DOCSLIB.ORG

Xylella Fastidiosa Rodrigo P.P

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Xylella Fastidiosa Rodrigo P.P 75 Xylella fastidiosa Rodrigo P.P. Almeida, Helvécio D. Coletta-Filho, and João R.S. Lopes contents 75.1 Introduction ..................................................................................................................................................................... 841 75.2 Classification and Morphology ........................................................................................................................................ 842 75.2.1 Classification ........................................................................................................................................................ 842 75.2.2 Morphology ......................................................................................................................................................... 842 75.3 Biology and Epidemiology .............................................................................................................................................. 843 75.3.1 Dual-Host Lifestyle .............................................................................................................................................. 843 75.3.2 Genome ................................................................................................................................................................ 843 75.3.3 Plant Colonization ............................................................................................................................................... 843 75.3.4 Disease Spread .....................................................................................................................................................844 75.3.5 Insect Vectors and Transmission .........................................................................................................................844 75.3.6 Mechanisms of Transmission by Vectors ............................................................................................................844 75.3.7 Pathogen Population Structure ............................................................................................................................ 845 75.3.8 Epidemiology ....................................................................................................................................................... 845 75.4 Pathogenesis ..................................................................................................................................................................... 845 75.5 Identification and Diagnosis of CVC ............................................................................................................................... 845 75.5.1 Disease Symptoms ............................................................................................................................................... 845 75.5.2 Bacterial Culture .................................................................................................................................................. 846 75.5.3 Serological Assays ............................................................................................................................................... 846 75.5.4 Molecular Tools ................................................................................................................................................... 846 75.6 Treatment and Prevention ................................................................................................................................................ 847 75.6.1 Planting of Certified Nursery Trees ..................................................................................................................... 847 75.6.2 Diseased Tree Removal or Pruning ..................................................................................................................... 847 75.6.3 Vector Control...................................................................................................................................................... 847 75.7 Conclusions and Future Perspectives............................................................................................................................... 847 References ................................................................................................................................................................................. 848 75.1 IntroductIon of São Paulo state, Brazil, were found to be diseased with previously unknown symptoms. Initial hypotheses on the The US Department of Agriculture currently lists fewer than a causes of this new disease included nutritional deficiencies, dozen plant-associated microbial species as select agents. This the emergence of a novel virus, and the introduction of the list is a by-product of the Agricultural Bioterrorism Protection etiological agent of the disease known as Huanglongbing [2]. Act, which is part of the larger Public Health Security and The first years after its discovery were followed by increased Bioterrorism Preparedness Response Act of 2002. Although disease spread, which could not be controlled effectively as there is discussion within the academic community about the its etiology was unknown. Initial spatiotemporal analyses of relative risk of taxa in that list [1], work within the United the epidemics indicated that a contagious and likely vector- States on any of these taxa is highly regulated, even if the borne pathogen was associated with the disease [3]. Early organism is already established in specific regions where work demonstrated that grafting of tissue from symptomatic research is being conducted and immediately needed to reduce plants resulted in transmission of the etiological agent, and pathogen spread. Among the taxa in this list is the citrus var- microscopic examination showed bacteria colonizing the iegated chlorosis (CVC) strain of the plant pathogenic bacte- xylem vessels of infected plants [4]. rium Xylella fastidiosa. Although we will focus this chapter The fulfillment of Koch’s postulates by independent groups on the phylogenetic group of X. fastidiosa causing CVC around 1993 [5,6] identified the bacterium X. fastidiosa as (subsp. pauca), general aspects of X. fastidiosa classification, the etiological agent of the disease, by then named CVC. detection, and biology require background that includes other Research expanded into various directions, from the identifi- subspecies, which are included here as