'Bordô' grapevines (Vitis labrusca) have great relevance to viticulture due to the quality they can impart to wines and juices. However, this cultivar has high variation in yield, ranging from 6 to 11 t ha-1. The use of clones with superior genetic potential related to scions currently marketed may increase crop profitability and revitalize its cultivation. The aim of this study was to evaluate the agronomical responses of twelve clones of the Bordô cultivar selected over a period of 15 years according to yield and quality. The vineyard was planted in 2008. Grape plants were grafted onto '1103 Paulsen' rootstock and trained on vertical shoot positioning. The agronomical evaluations, performed in the 2011, 2012 and 2013 seasons, covered the duration of their phenological cycles, shoot growth, yield per plant, estimated total yield and physicochemical characteristics. Differences were found between clones in terms of phenology, yield components, and berry composition. Clone 6 had the lowest yield, averaging 5.0 t ha-1 whereas clone 13 was the most productive with 14.9 t ha-1. Based on the most productive vineyards in the region (10.8 t ha-1), the adoption of more productive clones can generate an increase in yield of around 38 %.

O objetivo deste trabalho foi avaliar o efeito do etefon e de épocas de aplicação do ácido abscísico (ABA) na cor da uva de mesa 'Rubi'. Oito tratamentos foram avaliados: controle, sem aplicação; etefon 500 mg L‑1, aplicado sete dias após o início da maturação (7 DAIM); e duas concentrações de ABA (200 e 400 mg L‑1) arranjadas em três épocas de aplicação, aos 7 DAIM, aos 15 dias antes da colheita (DAC) e aos 7 DAIM + 15 DAC. O ABA não altera as características físico‑químicas dos cachos e melhora a cor das uvas, especialmente quando aplicado duas vezes (7 DAIM + 15 DAC), à concentração de 400 mg L‑1.

The objective of this work was to evaluate the effect of ethephon and of abscisic acid (ABA) application timing on the color of 'Rubi' Table grape. Eight treatments were evaluated: control, without application; ethephon 500 mg L‑1 applied seven days after veraison (7 DAV); and two concentrations of ABA (200 and 400 mg L‑1) arranged with three application timings at 7 DAV, at 15 days before harvest (DBH), and at 7 DAV + 15 DBH. ABA does not modify physical‑chemical characteristics of the cluster and improves the color of grapes, especially when applied twice (7 DAV + 15 DBH) at the concentration of 400 mg L‑1.

A produção de uvas para mesa vem passando por alguns desafios que demandam alterações nas tecnologias de produção, devido, principalmente, à intensa necessidade de controle de doenças fúngicas. O objetivo deste trabalho foi avaliar o comportamento da evolução da maturação da uva 'BRS Clara' enxertada sobre o porta-enxerto IAC 766 'Campinas', sob cultivo protegido produzida em safra fora de época. Os experimentos foram realizados em Uraí e Marialva (PR). Foram avaliadas semanalmente as características químicas das bagas, como teor de sólidos solúveis, acidez titulável, índice de maturação e pH, a partir do início da maturação até a colheita, em dois sistemas de cultivo protegido: cobertura plástica e sombrite. O delineamento experimental adotado em ambas as áreas foi o inteiramente casualizado com sete repetições. A evolução da maturação nos dois sistemas de cultivo protegido foi comparada por meio da análise de regressão. Em ambas as áreas experimentais, a cobertura plástica possibilitou a antecipação da colheita das uvas em seis dias em relação ao sombrite, considerando o teor de sólidos solúveis. Não houve influência da cobertura plástica sobre o índice de maturação das uvas.

The production of table grapes has been facing some challenges that require changes in production technologies, primarily due to the intense need to control fungal diseases. The aim of this study was to evaluate the ripening of 'BRS Clara' grapevines grafted on IAC 766 'Campinas' rootstock, under protected cultivation grown out of season. The experiments were performed at Uraí and Marialva, Paraná State, Brazil. The chemical characteristics of the berries such as soluble solids, titratable acidity, maturation index and pH were evaluated weekly from early ripening to harvesting, in two protected cultivation systems: under plastic cover and under plastic screen. The randomized design was used as a statistical model, in both experiments, with seven replications. The berry ripening evolution was compared by means of regression analysis. In both experimental areas, the plastic cover enabled earlier grape harvest (in six days) as compared to the plastic screen, being the harvest based on the soluble solids content. The plastic cover did not modify the maturation index of the berries of 'BRS Clara'.