DOCSLIB.ORG

Canopy Microclimate Modification for the Cultivar Shiraz II. Effects on Must and Wine Composition

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

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. Introduction This paper is a companion to that by SMART et al. (1985), which described the effect of canopy manipulation on the radiation microclimate. Now the effects of microclimate change on must and wine composition are investigated. The previous paper proposed that the effects of soil, climate and cultural practice on must composition and wine quality could be understood, at least in part, by recog­ nising the effect of these factors on canopy microclimate. A number of factors can cause stimulation of grapevine vigour and concomitantly yield, and unless there are changes made to the training system, increased within-can­ opy shading can be the consequence. Given that shading reduces wine quality as is demonstrated here, we believe that considering microclimate leads to an explanation of the common observation that high yields lead to reduced quality. Recent studies have demonstrated an effect of canopy microclimate on must com­ position and wine quality (CARBONN EAU and HuGLI N 1982; SMART 1982). Common quality defects for Australian dry red table wines are high pH and low colour and phenol con­ tent (SoMERS 1975). The present study was designed to investigate whether a shaded 1) Present address: Ruakura Soil and Plant Research Station, Hamilton, New Zealand. 120 R. E. SMART, J. B. ROBINSON, G. R. DUE and c. J . BRJEN canopy microclimate is associated with these problems. Four different methods of managing grapevine canopies were studied, as weil as a naturally occurring variation in vine vigour, for effects on microclimate and must and wine composition. Further­ more, a system of visually assessing grapevine canopies was evaluated for association with must and wine composition. Materialsand methods 1 . Vineyard treatments Full details of the experimental site are given by SMART et al. 1985. Four treatments were used to provide a range of canopy microclimates: T r e a t m e n t 1 - s h a d e ( T 1 ) : The vine foliage was constrained into a smaller volume using a thin filament bird netting. This produced a very shaded micro­ climate. Treatment 2 s l a s h ( T 2 ) : Shoots were trimmed to about 9 nodes per shoot. Treatment3 c o n t r o l ( T 3 ) : The canopies grew in the normal growth habit. T r e a t m e n t 4 G D C ( T 4 ) : The vines were trained to Geneva double cur- tain with proper shoot positioning as described by SHAULIS et al. 1966. There were nine replicates of each treatment. The blocks were arranged across a pronounced vigour measurement, with block 9 plots the most vigorous, and block 1 the least. The companion paper, SMART et al. 1985, outlined viticultural and microclimate measurements. 2. Fruit and wine measurements 50 berry samples were taken from each plot during ripening (9 February and 24 February). Juice was separated by pressing berries against a fine screen and then centrifuging before sugar, acid and pH determination. Samples diluted 1 : 1 were frozen for subsequent K and organic acid analysis. The fruit from each plot was processed into wine using a procedure described by SMART (1982). Yields ranged from 7.4 to 30.5 kg/vine, with an average of 17.l k g. Each must was adjusted to 7 g/l titratable acidity at the onset of fermentation. Many of the wines produced H2S during fermentation which was treated with up to 3 ppm Cu2+ prior to bottling. Organic acid analyses were made with HPLC and cation concentrations by flame photometry. The spectral measurements due to SOMERS and EVANS (1977) were used. Sensory evaluation was carried out on 20 October 1981, by six experienced enolo­ gists from the Australian wine industry. Ten different wines were presented to each judge in each of four sessions. Within each session, at least two w ines were repeated to allow assessment of the judge's performance. The other eight wines consisted of two replicates of four treatments. Wines from replicate one were not subjected to evalua­ tion due to presence of H2S . Wines were scored with standard Australian Wine Show system (3 points for colour, 7 points for bouquet and aroma and 10 points for palate). Subjective ratings were also given for colour density and hue, and fruit flavour on the palate and nose (ex 5 points). Taster reliability was evaluated by performing an analysis of variance on the pairs of scores for the eleven dup!icated wines. The intraclass correlation coefficient was cal­ culated as a me~sure of reliability. Canopy microclimate modification for the cultivar Shirai. II. 121 Results 1. Fruit composition Changes in fruit composition during ripening are shown in Table 1. Delayed maturity was evident for Tl shade, T2 s.lash and T4 GDC early in the period, but at har­ vest there was no significant difference. Juice.K concentration and pH were lower for T4 GDC over the period, the highest for Tl shade. Malic acid levels were highest for Tl shade at 24 February. Replicate effects were significant o n 1 y for sugar concentra­ tion, being highest on the low vigour plots. Table 1 Changes in fruit composition during ripening Die Veränderung der Beerenzusammensetzung während des Reifeverlaufes Treatment Variable Tl shade T2 slash T3 control T4GDC 5 0/o LSD 9 February Sugar (0 Brix) 15.2 17 .2 18.5 16.6 1.3 Titratable acidity (g/l) 10.l 9.1 8.3 10.4 0.6 pH 3.16 3.13 3.21 3.05 0.03 K(ppm) 1 760 1 840 1 770 1 730 NS Tartaric acid (g/1) 7.8 7.8 7.3 7.8 NS Malic acid (g/l) 4.5 3.8 3.6 4.6 NS 24 February Sugar (0 Brix) 18.5 20.2 21.3 19.5 1.0 Titratable acidity (g/l) 7.1 6.4 6.1 6.7 0.5 pH 3.54 3.44 3.54 3.36 0.04 K(ppm) 2 220 1 960 2 310 1 920 180 Tartaric acid (g/1) 6.4 . 7.0 7.3 7.2 NS Malic acid (g/l) 4.1 2.3 2.5 2.9 0.6 19 March (harvest) Sugar (0 Brix) 22.l 23".0 23.5 23.6 NS Titratable acidity (g/l) 4.2 3.9 3.8 3.8 NS pH 3.89 3.82 3.80 3.67 NS K(ppm) 1 930 1 780 1 780 1 502 170 NS ~ Not significant. 2. Wine composition Wine composition analyses, presented in Table 2, show that T4 GDC had generally the most desirable composition and Tl shade the least desirable. In particular, wines from Tl shade had lowest titratable acidity and tartaric acid, highest pH and K and succinic acid content, and lowest colour density, proportion of ionised anthocyanin, total and ionised anthocyanins and total phenols, and highest colour hue. Not all of these analyses reached significance at the 5 % level but the trends were consistent. 122 R. E. SMART, J. B. ROBI NSON, G. R: DUE and c. J. BRIEN Table 2 Effects of treatment on wine composition Der Einfluß der Behandlung auf die Weinzusammensetzung Treatment Variable Tl shade T2 slash T3 control T4GDC 5 % LSD Titratable acidity (g/l) 7.0 7.6 7.4 8.3 0.4 pH 3.62 3.46 3.54 3.35 0.09 K(ppm) 1 700 1 470 1 580 1 270 130 Tartaric acid (g/l) 2.24 2.44 2.28 2.91 0.16 Lactic acid (g/1) 0.82 0.75 0.71 0.83 0.047 Succinic acid (g/1) 0.23 0.18 0.22 0.15 0.029 Wine colour densityI) 8.6 11.8 12.6 12.2 NS Wine colour hue1) 0.54 0.48 0.49 0.45 NS a (%)') 24.7 31.7 29.l 34.0 3.6 a' (%)') 27.3 33.9 31.7 37.8 2.8 Total anthocyanins (mg/l)I) 340 371 437 405 NS Ionised anthocyanins (mg/1)1) 86 122 129 136 NS Total phenols 33.9 38.5 43.3 41.3 NS ') After techniques of Sm1ERS and EvANS (1977).
Recommended publications
  • View the PDF: 10F-Ideas-Z2-Design-Facility-San

