Pruning cuts affect wood necrosis but not the percentage of budburst or shoot development on spur pruned vines for different grapevine varieties

We carried out a comparative test with mixed planting in the same field using virus-free and virus-infected (leafroll and fleck) vines of red wine-grape cultivars, ‘Cabernet Sauvignon’ and ‘Cabernet Franc’ (Vitis vinifera L.). Although initially virus-free vines were 7 or 8 years old, they have been reinfected.In this paper, seasonal changes in °Brix and titratable acidity of grape juice were investigated over a 3 year period (1985 to 1987, tree age: 6 to 8 years), and we detected and identified the viruses of these cultivars.The results are as follows;1. At full maturity, the °Brix values of the juices of virus-free ‘Cabernet Sauvignon’ and ‘Cabernet Franc’ were higher than those of virus-infected vines, in 1985 (6-year-old vines). However, in 1987 (8-year-old vines), the °Brix values of the virus-free varieties were lower than those of virus-infected vines.2. Titratable acidities of the juices of virus-free ‘Cabernet Sauvagnon’ and ‘Cabernet Franc’ were lower than those of virus-infected vines at full maturity in 1985. However, in 1987, titratable acidities of virus-free ‘Cabernet Sauvignon’ and ‘Cabernet Franc’ were higher than those of virus-infected vines.3. We found that the initially virus-free vines were reinfected by leafroll and fleck viruses. We think that in 1987, the infection by leafroll and fleck viruses caused the decrease in °Brix and the increase in acidity of juices, as well as light-colored fruits and red leaves in these initially virus-free vines.

Grapevine red blotch virus (GRBV) is the causative agent of red blotch disease. Limited information is available on the seasonal variation of GRBV titer in relation to disease symptom expression in vineyards across the United States. In this study, no statistically significant difference in GRBV titer was found among asymptomatic infected vines in June ( P = 0.451) and among symptomatic infected vines in October ( P = 0.068) in a diseased ‘Cabernet franc’ vineyard in California, regardless of the years symptomatic, one to seven, as shown by qPCR. Similarly, there were no statistically significant differences in GRBV titer as it related to isolates of the two phylogenetic clades in asymptomatic infected ‘Cabernet franc’ and ‘Cabernet Sauvignon’ vines in June ( P = 0.138 and P = 0.778, respectively) and in symptomatic infected vines in October ( P = 0.806 and P = 0.490, respectively). GRBV titer differed among cultivars in diseased California vineyards ( P < 0.001) and increased over the course of the growing season in infected ‘Merlot’ and ‘Cabernet franc’ vines, but not in ‘Cabernet Sauvignon’ vines. Patterns observed in California were consistent in New York and Georgia vineyards. In a Geneva double curtain-trellised ‘Cabernet Sauvignon’ vineyard in Georgia, GRBV distribution was uneven between cordons, and virus titer was variable within the vine canopy in June ( P = 0.017) but not in October ( P = 0.107). This work revealed consistent patterns of GRBV titer during a growing season in different vineyards across the United States. It also highlighted relatively high virus titer in symptomless grapevines in June, when Spissistilus festinus-mediated GRBV transmission is documented in northern California.

A 3-yr study was conducted in 2 experimental vineyards near Bordeaux by using artificial infestations ofberry clusters with eggs of Lobesia botrana (Denis & Schiffermuller). Settling of neonates and subsequent larval survival were used to measure host susceptibility. Infestation by 2nd generation larvae was influenced significantly by the cultivar every year. The cultivars in increasing order of susceptibility were as follows: 'Merlot', 'Cabernet sauvignon', 'Cabernet franc', and 'Semillon'. The 3rd-generation infestations tended to confirm the same order of susceptibility, particularly in 1993. The susceptibility of 'Sauvignon' was variable and not significantly different from either Cabernet sauvignon or Cabernet franc. In 1994 and 1995, there was a high positive correlation between berry-cluster tightness and infestation by 2nd-generation larvae. The involvement of cluste compactness in susceptibility of grape cultivars to L. botrana is discussed.

