244 Technical Review February 2020

Technical Review 244 FEBRUARY 2020

Published by the Australian Wine Cnr Hartley and Paratoo Rd PO Box 197 T +61 8 8313 6600 Research Institute Ltd Urrbrae Glen Osmond F + 61 8 8313 6601 ABN 83 007 558 296 South Australia 5064 South Australia 5064 [email protected] Australia Australia www.awri.com.au Registered by Australia Post PP 531629/00034 Table of contents

In this issue 1 Technical notes 4

Grapevine Virus A and Shiraz Disease – What do Australian growers need to know? 4

Current literature 9

AWRI publications 34

AWRI events calendar 39

Editor: Michael Major, Michael Major Media All enquiries: Ella Robinson; email: [email protected] Copyright: Reprints and quotations of articles published herein are permitted on condition that full credit is given to both The Australian Wine Research Institute Technical Review and the author/s, and that the date of publication and issue number are stated.

ISSN 0816-0805

Published by The Corner of Hartley Grove PO Box 197 T +61 8 8313 6600 Australian Wine and Paratoo Road Glen Osmond F +61 8 8313 6601 Research Institute Ltd Urrbrae South Australia 5064 [email protected] ABN 83 007 558 296 South Australia 5064 Australia www.awri.com.au Australia In this issue TECHNICAL NOTES

Grapevine Virus A and Shiraz Disease – What do Australian growers need to know? A number of grapevine varieties are sensitive to Grapevine virus A (GVA), which is associated with the disorder known as Shiraz Disease. Shiraz Disease can have a major economic impact on affected vineyard businesses. Growers can take steps to minimise the risk of economic damage from Shiraz Disease.

CURRENT LITERATURE

OENOLOGY

General (page 10) Grape pomace as a promising antimicrobial alternative in feed: a critical review Going full circle

Juice and wine handling (page 10) Using magnetic polymers to remove overpowering green capsicum flavour from Cabernet Sauvignon wine

Gaseous SO2, its physico-chemical properties, production, use in oenology and future prospects

Alternatives to SO2: new applications and knowledge. Part 1 of 2: pre-fermentation stages and bioprotection from spoilage organisms Bioprotection: a biological alternative, partial or total, to the addition of sulfites Sulfur dioxide – effects and alternatives from the perspective of research oenology Microoxyenation: understanding the influence of oxygen on the polyphenolic composition of Pinot Noir wine and its impact on wine colour and mouth feel

Microbiology (page 12) Originality of a new inactivated yeast specifically for oxidative stability in white and Rosé wines What can a winemaker do about Brettanomyces bruxellensis present in oak barrels? Microbiological testing of casks and barrels Interaction between oak and Brettanomyces in wine Wine: a potential source of antimicrobial compounds From the vineyard to the winery: how microbial ecology drives regional distinctiveness of wine Ethanol-tolerant lactic acid bacteria strains as a basis for efficient malolactic fermentation in wine: evaluation of experimentally evolved lactic acid bacteria and winery isolates

Analysis and composition (page 14) Addition of mannoproteins and/or seeds during winemaking and their effects on pigment composition and color stability Quality and volatile compounds in red wine at different degrees of dealcoholization by membrane process A new, easier methodology for assessing copper in white wine Potential of lead elemental and isotopic signatures for authenticity and geographical origin of Bordeaux wines Research on the distinctiveness of Chardonnay wines of Burgundy: identification and quantification of new markers for hazelnut aroma

February 2020 Technical Review No. 244 1 Volatile composition and sensory profiles of a Shiraz wine product made with pre- and post- fermentation additions of Ganoderma lucidum extract Impact of oak wood barrel tannin potential and toasting on white wine antioxidant stability. Elicitors and pre-fermentative cold maceration: effects on polyphenol concentration in Monastrell grapes and wines Viability of IR spectroscopy for the accurate measurement of yeast assimilable nitrogen content of grape juice Absorption of 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) from wine by bottle closures

Sensory (page 17) Influence in wine tasting: how our brain modifies the taste of wine Investigating alcohol sweetspot phenomena in reduced alcohol red wines Impact of matrix variables and expertise of panelists on sensory thresholds of 1,1,6-trimethyl-1,2- dihydronaphthalene known as petrol off-flavor compound in Riesling wines

VITICULTURE

General (page 19) Old vines: the gift of time Spatio-temporal variability in vine vigour and yield in a Marlborough Sauvignon Blanc vineyard Leaf surface fully exposed. Part 2: NDVI using the Sentinel satellite Highlights of the 21st GiESCO international meeting in Greece Nothing in wine has changed more rapidly in 30 years Examining the impact of grapevine age on vigour, productivity and berry technological ripeness. Taking the stress out of vintage Supporting native bees and biodiversity in vineyards

Physiology and biotechnology (page 21) Light and temperature independently influence methoxypyrazine content of Vitis vinifera (cv. Cabernet Sauvignon) berries

Climate and soils (page 21) Vitis vinifera facing climate change. Long-term development of the course of grape ripening in Burgenland (Austria) and its dependence on different climatic factors

Vineyard management systems (page 22) Designing new vineyards for minimal pruning Early leaf removal can help reduce sunburn in grapes Ethanol sprays to release grapevine bud dormancy: a potential alternative to cyanamides Mechanical weed control Using common viticultural practices to modulate the rotundone and 3-isobutyl-2-methoxypyrazine composition of Vitis vinifera L. cv. Fer red wines from a temperate climate wine region with very cool nights Cover crop selection for vineyard conditions: you could just buy a standard blend, but is that the best you can do? Effect of manual leaf removal and its timing on yield, the presence of lateral shoots and cluster characteristics with the grape variety ‘Karaerik’ Conversion to mechanical pruning in vineyards maintains fruit composition while reducing labor costs in ‘Merlot’ grape production Improving vineyard soils prior to replanting through cover crops Conversion to organic and biodynamic viticultural practices: impact on soil, grapevine development and grape quality

2 Technical Review No. 244 February 2020 Simonit and Sirch: challenging conventional pruning methods to improve vine health An automated grape yield estimation system Cover crops: benefits for vineyards beyond enhanced biodiversity Making organic vineyards sustainable – the novel Amisfield approach

Pests and diseases (page 27) Fighting phylloxera in a Pinot Noir vineyard with imidacloprid (‘Confidor’) and spirotetramat (‘Movento’) Botanical products for vine mealybug control in organic vineyards Behavior of vine varieties resistant to fungal diseases in the Somontano region Lessons from the USA to help Australia prepare for Xylella The insidiousness of trunk disease Prevalence of grapevine trunk disease in New Zealand – observations from vineyard surveys Grapevine trunk disease research update Xylella: the front line

Vine improvement and varieties (page 29) Developing a smart, rapid screening method for desirable grapevine rootstock traits Corvina thrives in the NSW Hilltops Behind the top drops: Cloudy Bay Sauvignon Blanc Making marvellous Malbec Diverse and complex Australian Malbec Stars of the South The new Carménère Beyond the sea Elite phylloxera and root knot nematode breeding lines ‘in the pipeline’

Water and nutrition (page 31) Irrigation management during extended drought: a comparison of dry grown vines with moderate and early season irrigation Evaluating remotely-sensed grapevine (Vitis vinifera L.) water stress responses across a viticultural region State-of-the-art of tools and methods to assess vine water status

AWRI PUBLICATIONS (PAGE 33) First trials to assess the feasibility of grape seed powder (GSP) as a novel and sustainable bentonite alternative Ask the AWRI: Sustainable Winegrowing Australia. Supporting the nation’s growers and winemakers in demonstrating and improving their sustainability Making sense of yeast assimilable nitrogen (YAN) Elements of wine An investigation of the Pivot© Profile sensory analysis method using wine experts: comparison with descriptive analysis and results from two expert panels The impact of temperature fluctuations on closure performance Ask the AWRI: grape solids in white winemaking 2019 Report Thermal degradation of phytate produces all four possible inositol pentakiphosphates as determined by ion chromatography and 1H and 31P NMR spectroscopy Efficient TALEN-mediated gene editing in wheat Grape and wine flavonoid composition in transgenic grapevines with altered expression of flavonoid hydroxylase genes

February 2020 Technical Review No. 244 3 Technical notes

Grapevine Virus A and Shiraz Disease – What do Australian growers need to know?