necessary. cation of insect vectors to epidemiological studies and breed- CVC History: In 1987, sweet orange plants (Citrus sinen- ing programs. The majority of those studies were conducted sis) in commercial orchards located in the northwest region by local researchers and published in Portuguese in Brazilian 841 K15299_C075.indd 841 11/4/2013 1:14:37 PM 842 Manual of Security Sensitive Microbes and Toxins journals. Vector transmission of the bacterium in citrus was is based on DNA relatedness [16] and multilocus sequence first reported in 1996 [7]. Epidemiological studies showed typing (MLST) results [17,18]. In addition to biological dif- that vectors played a major role spreading the bacterium ferences among the subspecies, work has also indicated that within and between citrus orchards, along with planting of they represent allopatric populations with evidence of recent infected nursery trees that was responsible for long-distance long-distance dispersal. Subsp. pauca is limited to South dispersal [8,9]. Nursery trees can easily become infected America, while subsp. fastidiosa occurs in North America with X. fastidiosa by grafting of infected plant tissue or nat- but is much more diverse within Central America, suggesting urally by vectors if produced in open fields where CVC is the latter is its center of origin [13,19]. The subsp. multiplex endemic. As consequence of these findings, a disease man- and sandyi have only been found in North America, except agement program to prevent pathogen introduction and sec- for a population of subsp. multiplex colonizing plums in ondary spread was established based on the production and Brazil, which is thought to have been introduced in the 1900s planting of healthy nursery plants, as well as eradication or via contaminated plant material [20]. Because vegetative pruning of diseased trees and vector control with insecticides propagation through grafting is widely used for most long- in citrus orchards. In addition, all nursery plant production lived perennial X. fastidiosa hosts, transportation of live in São Paulo state changed from the open-field system to a plant tissue is a common practice in the various agricultural certified program with screen houses, which became manda- industries affected by this pathogen, eventually increasing its tory in 2003 [10]. geographic distribution. Today, CVC is endemic throughout the citrus regions Because DNA–DNA reassociation assays are not avail- in São Paulo state, as well as all other Brazilian states that able to most research groups, MLST has become the bench- have sweet orange planted over large areas. According to mark for X. fastidiosa classification. The current scheme uses recent surveys of disease incidence (www.fundecitrus.com. sequence data from seven housekeeping genes under neutral br), approximately 40% of the 200 million sweet orange selection [21]. The use of multiple genes is especially impor- plants in São Paulo show CVC symptoms. CVC is appar- tant because the species is naturally competent
Load more

Recommended publications
  • The 2014 Golden Gate National Parks Bioblitz - Data Management and the Event Species List Achieving a Quality Dataset from a Large Scale Event
    National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science The 2014 Golden Gate National Parks BioBlitz - Data Management and the Event Species List Achieving a Quality Dataset from a Large Scale Event Natural Resource Report NPS/GOGA/NRR—2016/1147 ON THIS PAGE Photograph of BioBlitz participants conducting data entry into iNaturalist. Photograph courtesy of the National Park Service. ON THE COVER Photograph of BioBlitz participants collecting aquatic species data in the Presidio of San Francisco. Photograph courtesy of National Park Service. The 2014 Golden Gate National Parks BioBlitz - Data Management and the Event Species List Achieving a Quality Dataset from a Large Scale Event Natural Resource Report NPS/GOGA/NRR—2016/1147 Elizabeth Edson1, Michelle O’Herron1, Alison Forrestel2, Daniel George3 1Golden Gate Parks Conservancy Building 201 Fort Mason San Francisco, CA 94129 2National Park Service. Golden Gate National Recreation Area Fort Cronkhite, Bldg. 1061 Sausalito, CA 94965 3National Park Service. San Francisco Bay Area Network Inventory & Monitoring Program Manager Fort Cronkhite, Bldg. 1063 Sausalito, CA 94965 March 2016 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado, publishes a range of reports that address natural resource topics. These reports are of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate comprehensive information and analysis about natural resources and related topics concerning lands managed by the National Park Service.
    [Show full text]
  • Screening and Characterization of Biosurfactant Produced by Pseudoxanthomonas Sp
    Journal of Petroleum Exploration and Production Technology https://doi.org/10.1007/s13202-019-0619-8 ORIGINAL PAPER - PRODUCTION ENGINEERING Screening and characterization of biosurfactant produced by Pseudoxanthomonas sp. G3 and its applicability for enhanced oil recovery Dea Indriani Astuti1 · Isty Adhitya Purwasena1 · Ratna Eka Putri1 · Maghfirotul Amaniyah1 · Yuichi Sugai2 Received: 8 September 2018 / Accepted: 7 February 2019 © The Author(s) 2019 Abstract Biosurfactants are one of the microbial bioproducts that are in most demand from microbial-enhanced oil recovery (MEOR). We isolated and screened potential biosurfactant-producing bacteria, followed by biosurfactant production and characteriza- tion, and a simulation of the MEOR application to biosurfactants in a sand-packed column. Isolate screening was conducted based on qualitative (hemolytic blood assay and oil-spreading test) and semi-qualitative (emulsification assay and interfacial tension measurement) parameters. Bacterial identification was performed using 16S rRNA phylogenetic analysis. Sequential isolation yielded 32 bacterial isolates, where Pseudomonas sp. G3 was able to produce the most biosurfactant. Pseudomonas sp. G3 had the highest emulsification activity (Ei = 72.90%) in light crude oil and could reduce the interfacial tension between oil and water from 12.6 to 9.7 dyne/cm with an effective critical-micelle concentration of 0.73 g/L. The Fourier transform infrared spectrum revealed that the biosurfactant produced was a glycolipid compound. A stable emulsion of crude extract and biosurfactant formed at pH 2–12, up to 100 °C, and with a NaCl concentration of up to 10% (w/v) in the response-surface method, based on the Box–Behnken design model. The sand-packed column experiment with biosurfactant resulted in 20% additional oil recovery.
