scholarly journals Spatial variability in Ontario Riesling vineyards: I. Soil, vine water status and vine performance

OENO One ◽  
2020 ◽  
Vol 54 ◽  
pp. 311-333
Author(s):  
Andrew Reynolds ◽  
James J Willwerth
Keyword(s):  
Spatial Distribution ◽  
Soil Texture ◽  
Yield Components ◽  
Water Status ◽  
Temporal Stability ◽  
Geographical Information ◽  
Soil Composition ◽  
Positioning Systems ◽  
Growing Seasons ◽  
Berry Weight

Aim: The major focus of this research was to explain the so-called terroir effects that impact grapevine yield components, berry composition, and wine varietal character. To elucidate potential contributors to the terroir effect, vine water status [midday leaf water potential (ψ)] was chosen as a major determinant. The hypothesis of this component of the study was that consistent leaf ψ zones could be identified within vineyard sites and that vine water status would play a major role in vine performance and yield components. Soil texture was anticipated to play a role indirectly through its water-holding capacity.Methods and materials: To test this hypothesis, ten Riesling vineyards representative of each Vintners Quality Alliance of Ontario sub-appellation were selected within the Niagara Peninsula. These vineyards were delineated using global positioning systems and 75–80 sentinel vines were geo-referenced within a sampling grid for data collection. During the 2005–2007 growing seasons, leaf ψ measurements were collected bi-weekly from a subset of these sentinel vines. Data were collected on soil texture and composition, soil water content (SWC), vine performance and yield components. These variables were mapped using geographical information systems software and relationships between them were elucidated.Results: Vineyards were variable in terms of soil texture, composition, nutrition, and moisture. However, in general, few consistent relationships with soil composition variables were found. As hypothesized, consistent leaf ψ zones were identified within vineyards in all three vintages. Some geospatial patterns and relationships were spatially and temporally stable within vineyards. In many cases, spatial distribution of leaf ψ was temporally stable within vineyards despite different weather conditions during each growing season. Spatial trends within vineyards for SWC and leaf ψ were temporally stable over the 3-year period for eight vineyards. Generally, spatial relationships between leaf ψ, SWC, vine size, berry weight and yield were also temporally stable. Some inconsistencies in spatial distribution of variables were attributable to winter injury.Conclusions: Many viticultural variables such as leaf ψ, vine size, berry weight, and yield were spatially variable and, as hypothesized, consistent leaf ψ zones were identified within vineyards in three distinct vintages. Many geospatial patterns and relationships were determined and were temporally stable, and this temporal stability in these variables occurred despite different growing seasons. The strongest relationships were those concerning leaf ψ, SWC, vine size, and berry weight. No consistent relationships were found concerning soil composition. The most consistent soil variables that impacted vine performance and yield components were physical properties, particularly texture.Significance and impact of the study: Soil had some indirect effects, but leaf ψ was more likely a major contributor to the terroir effect, as it had a major impact on vine size, berry weight and yield in many vineyards across multiple vintages. Temporal stability is required for many practical geomatic applications to be initiated in vineyards, but it is also of importance to future research endeavors for this project as well as others.

Spatial variability in Ontario Riesling vineyards. II. Berry composition

2020 ◽  
Vol 100 (5) ◽  
pp. 504-527
Author(s):  
James J. Willwerth ◽  
Andrew G. Reynolds
Keyword(s):  
Spatial Variability ◽  
Soil Texture ◽  
Water Status ◽  
Temporal Stability ◽  
Soluble Solids ◽  
Positioning Systems ◽  
Fruit Composition ◽  
Spatial Trends ◽  
Volatile Terpenes ◽  
Berry Composition

Spatial variability of berry composition was studied over a 3-yr period in 10 Riesling vineyards in the Niagara Peninsula in Ontario. Vineyards were delineated using global positioning systems (GPS), and 75–80 sentinel vines were georeferenced within a sampling grid for data collection. During 2005–2007, vine water status measurements [leaf water potential (ψ)] were collected biweekly from a subset of these sentinel vines. Data were collected on soil texture and composition, soil water content (SWC; %), leaf ψ, and fruit composition. These variables were mapped using GIS software, and relationships between them were elucidated. Temporal stability in spatial patterns of soil texture and composition, SWC, leaf ψ, soluble solids (Brix), titratable acidity, and monoterpenes were examined. Spatial trends in leaf ψ and (or) SWC showed widespread evidence of temporal stability. Fruit composition variables were not as stable over a 3-yr period. Spatial trends in Brix were temporally stable in seven vineyards, free volatile terpenes were temporally stable in three vineyards, and potentially volatile terpenes were temporally stable in two vineyards. Consistent leaf ψ zones were identified, and these were temporally stable despite different climatic conditions. Furthermore, some soil variables, and particularly vine water status, may contribute significantly to the terroir effect through their effects on vine size and fruit composition. For some vineyards, many viticulture and fruit composition variables were also temporally stable. There was evidence of strong spatial relationships between leaf ψ and fruit composition, suggesting a strong relationship between berry composition and vine water status.

