Delaying berry ripening through manipulating leaf area to fruit ratio

The viticulture practices have always been focused on the production of grapes with higher sugar level, and this tendency has been pronounced by the climate change. The objective consists on delaying berry ripeness by decreasing the ratio between the leaf area and yield, performing intense trimming treatments after berry set and establishing the consequences on grapevine productivity in the following years. Severe shoot trimming with two different intensity treatments were done during a 3-year period (2010-2012). Phenological, vegetative and productive parameters were examined. Veraison date was delayed around twenty days. Regarding the same harvesting date, the trim treatments had lower soluble solids level (15 % reduction), lower pH (0.1-0.3) and less total anthocyanin content (10-27 % reduction). The trim effect was also reflected in berry weight; as a consequence of that, bunch size and yield were also reduced by around 9 and 15 %. Overall, single trim treatment was superior to double trim treatment because it can achieve the same results in delayed ripening, reduced °Brix, pH and production but with a smaller reduction in anthocyanin content and without having any negative impact on following years.Peer Reviewe

Quantifying the effect of temperature on decoupling anthocyanins and sugars of the grape (Vitis vinifera L. 'Maturana Tinta de Navarrete')

The objective of this work consists of the quantification of decoupling anthocyanin: sugar ratio produced by higher temperature on Vitis vinifera L. 'Maturana Tinta de Navarrete'. Two vineyards were studied in two different climatic areas during a 3-year period (2010-2012). The average Winkler index during the three years in the two studied areas was 1364°C and 1619°C, respectively. This implies a difference of 1.3°C for the mean temperature between both areas from April to October. Both total anthocyanins and the anthocyanins: sugars ratio decreased, significantly, in the warmer area during the three years. The highest anthocyanin sugars decoupling occurred in the warmest year (2012) and the lowest in the coolest year (2010). Given that the grape ripening begins in August, it could be concluded that the above decoupling is higher as higher is the temperature in August. For further research, it would be very interesting to study the anthocyanins: sugar ratio at different times from veraison onwards.Peer Reviewe

Quantifying the effect of temperature on decoupling anthocyanins and sugars of the grape (Vitis vinifera L. 'Maturana Tinta de Navarrete')

The objective of this work consists of the quantification of decoupling anthocyanin:sugar ratio produced by higher temperature on Vitis vinifera L. 'Maturana Tinta de Navarrete'. Two vineyards were studied in two different climatic areas during a 3-year period (2010-2012). The average Winkler index during the three years in the two studied areas was 1364 °C and 1619 °C, respectively. This implies a difference of 1.3 °C for the mean temperature between both areas from April to October. Both total anthocyanins and the anthocyanins:sugars ratio decreased, significantly, in the warmer area during the three years. The highest anthocyanin sugars decoupling occurred in the warmest year (2012) and the lowest in the coolest year (2010). Given that the grape ripening begins in August, it could be concluded that the above decoupling is higher as higher is the temperature in August. For further research, it would be very interesting to study the anthocyanins : sugar ratio at different times from veraison onwards

Delaying berry ripening through manipulating leaf area to fruit ratio

The viticulture practices have always been focused on the production of grapes with higher sugar level, and this tendency has been pronounced by the climate change. The objective consists on delaying berry ripeness by decreasing the ratio between the leaf area and yield, performing intense trimming treatments after berry set and establishing the consequences on grapevine productivity in the following years. Severe shoot trimming with two different intensity treatments were done during a 3-year period (2010-2012). Phenological, vegetative and productive parameters were examined. Veraison date was delayed around twenty days. Regarding the same harvesting date, the trim treatments had lower soluble solids level (15 % reduction), lower pH (0.1-0.3) and less total anthocyanin content (10-27 % reduction). The trim effect was also reflected in berry weight; as a consequence of that, bunch size and yield were also reduced by around 9 and 15 %. Overall, single trim treatment was superior to double trim treatment because it can achieve the same results in delayed ripening, reduced °Brix, pH and production but with a smaller reduction in anthocyanin content and without having any negative impact on following years.