Portions of this article were previously published in Habili et al. 2016 Wine Vitic. J. 31 (6): 47–50 and are reproduced with permission from the publisher Winetitles.

Background Shiraz is Australia’s most planted red wine-grape variety, and is the basis of many of Australia’s most prestigious wines. This variety is, however, sensitive to a number of viruses including Grapevine virus A (GVA), which is associated with the disorder known as Shiraz Disease. GVA is a Vitivirus (family: Betflexiviridae) and a member of the group of grapevine viruses known as the ‘rugose wood complex’ group. Other members of this group include Grapevine viruses B, D, E, F and Grapevine rupestris stem-pitting-associated virus (GRSPaV).

Symptoms Symptomatic vines affected by Shiraz Disease show the following characteristics: • Their leaves turn red in late autumn and remain on the canopy throughout the winter (Figure 1). • They show restricted spring growth (RSG) compared with unaffected vines growing in the same row (Figure 2).

Figure 1. Shiraz Disease in Shiraz vines six years after being grafted onto Chardonnay rootstock. The symptomless Chardonnay was infected with GVA.

4 Technical Review No. 244 February 2020 • Occasionally, longitudinal cracking is seen on unlignified one-year-old wood of Shiraz, but not on the rootstock (Figure 3). Canes also show a mosaic of unlignified wood (Figure 3).

History GVA-associated Shiraz Disease was first reported in South Africa by Corbett and Wiid (1985). In Australia, the first evidence of Shiraz Disease was obtained from a Clare Valley Shiraz sample sent to Waite Diagnostics in September 1998. Healthy Shiraz samples from the

Figure 2. Shiraz vine grafted on GVA-positive Chardonnay showing restricted spring growth (vine at far right hand side of image).

Figure 3. Symptoms of Shiraz Disease on Shiraz canes in autumn: (A) cracks on unlignified cane; (B) cracks and swelling on Shiraz grafted onto Chardonnay; (C) a healthy cane (Habili et al. 2016)

February 2020 Technical Review No. 244 5 same row tested negative for GVA. At the same time, samples of two other varieties from the same vineyard (Cabernet Sauvignon and Crouchen) tested positive for GVA, but unlike the Shiraz, were symptomless (unpublished records from Waite Diagnostics). Shiraz Disease has so far only been reported in Australia and South Africa. This could be related to the genetic variability of GVA, which has three major genetic groups. Of these three groups, group II has been detected in both in Australia and South Africa and has been linked to Shiraz Disease by DNA testing (Goszczynski and Habili 2012, Qi Wu, pers. comm.). Genetic group I, mostly detected in Europe, is not associated with Shiraz Disease symptoms.

Not just in Shiraz – sensitive and tolerant grapevine varieties Shiraz, Merlot, Malbec, Ruby Cabernet and Sumoll have all been found to show the symptoms of Shiraz Disease (Habili and Randles 2004). Further research may reveal other susceptible varieties. White varieties, rootstocks and a number of red varieties including Cabernet Sauvignon, Grenache and Nero D’Avola do not display symptoms when infected with GVA. To avoid the risk of Shiraz Disease, sensitive varieties should not be grafted onto GVA-affected varieties.

Other viruses associated with Shiraz Disease In Shiraz Disease-affected vines, additional viruses other than GVA are commonly detected. One example of this is GRSPaV, which is present in more than 95% of Australian vines. The role of this symptomless minor virus is not known. Leafroll-associated viruses are also commonly found in combination with GVA in vines affected by Shiraz Disease.

How is GVA spread? GVA, a phloem-limited virus, is not transmitted by horticultural tools. Vitis spp. are the only natural hosts of the virus. It has been reported that mealybugs and soft scale insects can transmit GVA along with leaf-roll associated viruses (GLRaV-1 and GLRaV-3) from mixed infected grapevines (Bertin et al. 2016). Infection also occurs by grafting sensitive varieties onto GVA-infected rootstocks. For example, Shiraz vines grafted onto GVA-affected but symptomless varieties (such as Chardonnay, Riesling, Cabernet Sauvignon and Grenache) show the symptoms of Shiraz Disease and test positive for GVA.

One example of insect-spread GVA occurred in a McLaren Vale vineyard where grapevine scale insects (Parthenolecanium persicae) were highly abundant on GVA-infected Merlot vines (Figure 4). The Merlot block was adjacent to a Shiraz block which showed the spread of Shiraz Disease from the Merlot in a clustered pattern. In the nucleic acid extracts of scale insects collected from the infected Merlot vines, both GVA and GLRaV-3 were detected and it appeared that the concentration of leafroll virus was higher than GVA in the bodies of

6 Technical Review No. 244 February 2020 crawling nymphs of scale insects. This has recently been confirmed by a quantitative assay (qPCR). It appears that the same species of mealybug or scale insect can transmit both viruses.

Economic impact Shiraz Disease can have a major economic impact on affected vineyard businesses. For example, six years after grafting Shiraz onto GVA-positive Chardonnay (top-working, Figure 1) at McLaren Vale, the vineyard lost 98% of its yield (Habili and Randles 2012). At Langhorne Creek, a large block of Shiraz top-worked onto Chardonnay developed Shiraz Disease in 20% of its vines, displaying restricted spring growth. According to the grower, the cost of removing infected vines, replanting and loss of crop, was estimated to be around $400,000 for a 6-ha block. An independent vineyard consultant assessed the damage cost at $70,000/ha which was consistent with the above estimate.

Management strategies To minimise the risk of economic damage from Shiraz Disease, there are a number of steps that growers can take: 1. Use virus-tested planting material when establishing new vineyards or when conducting top-working. It is important that rootlings are purchased from accredited nurseries with a virus testing program. 2. Before planting or grafting susceptible varieties, make sure that the neighbouring blocks are free of Shiraz Disease-associated viruses. If removing GVA-positive vines from nearby is not possible, a non-susceptible variety should be planted or grafted instead; for example, a white variety or a tolerant red variety such as Cabernet Sauvignon, Grenache or Nero D’Avola, rather than Shiraz, Malbec and Merlot.

Figure 4. Parthenolecanium persicae (grapevine scale) on canes of Shiraz

February 2020 Technical Review No. 244 7 3. Remove and replant any vines that show definitive symptoms of Shiraz Disease. This protocol has been practised in South Africa and New Zealand for GLRaV-3 for years. Virus testing is an option for vines showing less definitive symptoms. 4. In vineyards where GVA is known, regularly monitor for insect vectors and adopt appropriate control measures. 5. If GVA is present, before removing affected vines and replanting, use insecticides to control the mealybug and scale and reduce the background levels of these insects. Remove cover crops that act as host plants to mealybug and scale. 6. When removing vines try to remove as much root matter from the top 30 cm of the soil as possible.

