the source-sink ratio; it reduced the source (canopy) but increased fruit yield, an important sink. Therefore, the time of trimming is an important management consideration because it can delay and slow ripening due to reduced source leaves but could potentially accentuate the delay via increasing yield (sink). This technique may represent a way to offset the acceleration of phenology and grape ripening that has been observed to occur as a result of warmer seasons.

Sugar is crucial for grape berry, whether used for fresh food or wine. However, berry enlargement treatment with forchlorfenuron (N-(2-chloro4-pyridyl)-N'-phenylurea) (CPPU, a synthetic cytokinin) and gibberellin (GA) always had adverse effects on sugar accumulation in some grape varieties, especially CPPU. Therefore exploring the molecular mechanisms behind these adverse effects could provide a foundation for improving or developing technology to mitigate the effects of CPPU/GA treatments for grape growers. In the present study, invertase (INV) family, the key gene controlling sugar accumulation, was identified and characterized on the latest annotated grape genome. Their express pattern, as well as invertase activity and sugar content, were analyzed during grape berry development under CPPU and GA3 treatment to explore the potential role of INV members under berry enlargement treatment in grapes. Eighteen INV genes were identified and divided into two sub-families: 10 neutral INV genes (Vv-A/N-INV1-10) and 8 acid INV genes containing 5 CWINV (VvCWINV1-5) and 3 VIN (VvVIN1-3). At the early development stage, both CPPU and GA3 treatment decreased the hexose level in berries of 'Pinot Noir' grape, whereas the activity of three types inverstase (soluble acid INV, insoluble acid INV, and neutral INV) increased. Correspondingly, most of INV members were up-regulated by GA3 /CPPU application at least one sampling time point during early berry development, including VvCWINV1, 2, 3, 4, 5, VvVIN1, 2, 3 and Vv-A/N-INV1, 2, 5, 6, 7, 8, 10. At maturity, the sugar content in CPPU-treated berries is still lower than that in the control. Soluble acid INV and neutral INV, rather than insoluble acid INV, presented lower activity in CPPU-treated berries. Meanwhile, several corresponding genes, such as VvVIN2 and Vv-A/N-INV2, 8, 10 in ripening berries were obviously down-regulated by CPPU treatment. These results suggested that most of INV members could be triggered by berry enlargement treatment during early berry development, whereas VvVINs and Vv-A/N-INVs, but not VvCWINVs, could be the limiting factor resulting in decreased sugar accumulation in CPPU-treated berries at maturity. In conclusion, this study identified the INV family on the latest annotated grape genome and selected several potential members involving in the limit of CPPU on final sugar accumulation in grape berry. These results provide candidate genes for further study of the molecular regulation of CPPU and GA on sugar accumulation in grape.

No Sul e Sudeste brasileiros, o excesso de chuvas durante o período de maturação afeta negativamente a qualidade dos vinhos tintos. Por outro lado, estas regiões possuem potencial para a elaboração de espumantes, uma vez que, para a elaboração desta bebida, a uva é colhida antes de completar o amadurecimento. No Estado de Minas Gerais, as condições de verão chuvoso estão presentes em todas as regiões de potencial vitícola, e a variação de altitude entre elas pode exercer influência na composição das uvas. Desta forma, este estudo buscou avaliar o potencial de maturação de uvas 'Chardonnay' e 'Pinot Noir' destinadas à elaboração de espumantes em dois locais de Minas Gerais: Cordislândia (873m) e Caldas (1.150m). As plantas foram enxertadas sobre 1.103 Paulsen e conduzidas em espaldeira. Foram avaliados os teores de sólidos solúveis totais, acidez total, ácidos málico e tartárico, e pH do mosto, tamanho e massa das bagas, compostos fenólicos nas cascas e sementes, antocianinas na casca e açúcares solúveis nas bagas, em duas safras consecutivas. As bagas apresentaram maior tamanho e massa quando cultivadas em Caldas. As uvas colhidas em Cordislândia apresentaram maior grau de maturação, sendo observados maior pH, maiores teores de glicose e frutose, e quantidade inferior de acidez e fenólicos totais nas sementes. Os maiores teores de ácido málico presentes nas uvas provenientes de Caldas sugerem que esta região pode ser mais indicada à produção de uvas para elaboração de vinhos espumantes.