Long-term effects of zero pruning on Grenache vines under drought conditions

Under drought conditions the influence of zero pruning (ZP) and hand pruning (HP) on yield, total soluble solids (degrees Brix), sugar production, dry matter production and total leaf area development of Grenache vines (Vitis vinifera L.) was assessed from 1988 to 1996. ZP was superior to HP for yield, sugar production and dry matter production. Total soluble solids were occasionally reduced by ZP. These effects of ZP can be explained by the larger total leaf area. These results are specifically important with regard to low-yield viticulture with a severely limited total leaf area

Vine vigor, yield and grape quality assessment by airborne remote sensing over three years: Analysis of unexpected relationships in cv. Tempranillo

© 2015 INIA. The prediction of grape composition is becoming more important due to the need of reducing the current levels of alcohol and pH of the wines, a problem that is exacerbated by climate change. This work presents a 3-year study of the spatial variability of grape composition in a rainfed Tempranillo vineyard located in Rioja (Spain). It is based on the acquisition of multispectral imagery at véraison (start of the ripening process); and zoning based on NDVI, to assess its performance for zonal management. The results reveal a high spatial variability within the plot, with a stable pattern over the years, even with very different climate conditions. NDVI was a good predictor of vegetative growth variables. However, the prediction of grape composition was more complex. Unexpectedly, anthocyanins were found to be higher in the highest vigor zone, which is probably related to the effects of climate change. This unexpected relationship is particularly discussed in the article.This work was financed by a CDTI (Spanish Centre for Industrial Technological Development) program IDI 20110576 in Bodegas Eguren Ugarte (Laguardia, Álava, Spain).Peer Reviewe

Reducing the Sugar and pH of the Grape (Vitis vinifera L. cvs. ‘Grenache’ and ‘Tempranillo’) Through a Single Shoot Trimming

Many vineyards all over the world can easily produce high potential alcohol levels, but the importanceof the sugar content in berries has been changing over the past few years. The objective of this work wasto reduce the sugar and pH of the grapes, delay berry ripening by decreasing the ratio between the leafarea and yield, perform an intense trimming treatment after berry set and establish the consequences forgrapevine productivity in the following year. Severe shoot trimming was done over a three-year period(2010 to 2012). Phenological, vegetative and productive parameters were examined. The date of véraisonwas delayed by about 20 days. On the same harvesting date, the trim treatment had lower soluble solids(12% to 15 % reduction), lower pH (0.1 to 0.3) and a lower total anthocyanin content (10% reduction). Thetrim effect was also reflected in berry weight; as a consequence, bunch size and yield were also reduced byaround 10%. If the trim treatment does not reduce the leaf area to fruit ratio below 0.50 m2/kg, there is nonegative impact on vine capacity in the next year

Genetic and ampelographic identification of different grape varieties known as 'Tempranillo' in Rioja (Spain)

Research Note

Reducing the sugar and pH of the grape (vitis vinifera l. Cvs. 'Grenache' and 'tempranillo') through a single shoot trimming

Many vineyards all over the world can easily produce high potential alcohol levels, but the importance of the sugar content in berries has been changing over the past few years. The objective of this work was to reduce the sugar and pH of the grapes, delay berry ripening by decreasing the ratio between the leaf area and yield, perform an intense trimming treatment after berry set and establish the consequences for grapevine productivity in the following year. Severe shoot trimming was done over a three-year period (2010 to 2012). Phenological, vegetative and productive parameters were examined. The date of véraison was delayed by about 20 days. On the same harvesting date, the trim treatment had lower soluble solids (12% to 15 % reduction), lower pH (0.1 to 0.3) and a lower total anthocyanin content (10% reduction). The trim effect was also reflected in berry weight; as a consequence, bunch size and yield were also reduced by around 10%. If the trim treatment does not reduce the leaf area to fruit ratio below 0.50 m 2/kg, there is no negative impact on vine capacity in the next year.Peer Reviewe

Does Full Exposure of Clusters Have Any Negative Effects on Tempranillo (Vitis vinifera L.) Grape Quality in La Rioja, Spain? The Use of Severe Cluster-zone Leaf Removal after Berry Set

A three-year experiment comprising severe leaf removal (LR) was carried out on Tempranillo grapes in Logroño, North-central Spain. For the LR treatment, six basal leaves, along with the basal lateral shoots, were removed two weeks after fruit set. Berry total soluble solids (TSS) were examined when the colour began to appear. Grapes from both the LR and control (C) vines were analysed at the same TSS level (≈ 22°Brix). LR advanced the onset of anthocyanin synthesis slightly but significantly. Yield components were not affected by LR and no symptoms of sunburn were observed. Both treatments showed similar juice pH and titratable acidity, although tartaric acid increased with LR while malic acid decreased with it. In spite of failing to increase the final anthocyanin concentration of the grape juice, LR enhanced the colour and body of the wine. These results indicate that a relatively early LR could be a viable way to improve the quality of grapes and wine under the climatic conditions of the Rioja wine region