333,795 research outputs found
Impact of drought on grape yields in the Western Cape, South Africa
No full textIncludes bibliographical references.Droughts remain a threat to grape yields in South Africa. Previous studies on the impact of climate variability on grape yield in South Africa have focussed on either the rainfall or the impact of temperature on the grape yields; meanwhile, the grape yields may be more influenced by impacts of drought (which is function of water balance) than that of rainfall or temperature. This study investigates the impact of drought on grape yields in the Western Cape. A drought index that is based on water balance (called, Standardized Precipitation Evapotranspiration Index; hereafter SPEI) was used to analyse drought events at both farm and district scale (Robertson, Olifants River and Stellenbosch districts). Correlation analysis was used to identify the association between drought and grape yield. In addition, the performance of a grape yield model (Agricultural Production Systems sIMulator, APSIM) in simulating the grape yield at farm scale and investigating the sensitivity of yields to drought, with and without irrigation was evaluated
Value added products from vineyard wastes - a review
No full textGrape pomace is about 10% by weight of the grape input and consists of pressed skins, disrupted cells from grape pulp, seeds and stems. Grape pomace is mainly used as cattle feed or for soil conditioning or dumped in disposal sites. Cell walls of grape pomace are composed of cellulose, hemicelluloses, pectin and lignin arranged in a complex network. Lignin constitutes about 38-40% of the total grape pomace mass. Grape pomace is rich in polyphenols, fibres, tannins, tartaric acid, citric acid, anthocyanin and neutral sugars. Pomace can be separated in to marc (skin and pulp) and seeds in a breaker. Grape marc constituted mainly industrial source of anthocyanin based colorants. Grape seeds are a complex matrix containing approximately 40% fibre, 16% oil, 11 % proteins and 7% complex phenols including tannins in addition to sugars and mineral salts. The seeds of the grapes contain about 8-22% edible oil and the seed oil has been identified as a potential product because of its low saturated fats content and its high concentration (70-75%) of linoleic acid. Grape pomace is rich in phenolic compounds and the interest in phenolic compounds are from their antioxidant properties and their ability to serve as free radical scavengers. Grape seed extracts are reported to possess anticancer, antiulcer, anticataract and antiarteriosclerosis effect. In conclusion grape pomace, the byproduct of wine industry has a huge potential for the isolation of compounds in food preservation as well as for nutraceuticals and therapeutic agents
Study on differential expression of 1-aminocyclopropane-1-carboxylic acid oxidase genes in table grape cv. Thompson Seedless
No full textAs a consequence of the non-climacteric status of grapes (Vitis vinifera), ethylene biosynthesis and signal transduction have scarcely been studied in this fruit. In spite this drawback, the available information suggests a role for ethylene in ripening grape berries. In this work, we report the identification of three homologous genes that encode 1-aminocyclopropane-1-carboxylic acid oxidase (ACO), a key component of ethylene biosynthesis. A comparison of protein sequences revealed that all three VvACOs harbor a 2OG-Fe(II) oxygenase domain, which is typical of the ACO gene family; however, VvACO1 showed a higher amino acid sequence homology with VvACO2 than with VvACO3. The expression pattern of VvACOs and the effect of exogenous ethylene on their transcript accumulation were evaluated during table grape berry development in the “Thompson Seedless” cultivar. A peak in VvACO1 transcript accumulation levels was registered around veraison that was 4-fold higher than at harvest, and this peak was confirmed during a second season in grapes that were harvested from three different vineyards. An enhancement in ethylene production and VvACO genes transcript levels was observed in grapes sprayed with ethephon during berry development. However, VvACO1 transcripts reached the highest accumulation earlier than VvACO2 and VvACO3. Altogether, these data confirmed that ethylene may have a role in some aspects of the grape ripening process, and they also highlighted the potential use of some VvACO genes as molecular markers for identifying grape veraison stages in grapes
Projected Climate Change Impacts on Grape Growing in the Okanagan Valley, British Columbia, Canada
No full textA statistical analysis was conducted on long-term climate records in the Okanagan Valley wine grape growing region of British Columbia, Canada. No observable trends for average annual temperatures were found in the region. Analyses of monthly mean and extreme temperatures show wide spatial and temporal heterogeneity, indicating that future studies using downscaling of global climate models for this region will require resolutions on the order of several kilometers. Mean winter temperatures are increasing throughout the valley, and extreme minimum temperatures are also increasing during the winter at the central and northern sites which have historically presented the most risk of winter damage to grapevines. Only the most southern and northern sub-regions are expected to see significant changes in their heat unit accumulations during the growing season. Over the coming century, the southern end of the valley will likely move from Winkler heat unit region 1 to 2. All regions of the Okanagan will continue to have latitude-temperature indices among the lowest of the world's fine table wine producing regions over the coming century. Growing season and dormant season average temperatures are