    [Show full text]
  • Canopy Microclimate Modification for the Cultivar Shiraz II. Effects on Must and Wine Composition
    Vitis 24, 119-128 (1985) Roseworthy Agricultural College, Roseworth y, South Australia South Australian Department of Agriculture, Adelaide, South Austraha Canopy microclimate modification for the cultivar Shiraz II. Effects on must and wine composition by R. E. SMART!), J. B. ROBINSON, G. R. DUE and c. J. BRIEN Veränderungen des Mikroklimas der Laubwand bei der Rebsorte Shiraz II. Beeinflussung der Most- und Weinzusammensetzung Z u sam menfa ss u n g : Bei der Rebsorte Shiraz wurde das Ausmaß der Beschattung innerha lb der Laubwand künstlich durch vier Behandlungsformen sowie natürlicherweise durch e ine n Wachstumsgradienten variiert. Beschattung bewirkte in den Traubenmosten eine Erniedri­ gung de r Zuckergehalte und eine Erhöhung der Malat- und K-Konzentrationen sowie der pH-Werte. Die Weine dieser Moste wiesen ebenfalls höhere pH- und K-Werte sowie einen venin­ gerten Anteil ionisierter Anthocyane auf. Statistische Berechnungen ergaben positive Korrelatio­ nen zwischen hohen pH- und K-Werten in Most und Wein einerseits u11d der Beschattung der Laubwand andererseits; die Farbintensität sowie die Konzentrationen der gesamten und ionisier­ ten Anthocyane und der Phenole waren mit der Beschattung negativ korreliert. Zur Beschreibung der Lichtverhältnisse in der Laubwand wurde ei11 Bonitierungsschema, das sich auf acht Merkmale stützt, verwendet; die hiermit gewonne nen Ergebnisse korrelierten mit Zucker, pH- und K-Werten des Mostes sowie mit pH, Säure, K, Farbintensität, gesamten und ionj­ sierten Anthocyanen und Phenolen des Weines. Starkwüchsige Reben lieferten ähnliche Werte der Most- und Weinzusammensetzung wie solche mit künstlicher Beschattung. K e y wo r d s : climate, light, growth, must quality, wine quality, malic acid, potassium, aci­ dity, anthocyanjn.