Future research Further research in collaboration with industry is needed to tackle several key questions about the devastating effects of Shiraz Disease. Key researchable questions include: • What is the economic threshold for removal of infected vines? • Which virus vectors are active in Australian vineyards and what are their natural enemies? • How widespread is GVA-associated Shiraz Disease in Australia? • Are herbicides effective at reducing virus-infected root material which is the food source of mealybug vectors living in soil?

References Bertin S., Paciﬁco D., Cavalieri V, Marzachì C, Bosco, D. 2016. Transmission of Grapevine virus A and Grapevine leafroll-associated viruses 1 and 3 by Planococcus ﬁcus and Planococcus citri fed on mixed-infected plants. Ann. Appl. Biol. 169: 53–63. Corbett, M.K., Wiid, J. 1985. Closterovirus-like particles in extracts from diseased grapevines. Phytopath. Med. 24: 91–100. Goszczynski, D.E., Habili, N. 2012. Grapevine virus A variants of group II associated with Shiraz disease I South Africa are present in plants affected by Australian Shiraz disease, and have also been detected in the USA. Plant Path. 61: 205–214. Habili, N., Randles, J.W. 2004. Descriptors for Grapevine virus A-associated syndrome in Shiraz, Merlot and Ruby Cabernet in Australia, and its similarity to Shiraz Disease in South Africa. Aust. N.Z. Grapegrower Winemaker 71: 1–4. Habili, N., Randles, J. W. 2012. Major yield loss in Shiraz vines infected with Australian Shiraz Disease associated with Grapevine virus A. Proceedings of the 17th Congress of the International Council for the Study of Virus and Virus-like Diseases of the Grapevine (ICVG), Davis, California, USA, October 7–14, 2012: 164–165. Habili, N., Wu, Q., Pagay, V. 2016. Virus-associated Shiraz Disease may lead Shiraz to become an endangered variety in Australia. Wine Vitic. J. 31(1): 47–50.

Nuredin Habili, Senior Research Scientist - Grapevine Virology Qi Wu, Laboratory Technician Mardi Longbottom, Senior Viticulturist Amy Rinaldo, Manager Applied Biosciences, [email protected]

8 Technical Review No. 244 February 2020 Current literature

Copies of all articles listed in this section are available for private study on request from the AWRI. Please use the request form provided in the centre pages of this issue or email [email protected]. Currently, a service charge of A$7.00 per request is applicable, plus a supply charge of 10¢ per page plus postage will apply (inclusive of GST).

In compliance with copyright legislation, abstracts are reproduced here exactly as originally printed. Oenology

General

244.01 Hassan, Y.I., Kosir, V., Yin, X., Ross, K., Diarra, M.S. Grape pomace as a promising antimicrobial alternative in feed: a critical review. Journal of Agricultural and Food Chemistry 67(35), 9705–9718; 2019.

Abstract available online at http://doi.org/dggn

244.02 Losh, C. Going full circle. Harpers Wine & Spirit 182, 10–11; 2019.

Andrew Caillard MW talks Chris Losh through the complex web of trends shaping the winemaking scene Down Under. Full text available online at https://bit.ly/2OIyx6F

Juice and wine handling

244.03 Liang, C., Ristic, R., Stevenson, R., Jiranek, V., Jeffery, D. Using magnetic polymers to remove overpowering green capsicum flavour from Cabernet Sauvignon wine. Wine & Viticulture Journal 34(4), 24–26; 2019.

In recent years, silicone and polylactic acid (PLA) polymeric materials have been adopted and assessed for their efficiency in removing alkylmethoxypyrazines (MPs) from wine without

February 2020 Technical Review No. 244 9 affecting the balance and distinct aroma. To increase selectivity, molecularly imprinted polymers (MIPs) have been proposed for the extraction of MPs from wines. MIPs act in a ‘lock-and-key’ manner that specifically recognises and binds target compounds. This ‘lock-and-key’ feature arises due to imprinting with a target compound acting as a template during preparation. Such methods have been adopted and trialled in winemaking as part of a PhD project at the University of Adelaide within the ARC Training Centre for Innovative Wine Production. Apart from the ‘lock-and-key’ imprinting, magnetic particles were also incorporated into the polymers for magnetic separation as an alternative to separating the polymer from wine through filtration or packing the polymer in a column.

© Reprinted with permission Liang, C., Ristic, R., Stevenson, R., Jiranek, V., Jeffery, D. Using magnetic polymers to remove overpowering green capsicum flavour from Cabernet Sauvignon wine. Wine & Viticulture Journal 34(4), 24–26; 2019. Copyright 2019 Winetitles Media Pty Ltd.

244.04

Moutounet, M., Mignonac, J.-M. Gaseous SO2, its physico-chemical properties, production, use in oenology and future prospects. Revue des Oenologues 173S, 28–32; 2019.

[French] Abstract not available for reproduction

244.05

Pillet, O., Vatin, L., Robillard, B. Alternatives to SO2: new applications and knowledge. Part 1 of 2: pre-fermentation stages and bioprotection from spoilage organisms. Revue des Oenologues 173S, 41–43; 2019.

[French] Abstract not available for reproduction

244.06 Simonin, S., Alexandre, H., Tourdot-Maréchal, R. Bioprotection: a biological alternative, partial or total, to the addition of sulfites. Revue des Oenologues 173S, 36–39; 2019.

[French] Abstract not available for reproduction

244.07 Teissedre, P.-L. Sulfur dioxide – effects and alternatives from the perspective of research oenology. Revue des Oenologues 173S, 24–27; 2019.

[French] Abstract not available for reproduction

244.08 Yang, B. Microoxyenation: understanding the influence of oxygen on the polyphenolic composition of Pinot Noir wine and its impact on wine colour and mouth feel. New Zealand Winegrower 117, 129–130; 2019.

The technique of microoxygenation (MOX) was developed in France at the beginning of the 1990s as an alternative and/or complementary method to barrel aging. Since then it has been applied to red wines all over the world.

10 Technical Review No. 244 February 2020 Full text available online at https://bit.ly/34EPWTf

© Reprinted with permission Yang, B. Microoxyenation: understanding the influence of oxygen on the polyphenolic composition of Pinot Noir wine and its impact on wine colour and mouth feel. New Zealand Winegrower 117, 129–130; 2019. Copyright 2019 New Zealand Winegrowers Inc. and New Zealand Winegrowers Research Centre Ltd.

Microbiology

244.09 Bahut, F., Silvano, A., Sieczkowski, N., Coelho, C., Nikolantonaki, M., Schmitt-Kopplin, P., Gougeon, R. Originality of a new inactivated yeast specifically for oxidative stability in white and rosé wines. Revue des Oenologues 173, 21–24; 2019.

[French] Abstract not available for reproduction

244.10 Cartwright, Z., Edwards, C. What can a winemaker do about Brettanomyces bruxellensis present in oak barrels? Wine & Viticulture Journal 34(4), 17–21; 2019.

Traditional methods involving the application of heat continue to be used to reduce microbial populations. Such methods include filling barrels with heated water (50° to 70°C) or using wand- type systems to apply steam for various amounts of time. While several studies have reported reductions in microbiological populations, some have concluded that even these methods do not satisfactorily sanitise wine barrels and therefore should not be considered primary control methods. To address this problem, studies were funded by the Washington State Grape and Wine Research Program to determine specific conditions for using steam or hot water as a means of eliminating Brettanomyces bruxellensis from oak staves.