Prohexadione-calcium (prohexadione-Ca) was evaluated for its ability to suppress vegetative growth of grapevines (Vitis vinifera L.) under field conditions. Two or three applications of 250 mg·L-1 prohexadione-Ca reduced primary shoot growth of `Cabernet Sauvignon', but had little effect on other canopy characteristics or cane pruning weights. The reduction of shoot growth was not persistent and shoot hedging was ultimately needed to avoid canopy shading. Similarly, three applications of either 125, 250, or 375 mg·L-1 prohexadione-Ca reduced `Cabernet franc' shoot growth, but again did not eliminate the need for shoot hedging. Cane pruning weights of `Cabernet franc' were unaffected by treatment, and canopy characteristics were generally not improved. Two prebloom and one postbloom application of 250 mg·L-1 prohexadione-Ca were evaluated on `Cabernet franc' and `Chardonnay' in separate field experiments. The prebloom treatments retarded shoot growth of `Chardonnay', but had no effects on `Cabernet franc' shoot characteristics. To retard shoot growth, prohexadione-Ca had to be applied prior to bloom; however, prebloom applications had the potential for severe reductions in crop yield.

Gibberellic acid (GA3 ), a plant-growth regulator, is often used to obtain enlarged table grape berries and induce seedlessness in them. However, the effects of GA3 on rachis elongation and bunch compactness have seldom been reported in wine-grape production. We assessed the effects of GA3 spraying on wine-grape inflorescences and bunches and their practical implications for viticulture in the Jiaodong Peninsula, China. Various GA3 concentrations were sprayed on field-grown Vitis vinifera L. 'Cabernet Franc' (CF) and 'Cabernet Sauvignon' (CS) grapevines before anthesis in the Jiaodong Peninsula, China, in 2015 and 2016. Inflorescence length during berry development was measured, and flavonoids and aroma compounds in the fruit were detected by high-performance liquid chromatography - mass spectrometry (HPLC-MS) and gas chromatography - mass spectrometry (GC-MS), respectively. For both cultivars, 50 and 100 mg L-1 GA3 caused significant elongation of the rachis, whereas there was no significant effect on inflorescence growth and berry seed number. Anthocyanin, flavonol, and flavan-3-ol levels in mature berries were not significantly influenced by GA3 spraying, whereas C13 -norisoprenoids were modified. The application of 50-100 mg L-1 GA3 prior to grapevine anthesis caused elongation of inflorescences and bunches, and eased cluster compactness in CF and CS, and no negative effects were observed on the yield and seed numbers. The concentration and composition of flavonoids and most aroma compounds were not influenced, except that the norisoprenoids were increased by 50 mg L-1 GA3 applications. © 2020 Society of Chemical Industry.

Cultivars of European grapevine, Vitis vinifera, show varying levels of susceptibility to Eutypa dieback and Esca, in terms of foliar symptoms. However, little is known regarding cultivar susceptibility of their woody tissues to canker formation. Accordingly, we evaluated the relative susceptibility of V. vinifera cultivars ('Cabernet Franc', 'Cabernet Sauvignon', 'Chardonnay', 'Merlot', 'Riesling', 'Petite Syrah', and 'Thompson Seedless') and species or interspecific hybrids of North American Vitis (Vitis hybrid 'Concord', V. arizonica 'b42-26', V. rupestris × V. cinerea 'Ill547-1', and Fennell 6 [V. aestivalis] × Malaga [V. vinifera] 'DVIT0166') to canker formation by seven trunk pathogens (Neofusicoccum parvum, Lasiodiplodia theobromae, Phaeomoniella chlamydospora, Togninia minima, Phomopsis viticola, Eutypa lata, and an undescribed Eutypa sp.). Susceptibility was based on the length of wood discoloration (LWD) in the woody stems of rooted plants in duplicate greenhouse experiments. Cultivars of V. vinifera and Concord did not vary significantly in susceptibility to N. parvum or L. theobromae (LWD of 21 to 88 mm at 14 weeks post inoculation; P > 0.16), suggesting that they are similarly susceptible to Botryosphaeria dieback. The table-grape Thompson Seedless was most susceptible to P. viticola (mean LWD of 61 mm at 11 months post inoculation; P < 0.0001). V. vinifera cultivars and Concord showed similar susceptibility to the Esca pathogens, Phaeomoniella chlamydospora and T. minima. Susceptibility to E. lata was greatest in V. arizonica b42-26 (mean LWD of 96 mm at 11 months post inoculation; P < 0.03). In fact, all four American Vitis spp. were more susceptible to Eutypa dieback than the V. vinifera cultivars. Our findings suggest that no one cultivar is likely to provide resistance to the range of trunk pathogens but that certain cultivars may be promising candidates for commercially relevant host resistance in grape-production systems where the dominant cultivars are very susceptible.