    [Show full text]
  • Managing Aboveground Pests: Arthropod Vectors of Citrus Pathogens: Part I February 13, 2019 Lecture Overview
    Managing aboveground pests: Arthropod vectors of citrus pathogens: Part I February 13, 2019 Lecture Overview Part I: • Vector-borne disease concepts • Introduction to Disease Vectors • Taxonomy • Biology • Vector-borne diseases of citrus • Viral Pathogens Part II: • Vector-borne diseases of citrus • Bacterial Pathogens • Case studies: • Citrus Variegated Chlorosis and Citrus greening disease Plant disease epidemics • Can result in large loss of crop yields or decimate entire plant species (e.g. Dutch elm disease) • Approximately 30-40% of damage/loss due to plant diseases Pathogen due to direct or indirect effects of (Vector) transmission and facilitation of pathogens by insects • Three elements needed for disease to occur (‘disease Susceptible Conducive triangle’) host environment • When a pathogen requires a vector to be spread, the vector must be plentiful and active for an epidemic to occur Disease Triangle • Not shown: time (latent period) for disease development Plant disease epidemics Host/Pathogen Relationships • Environmental and physiological factors contribute to the development of disease • Resistance: ability of a host to prevent infection and disease • Virulence: ability of a pathogen to produce disease • Many plant pathogens need to be transmitted by a vector • A pathogen’s host range may be determined by the host range of the vector - it can only infect plants that the insect vector feeds upon Vector/Host Relationships • Generally, the closer the association between vector and host, the greater the suitability of the vector
    [Show full text]
  • Lysobacter Enzymogenes
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Dissertations and Theses in Biological Sciences Biological Sciences, School of 8-2010 Detection Methods for the Genus Lysobacter and the Species Lysobacter enzymogenes Hu Yin University of Nebraska at Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/bioscidiss Part of the Life Sciences Commons Yin, Hu, "Detection Methods for the Genus Lysobacter and the Species Lysobacter enzymogenes" (2010). Dissertations and Theses in Biological Sciences. 15. https://digitalcommons.unl.edu/bioscidiss/15 This Article is brought to you for free and open access by the Biological Sciences, School of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Dissertations and Theses in Biological Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Detection Methods for the Genus Lysobacter and the Species Lysobacter enzymogenes By Hu Yin A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science Major: Biological Sciences Under the Supervision of Professor Gary Y. Yuen Lincoln, Nebraska August, 2010 Detection Methods for the Genus Lysobacter and the Species Lysobacter enzymogenes Hu Yin, M.S. University of Nebraska, 2010 Advisor: Gary Y. Yuen Strains of Lysobacter enzymogenes, a bacterial species with biocontrol activity, have been detected via 16S rDNA sequences in soil in different parts of the world. In most instances, however, their occurrence could not be confirmed by isolation, presumably because the species occurred in low numbers relative to faster-growing species of Bacillus or Pseudomonas.
    [Show full text]
  • Bacterial Leaf Scorch of Chitalpa”
    Extension Plant Pathology “Bacterial Leaf Scorch of Chitalpa” The Heat of Summer brings on Symptoms of Bacterial Leaf Scorch Symptoms on Chitalpa. Figure 1: Flowers on healthy chitalpa trees. (Photo N. Goldberg NMSU- PDC) Chitalpa trees (a hybrid between catalpa and desert willow) are susceptible to a xylem-limited bacterium called Xylella fastidiosa (Fig 1). The bacterium invades the plant and plugs up the water conducting vessels, known as the xylem vessels, making it difficult for the plant to get enough water to the leaves. The result on the plant is symptoms of water and nutrient stress - chlorosis and leaf scorch. Other symptoms include leaf spotting, small leaves, thin canopy, branch dieback, and eventually, tree death (Fig 2, 3, 4, 5). This disease was first discovered in New Mexico in 2006. It was also confirmed in grapes the same year. In grapes, the disease is known as Pierce’s Disease. In 2010, the disease was also confirmed in catalpa and peach. The disease is transmitted from one plant to another through xylem-feeding insects, most notably sharpshooters. While New Mexico has some native sharpshooters, the most efficient vectors for Xylella, the glassy-winged sharpshooter and the smoke-tree Figure 2: Leaf scorch and spotting symptoms on chitalpa leaves. (Photos: sharpshooter (Fig. 6), are not know to occur. N. Goldberg NMSU-PDC) Figure 3: Dieback symptoms on chitalpa. (Photo N. Goldberg NMSU-PDC) Research at New Mexico State University has shown that the bacterium is nearly identical in chitalpa, grape and catalpa. This indicates transmission, probably by native sharpshooters, between these hosts.