© Reprinted with permission Cartwright, Z., Edwards, C. What can a winemaker do about Brettanomyces bruxellensis present in oak barrels? Wine & Viticulture Journal 34(4), 17–21; 2019. Copyright 2019 Winetitles Media Pty Ltd.

244.11 David, V., Alexandre, H. Microbiological testing of casks and barrels. Revue des Oenologues 173, 33–34; 2019.

[French] Abstract not available for reproduction

244.12 Gerbaux, V., Briffox, C., Dumoulin, M., Bruno, A., Hardy, A. Interaction between oak and Brettanomyces in wine. Revue des Oenologues 173, 38–40; 2019.

[French] Abstract not available for reproduction

February 2020 Technical Review No. 244 11 244.13 Jamir, L., Kumar, V., Gat, Y., Kumar, A., Kaur, S. Wine: a potential source of antimicrobial compounds. Journal of Wine Research 30(3), 220–237; 2019.

With increase in the socioeconomic status, the demand of the health and nutraceutical food is increasing day-by-day. Wine contains a wide variety of the biologically active compounds including antimicrobial compounds (phenolics, acids, alcohols, bioamines, etc.) which possess the numerous health benefits. The concentration of these compounds changes according to the raw material their varieties and vinification process. Phenolics, such as epicatechin, gallic acid, catechin, caffeic acid, vannillic acid, p-coumaric acid and resveratrol, are present in different wines. Wine also contains various acids such as tartaric acid, succinic acid, acetic acid and malic acid. Alcohol includes majorly the ethanol with a minute quantity of methanol and other higher alcohols, whereas the bioamine includes the ethanolamine, ammonia and histamine. These all compounds have the ability to possess antimicrobial activity either independently or in the conjugative form with the other compounds. In this article, efforts have been made to document the different antimicrobial compounds present in wines and their antimicrobial activity. This review has the potential to attract readers; mainly researchers and industrialists for the future study and product development in the wine industry.

Abstract available online at http://doi.org/dgb7

© Reprinted with permission Jamir, L., Kumar, V., Gat, Y., Kumar, A., Kaur, S. Wine: a potential source of antimicrobial compounds. Journal of Wine Research 30(3), 220–237; 2019. Copyright 2019 Routledge.

244.14 Liu, D., Zhang, P., Chen, D., Howell, K. From the vineyard to the winery: how microbial ecology drives regional distinctiveness of wine. Frontiers in Microbiology 10(2679), 1–13; 2019.

Wine production is a complex process from the vineyard to the winery. On this journey, microbes play a decisive role. From the environment where the vines grow, encompassing soil, topography, weather and climate through to management practices in vineyards, the microbes present can potentially change the composition of wine. Introduction of grapes into the winery and the start of winemaking processes modify microbial communities further. Recent advances in next-generation sequencing (NGS) technology have progressed our understanding of microbial communities associated with grapes and fermentations. We now have a finer appreciation of microbial diversity across wine producing regions to begin to understand how diversity can contribute to wine quality and style characteristics. In this review, we highlight literature surrounding wine-related microorganisms and how these affect factors interact with and shape microbial communities and contribute to wine quality. By discussing the geography, climate and soil of environments and viticulture and winemaking practices, we claim microbial biogeography as a new perspective to impact wine quality and regionality. Depending on geospatial scales, habitats, and taxa, the microbial community respond to local conditions. We discuss the effect of a changing climate on local conditions and how this may alter microbial diversity and thus wine style. With increasing understanding of microbial diversity and their effects on wine fermentation, wine production can be optimised with enhancing the expression of regional characteristics by understanding and managing the microbes present.

12 Technical Review No. 244 February 2020 Full text available online at http://doi.org/dgw3

Copyright © 2019 Lui, Zhang, Chen and Howell. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

244.15 Sumby, K.M., Niimi, J., Betteridge, A.L., Jiranek, V. Ethanol-tolerant lactic acid bacteria strains as a basis for efficient malolactic fermentation in wine: evaluation of experimentally evolved lactic acid bacteria and winery isolates. Australian Journal of Grape and Wine Research 25(4), 404–413; 2019.

Background and Aims: Reliable malolactic fermentation (MLF) is essential for process efficiency and spoilage prevention in wine. This study extends previous research in our laboratory, aimed at the development and selection of new bacterial strains for reliable MLF in wine, focusing on ethanol-tolerant lactic acid bacteria (LAB) strains. Sensory differences of seven LAB strains were assessed, including two commercial strains, two ethanol-tolerant strains derived from directed evolution and three isolates from a high ethanol Grenache. Methods and Results: In this study, the performance of 30 LAB strains was first assessed in fermented chemically defined grape juice media. Seven of the best performing strains were then tested in small-scale (5 L) fermentations in Shiraz and Shiraz-Grenache blend wines. All wines were evaluated with a sensory panel using free choice profiling. Conclusions: Despite significantly different MLF kinetics between the strains there were no strain-specific differences on the final wines. The choice of LAB strain did not adversely change the sensory properties of either wine. Significance of the Study: These findings provide reassurance that the efficient LAB strains (G71 and G55) and the modified directed evolution strains do not compromise the sensory properties of wines despite their marked MLF benefits.

Abstract available online at http://doi.org/dgb9

© Reprinted with permission Sumby, K.M., Niimi, J., Betteridge, A.L., Jiranek, V. Ethanol-tolerant lactic acid bacteria strains as a basis for efficient malolactic fermentation in wine: evaluation of experimentally evolved lactic acid bacteria and winery isolates. Australian Journal of Grape and Wine Research 25(4), 404–413; 2019. Copyright 2019 Australian Society of Viticulture and Oenology.

Analysis and composition

244.16 Alcalde-Eon, C., Pérez-Mestre, C., Ferreras-Charro, R., Rivero, F.J., Heredia, F.J., Escribano- Bailón, M.T. Addition of mannoproteins and/or seeds during winemaking and their effects on pigment composition and color stability. Journal of Agricultural and Food Chemistry 67(14), 4031–4042; 2019.

Abstract available online at http://doi.org/dggp C

February 2020 Technical Review No. 244 13 L 244.17 Corona, O., Liguori, L., Albanese, D., Di Matteo, M., Cinquanta, L., Russo, P. Quality and volatile compounds in red wine at different degrees of dealcoholization by membrane process. European Food Research and Technology 245(11), 2601–2611; 2019.

Abstract available online at http://doi.org/dggm

244.18 Danenberg, E. A new, easier methodology for assessing copper in white wine. Australian & New Zealand Grapegrower & Winemaker 670, 54–55; 2019.

The author spoke to one of the Australian researchers behind a new method for assessing copper in white wine that can be carried out by wineries of any size using standard laboratory equipment.

© Reproduced with permission Danenberg, E. A new, easier methodology for assessing copper in white wine. Australian & New Zealand Grapegrower & Winemaker 670, 54–55; 2019. Copyright 2019 Winetitles Media Pty Ltd.

244.19 Epova, E.N., Bérail, S., Séby, F., Barre, J.P.G., Vacchina, V., Médina, B., Sarthou, L., Donard, O.F.X. Potential of lead elemental and isotopic signatures for authenticity and geographical origin of Bordeaux wines. Food Chemistry 303:125277; 2020.

