Mogućnosti promjene sadržaja etanola i ukupne kiselosti vina korištenjem Saccharomyces cerevisiae kvasaca

Utjecaj globalnog zagrijavanja nije zaobišao niti vinarsku industriju. To se najbolje očituje kroz porast alkoholne jakosti vina te smanjenje ukupne kiselosti što u konačnici dovodi do značajne promjene u senzornim svojstvima vina. Jedna od mogućnosti smanjenja alkoholne jakosti obuhvaća primjenu različitih selekcioniranih kvasaca (Saccharomyces i ne-Saccharomyces). U provedenom istraživanju ispitane su mogućnosti primjene komercijalnih Saccharomyces kvasaca (IONYSWF™, Enoferm RP15 i Uvaferm BDX) sa ciljem smanjenja alkoholne jakosti te povećanja ukupne kiselosti vina sorte Cabernet franc. Po provedenim fizikalno-kemijskim analizama utvrđeno je da je primjena kvasca IONYSWF™ dala vina manje alkoholne jakosti uz naglašeniju ukupnu kiselost. Nadalje, nisu utvrđene značajne razlike u kinetici alkoholne fermentacije među tretmanima, ali su utvrđene razlike u senzornim svojstvima. Prema rezultatima deskriptivne analize vino sorte Cabernet franc (Vitis vinifera L.) proizvedeno primjenom kvasca IONYSWF™ izdvojilo se nešto jačim tijelom te naglašenijim intenzitetom i trajnošću mirisa u kojem su dominirale začinske note i mirisi crvenog voća. Vino navedenog tretmana bilo je ujedno i najbolje brojčano ocjenjeno.

Dinâmica temporal da podridão cinzenta (Botrytis cinerea) na videira Cabernet Franc em função do aumento da carga de gemas

O aumento do dossel vegetativo e o adensamento de cachos na planta ocasionado pelo maior número de gemas planta-1 pode criar um microclima favorável para a ocorrência de podridão cinzenta. O presente trabalho teve como objetivo avaliar o efeito do aumento de carga de gemas planta-1, nas variáveis epidemiológicas de podridão cinzenta (Botrytis cinerea) na videira Cabernet Franc cultivada em região de altitude de Santa Catarina. O presente trabalho foi conduzido durante safra 2016/2017, em um vinhedo comercial, localizado no munícipio de São Joaquim. Os tratamentos consistiram em quatro diferentes níveis de poda: 15 gemas planta-1, 30 gemas planta-1, 50 gemas planta-1, 75 gemas planta-1. Avaliou-se: incidência máxima, severidade máxima, AACPID, AACPSD, TAMID, TAMSD e IAS. Observou-se efeito da carga de gemas planta-1 nas variáveis epidemiológicas da podridão cinzenta nos cachos da videira Cabernet Franc. O aumento da carga de gemas resultou em aumento da incidência e da severidade da doença, AACPID e AACPSD, sendo os maiores observados em plantas submetidas a poda de inverno com carga de gemas superiores a 50 gemas planta-1. A adoção de elevado número de gemas planta-1, deve ser acompanhada de práticas de manejo integrado de doenças que visam reduzir os efeitos ocasionados pela ocorrência de podridão cinzenta.

Ocorrência do míldio da videira (Plasmopora viticola L.) em função do aumento da carga de gemas da uva Cabernet Franc cultivada em região de elevada altitude de Santa Catarina