Introduction: The winters of northeast China are very cold. The existing cultivars of grape (Vitis vinifera L.) like 'Cabernet Sauvignon', 'Cabernet Franc', 'Riesling' and 'Chardonnay' etc. cannot mature and cannot survive through the winter because of the insufficient accumulated temperature and short frost-free period. Vitis amurensis Rupr. is a wild grapevine species originating from East Asia and is mainly distributed in Korea, Japan, and China. As one of the most cold-tolerant grapes, its stem can endure -40 to -50 °C. It also exhibits resistance to grape white rot and grape anthracnose which can severely damage Vitis vinifera grown worldwide. The Vitis amurensis grape berries have the characteristics of four highs and three lows, namely: high acidity, high tannin and polyphenols, high dry extract and high nutrition; low sugar, low juice yield, and low fermentation temperature. In view of these current situation, a new grape cultivar 'Beibinghong' was selected through multi-generation hybrids between species (Vitis amurensis and Vitis vinifera). The cultivar, released in 2008, overcomes the characteristic of Vitis amurensis being usued only for brewing sweet red wine. The cultivar is suitable for brewing dry red and ice red wine.

Four grapevine cultivars ('Pinot gris', 'Riesling', 'Cabernet franc', 'Cabernet Sauvignon') were subjected to six different field treatments in 2011 [two crop loads (full, half) X three harvest dates [normal (T0), 3 weeks after T0, 6 weeks after T0] in a randomized block design with a factorialized treatment arrangement. All treatments were sampled four times over the 2012 dormant season from January to March. Bud cold hardiness was evaluated for all four cultivars by measuring low temperature exotherms (LTEs) of dormant buds using differential thermal analysis. Cane carbohydrates (CHOs) were likewise analyzed in 'Pinot gris' and 'Riesling'. CHO analysis was done using an 80 % ethanol extraction and HPLC. Neither CHO levels nor cold hardiness were substantially affected by either crop level or harvest date. Consistent patterns of CHO changes and LTE values in each cultivar indicated that deacclimation was unaffected by treatment. Cold hardiness may be influenced more by cultivar specificity based on rates of maturation than by treatment.

The wine industry is a very important activity on the national scene, having important role in diversification and incorporation of income for small farms. Given the above, the aim of the present study was to evaluate pruning times associated with the use of hydrogen cyanamide for dormancy breaking into thin variety vines. ‘Cabernet Franc’, ‘Cabernet Sauvignon’, ‘Merlot’ and ‘Tannat’ in Marechal Cândido Rondon, Parana State, Brazil. The experiment was conducted in didactic orchard located in the Experimental Station Unioeste, between June and December/2012. The experimental design was randomized blocks in factorial 3 x 4 (pruning times x cultivars). The cultivars were grafted on rootstock Paulsen1103 and pruning on July 21, August 04 and August 18, where he was then the application of hydrogen cyanamide. Evaluated in the growing season overall growth of the branches and stem diameter. At harvest, they were evaluated biomass, volume, width, length and number of clusters, biomass rachis, biomass and diameter of berries, production and productivity. Within the vegetative parameters, the ‘Merlot’ presented larger diameter stems and the Cabernet Sauvignon highest total growth of branches. The variety Cabernet Franc’ showed higher production and productivity. Early pruning showed better results for the studied cultivars.