Lead concentrations and lead isotope ratios of 43 authentic Bordeaux wines from prestigious châteaux and 14 suspicious Bordeaux origin were determined to evaluate their potential for authenticity and geographical origin assessment. Results have shown that the total Pb concentrations in Bordeaux wines drastically decreased over the previous 50 years with a clear shift of isotopic signatures towards geogenic values corresponding to an overall trend of European environmental lead monitoring. The Pb isotopic ratios determined in both series of samples clearly demonstrated that suspicious Bordeaux wines displayed Pb isotopic signatures statistically distinctive from those obtained for authentic wines. This observation was confirmed by the three- isotope mixing lines obtained between the geogenic and the anthropogenic Pb isotopes data that characterize European and Asian sources. The use these specific three-isotope plots allows a non-ambiguous discrimination between authentic Pauillac AOC and the counterfeited ones.

Abstract available online at http://doi.org/dgwx

© Reprinted with permission Epova, E.N., Bérail, S., Séby, F., Barre, J.P.G., Vacchina, V., Médina, B., Sarthou, L., Donard, O.F.X. Potential of lead elemental and isotopic signatures for authenticity and geographical origin of Bordeaux wines. Food Chemistry 303, 1–10; 2020. Copyright 2020 Elsevier.

244.20 Gammacurta, M., Gros, J., Lavigne, V., Nazaris, B., Moine, V., Darriet, P., Marchal, A. Research on the distinctiveness of Chardonnay wines of Burgundy: identification and quantification of new markers for hazelnut aroma. Revue des Oenologues 173, 26–29; 2019.

[French] Abstract not available for reproduction

14 Technical Review No. 244 February 2020 244.21 Nguyen, A.N.H., Capone, D.L., Johnson, T.E., Jeffery, D.W., Danner, L., Bastian, S.E.P. Volatile composition and sensory profiles of a Shiraz wine product made with pre- and post- fermentation additions of Ganoderma lucidum extract. Foods 8(11):538; 2019.

Novel Shiraz red wine products enriched with Ganoderma lucidum (GL) extract, a traditional Asian medicinal mushroom, were developed and characterized. GL extract was added at different levels prior to and after primary fermentation to investigate its impact on the juice fermentation kinetics, and the chemical composition and sensory properties of the resulting wines. The fermentation kinetics of red grape juice were not significantly different between ferments. Basic chemical analyses plus headspace solid-phase micro-extraction (HS-SPME), gas chromatography‒mass spectrometry (GC-MS), and a rate-all-that-apply (RATA) (n = 65) sensory panel were used to investigate the influence of GL extract additions on wine composition and sensory characteristics. Of the 54 sensory attributes assessed, 39 significantly differentiated the wines. A clear separation between GL wine treatments was evident with PLS regression, where specific volatiles were correlated with relevant sensory attributes that dominated the wines. These products could be promising for emerging wine markets.

Full text available online at http://doi.org/dgw2

Copyright © 2019 by the Authors. Licensee MDPI, Basel, Switzerland. This is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

244.22 Nikolantonaki, M., Daoud, S., Noret, L., Coelho, C., Badet-Murat, M.-L., Schmitt-Kopplin, P., Gougeon, R.D. Impact of oak wood barrel tannin potential and toasting on white wine antioxidant stability. Journal of Agricultural and Food Chemistry 67(30), 8402–8410; 2019.

Abstract available online at http://doi.org/dggq

244.23 Paladines-Quezada, D.F., Moreno-Olivares, J.D., Fernández-Fernández, J.I., Bleda-Sánchez, J.A., Martínez-Moreno, A., Gil-Muñoz, R. Elicitors and pre-fermentative cold maceration: effects on polyphenol concentration in Monastrell grapes and wines. Biomolecules 9(11):671; 2019.

Vitis vinifera L cv Monastrell is the main red grape variety grown for vinification in the Denomination of Origin Jumilla (southeast Spain). Different strategies are still being tested to optimize available resources both in terms of the environment and to achieve wines with better organoleptic and functional characteristics. The objective of this work was to combine two strategies: the application of methyl jasmonate (MeJ), benzothiadiazole (BTH), and methyl jasmonate + benzothiadiazole (MeJ + BTH) elicitors to Monastrell leaves, and pre-fermentative cold maceration. During two seasons, the experiment was carried out to improve the extraction of the phenolic compounds, whose levels may have increased following the application of elicitors in the field, and to assess the effect of both strategies on the wine quality. Discriminant analysis revealed that independently of the meteorological conditions during both years, the pre-harvest response C

February 2020 Technical Review No. 244 15 L to the application of elicitors MeJ, BTH, and MeJ + BTH, induced increases in total anthocyanin concentration of the treated grapes, allowing the distinction of the treatments. This analysis also allowed the distinction between the types of maceration used, showing greater extraction of phenolic compounds by the application of low temperature, giving wines with a higher index of total phenols, a greater intensity of color, and a lower luminosity.

Full text available online at http://doi.org/dgwv

244.24 Petrovic, G., Aleixandre-Tudo, J.-L., Buica, A. Viability of IR spectroscopy for the accurate measurement of yeast assimilable nitrogen content of grape juice. Talanta 206:120241; 2020.

Up to date, there have been only a few reports on the measurement of YAN and/or its components using IR spectroscopy, suffering from various limitations (number of samples, validation strategies, etc.). In this work, three IR spectral instruments measuring in different modes and ranges of the IR spectrum (FT-IR, FT-NIR, and ATR-MIR), were compared and evaluated for their accuracy to measure both total YAN as well as the components, FAN and ammonia separately, using over 900 grape juice samples from 28 cultivars over three seasons. The global and vintage-based models were evaluated using R2CAL/VAL, RMSEC/P, and RPDCAL/VAL. Randomization tests were used for pair-wise comparison of models. FT-IR and FT-NIR instruments gave the best results, while ATR-MIR can be used for screening purposes. Considering the accuracy, robustness, high throughput, and cost-effective nature, the models produced by both FT-IR and FT-NIR spectroscopy can provide winemakers with the opportunity to make timelier and more informed nutrient supplementation decisions, facilitating the achievement of their desired wine style and quality.

Abstract available online at http://doi.org/dgxb

© Reprinted with permission Petrovic, G., Aleixandre-Tudo, J.-L., Buica, A. Viability of IR spectroscopy for the accurate measurement of yeast assimilable nitrogen content of grape juice. Talanta 206, 1–7; 2020. Copyright 2020 Elsevier Science.

244.25 Tarasov, A., Giuliani, N., Dobrydnev, A., Müller, N., Volovenko, Y., Rauhut, D., Jung, R. Absorption of 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) from wine by bottle closures. European Food Research and Technology 245(11), 2343–2351; 2019.

Abstract available online at http://doi.org/dggk

16 Technical Review No. 244 February 2020 Sensory

244.26 Morrot, G. Influence in wine tasting: how our brain modifies the taste of wine. Revue des Oenologues 173, 49–51; 2019.

[French] Abstract not available for reproduction

244.27 Pham, D.-T., Stockdale, V.J., Jeffery, D.W., Tuke, J., Wilkinson, K.L. Investigating alcohol sweetspot phenomena in reduced alcohol red wines. Foods 8(10):491; 2019.

Warmer growing seasons, variations to grape ripening dynamics, and stylistic changes have contributed to increased wine alcohol levels, which can negatively impact sensory properties. As a consequence, winemakers have sought technological innovations to produce reduced alcohol wine (RAW). The sensory methodology used by industry to optimize the ethanol content of RAW is known as ‘alcohol sweetspotting’. However, to date, there is no scientific evidence to support the alcohol sweetspot phenomenon, and the sensory methodology used for alcohol sweetspotting has not been validated. In this study, different methods of presenting wine samples (i.e., ordered vs. randomized, and linear vs. circular) were employed to determine to what extent presentation order influences the outcome of alcohol sweetspotting trials. Two different approaches to statistical analysis of sensory data, i.e., chi-square goodness of fit vs. one proportion tests, were also evaluated. Statistical analyses confirmed alcohol sweetspots were apparent in some sweetspot determination trials, but outcomes were not reproducible in replicate determinations (either by panel or by individual panelists). Analysis of data using the one proportion test improved the likelihood of identifying statistically significant differences between RAWs, but variation in individuals’ sensitivity to differences in sensory properties following ethanol removal prevented validation of the alcohol sweetspot phenomenon based on the wines studied.