SummaryAnthocyanin accumulation in grape berry skins is influenced by temperature during the maturation period. Although it has been reported that high temperatures result in lower anthocyanin concentrations in berry skins, their effects on anthocyanin composition remain unclear. To study the effect of high temperature on anthocyanin composition, the accumulation of individual anthocyanins in the skin of ‘Pinot noir’ berries was investigated in two experiments: Experiment 1, high morning and evening temperature treatment; Experiment 2, high day-time temperature treatment. High temperatures (30°C) in the morning and evening did not the affect the total anthocyanin content in the skin, but decreased the levels of delphinidin 3-glucosides, petunidin 3-glucosides and malvidin 3-glucosides, which are 3’,5’-hydroxylated, or methylated following 3’,5’-hydroxylation. A high day-time temperature (35°C) also decreased the levels of delphinidin, petunidin and malvidin 3-glucosides. In both Experiments, grape berries grown under high temperature had a low abundance of mRNA for flavonoid 3’, 5’-hydroxylase (F3’5’H) in the skin.These results suggest that changes in the accumulation of individual anthocyanins in the skins of ‘Pinot noir’ grape berries, due to high temperature, are regulated at the level of transcription of the F3’5’H gene.

Clonal selection of European winegrapes ( Vitis vinifera ) allows the exploitation of an important source of genetic diversity. In the 1980s, many `Pinot noir' clones, previously unavailable in the U.S., were imported from France. To provide information on their performance under Oregon soil and climate conditions, 20 `Pinot noir' clones were established in a replicated trial in Alpine, Ore., planted in 1989. In this study, yield components, pruning weight, and juice composition of the 20 clones were measured for the 1995 through 1999 seasons. Skin anthocyanin concentration was measured for the 1996 through 1999 seasons. Clones included in the trial were Colmar (COL) 538, Dijon (DJN) 10/18, DJN 113, DJN 114, DJN 115, DJN 375, DJN 60, Espiguette (ESP) 236, ESP 374, Foundation Plant Services (FPS) 2A, FPS 4, FPS 10, FPS 16, FPS 17, FPS 22, FPS 23, FPS 29, FPS 31, FPS 32, and FPS 33. For all responses except juice pH and skin anthocyanin concentration, there were significant clone by year interactions. COL 538 had the highest 5-year mean yield (2.93 kg/vine); FPS 29 had the lowest (1.21 kg/vine). DJN 10/18, FPS 4, FPS 22, and FPS 31 were among the five highest-yielding clones. Other low-yielding clones included DJN 115, ESP 374, FPS 17, and FPS 23. Pruning weights were generally correlated with yields. COL 538 had the highest 5-year mean pruning weight (0.81 kg/vine) and FPS 17 had the lowest (0.48 kg/vine). Other clones with relatively high pruning weights were FPS 2A, FPS 4, and FPS 22. Other clones with low pruning weights were FPS 23 and FPS 29. FPS 22 and FPS 17 had the highest (1.13 g/berry) and lowest (0.93 g/berry) 5-year mean berry weights, respectively. Clones with 5-year mean cluster weights >100 g included DJN 10/18, ESP 236, and FPS 31. Those with cluster weights <80 g were DJN 115, FPS 17, and FPS 29. FPS 2A had the highest 5-year mean juice soluble solids concentration (SSC) at harvest (23.8%). FPS 10, FPS 29, DJN 113, and DJN 115 also had relatively high SSC. DJN 60 had the lowest 5-year mean SSC at harvest (22.0%). FPS 22, FPS 33, COL 538, and ESP 374 also had relatively low 5-year mean SSC at harvest. DJN 115 had the highest 5-year mean juice pH (3.15). DJN 113, FPS 29, and FPS 10 also had relatively high juice pH. FPS 22 had the lowest 5-year mean juice pH at harvest (2.97), and DJN 10/18, FPS 2A, and FPS 17 also had relatively low pH. Clones with higher SSC and pH generally had lower titratable acidity. FPS 2A had both high SSC and high titratable acidity. FPS 23 and FPS 17 had the highest skin anthocyanin concentration (2.10 and 2.07 mg·g -1 berry, respectively). The range of skin anthocyanin concentration among the other clones was relatively narrow (1.17-1.47 mg·g -1 berry). FPS 2A, FPS 4, and FPS 10 generally had above mean SSC and yield. FPS 29, DJN 113, DJN 114, and DJN 115 consistently had above mean SSC but below mean yield.