&lt;p style="text-align: justify;"&gt;The behaviour of 4 grapevine varieties - Cabernet franc, Cabernet Sauvignon, Gamay noir and Grolleau noir – was studied from 1988 to 1998 at the INRA experimental Station, in Montreuil-Bellay, France. Very contrasted climatic years occurred within this period. The study of some phenological stages allowed to classify the varieties in 2 groups of maturation : early for Gamay and Grolleau, late for Cabernets. The former had large berries (&amp;gt;2 g), the latter small berries (&amp;lt;1,5 g). Sugar content of Cabernets and Gamay was much higher than for Grolleau, respectively &amp;gt;190 g/L and &amp;lt;170 g/L. For a same maturity index, titratable acidity of Gamay was higher than Grolleau, and Cabernet Sauvignon higher than Cabernet franc. Malic acid was identified as explaining better the acidity level. The anthocyanin content and polyphenolic index of late varieties was superior to those of the precocious ones. The variety and the climate of the vintage play an important role on final grape composition. Berry weight, sugar content, titratable acidity and malic acid could be explained by simple climatic variables, mainly temperature and rainfall during the vegetative cycle as well as wind velocity before harvest. For the phenolic compounds, the analysis looked more complex ; it seemed that the climatic variables had only a minor effect after veraison, but the role of each one of them before this stage is still to be understood.&lt;/p&gt;

Grape marc (skins and seeds) and lees (sediment solids) are the most abundant by-products of the winemaking process, because the first represents approximately 5% of the total grapes processed and the second, 4% of the total volume of wine produced. Some studies have shown that winery residues contain phenolic compounds, potent antioxidants that were not fully transferred to the wine during the winemaking process, thus with economic and functional interest. Thus, the objective of this work was characterize the phenolic compounds of industrials residues generated by the vinification and correlate their levels with the antioxidant capacity. The phenolic content of grapes in natura, grape marc (skins and seeds), and lees, in two consecutive years (2011 and 2012), of varieties BRS Violeta, BRS Lorena, Cabernet sauvignon and Cabernet franc, was determined by SPE and HPLC-DAD-ESI MS/MS. The effect of three drying techniques applied to vinification by-products (grape marc and lees) was also evaluated: dried at 50 C, drying by spray-drying and freeze-drying, as well as the stability of by-products dried submited at 25C in 0, 30 and 90 days. The antioxidant capacity was evaluated by ORAC, FRAP, ABTS and caroteno/linoleic acid, and their correlations with total anthocyanins and phenolics. Were identified 25 anthocyanins and 9 piranoathocyanins in the samples analyzed. The composition of anthocyanins BRS Violeta was mainly derived by diglucosides. However, in samples of Cabernet sauvignon and Cabernet franc antocynanins 3-glucosides were majority. The pyranoanthocyanins were found only in fermented skins of the cultivars Cabernet sauvignon and Cabernet franc and the lees of all cultivars. Flavonols were found mainly quercetin, isorhamnetin, myricetin, laricitrin, and syringetin. In grape glycosides predominated, and residues were obtained higher proportions of free aglycones, especially the lees of wine (85%). In BRS Lorena, type flavonol quercetin was the majority in the skin (91%) and the lees (95%). Already in all samples BRS Violeta, derivatives of caffeic acid were predominant. The caftaric acids (53%) and coutaric acid (17%) were high in the samples of the cultivars Cabernet sauvignon and Cabernet franc. In all samples of grapes and lees were detected the presence of trans-resveratrol, trans-piceid and cis-piceid (except BRS Violeta). In the residue dried at 50 C and spray-drying showed a 50% reduction in the total phenolic content of the residues of four different varieties of grape at time zero when compared to the lyophilized. In all methods of antioxidant capacity, BRS Violeta samples showed higher values when compared to BRS Lorena, Cabernet sauvignon and Cabernet franc. The byproducts of winemaking had elevated total phenolics, average values ranged from 810 to 8557 mg/kg for fermented skins; 1515 to 9520 mg/kg for seeds, and 1148 to 4261 mg/kg for lees. In grapes used in the processing of wine the phenolic content was found of 530 to 4330 mg/kg dried grape. Thus, the by-products have a high content of antioxidant compounds and therefore have the potential for industrial reuse.