    View the PDF: 10F-Ideas-Z2-Design-Facility-San

    C A S E S T U D Y D I e A s Z 2 DESIGN FACILITY t the first conceptual The team needed a fully integrated BUILDING AT A GLANCE design charrette, the design process, in which the differ- design team decided to ent design disciplines and the gen- Name IDeAs Z2 Design Facility 2 target a “Z ” goal — eral contractor make key decisions Location San Jose, Calif. Azero energy and zero carbon — to together to optimize the building as Owner Integrated Design Associates advance the state of green build- an integrated system. For example, (IDeAs) ing and to showcase the low energy carefully designed sun shading and When Built mid-1960s (originally a electrical and lighting design skills state-of-the-art glazing would allow bank branch office) of the client. For the project to be the team to make many incisions Major Renovation 2007 Renovation Scope Skylights, window replicable, the team wanted a low into the roof and concrete walls to walls, upgraded insulation and energy building that uses exist- harvest more daylight. This would glazing, high-efficiency HVAC system, high-efficiency lighting and office equip- ing technology at a reasonable cost reduce the need for electric lighting ment, rooftop and canopy photovoltaic premium. By maximizing efficiency and its attendant energy consump- system, monitoring equipment of building systems before sizing tion, while also providing outside Principal Use Commercial office the photovoltaic arrays to cover the views for building occupants. Occupants 15 remaining loads, the costs were kept Team members collaborated on Gross Square Footage 7,000 to a minimum.
  • Multi-Scale Analysis of the Surface Layer Urban Heat Island Effect in Five Higher Density Precincts of Central Sydney

