Biochemical and agronomical responses of grapevines to alteration of source-sink ratio by cluster thinning and shoot trimming

The control of leaf to fruit ratio by the practice of entire clusters removal from the vine upon berry set has been used in traditional vineyards in order to regulate yield and to improve chemical composition of the berries. Although this practice has been settled in temperate zones, little is known about grapevines behavior in tropical growing areas. The aim of this work was to evaluate the biochemical and agronomical responses of two Vitis vinifera cultivars (Merlot and Cabernet Sauvignon) grown in Caldas, Minas Gerais, Brazil, a new winegrape region. Grapevines were submitted to cluster thinning (0%, 50% and 75% of cluster removal) and trimming treatments (trimmed and untrimmed) imposed at pea size stage. The source-sink alteration by fruit removal and shoot trimming had impact on yield, leaf sugar metabolism and grape composition. Although there was an improvement in color intensity of the berries with reduction of fruit load, the cluster thinning practice should be avoided in vineyards grown in the south of Minas Gerais State without impairment of wine grape quality. On the other hand, shoot trimming practice should be recommended only for Merlot in order to improve sugar grapes from vines with no cluster removal.

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Wine grape quality of grapevines grown in the cerrado ecoregion of Brazil

OENO One ◽

10.20870/oeno-one.2011.45.2.1486 ◽

2011 ◽

Vol 45 (2) ◽

pp. 101

Author(s):

Renata Vieira Da Mota ◽

Ana Carolina Favero ◽

Camila Pinheiro Carvalho Silva ◽

Eduardo Purgatto ◽

Tânia Misuzu Shiga ◽

...

Keyword(s):

Titratable Acidity ◽

Minas Gerais ◽

Soluble Solids ◽

Winter Period ◽

Cabernet Sauvignon ◽

Wine Grape ◽

Wine Quality ◽

Cabernet Franc ◽

Grape Quality ◽

Minas Gerais State

Aims: Geographical indication plays an important role in the improvement of wine quality. In this context, the search for new grape growing areas has been constant. The São Francisco River Valley in the cerrado of Minas Gerais State (Brazil) has been pointed out in the Geoviticulture Multicriteria Climatic Classification System (MCC System) as a potentially winegrowing region, especially considering the autumn-winter period when night temperatures are favorable to grape ripening. In this work, we studied the maturation curves and fruit composition of four wine grape varieties (Syrah, Merlot, Cabernet-Sauvignon and Cabernet Franc) in two growing seasons in order to validate the state of Minas Gerais as a new winegrowing region in Brazil.Methods and results: Quality parameters (berry weight, pH, titratable acidity and total soluble solids) were measured weekly from véraison to harvest, and sugar, organic acid, anthocyanin and phenolic concentrations were determined in must and berry skins and seeds at harvest. Syrah berries showed the highest weight throughout maturation which contributed to higher yield (8.92 ton ha-1), followed closely by Merlot (8.07 ton ha-1). Berry sugar concentrations were higher and malic acid levels were lower than the values usually observed in wine grapes harvested during summer in traditional winegrowing regions in Brazil. Cabernet Franc showed lower levels of anthocyanins and skin phenolics per kg berries and the highest values of seed phenolics, which were not affected by growing season.Conclusion: Weather conditions of the cerrado of Minas Gerais State in Brazil during winter allowed complete maturation of Cabernet-Sauvignon, Cabernet Franc, Merlot and Syrah cultivars as revealed by the satisfactory sugar, anthocyanin and skin phenolic accumulation.Significance and impact of the study: This study revealed the potential of the cerrado ecoregion in the northeast of Minas Gerais to become a new winemaking region in Brazil.

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Bioactive compounds in wines produced in a new area for vitiviniculture in Brazil

Bioscience Journal ◽

10.14393/bj-v35n5a2019-42268 ◽

2019 ◽

Vol 35 (5) ◽

Author(s):

Ana Carolina Vilas Boas ◽

Rita de Cássia Mirela Resende Nassur ◽

Paôla De Castro Henrique ◽

Giuliano Elias Pereira ◽

Luiz Carlos Oliveira de Lima

Keyword(s):

