[PDF] Responses Of Grapevines To Timing And Method Of Leaf Removal eBook

Author : Patricia Chalfant
Publisher :
Page : 89 pages
File Size : 12,73 MB
Release : 2012
Category :
ISBN :

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Abstract: Several winegrapes grown in cool climates, including Vitis vinifera Cabernet Franc and Vitis sp. Chambourcin, benefit from crop reduction. The practice promotes timely fruit maturation and can improve fruit quality. Balanced pruning and cluster thinning are the cultural practices used to attain the desired crop load. However, crop reduction by cluster thinning is labor intensive, costly and typically not mechanized for winegrapes. In this study, the practice of early season leaf removal by hand and with a mechanized leaf remover is proposed as an alternate tool to reduce crop level, thereby optimizing crop load and fruit quality. The objectives were to determine the effects of the timing of leaf removal (pre-bloom, bloom, or fruitset) on yield components, crop load, fruit quality, and cold hardiness in Chambourcin and to 2) determine the effects of manual versus mechanical leaf removal at different phenological stages on yield components, growth, crop load, and fruit quality in Cabernet Franc. In Chambourcin, leaf removal at pre-bloom in 2010 and bloom in 2010 and 2011 reduced yield as compared to defoliation at fruitset and control (no removal). Early season leaf removal reduced crop load (Ravaz index) in both years. Defoliation at bloom increased bud lignification in both years and reduced bud injury in fall of 2010. Defoliation at pre-bloom reduced bud injury in winter in one of two years. In Cabernet Franc, manual leaf removal at pre-bloom and mechanical leaf removal at bloom reduced yield. Leaf removal had no negative effects on pH, titratable acidity, soluble solids, or total phenolics in either cultivar in either year. Early season leaf removal can be used to control yield without negatively impacting growth, cluster compactness, disease incidence, fruit composition, or lignification. It is concluded that early season leaf removal is a viable alternative to cluster thinning as a method of yield reduction in Chambourcin. Early season mechanical leaf removal is a viable alternative to manual leaf removal.

Author : Joshua VanderWeide
Publisher :
Page : 127 pages
File Size : 32,85 MB
Release : 2020
Category : Electronic dissertations
ISBN :

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Removal of basal leaves early in the vegetative and reproductive development of grapevines is a tool used to decrease fruit set, lower cluster rot severity, and improve fruit quality. However, the considerable time required for implementation limits its use by grape growers. Efficient mechanization can potentially mitigate these issues, studies are lacking in a cool climate setting where short seasons and humid summers limit grape production. Therefore, the goal of these studies were to compare mechanical leaf removal with the manual removal of six leaves at the pre-bloom and after-bloom phenological stages over two seasons in Pinot Grigio, a tight-clustered cultivar susceptible to bunch rot, and Merlot, which reaches suboptimal fruit quality in some seasons. For Pinot Grigio (Chapter 3), the loss of fruit to gray mold was lowered by all leaf removal treatments in the drier 2017 season, but only manual treatments mitigated loss from sour rot in that year. This indicates that a clear fruit zone and reduced cluster compactness are both needed to lower the effect of cluster rot disease. Only pre-bloom treatments enhanced fruit quality, likely driven by a similar reduction in cluster compactness. The results suggest that mechanical leaf removal at pre-bloom may be used to enhance fruit total soluble solids, while pre-bloom manual removal can be an effective means to reduce fruit loss to sour rot severity.For Merlot (Chapter 4), berry total soluble solids were highest with pre-bloom mechanical treatment. Furthermore, metabolomics analysis revealed that this treatment favored the accumulation of significantly more disubstituted anthocyanins and flavonols and OH-substituted anthocyanins compared with manual application. Given that vine balance was similar between treatments, increased ripening with PB-ME is likely due to enhanced microclimate conditions and higher carbon partitioning through a younger canopy containing basal leaf fragments proximal to fruit. Despite these results, it was not clear which factor was controlling the increase in fruit quality in response to pre-bloom mechanical leaf removal. In Chapter 5, an experiment was established where 60% of leaf area was removed from shoots in three ways: 1) manual removal of 5 leaves (PB-MA), 2) mechanical removal (PB-ME), and 3) simulated mechanical removal (PB-SIM), which was implemented to understand whether PB-ME improves fruit quality via enhanced microclimate conditions, or stress. Major phenylpropanoid classes were enhanced by PB-ME, however neither ABA nor ethylene were similarly altered, suggesting their lack of involvement in promoting phenylpropanoid biosynthesis in response to ELR. Instead, the leaf area at nodes above the fruit-zone was lower in PB-ME compared to C, which increased post-veraison fruit temperature (+2.8°C). These parameters correlated with anthocyanins at harvest. In conclusion, skin phenylpropanoid concentrations are influenced by canopy density above the fruit-zone. Finally, in Chapter 6, the influence of vine balance and light exposure on fruit quality parameters were compared in two locations (Michigan, Italy). Primary metabolism was not significantly altered with the excepting of titratable acidity being decreased by LR8 having the greatest light exposure during ripening. Flavonol biosynthesis was significantly altered by light exposure in both locations, but not by vine balance. The results indicate that fruit exposure to light, rather than source-to-sink balance has a greater influence on flavonoid biosynthesis in grape berries.