O objetivo do trabalho foi avaliar o efeito do aumento da carga de gemas na ocorrência do míldio da videira Cabernet Franc. O experimento foi conduzido na safra 16/17, no munícipio de São Joaquim. Os tratamentos consistiram em quatro níveis de poda: 15, 30, 50 e 75 gemas planta-1. O início do aparecimento dos sintomas foi mais lento nas cargas de 15 e 30 gemas planta-1, enquanto o tempo para atingir a máxima incidência e severidade da doença não foi influenciada pelas cargas de gemas planta-1. A incidência do míldio foi menor, 96,2%, na carga de 15 gemas planta-1. As menores severidades de míldio foram observadas nas cargas de 15 e 30 gemas planta-1, apresentando 4,3 e 6,5%. Para a variável AACPID, observou-se os maiores valores para as cargas de 50 e 75 gemas planta-1, com valores de 3920,3 e 4074,6, e a variável AACPID, observou-se que as cargas de 50 e 75 gemas planta-1resultaram nos maiores valores de AACPSD, 175,7 e 221,5, respectivamente. Conclui-se que o aumento da carga de gemas propicia aumento da ocorrência do míldio, e deve-se adotar estratégias preventivas de manejo integrado do míldio da videira, a fim de evitar prejuízos ocasionados pela elevada ocorrência da doença. Palavras-chave: Vitis vinífera L.; manejo integrado de doenças; dossel vegetativo; epidemiologia.

Modifying Shoot Tip Management to Reduce Cluster Compactness and Lateral Emergence in ‘Cabernet franc’ Grapevines

To manage excessive vine vigor, Vitis vinifera L. ‘Cabernet franc’ grapevines were subjected to shoot wrap, shoot tuck, and hedge (control) techniques at one of two growth stages (shoot tips at 30 cm or at 90 cm above the top catch wire) in the Finger Lakes region of New York from 2016 to 2019. Shoot tuck and shoot wrap both reduced fruit zone lateral counts, with reductions up to 33% and 56% compared with the control, respectively. Shoot wrap reduced fruit zone lateral lengths by up to 50% and cluster compactness by up to 2.4 fewer berries per centimeter rachis. Although shoot wrap improved spray penetration to the clusters by up to 28% in one year of the study, enhanced point quadrat analysis indicated that occlusion layer number was not affected by the treatments. Shoot tip management treatments did not affect yield or fruit composition consistently. Phenological timing of shoot tip management had little impact on vine growth. Although the impacts of these modified shoot tip management practices on lateral emergence and cluster morphology were generally positive, the required hand labor to apply the treatments on a large scale may discourage the use of these management practices.

Terroir of Winter Hardiness: Bud LT50, Water Metrics, Yield, and Berry Composition in Ontario Cabernet franc

Winter hardiness may be influenced by vineyard terroir-driven factors, and vineyard zones with low water status [leaf water potential (ψ)] could be more winter hardy than vines with high water status (higher leaf ψ). Six Cabernet franc vineyards were chosen throughout the Niagara Region in Ontario. Data were collected at fruit set, lag phase, and veraison [soil water content (SWC), leaf ψ], at harvest (yield components, berry composition), and three times during winter (LT50; the temperature at which 50% of buds die) in the 2010-12 seasons. Interpolation by kriging and mapping of variables was completed using ArcGIS, and statistical analyses (linear correlation, k-means clustering, principal components analysis, multilinear regression) were performed. Spatial trends were observed in each vineyard for SWC, leaf ψ, yield components, berry composition, and LT50. GIS and statistical analysis revealed that leaf ψ could predict LT50, with strong positive correlations between LT50 and leaf ψ values in most vineyards in 2010-11. In the dry 2012 season, leaf ψ (particularly at veraison; range -1.3 to -1.6 MPa) was positively correlated to LT50, yield, titratable acidity, pH, and Brix and negatively to SWC, color, anthocyanins, and phenols. Overall, vineyards in different appellations (Niagara Lakeshore, Lincoln Lakeshore, Four Mile Creek, Beamsville Bench) showed many similarities. These results suggest that there is a spatial component to winter injury, as with other aspects of terroir. Furthermore, this study allows for means by which to compare winter hardiness to other critical variables in order to better understand the terroir of the Niagara region.