    Multi-Scale Analysis of the Surface Layer Urban Heat Island Effect in Five Higher Density Precincts of Central Sydney

    Sharifi, E., Philipp, C., & Lehmann, S. (2015). Multi-scale analysis of the surface layer urban heat island effect in five higher density precincts of central Sydney. In S. Lehmann (Ed.), Low Carbon Cities (pp. 375-393). New York: Routledge. Chapter 21 Multi-scale analysis of the surface layer urban heat island effect in five higher density precincts of central Sydney Ehsan Sharifi, Conrad Philipp and Steffen Lehmann Summary The urban heat island (UHI) effect is invariably present in cities, mainly due to increased urbanisation. It can result in higher urban densities being significantly hotter (frequently more than 4°C, even up to 10°C) than their peri-urban surroundings. Urban structure and land cover are key contributors to the surface layer urban heat island (sUHI) effect at city and district scale. This research aims to explore which urban configurations can make urban precincts and their microclimates more resilient to the dangerous sUHI effect. In the context of the city of Sydney, Australia, the research aims to explore the most heat resilient urban features for neighbourhoods, at precinct scale. The investigation examines five high density precincts in central Sydney. The analysis of these precincts is based on remote sensing thermal data of two independent sources: a nocturnal remote-sensing thermal image of central Sydney on 6 February 2009 and a diurnal Landsat 7– ETM+ data from 2008-2009. Comparing the surface temperature of streetscape and buildings’ rooftop feature layers indicates that open spaces are the urban elements most sensitive to the sUHI effect. Therefore, the correlations between street network intensity, open public space ratio, and urban greenery plot ratio and sUHI effect are being analysed in the five high density precincts selected.
  • Kentucky Viticultural Regions and Suggested Cultivars S

    Kentucky Viticultural Regions and Suggested Cultivars S

    HO-88 Kentucky Viticultural Regions and Suggested Cultivars S. Kaan Kurtural and Patsy E. Wilson, Department of Horticulture, University of Kentucky; Imed E. Dami, Department of Horticulture and Crop Science, The Ohio State University rapes grown in Kentucky are sub- usually more harmful to grapevines than Even in established fruit growing areas, ject to environmental stresses that steady cool temperatures. temperatures occasionally reach critical reduceG crop yield and quality, and injure Mesoclimate is the climate of the vine- levels and cause significant damage. The and kill grapevines. Damaging critical yard site affected by its local topography. moderate hardiness of grapes increases winter temperatures, late spring frosts, The topography of a given site, including the likelihood for damage since they are short growing seasons, and extreme the absolute elevation, slope, aspect, and the most cold-sensitive of the temperate summer temperatures all occur with soils, will greatly affect the suitability of fruit crops. regularity in regions of Kentucky. How- a proposed site. Mesoclimate is much Freezing injury, or winterkill, oc- ever, despite the challenging climate, smaller in area than macroclimate. curs as a result of permanent parts of certain species and cultivars of grapes Microclimate is the environment the grapevine being damaged by sub- are grown commercially in Kentucky. within and around the canopy of the freezing temperatures. This is different The aim of this bulletin is to describe the grapevine. It is described by the sunlight from spring freeze damage that kills macroclimatic features affecting grape exposure, air temperature, wind speed, emerged shoots and flower buds. Thus, production that should be evaluated in and wetness of leaves and clusters.
  • Environmental Study