Winter pruning is the principal method for regulating yield in viticulture. The aim of this work was to investigate the effectiveness of cane and spur pruning on yield, and on grape and wine composition. Cane and spur pruning were investigated in Vitis vinifera L. 'Pinot noir' and 'Chardonnay' vertically-shoot-positioned vines over three seasons. Effects on vine carbohydrates, yield components, leaf area, grape and base wine composition were determined. The canopies of spur pruned vines established more rapidly than cane pruned vines in the 2009/10 season, for both 'Pinot noir' and 'Chardonnay'. The canopies were denser under spur pruning than cane pruning. Pruning treatment had no effect on total yield for either cultivar in any of the three seasons. Total soluble solids (TSS) and titratable acidity were unaffected by pruning treatment, except in 2012 where TSS and pH were higher for spur pruned 'Chardonnay' vines. Apart from spur pruned 'Pinot noir' vine wood being higher in starch in the winter of 2011, overwintering starch and soluble sugar concentrations were not different between pruning treatments for 'Pinot noir' and 'Chardonnay'. Although not different in yield or basic fruit composition, fruit from spur pruned vines resulted in distinctly different phenolic profiles of base wines, with cane pruning appearing to negatively impact on the low molecular weight phenolics in the wine. The results presented here provide confidence that quality is not lessened, in fact could be improved, by shifting from the industry norm of cane to spur pruning for sparkling wine production in cool climates.

Glasshouse-grown `Pinot noir' and `Riesling' grapevines (Vitis vinifera L.) were subjected to one of four water stress durations [no water deficit (control); and water deficits imposed postbloom, lag phase, and veraison] in combination with three soil water-holding capacities (0%, 26%, and 52% gravel, by volume). Vines subjected to increasing water stress duration had less cumulative lateral shoot length and lower shoot count, leaf size, and berry weights than those not stressed. Soluble solids concentration (SSC) during maturation and pH at harvest also increased with increasing water stress duration, but titratable acidity was not affected. Transpiration and stomatal conductance also were reduced with increased water stress duration, but soil water increased, reflecting the larger leaf surface on vines with veraison-imposed deficits. Reducing water-holding capacity (by increasing the percentage of gravel in the soil) tended to increase berry weight and SSC but reduced lateral shoot growth. The 52% gravel treatments increased transpiration rate and stomatal conductance for `Riesling' but reduced them slightly in `Pinot noir'. Percentage of soil moisture was reduced linearly with reduced water-holding capacity. These results indicate that early irrigation deficits may advance fruit maturity of wine grapes with concomitant reductions in vegetative growth. Differential responses of these cultivars to soil water-holding capacity also should help to identify suitable wine grape cultivars as the wine grape industry expands into areas with low water-holding capacity soils.