    [Show full text]
  • Characterization of Environmental and Cultivable Antibiotic- Resistant Microbial Communities Associated with Wastewater Treatment
    antibiotics Article Characterization of Environmental and Cultivable Antibiotic- Resistant Microbial Communities Associated with Wastewater Treatment Alicia Sorgen 1, James Johnson 2, Kevin Lambirth 2, Sandra M. Clinton 3 , Molly Redmond 1 , Anthony Fodor 2 and Cynthia Gibas 2,* 1 Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; [email protected] (A.S.); [email protected] (M.R.) 2 Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; [email protected] (J.J.); [email protected] (K.L.); [email protected] (A.F.) 3 Department of Geography & Earth Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-704-687-8378 Abstract: Bacterial resistance to antibiotics is a growing global concern, threatening human and environmental health, particularly among urban populations. Wastewater treatment plants (WWTPs) are thought to be “hotspots” for antibiotic resistance dissemination. The conditions of WWTPs, in conjunction with the persistence of commonly used antibiotics, may favor the selection and transfer of resistance genes among bacterial populations. WWTPs provide an important ecological niche to examine the spread of antibiotic resistance. We used heterotrophic plate count methods to identify Citation: Sorgen, A.; Johnson, J.; phenotypically resistant cultivable portions of these bacterial communities and characterized the Lambirth, K.; Clinton,
    [Show full text]
  • Grape Growing
    GRAPE GROWING The Winegrower or Viticulturist The Winegrower’s Craft into wine. Today, one person may fill both • In summer, the winegrower does leaf roles, or frequently a winery will employ a thinning, removing excess foliage to • Decades ago, winegrowers learned their person for each role. expose the flower sets, and green craft from previous generations, and they pruning, taking off extra bunches, to rarely tasted with other winemakers or control the vine’s yields and to ensure explored beyond their village. The Winegrower’s Tasks quality fruit is produced. Winegrowers continue treatments, eliminate weeds and • In winter, the winegrower begins pruning • Today’s winegrowers have advanced trim vines to expose fruit for maximum and this starts the vegetative cycle of the degrees in enology and agricultural ripening. Winegrowers control birds with vine. He or she will take vine cuttings for sciences, and they use knowledge of soil netting and automated cannons. chemistry, geology, climate conditions and indoor grafting onto rootstocks which are plant heredity to grow grapes that best planted as new vines in the spring, a year • In fall, as grapes ripen, sugar levels express their vineyards. later. The winegrower turns the soil to and color increases as acidity drops. aerate the base of the vines. The winegrower checks sugar levels • Many of today’s winegrowers are continuously to determine when to begin influenced by different wines from around • In spring, the winegrower removes the picking, a critical decision for the wine. the world and have worked a stagé (an mounds of earth piled against the base In many areas, the risk of rain, hail or apprenticeship of a few months or a of the vines to protect against frost.
    [Show full text]
  • Hemiptera: Cicadellidae) De La Argentina DELLAPÉ, Gimena1,2 & Susana L
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE Nota Científica provided by Centro deScientific Servicios en NoteGestión de Información ISSN 0373-5680 (impresa), ISSN 1851-7471 (en línea) Revista de la Sociedad Entomológica Argentina 72 (3-4): 231-235, 2013 Nuevos registros de Proconiini (Hemiptera: Cicadellidae) de la Argentina DELLAPÉ, Gimena1,2 & Susana L. PARADELL1,3 1División Entomología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Paseo del Bosque, B1900FWA La Plata, Argentina. 2Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), [email protected] 3Comisión de Investigaciones Científicas de la provincia de Buenos Aires (CIC) New records of Proconiini (Hemiptera: Cicadellidae) from Argentina ABSTRACT. Acrogonia citrina Marucci & Cavichioli, Molomea confluens (Melichar), Tretogonia dentalis Emmrich, and Propetes schmidti Melichar are recorded for the first time from Argentina, being the first mention of the genus Propetes Walker in the country. Diagnosis, geographical distribution, and aspects of the biology or phy- tosanitary importance for each species are provided. In addition, geographical dis- tribution in Argentina of another 16 species of the tribe Proconiini is here included. KEY WORDS. Auchenorrhyncha. Sharpshooters. Xylella. Acrogonia. Propetes. RESUMEN. Acrogonia citrina Marucci & Cavichioli, Molomea confluens (Melichar), Tretogonia dentalis Emmrich y Propetes schmidti Melichar, son registradas por primera vez en la Argentina. Esta es la primera mención del género Propetes Walker para el país. Para cada especie se brinda una diagnosis, su distribución geográfica y aspectos de su biología o importancia fitosanitaria. Adicionalmente se amplía la distribución en la Argentina de otras 16 especies de la tribu Proconiini. PALABRAS CLAVE.