    Environmental Study

    Initial Environmental Review: 9000 Block Highway 99, BC Prepared by: Cascade Environmental Resource Group Ltd. Unit 3 – 1005 Alpha Lake Road Whistler, BC V0N 1B1 Prepared for: 28165 Yukon Inc. 5403 Buckingham Avenue Burnaby, BC, V5E 1Z9 Project No.: 089-05-18 Date: August 1, 2019 Table of Contents Statement of Limitations ............................................................................................................................ 1 1 Introduction .......................................................................................................................................... 2 1.1 Scope .............................................................................................................................................. 2 1.2 The Project Team ........................................................................................................................... 2 1.3 Location .......................................................................................................................................... 2 1.4 SLRD Bylaw Zoning........................................................................................................................ 2 1.5 Methodology ................................................................................................................................... 3 2 Existing Environmental Conditions ................................................................................................. 11 2.1 Historical and Existing Land Use .................................................................................................
  • Bacterial Leaf Scorch of Chitalpa”

    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.
  • Grape Growing

    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.
  • Measuring Microclimate Variations in Two Australian Feedlots

    Measuring Microclimate Variations in Two Australian Feedlots

    Measuring Microclimate Variations In Two Australian Feedlots Project number FLOT.310 Final Report prepared for MLA by: E.A. Systems Pty Limited PO Box W1029 16 Queen Elizabeth Drive ARMIDALE NSW 2350 Meat and Livestock Australia Ltd Locked Bag 991 North Sydney NSW 2059 ISBN 1 74036 761 8 YSTEMS Pty Limited E.A. S Environmental & Agricultural Science & Engineering May 2001 MLA makes no representation as to the accuracy of any information or advice contained in this document and excludes all liability, whether in contract, tort (including negligence or breach of statutory duty) or otherwise as a result of reliance by any person on such information or advice. MLA © 2004 ABN 39 081 678 364 1 Measuring Microclimate Variations in Two Australian Feedlots ABSTRACT Heat stress has caused catastrophic stock losses infrequently in Australia and does cause production losses over summers. While a considerable body of research has been undertaken on defining heat stress with respect to cattle comfort, health and production, few data are available on the micrometeorological characteristics of feedlots, shaded pens in feedlots and differences between feedlots and their surrounds. A study was undertaken to define these microclimates and therefore to identify the probable causes of heat stress. The study found that feedlot climates are different to their surrounds. Generally they are hotter and more humid and have lower wind speeds under shade. The study found that shade benefit cattle by reducing radiation heat loads but have the deleterious effects of increasing manure moisture contents, relative humidity and ammonia levels. Ammonia is identified as a possible stressor but its importance must be further defined.
  • Victoria Mara Heilweil Photographic Artist, Curator, Educator 3270 20Th Street San Francisco, CA 94110

    Victoria Mara Heilweil Photographic Artist, Curator, Educator 3270 20Th Street San Francisco, CA 94110

    Victoria Mara Heilweil Photographic Artist, Curator, Educator 3270 20th Street San Francisco, CA 94110 (510) 918-4631 [email protected] www.victoriaheilweil.com Education 1995 MFA PHOTOGRAPHY California College of Arts and Crafts, Oakland, CA 1987 BFA FILM AND VIDEO New York University, New York, NY Recent Exhibitions 2019 BONE BLACK, group exhibition, DZINE Gallery, San Francisco, CA TEMPLE OF DIRECTION, group exhibition in collaboration with Phil Spitler, Burning Man Festival, Black Rock City, NV WATER MUSIC, group exhibition, DZINE Gallery, San Francisco, CA ORDINARY, group exhibition, Art Works Downtown, San Rafael, CA 2018 REASON AND REVERIE, group exhibition, Natalie and James Thompson Gallery, San Jose State University, CA Curator: Aaron Wilder DROP, solo exhibition, Art Works Downtown, San Rafael, CA EXPOSURE 2018: TO THOSE WHO SERVE, group exhibition, New Hope Arts, New Hope, PA WONDERSPACES, group exhibition in collaboration with Phil Spitler, San Diego, CA stARTup Art Fair, San Francisco, CA CURATED FRIDGE WINTER 2018, group exhibition, Cambridge, MA Juror: J. Sybylla Smith IMOTIF, group exhibition, Sohn Fine Art Gallery, Lenox, MA WHAT KEEPS YOU UP AT NIGHT?, group exhibition, Mendocino College Art Gallery, Ukiah, CA Curator: Tomiko Jones 2017 SIZE MATTERS, group exhibition, Helmuth Projects in conjunction with Medium Festival of Photography, San Diego, CA Juror: Katherine Ware, Photography Curator, Santa Fe Museum of Art COMMUNITY SOURCE(D), solo exhibition in collaboration with Mobile Arts Platform: Peter Foucault
  • Doppler Lidar Measurements of Boundary Layer Heights Over San Jose, California