expected to change by only a modest amount by 2100. Current climate maturity groupings for ripening grape varieties will likely stay constant at cool (central and southern areas) and intermediate (south-central) for all sites except Osoyoos (south). The climate trendings at Osoyoos suggest it will transition from an intermediate to a warm grouping by about 2050. The early to mid-season ripening capacity of the region may improve due to climate changes, but there is a risk of the asymmetric late season increases in minimum daily temperatures lowering the daily temperature range at some sites, possibly leading to difficulties in maintaining a balanced between sugar and sensory profiles as wine grapes approach maturity. The projected warming at the southern end of the valley should favor improved and increased Merlot production, will require Chardonnay production to shift northwards, and will allow growing of warmer climate wine grape varieties currently inaccessible because of low winter temperatures and a lack of growing season heat units. Increasing winter temperatures throughout the region are expected to result in increased risk of pests such as Pierce’s disease
GBDD
No full textWe present a Gender Board Diversity Dataset (GBDD), which provides a cross-country perspective on women in management and supervisory boards that spans between 1985 and 2020. The data covers 43 European countries and accounts for private companies in addition to the stock-listed ones. GBBD was created using firm-level Orbis data. Our measures are based on a sample of more than 28 million unique firms observed for nearly seven years on average and reporting data about nearly 59 million individuals on management and supervisory boards. We provide the measures at the level of industry, country and year (firm-level data is proprietary). We provide three measures. The first is the share of women among all board members in a given industry, country, and year. The second one is the average of the shares of women across firms in a given industry, country and year. We also provide a new measure: the share of firms in a given industry, country and year which report no single woman on their board(s)
Exploitation of Bioactive Constituents of Olive Leaves, Grape Pomace, Olive Mills Waste Water and their Application in Phytoprotection
No full textPure plants extracts or/and essential oils show antifungal and antibacterial activity
against a wide range of fungi and bacteria. Recently there has been increasing interest
in the effects of natural compounds against important plant pathogens (fungi and
bacteria). Although the antimicrobial activity of oleuropein, grape pomace (GPE) and
olive mills waste water (OMWW) extracts have been studied widely, little research
has been done on the in vitro and in vivo evaluation of these extracts efficiency
against important plant diseases and postharvest treatments.
The overall objectives of this study were firstly to extract and isolate from olive leaves
(oleuropein), olive mills waste water and from grape pomace (winery by-products)
natural compounds in order to be used for in vitro and in vivo experiments.
In particular, all three natural extracts were found to restrain in vitro growth of a
series of important bacterial and fungal pathogens, such as: Botrytis cinerea, the cause
of grey mold disease, Alternaria alternata, causing leaf spots and moulds on several
plant species, Fusarium oxysporum fsp melonis, causing Fusarium wilt of melon, a
Rhizopus species (a genus causing fruit and vegetable decays), the crucifer pathogen
Colletotrichum higginsianum, causing anthracnose leaf spot disease on several
Brassica and Raphanus species and Phytophthora parasitica var. nicotianae, the
causal agent of the black shank disease of tobacco. Bacterial strains including
Clavibacter michiganensis spp. michiganensis, the cause of bacterial canker of
tomato, Ralstonia solanacearum causing bacterial wilt in solanaceous plants,
Pseudomonas syringae pv. tomato, the cause of bacterial speck on tomato and
Arabidopsis and Xanthomonas campestris pv. vesicatoria causing the bacterial spot
disease of pepper and tomato were tested. Oleuropein (semipure and pure) showed
remarkable antibacterial activity. The minimal inhibitory concentration (MIC), at least
of oleuropein was lower than 0.1%. MICs values for GPE and OMWW extract ranged
from 0.1% to 0.2%. Moreover, these natural extracts were shown to inhibit and/or
restrain spore germination of fungi in solid media, however grape pomace extract,
was sufficiently effective to inhibit spore germination and germ tube of C.
higginsianum and B. cinerea.
Furthermore in vivo antibacterial activity of pure oleuropein and OMWW extract was
assessed in greenhouse experiments, on Xanthomonas campestris pv. vesicatoria, the
cause of bacterial spot of pepper plants and Pseudomonas syringae pv. tomato, the
cause of bacterial speck of tomato plants, respectively. It seems that 0.1% pure
oleuropein (98%) and 0.1% OMWW extract had a protective effect against bacterial
spot and bacterial speck respectively, which is more obvious when oleuropein
application started before infection. Besides endophytic growth of Phytophthora
parasitica var. nicotianae, causal agent of the black shank disease of tobacco, on
tobacco leaves by measuring its radial growth inside the infected tissue, was assessed.
0.1% GPE showed the most significant inhibition in all tobacco leaves treatments.
The potential of postharvest treatment of table grapes with the grape pomace extract
(GPE) to restrain grey mould (Botrytis cinerea) disease incidence and development
was estimated. 5% GPE treatments produced the strongest inhibitory effect against B.
cinerea incidence on grape berries and the time after treatment influenced the
numbers of decayed berries.