    [Show full text]
  • Characterization of Bacterial Communities Associated
    www.nature.com/scientificreports OPEN Characterization of bacterial communities associated with blood‑fed and starved tropical bed bugs, Cimex hemipterus (F.) (Hemiptera): a high throughput metabarcoding analysis Li Lim & Abdul Hafz Ab Majid* With the development of new metagenomic techniques, the microbial community structure of common bed bugs, Cimex lectularius, is well‑studied, while information regarding the constituents of the bacterial communities associated with tropical bed bugs, Cimex hemipterus, is lacking. In this study, the bacteria communities in the blood‑fed and starved tropical bed bugs were analysed and characterized by amplifying the v3‑v4 hypervariable region of the 16S rRNA gene region, followed by MiSeq Illumina sequencing. Across all samples, Proteobacteria made up more than 99% of the microbial community. An alpha‑proteobacterium Wolbachia and gamma‑proteobacterium, including Dickeya chrysanthemi and Pseudomonas, were the dominant OTUs at the genus level. Although the dominant OTUs of bacterial communities of blood‑fed and starved bed bugs were the same, bacterial genera present in lower numbers were varied. The bacteria load in starved bed bugs was also higher than blood‑fed bed bugs. Cimex hemipterus Fabricus (Hemiptera), also known as tropical bed bugs, is an obligate blood-feeding insect throughout their entire developmental cycle, has made a recent resurgence probably due to increased worldwide travel, climate change, and resistance to insecticides1–3. Distribution of tropical bed bugs is inclined to tropical regions, and infestation usually occurs in human dwellings such as dormitories and hotels 1,2. Bed bugs are a nuisance pest to humans as people that are bitten by this insect may experience allergic reactions, iron defciency, and secondary bacterial infection from bite sores4,5.
    [Show full text]
  • The Effect of Canopy Area on Ripening and Wine Quality (2017) Rosemont Vineyards and Winery Submitted by Justin Rose
    The Effect of Canopy Area on Ripening and Wine Quality (2017) Rosemont Vineyards and Winery Submitted by Justin Rose Summary This study examines the impact of canopy height and ripening on wine quality in Merlot. Three sets of five rows of Merlot were hedged to different heights in mid-June: 52 inches (High canopy), 44 Inches (Medium canopy, normal height), and 36 inches (Short canopy). All other vineyard treatments were identical. Not much additional shoot growth occurred after hedging. Grapes were harvested on August 25 and processed into separate T Bins. All other treatments were identical. Juice Brix was slightly higher for the short canopy compared to the higher canopy. This may have been due to a seeming resistance to rain dilution seen in the short canopy vine compared to the medium and higher canopy vines. The ethanol, TA, color, and tannin increased with decrease in canopy height, and pH decreased with canopy height. Overall, descriptive analysis had difficulty distinguishing the wines consistently. The short canopy treatment tended to have slightly more Bitterness and Overall Aromatic Intensity. The short canopy wine also exhibited some slight reduction relative to the other two wines, which may have influenced results. Fruit Intensity and Astringency tended to vary between wines between tastings. In general, the high canopy wine tended to be the most preferred. Future studies should examine how bud fruitfulness and yield are impacted by multiple vintages of heavy hedging, pick fruit at different times depending on which treatment is deemed “optimally” ripe, and hedging shoots when they reach their designated height to try to force lateral growth.
    [Show full text]
  • Leaf Removal Applied to a Sprawling Canopy to Regulate Fruit Ripening in Cabernet Sauvignon
    plants Article Leaf Removal Applied to a Sprawling Canopy to Regulate Fruit Ripening in Cabernet Sauvignon Patrick O’Brien 1, Cassandra Collins 1,2 and Roberta De Bei 1,* 1 Waite Research Institute, School of Agriculture, Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia; [email protected] (P.O.); [email protected] (C.C.) 2 ARC Industrial Transformation Training Centre for Innovative Wine Production, Waite Research Institute, PMB 1, Glen Osmond, SA 5064, Australia * Correspondence: [email protected] Abstract: Under the effects of climate change, it is becoming increasingly common to observe excessively fast grape sugar accumulation while phenolic and flavour development are lagging behind. The aim of this research was to quantify the impacts of three different leaf removal techniques on the canopy architecture and ripening of Cabernet Sauvignon trained in a sprawl trellis system. Treatments were performed at veraison (~14 ◦Brix) and included (i) control; (ii) leaf plucking in the bunch zone; (iii) leaf plucking the top two-thirds of shoots, apical to the bunches; and (iv) shoot trimming. On the date of harvest, no significant difference in total soluble solids was observed between treatments. Other results including the effect of the treatments on fruit acidity, anthocyanins, phenolics, and tannins were somewhat inconclusive. While various other studies have shown the potential of leaf removal to achieve slower grape sugar accumulation without affecting the concentration of anthocyanins, phenolics, and tannins, the results of this study do not indicate a decrease in the rate of grape sugar accumulation as a result of the investigated defoliation techniques.
    [Show full text]