    Doppler Lidar Measurements of Boundary Layer Heights Over San Jose, California

    San Jose State University SJSU ScholarWorks Master's Theses Master's Theses and Graduate Research Fall 2017 Doppler LiDAR Measurements of Boundary Layer Heights Over San Jose, California Matthew Robert Lloyd San Jose State University Follow this and additional works at: https://scholarworks.sjsu.edu/etd_theses Recommended Citation Lloyd, Matthew Robert, "Doppler LiDAR Measurements of Boundary Layer Heights Over San Jose, California" (2017). Master's Theses. 4880. DOI: https://doi.org/10.31979/etd.w6tv-6x88 https://scholarworks.sjsu.edu/etd_theses/4880 This Thesis is brought to you for free and open access by the Master's Theses and Graduate Research at SJSU ScholarWorks. It has been accepted for inclusion in Master's Theses by an authorized administrator of SJSU ScholarWorks. For more information, please contact [email protected]. DOPPLER LIDAR MEASUREMENTS OF BOUNDARY LAYER HEIGHTS OVER SAN JOSE, CALIFORNIA A Thesis Presented to The Faculty of the Department of Meteorology and Climate Science San José State University In Partial Fulfillment of the Requirements for the Degree Master of Science by Matthew R. Lloyd December 2017 © 2017 Matthew R. Lloyd ALL RIGHTS RESERVED The Designated Thesis Committee Approves the Thesis Titled DOPPLER LIDAR MEASUREMENTS OF BOUNDARY LAYER HEIGHTS OVER SAN JOSE, CALIFORNIA by Matthew R. Lloyd APPROVED FOR THE DEPARTMENT OF METEOROLOGY AND CLIMATE SCIENCE SAN JOSÉ STATE UNIVERSITY December 2017 Dr. Craig Clements Department of Meteorology and Climate Science Dr. Martin Leach Department of Meteorology and Climate Science Dr. Neil Lareau Department of Meteorology and Climate Science ABSTRACT DOPPLER LIDAR MEASUREMENTS OF BOUNDARY LAYER HEIGHTS OVER SAN JOSE, CALIFORNIA by Matthew R.
  • 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

    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.
  • Leaf Removal Applied to a Sprawling Canopy to Regulate Fruit Ripening in Cabernet Sauvignon

    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.
  • Effect of Canopy Microclimate, Season and Region on Sauvignon Blanc Grape Composition and Wine Quality J

    Effect of Canopy Microclimate, Season and Region on Sauvignon Blanc Grape Composition and Wine Quality J

    Effect of Canopy Microclimate, Season and Region on Sauvignon blanc Grape Composition and Wine Quality J. Marais, J.J. Hunter and P.D. Haasbroek ARC-Fruit, Vine and Wine Research Institute, Nietvoorbij Centre for Vine and Wine, Private Bag X5026, 7599 Stellenbosch, South Africa Submitted for publication: February 1999 Accepted for publication: May 1999 Key words: Microclimate, season, region, Sauvignon blanc, aroma, wine quality The effect of canopy microclimate on the grape aroma composition and wine quality of Sauvignon blanc was inves- tigated in three climatically-different regions, i.e. in the Stellenbosch (1996 and 1997 season), Robertson and Elgin regions (1997 and 1998 season). A canopy shade treatment altering microclimate in a natural way, was applied to Sauvignon blanc vineyards in the three regions. Control vines were not manipulated. The concentrations of aroma compounds in the grapes, namely monoterpenes, C 13-norisoprenoids and 2-methoxy-3-isobutylpyrazine, were determined weekly during the respective ripening periods. Solar radiation above and within the canopies as well as temperature within the canopies were also measured continually during the ripening periods. The highest canopy solar radiation, temperature, and monoterpene and C 13-norisoprenoid concentrations were found for the control treatments, followed by the shaded treatments. An opposite tendency was found for 2-methoxy-3-isobutylpyrazine, which is one of the most important components responsible for the typical green pepper/asparagus aroma of Sauvignon blanc. There appears to be a relationship between chemical and microclimatic data in each region and over seasons. Marked temperature and aroma component concentration differences were observed among the three regions during the cool 1997 season, which manifested in wine aroma parameters such as fruitiness and vegeta- tive/asparagus/green pepper nuances.