Author : José Tomás Matus
Publisher : Frontiers Media SA
Page : 423 pages
File Size : 12,58 MB
Release : 2019-12-06
Category :
ISBN : 2889632113

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Fruits play a substantial role in the human diet as a source of vitamins, minerals, dietary fiber and a wide range of molecules relevant to health promotion and disease prevention. The characterization of genes involved in the accumulation of these molecules during fruit development and ripening, and in the overall plant’s response to the environment, constitutes a fundamental step for improving yield- and quality-related traits, and for predicting this crop’s behavior in the field. This is certainly the case for grapevine (Vitis vinifera L.), one of the most largely cultivated fruit crops in the world. The cultivation of this species is facing challenging scenarios driven by climate change – including increases in atmospheric carbon dioxide (CO2), solar radiation, and earth surface temperature, and decreases of water and nutrient availability. All these events will potentially affect the grapevine phenology, physiology, and metabolism in many growing regions and ultimately affect the quality of their fruits and of the most important derived product, the wine. The sequencing of the grapevine genome has given rise to a new era, characterized by the generation of large-scale data that requires complex computational analyses. Numerous transcriptomic and metabolomic studies have been performed in the past fifteen years, providing insights into the gene circuits that control the accumulation of all sorts of metabolites in grapevines. From now on, the integration of two or more ‘omics’ will allow depicting gene-transcript-metabolite networks from a more holistic (i.e. systems) perspective. This eBook attempts to support this new direction, by gathering innovative studies that assess the impact of genotypes, the environment, and agronomical practices on fruits at the ‘ome’-scale. The works hereby collected are part of a Research Topic covering the use of ‘omics’-driven strategies to understand how environmental factors and agronomical practices – including microclimate modification (e.g. sunlight incidence or temperature), water availability and irrigation, and postharvest management – affect fruit development and composition. These studies report well-settled transcriptomic and metabolomic methods, in addition to newly-developed techniques addressing proteome profiles, genome methylation landscapes and ionomic signatures, some of which attempt to tackle the influence of terroir, i.e. the synergic effect of (micro)climate, soil composition, grape genotype, and vineyard practices. A few reviews and opinions are included that focus on the advantages of applying network theory in grapevine research. Studies on vegetative organs in their relation to fruit development and on fruit-derived cell cultures are also considered.

Author : Bruce Schaffer
Publisher : CRC Press
Page : 368 pages
File Size : 22,36 MB
Release : 2018-05-04
Category : Science
ISBN : 1351442791

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These exciting new companion handbooks are the only ones of their kind devoted solely to the effects of environmental variables on the physiology of the world's major fruit and nut crops. Their cosmopolitan scope includes chapters on tropical and temperate zone species written by scientists from several continents. The influence of environmental factors, such as irradiance, temperature, water and salinity on plant physiology and on vegetative and reproductive growth, is comprehensively discussed for each crop. In addition to being a thorough and up-to-date set of textbooks, the organzation of the two volumes makes them an excellent reference tool. Each chapter focuses on a single crop, or a group of genetically or horticulturally related crop, and is appropriately divided into subsections that address individual environmental factors. Some chapters emphasize whole-plant physiology and plant growth and development, while other chapters feature theoretical aspects of plant physiology. Several chapters provide botanical background discussions to enhance understanding of the crop's response to its environment.

Author : Ronald S. Jackson
Publisher : Academic Press
Page : 1032 pages
File Size : 25,89 MB
Release : 2020-04-04
Category : Technology & Engineering
ISBN : 0128165375

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Wine Science: Principles and Applications, Fifth Edition, delivers in-depth information and expertise in a single, science-focused volume, including all the complexities and nuances of creating a quality wine product. From variety, to the chemistry that transforms grape to fruit to wine, the book presents sections on the most important information regarding wine laws, authentication, the latest technology used in wine production, and expert-insights into the sensory appreciation of wine and its implications in health. This book is ideal for anyone seeking to understand the science that produces quality wines of every type. Presents thorough explanations of viticulture and winemaking principles from grape to taste bud Addresses historical developments in wine production, notably sparkling wines Provides techniques in grapevine breeding, notably CRISPR Compares production methods in a framework that provides insights into the advantages and disadvantages of each

Author : Anna Nguyen
Publisher :
Page : 0 pages
File Size : 13,98 MB
Release : 2022
Category :
ISBN :

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The influences of harvest date and leaf removal on aroma compounds of Grüner Veltliner (Vitis vinifera; GV) grown at Galen Glen winery located in Pennsylvania were examined. These grapes were harvested in 2021 as part of a field study conducted by Adams (2021) on yield components, fruit composition, and economic cost in response to harvest date and leaf removal. In this research, the obtained berries were used to evaluate changes in aroma compounds known to be important in this cultivar, specifically isoamyl acetate, hexyl acetate, 1-hexanol, ethyl octanoate, and linalool as a result of harvest schedule, leaf removal timing, and leaf removal severity levels. It is hypothesized that the grapes harvested according to the winery's standard would produce wines of highest levels of aroma compounds compared to those that were harvested early. However, if combined with early leaf removal, early harvest grapes could have comparable levels of aroma compounds compared to late harvest grapes. The frozen grape juice was vinified using standard method to prevent introducing unaccounted variables, and aroma compound analysis was performed via headspace -- solid phase microextraction -- gas chromatography -- mass spectrometry (HS-SPME-GC-MS). Finally, one-way and two-way ANOVA tests were conducted to determine if there was any significant relationship existed between harvest schedule, leaf removal timing, and leaf removal severity, in addition to their effects on the chosen aroma compounds' concentrations. Harvest schedule was found to have a significant effect on the mean concentrations of isoamyl acetate, hexyl acetate, 1-hexanol, and ethyl octanoate. However, when combined with leaf removal timing, harvest schedule only significantly impacted the mean concentrations of hexyl acetate and 1-hexanol, and the treatments that received early leaf removal were observed to contain higher concentrations of these compounds compared to their late leaf removal counterparts. Linalool mean concentrations were not impacted by harvest schedule, leaf removal timing, leaf removal severity, or their combinations. Hence, if the compound of interest is linalool, it would be acceptable to harvest GV grapes earlier to avoid frost damage and fungal diseases.