Background and Aims. Rootstocks are widely used in the viticulture industry to manage biotic stress, particularly the infestation of phylloxera, and to improve tolerance to abiotic stress. Grafting grapevines to rootstocks affects the berry quality and may influence the wine composition. This project investigated the impacts of 14 different rootstocks on the berry and wine chemical properties, phenolic profile, and volatile profile of grafted Vitis vinifera L. cv Pinot noir MV6. Methods and Results. This study was conducted at a commercial vineyard located in Mornington Peninsula, Victoria, Australia. The scions of V. vinifera L. cv Pinot noir clone MV6 were grafted onto 14 rootstocks, including 101‐14 Millardet et de Grasset (101‐14 Mgt), 1103 Paulsen, Selection Oppenheim (SO4), 110 Richter, Schwarzmann, 5C Teleki, 3309 Couderc (3309C), Merbein 5489, Merbein 6262, Merbein 5512, C20, C29, C113, and C114, with own‐rooted vines acting as the control group. Berries were collected at harvest in the 2020 and 2021 vintages for small‐scale winemaking. The pH, titratable acidity, phenolic content, and antioxidant activity of both the berries and wine were measured using conventional chemical analysis. The phenolic composition of the wine over the two vintages was identified and quantified by high‐performance liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry (HPLC‐QTOF‐MS/MS) and HPLC with diode‐array detection (HPLC‐DAD). The volatile composition was measured by headspace solid‐phase microextraction (HS‐SPME) coupled with gas chromatography‐mass spectrometry (GC‐MS). Grafting Pinot noir onto 3309C caused a reduction in the berry and wine pH without affecting the titratable acid. Several rootstocks, such as 1103 Paulsen, SO4, Schwarzmann, and 5C Teleki, reduced the total phenolic content (TPC) in both the berries and wine of Pinot noir. Conversely, Merbein 5489 increased the berry and wine TPC by 15% and 63%, respectively, compared to ungrafted Pinot noir MV6. A similar tendency was also found in the condensed tannin content (CTC), where Merbein 5489 increased the berry and wine CTC by 35% and 112%, respectively, compared to ungrafted vines. Several rootstocks, such as 3309C and Merbein 6262, increased the wine anthocyanin content (especially malvidin 3‐O‐glucoside), which may contribute to enhanced colour intensity. The concentrations of several ethyl ester compounds in wine responsible for the fruity aroma, including ethyl hexanoate, ethyl octanoate, and ethyl butanoate, were significantly higher in scions grafted to Schwarzmann, 3309C, Merbein 5489, and C29, compared to scions grafted to 101‐14 Mgt, 1103 Paulsen, and ungrafted vines. This suggests that rootstock plays an important role in altering the texture and flavour of Pinot noir wine. Conclusions. Grafting Pinot noir to any rootstock in this study caused changes in the phenolic and volatile content of Pinot noir wine, likely affecting the perceived wine quality. Wine from Pinot noir grafted onto Merbein 5489, in particular, with relatively high CTC and anthocyanin content, as well as higher concentrations of volatile compounds contributing to the fruity aroma, represents an attractive option for grafting Pinot noir MV6 in cool climates. Significance of the Study. The present study provides results reflecting the impacts of grapevine rootstocks on Pinot noir berry and wine composition, supporting rootstock selection for Pinot noir. The findings offer guidance to vignerons in choosing suitable rootstocks to manage berry and wine acidity, phenolic accumulation and composition, and volatile profile, thereby improving the wine quality. Furthermore, the results could guide future studies in understanding the roles of rootstocks in regulating the metabolic pathways of phenolic and volatile production in the berries of grafted Pinot noir at the molecular level.

Late-season bunch rot can cause substantial yield loss in grapevines grown in humid regions. Fruit-zone leaf removal has been widely used to reduce bunch rot and pesticide applications through improvements in canopy microclimate and grape cluster morphology. In this study, we evaluated whether mechanical leaf removal can be a valid alternative to a labor-intensive manual application by comparing prebloom manual (PB-MA) and mechanical (PB-ME) leaf removal. We also evaluated the effects of the timing of mechanical application, prebloom (PB-ME) versus fruit set (FS-ME), on fruit traits and bunch rot, caused by Botrytis cinerea. Our trials were conducted on two Vitis vinifera 'Pinot noir' and 'Pinot gris' vineyards in the Northeastern United States over two seasons (2017 to 2018). Major findings were overall consistent between cultivars and years. Leaf removal provided reductions in fruit-zone canopy density regardless of method or timing. In general, PB-ME provided similar shifts in cluster morphological traits to PB-MA, including lower number of berries per cluster, cluster compactness, and cluster weight compared with control (no leaf removal) vines. At harvest, both prebloom leaf removal methods equally reduced Botrytis bunch rot severity, whereas Botrytis bunch rot incidence in Pinot noir was lowest for PB-ME in 1 year and PB-MA in the next year. When comparing timing of mechanical leaf removal, FS-ME provided Botrytis bunch rot reductions similar to PB-ME, without effects on cluster weight. Thus, under our growing conditions, FS-ME was considered the best mechanical leaf removal option to help manage Botrytis bunch rot without causing undesirable yield reductions.

