Abstract Sunlight and heating influence leaf and grape metabolism and therefore wine quality. As a recent management tool, no information exists on the effects of grapevine row orientation on the wine composition of Syrah vines within the context of double pruning management, a technique used to transfer the grape harvest from the wet summer to the dry winter season. This is a first attempt to investigate the wine composition from north-south- (NS) and east-west- (EW) oriented Syrah winter vines. EW wine samples had higher total acidity, residual sugars, alcohol and color hue, whereas NS wines exhibited higher content of color intensity, anthocyanins, total phenolics, total phenolic index, ashes and pH. The identification of volatile compounds was tentatively performed and demonstrated the presence of alkanes, volatile phenols and alkyl sulfide in NS wines, while butyrolactone and beta-damascenone were found mainly in EW wines. Row orientation contributed to wine composition and could be used as a management tool for obtaining individual wine styles.

ABSTRACT The sunlight and heating effects on leaves and grapes are directly influenced by row orientation in vineyards. Row orientation studies have not been addressed under double pruning management, a technique used to transfer the wine grape harvest from wet summer to dry winter season in Brazilian Southeast. Effects of grapevine row orientation (north/south - NS and east/west - EW) of vertically trellised and shoot positioned Vitis vinifera L. Syrah grafted onto 1103 Paulsen were investigated in the South of Minas Gerais State. The vegetative vigor was increased in NS oriented vines, probably due to high photosynthesis as suggested by the highest leaf starch accumulation. The leaf and stem water potential were slight affected by row orientation. NS orientation increased the cluster weight, but cluster number and yield per vine were not affected by treatments. Berries from NS oriented vines also showed the highest values of anthocyanins and total phenols. Under NS orientation there was a reduction on tartaric acid and soluble sugar in berries probably diluted by increased cluster weight. This study showed that vineyard under NS orientation improved grapevine vigor and promoted better phenolic maturity in wine grapes harvested during the winter season than EW orientation.

RESUMO Este trabalho teve como objetivo avaliar a influência do sistema de condução na qualidade de bagas de uvas 'Niágara Rosada' e 'Folha-de-Figo' cultivadas em Caldas-MG. Foram avaliados a produção por planta, o diâmetro, a massa, o teor de potássio e a temperatura das bagas, pH, teor de sólidos solúveis, açúcares redutores, acidez total e ácidos orgânicos do mosto, compostos fenólicos nas cascas e sementes, e antocianinas. As plantas foram conduzidas em espaldeira, lira, latada ou cordão simples, e os frutos, avaliados nas safras de 2006 e 2007. As videiras de 'Niágara Rosada' cultivadas em latada e 'Folha-de-Figo' em lira apresentaram produção significativamente superior aos demais sistemas de condução. Em todos os casos, as bagas apresentaram temperatura inferior à ambiente, indicando sombreamento completo ou parcial dos cachos. No sistema latada, houve menor acúmulo de sólidos solúveis e açúcares redutores nas duas cultivares. Estes resultados preliminares indicam que a composição das bagas foi pouco influenciada pelo sistema de condução.

ABSTRACT This work aimed on evaluating the influence of training systems in berries composition of 'Niágara Rosada' and 'Folha-de-Figo' grapevines grown in Caldas, MG. Yield per plant; diameter, weight, temperature and potassium content of the berries; pH, soluble solids, reducing sugars, total acidity and organic acids of the must; anthocyanins and phenolic compounds of the skins and phenolic compounds of the seeds were evaluated in grapevines training in vertical shoot position, lyre trellis, pergola Veronese or simple string in 2006 and 2007 seasons. 'Niágara Rosada' and 'Folha-de-Figo' grapevines training in pergola Veronese and lyre trellis, respectively, showed higher yield than the other training systems under study. Berries grown under the four different training systems were cooler than ambient temperature, resulting from partial or deep shade clusters. Berries harvested from pergola Veronese trellis system showed lower soluble solids and reducing sugars levels in both cultivars. These preliminary data show that training systems exerted little influence on berries composition.

Este trabalho teve como objetivo avaliar o potencial de maturação das cultivares Pinot Noir, Tempranillo, Merlot, Cabernet Sauvignon, Syrah, Chardonnay e Sauvignon Blanc submetidas ao regime de dupla poda, em Cordislândia, região cafeeira do sul de Minas Gerais. As plantas foram submetidas a dois ciclos de produção, um de primavera-verão, compreendido entre agosto e janeiro, e outro ciclo de outono-inverno, entre janeiro e julho. Como parâmetros de qualidade, foram avaliados os diâmetros transversal e longitudinal da baga, acidez, ácidos tartárico e málico, pH, sólidos solúveis, antocianinas, fenólicos totais e os teores de glicose, frutose e sacarose. Todas as variedades apresentaram maiores teores de pH, sólidos solúveis, açúcares, antocianinas e fenólicos totais, e redução nos diâmetros transversal e longitudinal na safra de inverno. A cultivar Syrah destacou-se das demais no conteúdo de antocianinas e fenólicos totais tanto no verão quanto no inverno, entretanto apresentou o menor conteúdo de açúcares. A alteração do ciclo de produção da videira através da técnica da dupla poda para colheita, no período de inverno, na região cafeeira de Minas Gerais, favorece a maturação dos frutos e melhora consideravelmente a qualidade das uvas para vinificação.