Antioxidant Activity ◽

Bioactive Compounds ◽

Phenolic Acids ◽

Total Phenolics ◽

Minas Gerais ◽

Cabernet Sauvignon ◽

Red Wines ◽

White Wines ◽

Sauvignon Blanc ◽

Minas Gerais State

Wines are known for its high content of bioactive compounds that can be influenced by the region and climate where the grapes are produced. New regions of production are normally developed using techniques and standards for other traditional regions, but is important to characterize the wine profile, which is different according to the terroir, and can be important for future geographic indications. The aim of this study was to evaluate color, antioxidant activity, anthocyanin content and phenolic compounds profile in wines produced in Minas Gerais State, Brazil. Wines were produced in different wineries of the same region using the varieties Syrah, Merlot, Cabernet Sauvignon, Cabernet Franc (red), Chardonnay and Sauvignon Blanc (white) and Syrah (rose), from municipalities of Cordislândia, Boa Esperança and Três Corações, located in the south of Minas Gerais State, Brazil. Wines produced in Minas Gerais State presented contents of t-resveratrol, total phenolics, anthocyanins, flavonols, flavanols and phenolic acids consistent to the contents observed in wines from traditional regions of production. However, the terroir and the grape variety can result in a differentiation of compounds observed in wines. Syrah red wines produced in Boa Esperança stood out with higher amounts of anthocyanins (24.29 mg L-1), phenolic acids (123,19 mg L-1 ) and flavonols (35.55 mg L-1), when compared to wines from the same variety from other municipalities and other evaluated red wines. Sauvignon Blanc wines from Boa Esperança presented higher contents of phenolic acids and total flavonols, when compared to wines of the same variety produced in Cordislândia. Chardonay wines presented higher total phenolics content, when compared to ohther evaluated white wines. Rose wine produced in the South of Minas Gerais presented the phenolic acids content of 36,33 mg L-1 and total flavonols content of 29,7 mg L-1. The highest antioxidant activity using the DPPH method, (% of free radicals scavenging - FRS) was observed for Syrah wines from Três Corações, (75.37%), but not different from Cabernet Sauvignon wines from Cordislândia (72.50%), values that can be correlated with the largest content of phenolics observed in wines as phenolic compounds (3009 mg L-1). No differences were observed in the contents of the antioxidant activity of white wines. This results indicate that the studied wines present the necessary nutritional and beneficial characteristics to compete in the supply of bioactive compounds during consumption, when compared to wines produced in traditional and different regions in Brazil and other countries.

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The impact of cluster thinning and leaf removal timing on the grape quality and concentration of monomeric anthocyanins in Cabernet-Sauvignon and Probus (Vitis vinifera L.) wines

OENO One ◽

10.20870/oeno-one.2020.54.1.2505 ◽

2020 ◽

Vol 54 (1) ◽

pp. 63-74 ◽

Cited By ~ 2

Author(s):

Dragoslav Ivanišević ◽

Mladen Kalajdžić ◽

Mato Drenjančević ◽

Vladimir Puškaš ◽

Nada Korać

Keyword(s):

Vitis Vinifera ◽

Titratable Acidity ◽

Vitis Vinifera L ◽

Cabernet Sauvignon ◽

Leaf Removal ◽

Time Points ◽

Grape Quality ◽

Cluster Thinning ◽

The Impact ◽

Monomeric Anthocyanins

Aim: Leaf removal around clusters and cluster thinning are techniques usually applied in cool-climate vineyards in order to achieve optimal grape maturity. However, the impact of the timing of these two operations differs across varieties. Thus, the aim of the present work was to investigate the effects of cluster thinning and leaf removal timing (performed at three specific time points) on grape quality and monomeric anthocyanins in the wines of Cabernet-Sauvignon and Probus (Kadarka × Cabernet-Sauvignon, Vitis vinifera L.)Methods and results: The experiment was conducted in Sremski Karlovci (Northern Serbia) in 2014, 2015, and 2016. Leaf removal was applied on six basal nodes of each shoot at three time points, 7 days after flowering, 30 days after flowering, and at veraison, i.e., at the onset of berry ripening. After cluster thinning, which was performed 7 days after flowering, one cluster per shoot was retained. On the treated vines, leaf removal treatment and cluster thinning were applied only once. Leaf removal was more effective than cluster thinning in respect to grape quality. Leaf removal, applied 7 and 30 days after flowering, decreased titratable acidity in Cabernet-Sauvignon, while in Probus an interaction of leaf removal and year was observed. Moreover, early leaf removal decreased the incidence of Botrytis sp. in Probus. The varieties reacted differently to cluster thinning in respect to grape quality: cluster thinning increased total soluble solids in Probus and lowered titratable acidity in Cabernet-Sauvignon. In 2015, both cluster thinning and leaf removal yielded changes in the anthocyanin ratios in the wines. Cluster thinning increased total and acylated anthocyanins in the wine of Cabernet-Sauvignon compared to wine derived from unthinned vines. The peonidin content was 40 % higher in the Cabernet-Sauvignon wine if the vines were subjected to leaf removal treatments.Conclusions: Cluster thinning and leaf removal affected both Cabernet-Sauvignon and Probus (Vitis vinifera L.) grape quality and wine composition. Early leaf removal was the most effective treatment in both varieties. Therefore, combined application of cluster thinning and early leaf removal is highly recommended in the production of high-quality red wines in Serbia.Significance and impact of the study: Timing of leaf removal application was usually investigated around flowering and veraison. Our results suggested that leaf removal between these two phenological stages also improves grape quality and changes the ratio of the monomeric anthocyanins in the wine.

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