Full text available online at http://doi.org/dgww

February 2020 Technical Review No. 244 17 L 244.28 Ziegler, M., Gök, R., Bechtloff, P., Winterhalter, P., Schmarr, H.-G., Fischer, U. Impact of matrix variables and expertise of panelists on sensory thresholds of 1,1,6-trimethyl-1,2- dihydronaphthalene known as petrol off-flavor compound in Riesling wines. Food Quality & Preference 78:103735; 2019.

1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) is known to elicit the perception of ‘petrol off- flavor’ in wine, most prominent in the variety Riesling. This study was focused on the impact of matrix variables such as ethanol and carbonation on the odor detection threshold of TDN. Increasing carbonation nearly doubled the detection threshold in water, however, this effect could not be observed in alcoholic matrices. Ethanol enhanced detection thresholds presumably due to diminished volatilization, which was only partially supported by measurement of partition coefficients using GC–MS. Overall, the impact of matrix changes was small ranging from 1.1 µg/L in still water to 4.0 µg/L in Riesling sparkling wine. Consumer detection threshold of 14.7 µg/L TDN determined with 156 consumers exceeded the threshold of the trained panel by a factor of five and varied by consumers’ age and gender. Rejecting a Riesling wine due to its petrol off- flavor, 60 µg/L TDN were required in a young and 91 µg/L in an eight-year-old Riesling wine. Based on analytical data for more than 250 commercial Riesling wines, geographic origin and to a smaller extent wine age contributed to large differences in TDN concentrations. About half of the investigated wines exceeded the detection threshold of the trained panel, whereas consumers would have noticed TDN in only less than 15% of the Riesling wines. Merely 3% of the wines actually exceeded the consumer rejection threshold of TDN. For both, detection and consumer rejection thresholds, the applied methodology contributed considerably to the final values, which is discussed critically.

Abstract available online at http://doi.org/dgvc

© Reprinted with permission Ziegler, M., Gök, R., Bechtloff, P., Winterhalter, P., Schmarr, H.-G., Fischer, U. Impact of matrix variables and expertise of panelists on sensory thresholds of 1,1,6-trimethyl-1,2- dihydronaphthalene known as petrol off-flavor compound in Riesling wines. Food Quality & Preference 78, 1–12; 2019. Copyright 2019 Elsevier Science.

18 Technical Review No. 244 February 2020 Viticulture

General

244.29 Atkin, T. Old vines: the gift of time. Decanter 45(1), 44–50; 2019.

With many vineyard sites established in the 16th century or possibly earlier, Latin America boasts a significant number of old vines. But as the author discovers, winemakers don’t like to shout about it.

244.30 Bramley, R.G.V., Ouzman, J., Trought, M.C.T., Neal, S.M., Bennett, J.S. Spatio-temporal variability in vine vigour and yield in a Marlborough Sauvignon Blanc vineyard. Australian Journal of Grape and Wine Research 25(4), 430–438; 2019.

Background and Aims: Previous work has indicated that patterns of within-vineyard variation in vine vigour are stable in time and, in the case of spur-pruned vineyards, closely match patterns of variation in yield. However, whether this yield : vigour interaction also occurs in cane-pruned vineyards is uncertain. This work sought to better understand this issue in support of efforts to improve yield estimation in cane-pruned Marlborough Sauvignon Blanc. Methods and Results: Vine vigour, measured as pruning mass, trunk cross-sectional area and using remotely sensed imagery, and the components of yield were measured in a 5.9 ha Marlborough Sauvignon Blanc vineyard on vines which had been pruned to retain either two or four canes. The results suggest that whereas patterns of variation in vine vigour are stable in time, and related to variation in the land underlying the vineyard, patterns of yield variation are neither temporally stable nor related to variation in vine vigour or the inherent underlying characteristics of the block. Conclusions: For all practical purposes, variation in the yield of Marlborough Sauvignon Blanc within vineyard ‘zones’ identified on the basis of variation in vine vigour or soil properties can be regarded as random. Nevertheless, given a diversity of product offering, and because variation in vigour can have a marked impact on fruit composition, remotely sensed indices of vigour do provide a valuable basis for targeting sampling or sensor deployment aimed at yield estimation. Significance of the Study: This work highlights the need to differentiate between spur- and cane-pruned vineyards in considering how vineyard variability should be assessed, and how the tools of precision viticulture and targeted management are applied.

Abstract available online at http://doi.org/dgb8

© Reprinted with permission Bramley, R.G.V., Ouzman, J., Trought, M.C.T., Neal, S.M., Bennett, J.S. Spatio- temporal variability in vine vigour and yield in a Marlborough Sauvignon Blanc vineyard. Australian Journal of Grape and Wine Research 25(4), 430–438; 2019. Copyright 2019 Australian Society of Viticulture and Oenology.

February 2020 Technical Review No. 244 19 L 244.31 Demestihas, C., Debuisson, S., Descôtes, A. Leaf surface fully exposed. Part 2: NDVI using the Sentinel satellite. Le Vigneron Champenois 140(8), 28–34; 2019.

[French] Abstract not available for reproduction

244.32 Gouot, J., Barril, C., Gambetta, J. Highlights of the 21st GiESCO international meeting in Greece. Wine & Viticulture Journal 34(4), 38–45; 2019.

The 21st GiESCO meeting was held in Thessaloniki (Greece) from the 23–28 June 2019. More than 300 participants attended the congress and a total of 82 orals and more than 150 posters were presented during the conference around diverse topics such as climate change, soil and zoning, vine genetic resources, vine physiology and grape ripening, viticultural techniques, precision viticulture, new technologies and vineyard mechanisation, and vine protection and sustainability.

© Reprinted with permission Gouot, J., Barril, C., Gambetta, J. Highlights of the 21st GiESCO international meeting in Greece. Wine & Viticulture Journal 34(4), 38–45; 2019. Copyright 2019 Winetitles Media Pty Ltd.

244.33 Jefford, A. Nothing in wine has changed more rapidly in 30 years. Decanter 45(2), 12; 2019.

The economic and political emancipation of Europeans and others who had spent most of the 20th century living under the Soviet shadow has been one of the great events of the last century. Wine production is not in itself a primary focus of these changes – but it has changed along with everything else.

244.34 Nader, K.B., Stoll, M., Rauhut, D., Patz, C.-D., Jung, R., Loehnertz, O., Schultz, H.R., Hilbert, G., Renaud, C., Roby, J.-P., Delrot, S., Gomes, E. Examining the impact of grapevine age on vigour, productivity and berry technological ripeness. Wine & Viticulture Journal 34(4), 46–54; 2019.

It has long been suggested that grapevines produce wines of increasing quality as they grow older, which as a concept finds no parallel in other crops. Consumers and participants in the wine sector seem to agree on the ability of old vines to produce better wines, but the validity of this point of view remains debated and questions about the mechanisms through which old vines would result in superior wines remain numerous. To try to answer them, the impact of vine age on physiology and berry technological ripeness was studied in an experimental vineyard in Geisenheim, Germany.