Rootstocks influence the response of ripening grape berries to leafroll associated viruses

Grapevine leafroll-associated virus (GLRaV) infections are accompanied by symptoms with varying severity. Using a dedicated experimental vineyard, we studied the responses to GLRaVs in ripening berries from Cabernet franc grapevines grafted to different rootstocks and with zero, one, or pairs of leafroll infection(s). RNA sequencing data were mapped to a high-quality Cabernet franc genome reference assembled to carry out this study and integrated with hormone and metabolite abundance data. This study identified several molecular levers that participate in responses to GLRaVs, including those that are condition-dependent. This included describing common responses to GLRaVs that were reproduced in two consecutive years, in plants grafted to different rootstocks, and in more than one infection condition. Though different infections were inconsistently distinguishable from one another overall, the effects of infections in plants grafted to different rootstocks were distinct at each developmental stage. Conserved responses included the modulation of pathogen detecting genes, increases in abscisic acid signaling and cytoskeleton remodeling gene expression. The abundance of abscisic acid (ABA), related metabolites, ABA and hormone signaling-related gene expression, and the expression of several transcription factor families differentiated rootstocks overall. These data show that rootstock influences the effect of GLRaVs in ripening berries.

Effects of Salinity and Rootstock on Nutrient Element Concentrations and Physiology in Own-Rooted or Grafted to 1103 P and 101-14 Mgt Rootstocks of Merlot and Cabernet Franc Grapevine Cultivars under Climate Change

Under the current and future climate crisis, a significant rise in soil salinity will likely affect vine productivity in several Mediterranean regions. During the present research, the rootstock effects on salinity tolerance of Merlot and Cabernet Franc grapevine cultivars were studied. In a pot hydroponic culture, own-rooted Merlot and Cabernet Franc grapevine cultivars or grafted onto the rootstocks 1103 P and 101-14 Mgt were drip-irrigated with saline water. A completely randomized 3 × 2 × 2 factorial experiment was designed with two vine rootstocks or own-rooted vines, two scion cultivars, and 100 mM NaCl salinity or control treatments, with six replications. A significant effect of scion cultivar, rootstock, and salinity was observed for most of the measured parameters. At the end of salinity stress period, leaf, shoot, root, and trunk nutrient concentrations were measured. Salinity stress increased Chloride (Cl−) and Sodium (Na+) concentrations in all parts of the vines and decreased leaf concentrations of Potassium (K+), Calcium (Ca+2), Magnesium (Mg+2), Nitrogen (N), and Iron (Fe). In contrast, salinity stress increased leaf Boron (B) concentrations, whereas that of Manganese (Mn) remained unaffected. Leaf chlorophyll concentration decreased from 42% to 40% after thirty and sixty days of salt treatment, respectively. A similar trend was observed for the CCM-200 relative chlorophyll content. Salinity significantly decreased steam water potential (Ws), net CO2 assimilation rate (A), and stomatal conductance(gs) in all cases of grafted or own-rooted vines. Sixty days after the beginning of salt treatment, total Phenolics and PSII maximum quantum yield (Fv/Fm) decreased significantly. The rootstock 1103 P seems to be a better excluder for Na+ and Cl− and more tolerant to salinity compared to 101-14 Mgt rootstock.

Assessing grapevine phenological models under Chinese climatic conditions

The objective of this work was to perform preliminary assessment of the performance of different models for the simulation of three main phenology stages (budburst, flowering, and veraison) of grapevine in China. This work utilized observations from five representative wine regions (Changli, Laixi, Shangri-La, Xiaxian, and Yanqi) and four widely cultivated grape cultivars (Cabernet Sauvignon, Cabernet Franc, Merlot, and Chardonnay) in China. The corresponding daily temperature data were used to simulate the timing of grape phenology stages based on the different phenological models. The dates based on the simulation and the actual dates were compared and the performance of these models were assessed for different cultivars and wine regions. The GDD10 model exhibited the best performance for budburst simulation in soil-burying regions, irrespective of the cultivar and location. For flowering and veraison, the optimal model varied in performance between cultivars and locations, and non-linear models exhibited better performance than linear models. In general, the performance of these models was better for the latter two stages than for budburst. The models with relatively good performance were selected for further calibration using these limited Chinese observations. The impact of soil-burying management on budburst simulation was also estimated. These results highlight the strengths of some phenological models for use in China. This study also reiterates the strong need for establishment of a grapevine phenology observation network in China to obtain more comprehensive data.