Abstract: The objective of this work was to estimate the plastochron index of the 'Cabernet Sauvignon' and 'Chardonnay' grapevine varieties in Fronteira Oeste, in the state of Rio Grande do Sul, Brazil. The experiment was conducted in 2010, in a completely randomized design, using 'Cabernet Sauvignon' and 'Chardonnay' grapevines grown in the municipalities of Itaqui, São Borja, and Maçambará, which were referred to as sites 1, 2, and 3, respectively. Phenological monitoring of the varieties was done from the beginning of sprouting until the pruning of canes (green trimming). The daily thermal sum (dTS, oC day) was calculated using the cardinal temperatures for node appearance in grapevines (10, 25, and 35ºC), whereas the accumulated thermal sum (aTS, oC day) was obtained by adding up the dTS. The plastochron index was estimated by the inverse of the angular coefficient of the linear regression between the number of nodes per cane and aTS. In all three sites, both 'Cabernet Sauvignon' and 'Chardonnay' required degree-days of 10°C and aTS of 810ºC to complete the cycle from the beginning of sprouting until the end of flowering. The estimated plastochron indexes of the 'Cabernet Sauvignon' and 'Chardonnay' grapevines, in Fronteira Oeste, in the state Rio Grande do Sul, were 40.4 and 49.7ºC day per node, respectively.

Prohexadione-calcium (prohexadione-Ca) was applied to field-grown Cabernet franc, Cabernet Sauvignon, Chardonnay, and Seyval to evaluate rates and timing effects on fruit yield components and on fruit and wine composition. Berries per cluster, berry weight, cluster weight, and clusters per shoot in the subsequent season were all decreased by multiple, prebloom plus postbloom, applications to Cabernet Sauvignon and Cabernet franc. Similar reductions in current season components of yield were observed with Seyval. Application (250 mg/L) to single clusters of Cabernet Sauvignon and Chardonnay at bloom, or in the one-to-two-week prebloom period decreased fruit set, whereas applications one to two weeks postbloom reduced berry weight, with no impact on fruit set. Berry weight reduction correlated to increased color intensity (420 nm + 520 nm), total anthocyanins, total phenols, and phenol-free glycosyl-glucose (PFGG) in Cabernet Sauvignon. In a separate experiment, prohexadione-Ca increased Cabernet franc must color intensity, total anthocyanins, and total phenols, despite having minimal effects on berry weight or crop yield. Aroma and flavor triangle difference tests did not distinguish treatment differences with young Cabernet franc wines. This study of prohexadione-Ca effects on grape reproductive development illustrated that berry set and berry weight were responsive to application timing, with the one-to-two-week period after bloom most sensitive to reductions in berry weight. The concurrent effects on fruit composition were generally positive, while the full impact on wine quality remains equivocal, but worthy of further evaluation.

不同酿酒葡萄品种C6 醛、醇风味化合物的比较

Spring frosts and subsequent crop losses threaten the economic sustainability of fruit crop producers all over the world. This study used a controlled-freezing technique to impose a post-budburst freezing stress to grapevine shoots forced from one-node cuttings [‘Albariño’, ‘Cabernet Franc’, ‘Cabernet Sauvignon’, and ‘Pinot Grigio’ ( Vitis vinifera )] and whole plants [‘Noiret’ ( Vitis hybrid)]. Our goal was to investigate the incidence of freeze injury among cultivars, stage of phenological development, and a potassium salt-based fertilizer (KDL) with potential cryoprotectant activity. Among the V. vinifera cultivars, the incidence of mortality of shoots exposed to −3.5 °C was highest for ‘Albariño’ (71%) and lowest for ‘Cabernet Sauvignon’ (51%). Cuttings sprayed with KDL 24 hours before cold temperature exposure exhibited 16% lower shoot mortality and lower osmotic potential (Ψ s ) (−0.92 MPa) than the unsprayed cuttings (−0.77 MPa). However, application of KDL did not impact shoot mortality for whole ‘Noiret’ vines. Mortality for ‘Noiret’ shoots greatly increased with the advancement of phenological development, ranging from 10% in wooly buds to 78% in shoots ≈10-cm long. The practical significance of KDL remains questionable; cultivar selection still appears to be a more reliable method for avoiding spring frost, by planting late bursting cultivars in more frost-prone areas.