Estimation of grape quality in vineyards using a new viticultural index

Crop yield, total leaf area, canopy surface area and other vineyard parameters were determined on different 'Tempranillo' and 'Grenache' (Vitis vinifera L.) vineyards situated in Rioja appellation (Spain). All parameters were determined during three years. Grape vineyard assessment was performed by Vitur scoresheet, proposed by TARDAGUILA and MARTINEZ DE TODA (2005). The main chemical composition parameters of grape pulp and skin were also determined. The correlations between the viticultural variables and the chemical composition variables of the grapes were also analysed. The parameter that displayed the best correlation with grape phenolic composition was the CSA/Y/ShL parameter, referred to as the Toda Index. This index could be used to estimate the phenolic composition of grapes. It also presented the best correlations with grape quality, estimated using the Vitur score-sheet. These results suggest that, for winegrape vineyard assessment, Vitur score-sheet (necessarily subjective) may be replaced with the new Toda index (faster and objective). The main advantage of this new parameter is that it is easy to determine and is completely objective, unlike visual estimation which offers a high degree of subjectivity.

Manejo do dossel vegetativo e seu efeito nos componentes de produção da videira Merlot.

A poda verde é uma prática cultural utilizada para melhorar as condições do dossel vegetativo dos vinhedos, visando a favorecer a qualidade da uva e do vinho. Nesse sentido, realizou-se este experimento entre as safras de 1993/1994 e 1996/1997, com diferentes modalidades de poda verde, num vinhedo do cv. Merlot conduzido em latada. Houve 12 tratamentos e três repetições, sendo o delineamento experimental em blocos casualizados. Os tratamentos constituíram-se da testemunha e de 11 diferentes modalidades de poda verde, ou seja, desbrota, desponta e desfolha, algumas delas em diferentes épocas do ciclo vegetativo da videira. O componente principal 1, da análise de componentes principais (ACP) feita em cada ano, separadamente, mostra que o tratamento 10 (desbrota + desponta + desfolha realizada no início da floração, eliminando-se as folhas abaixo dos cachos) discriminou-se nos quatro anos, e os tratamentos 7 (desfolha realizada 21 dias antes da colheita, eliminando-se metade das folhas abaixo dos cachos) e 6 (desfolha realizada 21 dias antes da colheita, eliminando-se as folhas abaixo dos cachos), em três deles; a ACP da média dos quatro anos também evidencia essa discriminação entre eles. Constata-se que o tratamento 10 foi um dos que tiveram intensidade de poda verde mais intensa, caracterizando-se por variáveis indicativas de plantas com vigor e produtividade mais baixos que os demais

Impact of Leaf Removal, Applied Before and After Flowering, on Anthocyanin, Tannin, and Methoxypyrazine Concentrations in ‘Merlot’ (Vitis viniferaL.) Grapes and Wines

7siThe development and accumulation of secondary metabolites in grapes determine wine color, taste, and aroma. This study aimed to investigate the effect of leaf removal before flowering, a practice recently introduced to reduce cluster compactness and Botrytis rot, on anthocyanin, tannin, and methoxypyrazine concentrations in Merlot' grapes and wines. Leaf removal before flowering was compared with leaf removal after flowering and an untreated control. No effects on tannin and anthocyanin concentrations in grapes were observed. Both treatments reduced levels of 3-isobutyl-2-methoxypyrazine (IBMP) in the grapes and the derived wines, although the after-flowering treatment did so to a greater degree in the fruit specifically. Leaf removal before flowering can be used to reduce cluster compactness, Botrytis rot, and grape and wine IBMP concentration and to improve wine color intensity but at the expense of cluster weight and vine yield. Leaf removal after flowering accomplishes essentially the same results without loss of yield. © 2016 American Chemical Society.reservedmixedSivilotti, Paolo; Herrera, Jose Carlos; Lisjak, Klemen; Baša Česnik, Helena; Sabbatini, Paolo; Peterlunger, Enrico; Castellarin, Simone DiegoSivilotti, Paolo; Herrera, Jose Carlos; Lisjak, Klemen; Baša Česnik, Helena; Sabbatini, Paolo; Peterlunger, Enrico; Castellarin, Simone Dieg

The Polygenic and Monogenic Basis of Blood Traits and Diseases

Blood cells play essential roles in human health, underpinning physiological processes such as immunity, oxygen transport, and clotting, which when perturbed cause a significant global health burden. Here we integrate data from UK Biobank and a large-scale international collaborative effort, including data for 563,085 European ancestry participants, and discover 5,106 new genetic variants independently associated with 29 blood cell phenotypes covering a range of variation impacting hematopoiesis. We holistically characterize the genetic architecture of hematopoiesis, assess the relevance of the omnigenic model to blood cell phenotypes, delineate relevant hematopoietic cell states influenced by regulatory genetic variants and gene networks, identify novel splice-altering variants mediating the associations, and assess the polygenic prediction potential for blood traits and clinical disorders at the interface of complex and Mendelian genetics. These results show the power of large-scale blood cell trait GWAS to interrogate clinically meaningful variants across a wide allelic spectrum of human variation. Analysis of blood cell traits in the UK Biobank and other cohorts illuminates the full genetic architecture of hematopoietic phenotypes, with evidence supporting the omnigenic model for complex traits and linking polygenic burden with monogenic blood diseases

Oxygen isotope composition of must water in grapevine. Water deficit and rootstock effect

The influence of soil moisture and different rootstock genotypes on the 18O/16O ratio of must-water in grapes was investigated. Grapevines (Vitis vinifera L.) with cv. Cabernet Sauvignon as scion grafted on rootstocks 101-14, 420A and 41B were subjected to three levels of plant-available soil-water from veraison to harvest. Significant differences were observed in the 18O level of must-water, the differences being related to water regime and rootstock genotype, with 18O increasing as soil-water became less available. The higher the canopy-air vapour pressure gradient (VPG), the larger was the oxygen isotope content of must-water, indicating that VPG is an important factor in determining the degree of must-water enrichment under water deficit conditions. In all water regimes of soil, 41B induced the highest degree of 18O enrichment in must-water. The differences between rootstocks in must-water 18O could not fully be explained either by the rootstock effect on VPG or on root distribution

Use of non-invasive RGB imaging to assess the canopy status in organic viticulture

In organic viticulture, canopy features such as leaf area, canopy porosity and fruit exposure are critical due their impact on fungal disease incidence and grape composition. An adequate and accurate assessment of the canopy status is the first step towards appropriate and effective grapevine canopy management, therefore an easy, non-invasive, robust method to evaluate the main features of a grapevine canopy is needed. In this work a protocol for canopy status assessment based on non-invasive RGB imaging is presented and used to ascertain differences in the canopy status of grapevines grown under different degraded and non-degraded soil conditions. RGB images were processed using a classification algorithm based on the Mahalanobis distance, and then the pixels were classified in four classes: clusters, leaves, gaps and shoots. Overall, higher leaf exposure was observed in vines grown in non-degraded soil while the highest percent of gaps or canopy porosity corresponded to vines of the two cover crop treatments