Influence of grapevine leafroll associated viruses (GLRaV-2 and -3) on the fruit composition of Oregon Vitis vinifera L. cv. Pinot noir: Free amino acids, sugars, and organic acids

Analysis of grape polyamines from Grapevine leafroll associated viruses (GLRaV-2 and -3) infected vines

This study aimed to clarify the relationship between grape ( Vitis vinifera L.) quality and environmental factors (climate and soil), and to elucidate the theoretical basis and provide technical guidance for the rational planning of the cultivation area and the precise regulation of the cultivation mode in the future. The fruits of three different grape cultivars, Pinot Noir, Merlot, and Vidal, as well as soil samples and meteorological data were collected from three wine grape growing areas (Wuwei, Zhangye, and Jiayuguan) in the Hexi Corridor, Northwest China. Principal-component analysis (PCA) and correlation analysis were conducted to understand the relationship of grape quality with weather conditions and soil properties. The results showed that the titratable acid content of grape berries was significantly negatively correlated with average temperature from August to September, average minimum temperatures from August to September, and from April to October, mean annual minimum temperature, growing degree days from August to September, and soil total nitrogen content, and significantly positively correlated with average rainfall from April to October, annual mean rainfall, and soil available potassium content. In addition, the pH of grape juice was significantly negatively correlated with annual mean rainfall and soil available potassium content. However, it was significantly positively correlated with average temperature and average minimum temperature from August to September, average minimum temperature from April to October, growing degree days from August to September, as well as soil total nitrogen content. In addition, the results of PCA showed that the fruit quality scores of ‘Vidal’ in Jiayuguan, ‘Merlot’ in Zhangye, and ‘Pinot Noir’ in Wuwei were the highest, respectively. In conclusion, the contents of titratable acid, pH, and Brix° are greatly affected by climate and soil factors. ‘Vidal’, ‘Merlot’, and ‘Pinot Noir’ were suitable for planting in Jiayuguan, Zhangye, and Wuwei, respectively. Nowadays, few reports focus on the relationship between grape quality and soil and climate conditions. Based on the investigation and analysis of the differences of climate, soil, and grape berries quality in the three production areas of Hexi Corridor, the relationship among climate, soil, and grape quality by using statistical methods was studied, which could provide references for clarifying the reasons why environmental factors affect grape quality and select the suitable area for wine grape cultivation.

Renewed interest in varieties that are more tolerant to diseases has emerged, which is mainly due to increased awareness by producers and consumers regarding the impact of phytochemicals in the environment. This paper describes the first Slovenian grapevine variety ‘Pinore’ crossed between the Vitis vinifera L. ‘Pinot Noir’ clone Mf and ‘Regent’ vines. The aim was to create an early ripening grape cultivar that has a good tolerance to biotic stress (e.g., downy and powdery mildew, botrytis) combined with the benefits of established cultivars and their intense wine colors. Some ampelographic characteristics of young shoots, mature leaves, bunches, and berries are presented, and its major agronomic traits, ripening time, grape yield, quality performances, and disease resistance were evaluated over a three-year period (2014–2017). Wine sensory analyses were performed and compared with the international variety ‘Pinot Noir’. The examined genotype showed good agronomic performance and a high wine quality as far as the content of polyphenols is concerned, especially in terms of anthocyanins and tolerance to diseases (Ren3/9 and Rpv3.1); it is significantly different compared to the reference variety ‘Pinot Noir’. In terms of ampelographic characteristics, the main differences are in the number of leaf lobes, the depth of the lateral sinuses, and the content of anthocyanins in its flesh. The investigated genotype has been proposed to the Committee of new varieties in Slovenia for the variety recognition procedure, and completion of the procedure planned for the end of 2023.