© Reprinted with permission Nader, K.B., Stoll, M., Rauhut, D., Patz, C.-D., Jung, R., Loehnertz, O., Schultz, H.R., Hilbert, G., Renaud, C., Roby, J.-P., Delrot, S., Gomes, E. Examining the impact of grapevine age on vigour, productivity and berry technological ripeness. Wine & Viticulture Journal 34(4), 46–54; 2019. Copyright 2019 Winetitles Media Pty Ltd.

20 Technical Review No. 244 February 2020 244.35 Rose, B. Taking the stress out of vintage. Australian & New Zealand Grapegrower & Winemaker 669, 28–30; 2019.

In a few short months, vineyard and winery operators across Australia and New Zealand will be gearing up for vintage 2020. Harvest time can sometimes be more stressful than it has to be, writes Ben Rose, who offers some advice in preparing for the upcoming harvest to avoid the unexpected or unwanted, highlighting the importance of accurate crop estimation in particular.

244.36 Schmidt, J. Supporting native bees and biodiversity in vineyards. Das Deutsche Weinmagazin 18, 19–21; 2019.

[German] Abstract not available for reproduction

Physiology and biotechnology

244.37 Plank, C.M., Hellman, E.W., Montague, T. Light and temperature independently influence methoxypyrazine content of Vitis vinifera (cv. Cabernet Sauvignon) berries. HortScience 54(2), 282–288; 2020.

Abstract available online at http://doi.org/dgw4

Climate and soils

244.38 Teslić, N., Ricci, A., Parpinello, G.P., Versari, A. Vitis vinifera facing climate change. Internet Journal of Enology and Viticulture 11(1), 1–5; 2019.

The entire wine industry production could roughly be separated into two major parts which are grapevine cultivation and winemaking, whereas the influence of climate change is more directly related to processes in the vineyard and grape production. On the other hand, even though winemaking can be directly affected by climate change (i.e. higher energy consumption for cooling systems during harvest period) it is mostly indirectly influenced through the usage of grapes which are nowadays cultivated in hotter and drier climate in certain wine regions. Therefore, to closely understand the impact of climate change on wine industry it is required to determine links between the major berry compounds (sugars, organic acids, aromatic and phenolic compounds) and weather factors.

Full text available online at https://bit.ly/36t3Qs6

© Reprinted with permission Teslić, N., Ricci, A., Parpinello, G.P., Versari, A. Vitis vinifera facing climate change. Internet Journal of Enology and Viticulture 11(1), 1–5; 2019. Copyright 2019 Vinideanet. C

February 2020 Technical Review No. 244 21 L 244.39 Tiefenbrunner, M., Wuketich, A., Tiefenbrunner, W. Long-term development of the course of grape ripening in Burgenland (Austria) and its dependence on different climatic factors. Mitteilungen Klosterneuburg Rebe und Wein 69(2), 124–140; 2019.

[German] Abstract not available for reproduction

Vineyard management systems

244.40 Ochßner, T. Designing new vineyards for minimal pruning. Das Deutsche Weinmagazin 21, 26–29; 2019.

[German] Abstract not available for reproduction

244.41 Anon. Early leaf removal can help reduce sunburn in grapes. Australian & New Zealand Grapegrower & Winemaker 670, 20; 2019.

Research by the National Wine and Grape Industry Centre (NWGIC) has shone new light on how to reduce sunburn damage on grapes by identifying the best time to remove leaves from the vine.

244.42 Chervin, C., Fennell, A. Ethanol sprays to release grapevine bud dormancy: a potential alternative to cyanamides. OENO one 53(4), 661–666; 2019.

Aim: Grape growers sometimes use cyanamides (calcium or hydrogen) to release bud dormancy in warm climate regions, where the chilling requirement has not been met during winter. However, these products can cause damage to plants and are dangerous to handle, so alternatives would be welcomed by growers. Connections between metabolisms of ethanol, ethylene and cyanide revealed by previous studies led us to test the potential of ethanol sprays on bud break and early shoot growth. Methods and Results: Trials were performed over three years on Vitis vinifera grapevines trained in Guyot or cordon, and on cuttings in growth chambers. Cultivars used in the studies included Cabernet-Sauvignon, Syrah and Ugni blanc. The results show that ethanol can advance bud break of all three cultivars at concentrations ranging from 2.5 to 10 % ethanol in water. Ethanol stimulates bud development in both Guyot and cordon training systems. However, the timing of ethanol application is crucial, and late spring season applications reduce the effectiveness of the treatment. Conclusions: Observations were performed over three different seasons. The trials revealed that ethanol sprays can advance bud break of different Vitis vinifera vines, trained with cane or spur systems. Significance and impact of the study: Climate change impacts dormancy release, making it an increasingly important issue over the next few decades. An alternative to the dangerous use of cyanamides to promote bud break would greatly help growers. These preliminary

22 Technical Review No. 244 February 2020 results with ethanol are promising but should lead to trials in various growing areas and with various cultivars in order to confirm their potential for viticulture.

Full text available online at http://doi.org/dgw6

Copyright © 2019 by the authors. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

244.43 Gaviglio, C. Mechanical weed control. Revue des Oenologues 173, 18–20; 2019.

[French] Abstract not available for reproduction

244.44 Geffroy, O., Li Calzi, M., Ibpfelt, K., Yobrégat, O., Feilhès, C., Dufourcq, T. Using common viticultural practices to modulate the rotundone and 3-isobutyl-2-methoxypyrazine composition of Vitis vinifera L. cv. Fer red wines from a temperate climate wine region with very cool nights. OENO one 53(4), 581–595; 2019.

Aim: Rotundone and 3-isobutyl-2-methoxypyrazine (IBMP) are two potent aroma compounds responsible for pepper and bell pepper notes in red wines, respectively. The aim of the study was to modulate, through common viticultural practices, the volatile composition in these two molecules of Fer red wines from a temperate climate wine region with very cool nights, located in the southwest of France. Methods and Results: Three viticultural practices (leaf removal 10 days after berry set, removal of lateral shoots, and delayed harvest 7 days after the control) were investigated in 2015 and in 2016. Rotundone concentrations up to 69 ng/L were found in experimental wines. IBMP concentrations were below perception level in wines from 2016 and below detection level in wines from 2015, a vintage with particularly hot climatic conditions between berry set and bunch closure. Delayed harvest induced an increase in rotundone concentration while leaf removal and the removal of lateral shoots had no significant impact on rotundone concentration. Delayed harvest and the removal of lateral shoots were the most efficient practices to decrease IBMP in wines. The three techniques made it possible to increase the odour activity values (OAV) ratio of OAV rotundone to OAV IBMP, with the greatest impact observed for delayed harvest. Conclusion: According to our results, delayed harvest appears to be the best practice to modulate the volatile composition of Fer wines toward an increase in the OAV rotundone to OAV IBMP ratio. Significance and impact of the study: Our results may assist local grape growers to modulate the volatile composition of their wines.

Full text available online at http://doi.org/dgw9

February 2020 Technical Review No. 244 23 L 244.45 Greenspan, M. Cover crop selection for vineyard conditions: you could just buy a standard blend, but is that the best you can do? Wine Business Monthly 26(10), 74–78; 2019.

