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Gomez I.,Tresge Wine Consulting S.L. | Revert J.,Celler Del Roure S.L. | Esteve M.D.,Polytechnic University of Valencia | Climent M.D.,Polytechnic University of Valencia | And 3 more authors.
Acta Horticulturae | Year: 2012

In the old-world viticulture autochthonous varieties are an important inheritance because they can provide wines with authenticity and distinction. Cultivar Mandó is an almost extinguished variety from the south-east of Spain with very large and tight clusters. The aim of this study was to assess the usefulness of early defoliation as a possible tool to reduce cluster compactness, improving fruit composition. With this in mind, an experiment was conducted with 'Mandó' in deficit irrigated vines trained with a divided Lyre system. Control (C), non-defoliated vines, were compared with defoliation carried out either just before anthesis (phenological phase H, (Def-H)), at flowering (phenological phase I, (Def-I)) or at fruit set (phenological stage J, (Def-J)). In all the defoliation treatments, leaves from the first eight nodes, including laterals, were removed. The experimental design was a complete randomized block with three replicates per treatment and 24 experimental vines per experimental plot. As an average for all defoliation treatments, berry number per cluster, berry weight and yield were reduced by 44%, 16% and 45%,in Def-H, Def-I and Def-J respectively. Defoliation increased berry soluble solids concentration only in the Def-H treatment. On the other hand, berry acidity was only decreased in the Def- H treatment. In the ED and LD defoliation treatments, leaf pulling improved berry quality determined by a berry tasting panel. In agreement, berries from the ED and LD also had higher total phenolics, anthocyanins and tannin concentration. Results obtained were judged positively by the winery owners and defoliation, particularly at stage J, will now be more widely conducted in the vineyards planted with the 'Mandó' cultivar. The research is indeed an example of a successful transfer of a research technique under commercial situations.

Gomez I.,Tresge Wine Consulting S.L. | Revert J.,Celler del Roure SL. | Lizama V.,Universidad Politécnica de Ingeniería | Garcia-Esparza M.J.,Universidad Politécnica de Ingeniería | And 4 more authors.
Acta Horticulturae | Year: 2011

In the old-world viticulture, there is a common but most often not scientifically proven consideration that supplemental irrigation should detrimentally affect berry and wine composition. In the semi-arid and warm climate of in-land Valencia, we tested the hypothesis that deficit irrigation might, not only improve yield, but also fruit composition. The experiment was performed with 'Cabernet Sauvignon' vines at the Celler del Roure SL vineyard, located in the D.O. Valencia. Rainfed vines were compared with three different post-veraison irrigation regimes with water application at either 10, 20, or 30% of reference evapotranspiration, resulting in water application of 26, 34 and 57, mm respectively. The experimental design was a randomised block with three replicates per treatment and 308 experimental vines per experimental plot. The experiment was conducted in a very dry and warm 2009 season, with substantial no rainfall from August up to harvest and average temperature during ripening of 24°C. Rainfed vines experienced quite severe plant water stress with an average midday stem water potential of -1.45 MPa. Supplemental irrigation improved plant water status and increased yield in proportion to the amount of water applied mostly because irrigation avoided berry and whole clusters dehydration that occurred in the rainfed vines during ripening. The most important effect of irrigation was to avoid the excessive increase in berry sugar content that, at the right phenolic ripening time, reached in the rainfed treatment up to 16.5° of probable alcohol. Irrigation did not affect must acidity and improved berry quality determined by a berry tasting panel. In addition the supplemental irrigation did not decrease total berry phenolic and anthocyanin potential. On the other hand irrigation slightly decreased the extractable values. This suggests that different maceration procedures should be applied depending on grape origin. Under very dry and warm seasons, irrigation can be used to mitigate the negative effect of low plant water status on berry dehydration and unbalanced ripening. © ISHS.

Bertolini E.,Instituto Valenciano Of Investigaciones Agrarias | Garcia J.,Instituto Tecnologico Of Viticultura Y Enologia | Yuste A.,Polytechnic University of Valencia | Olmos A.,Instituto Valenciano Of Investigaciones Agrarias
European Journal of Plant Pathology | Year: 2010

Table grapes from one of the most important growing area in Spain (Vinalopó, Alicante) protected by the Designation of Origin "Vinalopó bagged table grape", were surveyed and analysed to determine the prevalence of the five viruses included in the Spanish certification program: Arabis mosaic virus (ArMV), Grapevine fanleaf virus (GFLV), Grapevine fleck virus (GFkV), Grapevine leafroll associated virus-1 (GLRaV-1) and Grapevine leafroll associated virus-3 (GLRaV-3). Ninety five sampling points were selected and the position of grapevine plants georeferenced. Samples were collected in two different vegetative periods and analyses were performed by ELISA and real-time RT-PCR. Purified RNA and immobilized viral targets from plant extracts on nylon membranes were used in parallel assays as templates for PCR assays. In order to analyse these five viral species by real-time RT-PCR, new specific primers and TaqMan probes were designed for detection of ArMV and GFkV. Real time RT-PCR from purified RNA was more sensitive than spot version and ELISA tests. The most prevalent virus was GFLV (95.8%) followed by GLRaV-3 (94.7%), GLRaV-1 (66.3%) and GFkV (65.3%). ArMV was not detected in any sample. The high level of viral infections and the presence of mixed infections suggest that initial infected plant material and uncontrolled traffic of propagation material have played an important role in the spread of viruses. © 2010 KNPV.

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