Growers of high-end ‘Pinot noir’ wine grapes ( Vitis vinifera L.) commonly reduce yield by cluster thinning with the goal of increasing fruit quality; however, there are no objectively defined yield targets to achieve optimum fruit composition. Canopy leaf area relative to fruit yield can affect total soluble solids (TSS), and recommendations have been established for warm wine grape production regions. However, the relationship between leaf area and photoassimilation differs among climates and training systems. Leaf area to yield (LA:Y) ratios developed in warm, arid regions may not be suitable for cool, wet regions such as western Oregon. A 3-year field study was conducted to elucidate relationships between canopy to yield ratios and berry composition for ‘Pinot noir’. Vegetative growth and fruit yield were manipulated through competitive cover cropping and cluster thinning. Growth was manipulated in three ways: perennial red fescue ( Festuca rubra L.) was grown in 1) both (Grass), 2) one (Alternate), or 3) neither (Tilled) of the alleyways flanking the vine row. Within each vineyard floor treatment, fruit clusters were thinned to one per shoot (Half Crop) or vines were left unthinned (Full Crop). Floor management influenced both canopy size and yield because of altered vine nitrogen (N) status. Effects of crop load on berry components were not always consistent between the crop load metrics used [yield to pruning weight (Y:PW) ratio or LA:Y]. In 2 years, TSS reached a maximum at similar LA:Y; however, this did not necessarily produce optimum TSS. Yield had the greatest influence on pH and total anthocyanins (ACY) in the highest yielding, coolest year. Crop load metrics were not reliable predictors of TSS because of the dominant effect of seasonal variation. Relationships between canopy to yield metrics and other berry components were partially explained by tissue N, photosynthetic photon flux ( PPF ) through the cluster zone, and/or yield. Cluster thinning to adjust yields may not alter source to sink relationships or canopy to yield ratios enough to overcome ripening limitations in cool climates. Only one wine vintage had sensory differences with Alternate-Half Crop and Alternate-Full Crop wines ranked high quality and Tilled-Half Crop and Tilled-Full Crop wines ranked low quality by both consumer and winemaker panels. Therefore, cluster thinning may have limited impact on wine sensory properties.

The abundance of the European earwig Forficula auricularia L. (Dermaptera, Forficulidae) in European vineyards increased considerably over the last few years. Although earwigs are omnivorous predators that prey on viticultural pests such as grape moths, they are also known to erode berries and to transfer fungal spores. Moreover, they are suspected to affect the human perception of wines both directly by their processing with the grapes and indirectly by the contamination of grape clusters with their faeces. In this study we artificially contaminated grapes with F. auricularia adults and/or their faeces and determined the impact on aroma and taste of white 'Chasselas' and red 'Pinot noir' wines. Whereas the addition of five living adults/kg grapes affected the olfactory sensation of 'Chasselas' wines only marginally, 0.6 gram of earwig faeces/kg grapes had a strong effect on colour, aroma and the general appreciation of 'Chasselas' wines. Faeces-contaminated wines were less fruity and less floral, the aroma was described as faecal and they were judged to be of lower quality. The contamination of 'Pinot noir' grapes with four different densities of living earwig adults (e.g. 0, 5, 10 and 20 individuals/kg grapes) showed that only wines contaminated with more than 10 earwigs/kg grapes smelled and tasted significantly different than the uncontaminated control wine. Earwig-contaminated 'Pinot noir' wines were judged to be of lower quality. The descriptors “animal”, “reductive”, “vegetal”, “acidic”, “bitter” and “tannic” characterised their sensory perception. In conclusion, our results show that there is a real risk of wine contamination by F. auricularia. In particular, earwig faeces and earwig adults at densities above a threshold of 5 to 10 individuals/kg grapes have the potential to reduce the quality of wines. The evolution of earwig populations in vineyards should therefore be monitored carefully in order to anticipate problems during vinification.