scholarly journals Sensory analysis of Ontario Riesling wines from various water status zones

OENO One ◽  
2018 ◽  
Vol 52 (2) ◽  
pp. 145-171 ◽  
Author(s):  
James Willwerth ◽  
Andrew Reynolds ◽  
Isabelle Lesschaeve
Keyword(s):  
Water Status ◽  
Descriptive Analysis ◽  
Sensory Attributes ◽  
Sensory Properties ◽  
Tropical Fruit ◽  
Substantial Impact ◽  
Positioning Systems ◽  
Growing Seasons ◽  
Quality Threshold ◽  
Sensory Profiles

Aims: Determinants of the terroir effect in Riesling were sought by choosing vine water status as a major factor. It was hypothesized that consistent water status zones could be identified within vineyards, and, differences in wine sensory attributes could be related to vine water status.Methods and results: To test our hypothesis, 10 Riesling vineyards representative of each Ontario Vintners Quality Alliance sub-appellation were selected. Vineyards were delineated using global positioning systems and 75 to 80 sentinel vines were geo-referenced within a sampling grid for data collection. During 2005 to 2007, vine water status measurements [leaf water potential (ψ)] were collected bi-weekly from a subset of these sentinel vines. Vines were categorized into “low” and “high” leaf ψ zones within each vineyard through use of geospatial maps and replicate wines were made from each zone. Wines from similar leaf ψ zones had comparable sensory properties ascertained through sorting tasks and multidimensional scaling (2005, 2006). Descriptive analysis further indicated that water status affected wine sensory profiles, and attributes differed for wines from discrete leaf ψ zones. Multivariate analyses associated specific sensory attributes with wines of different leaf ψ zones. Several attributes differed between leaf ψ zones within multiple vineyard sites despite different growing seasons. Wines produced from vines with leaf ψ >-1.0 MPa had highest vegetal aromas whereas those with leaf ψ <-1.3 MPa were highest in honey, petrol and tropical fruit flavors. Vines under mild water deficit had highest honey, mineral, and petrol and lowest vegetal aromas.Conclusion: Results indicate that water status has a profound impact on sensory characteristics of Riesling wines and that there may be a quality threshold for optimum water status.Significance and impact of the study: These data suggest that vine water status has a substantial impact on the sensory properties of Riesling wines. Variability of leaf ψ within vineyards can lead to wines that differ in their sensory profiles. These findings were consistent among vineyards across the Niagara Peninsula. These strong relationships between leaf ψ and sensory attributes of Riesling suggest that vine water status is a major basis for the terroir effect.

scholarly journals Influence of flowers per cluster, fruit-set and berry weight on cluster weight in Verdejo grapevine (Vitis vinifera L.)

OENO One ◽  
2004 ◽  
Vol 38 (1) ◽  
pp. 41
Author(s):  
Santiago López-Miranda ◽  
Jesús Yuste
Keyword(s):  
Vitis Vinifera ◽  
Yield Components ◽  
Fruit Set ◽  
Water Status ◽  
Yield Component ◽  
Harvest Date ◽  
Natural Factors ◽  
Berry Weight ◽  
Weight Variation ◽  
The Future

<p style="text-align: justify;">Estimation of yield has always been one of the greatest concerns in the wine-making industry, which is why researchers have attempted to create models and methods that make accurate predictions. However, the variability of the yield components, which depends on the environmental factors, like light and temperature, and on cultural and natural factors which affect vigor, water status, photosynthetic and hormonal activity and the accumulation of reserve substances, make the prediction of the future harvest very difficult to calculate. In certain situations, fertility expressed as the number of bunches, tends to display very stable values from one harvest to the next. The weight of the cluster is the performance factor that has the greatest variability and mostly causes the variations in production. In this report, we analyze the influence of the number of flowers per cluster, the fruit-set percentage, the number of berries per cluster and the berry weight in the variability of the cluster weight of the Verdejo variety (<em>Vitis vinifera</em> L.). The cluster weight and its components have been determined along canes of 6 and 10 buds, in the harvests of 1999, 2000 and 2001. The yield component upon which cluster weight variation fundamentally depends has been the number of berries it contains, whereas the berry weight has had much less of an effect. The number of berries per cluster is mainly determined by the number of flowers per inflorescence, a yield component which has gone so far as to explain, by itself, an average of 75%of the variability in the number of berries per cluster and 70 % of the variability of the cluster weight. Despite the possible influence that the fruit-set percentage may have on the variability in the number of berries per cluster, measuring the number of flowers per inflorescence would make it possible to know, to a reasonable level of accuracy, the future number of berries per cluster long before the harvest date. At the same time, if a yield estimate is not needed far in advance, prediction of the future cluster weight can be determined by measuring the number of berries per cluster 15 or 20 days after fruit-set time, when the falling of small fruits is right minimal. In any case, whether by using the number of flowers per inflorescence or the number of berries per cluster, the berry weight on the harvest date would be the only yield component that would require estimation, which is usually much easier to achieve due to the lesser variability seen in this parameter.</p>

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

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