This work aimed to evaluate some ripening parameters of cultivars Pinot Noir, Tempranillo, Merlot, Cabernet Sauvignon, Syrah, Chardonnay and Sauvignon Blanc submitted to the double-pruning management in Cordislândia, in the coffee region of the south of Minas Gerais State. Grapevines were cultivated in two different growing seasons, spring-summer from August to January and autumn-winter from January to July. Quality parameters such as berry transversal and longitudinal diameters, acidity, tartaric and malic acids, pH, soluble solids, anthocyanins, phenolic compounds, glucose, fructose and sucrose were evaluated. All cultivars showed higher pH, soluble solids, sugars, anthocyanins and phenolic compounds levels and lower transversal and longitudinal diameters in winter cycle. Syrah cultivar pointed out with higher anthocyanin and phenolic compounds levels in summer and winter cycles however showed lower reducing sugars levels in must. The alteration of the production cycle through double-pruning management in order to harvest grapes in the winter in the coffee region of Minas Gerais favours the ripening of the fruits and improves the quality of wine grapes.

O controle da razão folhas:frutos pela prática da remoção de cachos inteiros após o estabelecimento das bagas tem sido utilizado nos vinhedos tradicionais, a fim de regular a produção e melhorar as características químicas das bagas. Embora essa prática esteja bem estabelecida em regiões temperadas, pouco se sabe a respeito do comportamento das videiras cultivadas em áreas tropicais. O objetivo deste trabalho foi avaliar as respostas agronômicas e bioquímicas de duas cultivares de Vitis vinifera (Merlot e Cabernet Sauvignon) cultivadas em Caldas, Minas Gerais, Brasil, nova região produtora de uvas finas. As videiras foram submetidas a tratamentos de desbaste de cachos (0%, 50% e 75% de cachos retirados) e desponte (com e sem desponte) realizados no estágio de ervilha. A alteração da fonte-dreno pela remoção dos frutos e desponte afetou a produção, o metabolismo de açúcares nas folhas e a composição das bagas. Embora tenha sido observado um aumento na intensidade de cor das bagas com a redução da carga de frutos, a prática do desbaste de cachos pode ser evitada nos vinhedos do sul de Minas Gerais, sem prejuízo à qualidade das uvas viníferas, enquanto a prática do desponte deve ser recomendada somente para Merlot, a fim de melhorar a concentração de açúcares nas uvas de videiras sem desbaste de cachos.

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.

O objetivo deste trabalho foi avaliar a influência de nove porta-enxertos na produção e composição química das bagas de uvas de mesa e de processamento durante o período de 2006 a 2008 em Caldas, MG. As cultivares Niágara Rosada e Folha de Figo foram enxertadas sobre 'IAC 572', 'IAC 313', 'IAC 766', '420 A', '1103 Paulsen', 'Traviú', '196-17', 'Gravesac' e 'RR 101-14' e submetidas ao delineamento em blocos ao acaso com dez tratamentos (nove porta-enxertos e o pé-franco) e quatro repetições. Ambas cultivares apresentaram maior produção sobre 'IAC 572', porém com prejuízo para a qualidade das bagas que apresentaram menor relação sólidos solúveis/acidez, menor teor de antocianinas e de compostos fenólicos e maior acidez. A absorção de potássio foi mais dependente do porta-enxerto em 'Niágara Rosada'; a maior absorção foi com os porta-enxertos 'IAC 766' e 'Traviú'. Videiras enxertadas sobre '196-17' apresentaram o menor teor de potássio nas bagas. 'Niágara Rosada' apresentou produção de 9 kg por planta e elevada relação sólidos solúveis/acidez sobre 'RR 101-14', '420 A' e 'Gravesac'. Entretanto, 'Gravesac' proporcionou maior concentração de antocianinas. 'Folha de Figo' enxertada em '196-17' apresentou elevado teor de sólidos solúveis, antocianinas e fenólicos nas cascas e menor teor de acidez e fenólicos nas sementes, além de produção de 5 kg por planta, estatisticamente semelhante aos porta-enxertos mais produtivos.

This work aimed at evaluating the influence of nine rootstocks on the productivity and chemical composition of table and processing grapes from 2006 to 2008 in Caldas, MG. The cultivars Niagara Rosada and Folha de Figo were grafted onto 'IAC 572', 'IAC 313', 'IAC 766', '420 A', '1103 Paulsen', 'Traviú', '196-17', 'Gravesac' and 'RR 101-14' and submitted to a randomized block design with ten treatments (nine rootstocks and ungrafted plant) with four replicates. Both cultivars had higher yields when grafted onto 'IAC 572', however with impairment to berry quality, showed by lower soluble solids/acidity ratio, anthocyanins and phenolic compounds and higher total acidity. The effect of rootstock on potassium uptake was more pronounced in 'Niagara Rosada' than in 'Folha de Figo', whereby 'IAC 766' and 'Traviú' were responsible for the highest potassium uptake. Vines grafted onto '196-17' showed lower potassium levels on berries. 'Niagara Rosada' yielded 9 kg per plant and showed high soluble solids/acidity ratio when grafted onto 'RR 101-14', '420 A' and 'Gravesac'. 'Gravesac', however, provided the higher anthocyanin content. 'Folha de Figo' grafted onto '196-17' showed high soluble solids, anthocyanins and skin phenolic compounds contents and low acidity and seeds phenolic compounds, with a yield of 5 kg per plant, behaving statistically similarly to the most productive rootstocks.