Finally the use of pure oleuropein as antibacterial in vase solution for cut flowers
(carnation) was evaluated. Oleuropein showed strong antibacterial activity as vase
solution and carnations vase life was more than doubled by using oleuropein 200ppm
and 400ppm, compared with control (water)
Changes in polyphenol and polysaccharide content of grape seed extract and grape pomace after enzymatic treatment
No full textGrape seed extract and grape pomace are rich sources of polyphenols. The aim of this study was to evaluate the release of polyphenols, the solubilisation of carbohydrate, and the antioxidant capacity of these grape by-products after enzymatic reaction with carbohydrases (cellulolytic and pectinolytic activities) and tannase for 24 h. The use of tannase in these by-products, and pectinase in grape pomace changed the galloylated form of catechin to its free form, releasing gallic acid and increasing the antioxidant activity. In grape pomace, cellulase treatment was not efficient for phenolic release and antioxidant activity improvement. The addition of carbohydrases to grape pomace, either alone or in combination, degraded the cell wall polysaccharides, increasing the content of monosaccharides. These results provide relevant data about the potential of pectinase, tannase and combinations of enzymes on the release of polyphenols and monosaccharides from grape by-products, improving the antioxidant capacity and the nutritional value. © 2012 Elsevier Ltd. All rights reserved.Peer Reviewe
Non-destructive ripening evaluation of chilean grape by a portable vis/NIR system
No full textGrape composition at harvest is a key factor determining the quality of future wine. For this reason, measurement of grape characteristics in field during the ripening is a requirement to evaluate the right moment for the harvest. Classical chemical analyses, common at the moment in wine industry, have several limits: these take time, are wasteful, destructive, and ultimately inadequate to test fruit in field. Wineries need new practical and quick instruments, non-destructive, and able to quantitatively estimate, in field and on a large scale, the interesting parameters. The goal of the present study was to test an optical portable system for prediction of ripening parameters of fresh berries of grape (Vitis vinifera L. ‘Cabernet Sauvignon’ and ‘Sauvignon Blanc’). In particular, the evaluation of the correlation between vis/NIR spectra and classical destructive ripening parameters was targeted, for samples of both red and white grapes. Each sample was obtained in a different date during the last period of ripening, by averaging the spectral acquisitions of several individual berries. A chemometric regression model was created for each parameter considered. Vis/NIR spectra were correlated with ripening parameters (total soluble solids content TSS, titratable acidity, pH, weight of 200 berries, potential alcoholic degree PAD and sugar/acidity ratio) and with phenolic ripening parameters (extractable anthocyanins EA, total anthocyanins TA and tannins) using the partial least square (PLS) regression algorithm. Principal component analysis (PCA) was performed on spectra too. For both red and white grapes, PCA showed a significant sample grouping for the different acquisition times. PLS models on red grape gave good predictive skills for TSS, acidity and PAD (0.7 < R2 < 0.8, low values of RMSE), and for EA (R2cv = 0.74), while less accurate was the model elaborated for TA. Similar results were obtained for white grape (RMSE < 0.9 °Brix for TSS)
The Contribution of the Grape and Wine Industry to Idaho’s Economy: Agribusiness and Tourism Impacts
No full textThe impact of Idaho’s wine and grape industry was assessed as an agribusiness and as a tourist industry. Idaho’s grape and wine industry is in its infancy, with wine sales of 15 million in sales and 120 jobs in Idaho, and $23 million and 140 jobs for Canyon County. In contrast, tourism expenditures stimulate other businesses in addition to the agribusiness linkages of grape and wine production. Thus, only about three-fourths of the current wine production would be required to be sold to out-of-region tourists to equal the impact of the wine and grape industry as an agribusiness industry.Idaho, impact analysis, input/output models, tourism, wine, wine agribusiness, Agribusiness, Research and Development/Tech Change/Emerging Technologies,
Grape Guard: A YOLO-based mobile application for detecting grape leaf diseases
No full textGrape crops are a great source of income for farmers. The yield and quality of grapes can be improved by preventing and treating diseases. The farmer's yield will be dramatically impacted if diseases are found on grape leaves. Automatic detection can reduce the chances of leaf diseases affecting other healthy plants. Several studies have been conducted to detect grape leaf diseases, but most fail to engage with end users and integrate the model with real-time mobile applications. This study developed a mobile-based grape leaf disease detection (GLDD) application to identify infected leaves, Grape Guard, based on a TensorFlow Lite (TFLite) model generated from the You Only Look Once (YOLO)v8 model. A public grape leaf disease dataset containing four classes was used to train the model. The results of this study were relied on the YOLO architecture, specifically YOLOv5 and YOLOv8. After extensive experiments with different image sizes, YOLOv8 performed better than YOLOv5. YOLOv8 achieved 99.9 % precision, 100 % recall, 99.5 % mean average precision (mAP), and 88 % mAP50–95 for all classes to detect grape leaf diseases. The Grape Guard android mobile application can accurately detect the grape leaf disease by capturing images from grape vines
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