Use of sown cover crops is not universal, but in the North Coast, it is quite common. In wet winter climates, they are sown in the tractor rows usually following harvest (and occasionally before harvest if the harvest drags on long enough). Lack of cover crops in wet climates can lead to serious issues of erosion and compaction, not to mention the absence of their benefits, which will be discussed below. In dry winter climates, cover crop establishment can be challenging, or borderline impossible, because it requires rainfall – specifically, rainfall when temperatures are moderate. Of course, overhead sprinklers could supplement rainfall to establish a cover crop, but using additional water to grow a cover crop that sucks up more water from the ground in a dry climate does not seem desirable or logical.

Abstract available online at https://www.winebusiness.com/wbm/

© Reprinted with permission Greenspan, M. Cover crop selection for vineyard conditions: you could just buy a standard blend, but is that the best you can do? Wine Business Monthly 26(10), 74–78; 2019. Copyright 2019 Wine Communications Group, Inc.

244.46 Kaya, Ö. Effect of manual leaf removal and its timing on yield, the presence of lateral shoots and cluster characteristics with the grape variety ‘Karaerik’. Mitteilungen Klosterneuburg Rebe und Wein 69(2), 83–92; 2019.

Abstract not available for reproduction

244.47 Kurtural, S.K., Beebe, A.E., Martínez-Lüscher, J., Zhuang, S., Lund, K.T., McGourty, G., Bettiga, L.J. Conversion to mechanical pruning in vineyards maintains fruit composition while reducing labor costs in ‘Merlot’ grape production. HortTechnology 29(2), 128–139; 2019.

A field study was conducted for three consecutive seasons in the hot climate of central California to assess the performance of ‘Merlot’ grapevine (Vitis vinifera) grafted onto ‘Freedom’ [Fresno 1613–59 × Dog Ridge 5 (27% V. vinifera hybrid)] during training system conversion to facilitate mechanization. The traditional head-trained and cane-pruned (CP) system was either retained or converted either to a bilateral cordon-trained, spur-pruned California sprawl training system (HP), or to a bilateral cordon-trained, mechanically box-pruned single high-wire sprawling system (SHMP). After the conversion, SHMP sustained greater yield with more clusters per vine and smaller berries without affecting the canopy microclimate. This was due to a higher number of nodes retained after dormant pruning. The SHMP canopies, compared with CP and HP; filled allotted canopy space earlier based on photosynthetically active radiation (PAR) transmitted through the canopies, populating the space allotted per vine, favoring higher production efficiency. There were no adverse effects of training systems on berry composition or flavonoid concentration, during or after conversion to mechanical management. However, experimental year effect was obvious on anthocyanin composition of ‘Merlot’ berries, increasing trihydroxylated

24 Technical Review No. 244 February 2020 (i.e., delphinidin-based) anthocyanins in the latter years of the experiment. Our results also provided evidence that earlier canopy growth coupled with sufficient reproductive compensating responses allowed for increased yields while reaching commercial maturity without a decline in anthocyanin content with the SHMP. Converting CP to SHMP reduced labor operations costs by 90%. Furthermore, the SHMP had greater gross revenue and resulted in greater net income per acre even when the conversion year was taken into account. Therefore, SHMP is recommended for growers within the hot climate of the central San Joaquin Valley as a means to maintain productivity of vineyards while not sacrificing berry composition at the farm gate.

Full text available online at http://doi.org/dgw5

244.48 Ladach, M. Improving vineyard soils prior to replanting through cover crops. Das Deutsche Weinmagazin 22, 22–25; 2019.

[German] Abstract not available for reproduction

244.49 Meissner, G., Athmann, M.E., Fritz, J., Kauer, R., Stoll, M., Schultz, H.R. Conversion to organic and biodynamic viticultural practices: impact on soil, grapevine development and grape quality. OENO one 53(4), 639–659; 2019.

Aim: The effects of integrated, organic and biodynamic management on soil quality and the growth and morphological development of Riesling grapevines were assessed during the first 4 years of a long-term field trial in Geisenheim, Germany. The overall aim was to understand the effects of these different viticultural practices on soil quality and plant morphology as the basis for product quality. Methods and Results: As indicators of soil quality, earthworm abundance and the activity of selected enzymes were assessed. The vegetative and reproductive development of the grapevines, as well as their susceptibility to fungal diseases in the field, wood and grape composition, and grape yield, were investigated. Individual variables were subjected to analysis of variance. Additionally, all variables were subjected to multivariate principal component analysis. Compared with plots under integrated management, plots under the two biological treatments were characterized by higher soil quality and lower vegetative growth and grape yield, and therefore higher exposure of grapes and lower grape cluster compactness, and, probably as a result of these morphological differences, lower incidence of acetic acid rot. Principal component analysis clearly differentiated the three treatments, and showed that biodynamic management had more pronounced effects than organic management in terms of enhanced soil fertility and reduction of vegetative growth. Conclusions: In the present study, organic and especially biodynamic management resulted in a morphology favouring production of high-quality grapes. The treatments differed in terms of fertilization and plant protection methods as well as choice of cover crops. Therefore, further research is necessary with respect to root growth and the nitrogen and water uptake dynamics of vines and cover crops. The differences between grapes produced under organic and biodynamic management emphasize the need for more research on the mode of action of biodynamic preparations. Significance and C

February 2020 Technical Review No. 244 25 L impact of the study: In recent years, both winegrowers and consumers have expressed steadily growing interest in organic and especially biodynamic wine production. The present study contributes to a better understanding of the effects on grapevine growth and morphological development of shifting to these methods as a way to increase product quality.

Full text available online at http://doi.org/dgw7

244.50 Mick, H. Simonit and Sirch: challenging conventional pruning methods to improve vine health. Australian & New Zealand Grapegrower & Winemaker 669, 40–43; 2019.

More workshops on the Simonit and Sirch pruning technique were held in Australia this season, surprising and inspiring further vineyard operators to adopt the modified Pousset method.

© Reprinted with permission Mick, H. Simonit and Sirch: challenging conventional pruning methods to improve vine health. Australian & New Zealand Grapegrower & Winemaker 669, 40–43; 2019. Copyright 2019 Winetitles Media Pty Ltd.

244.51 Parr, B., Legg, M. An automated grape yield estimation system. New Zealand Winegrower 113, 76–77; 2019.

Accurate yield estimation is essential for optimal vineyard and winery management. Vineyards often have contractual requirements to wineries to produce a predetermined yield and quality of fruit. Full text available online at https://bit.ly/2DBu2V9

© Reprinted with permission Parr, B., Legg, M. An automated grape yield estimation system. New Zealand Winegrower 113, 76–77; 2019. Copyright 2019 New Zealand Winegrowers Inc. and New Zealand Winegrowers Research Centre Ltd.

244.52 Schmidt, J. Cover crops: benefits for vineyards beyond enhanced biodiversity. Das Deutsche Weinmagazin 21, 30–31; 2019.

[German] Abstract not available for reproduction

244.53 Smart, R. Making organic vineyards sustainable – the novel Amisfield approach. New Zealand Winegrower 113, 52–54; 2019.

A new approach to viticulture has been developed in Amisfield in Central Otago, which can improve the sustainability of drip-irrigated organic vineyards worldwide. In fact, these techniques

26 Technical Review No. 244 February 2020 will likely also find application in sustainable and conventional vineyards as well, as they are based on current concepts of economically sustainable production. These ideas are quite novel, hence the title inferences about sustainability, normally considered an alternative to organic production. But this new approach at Amisfield does lead to better vineyard economics within a more sustainable environment.

Full text available online at https://bit.ly/2DBu2V9

Pests and diseases

244.54 Bleyer, K. Fighting phylloxera in a Pinot Noir vineyard with imidacloprid (‘Confidor’) and spirotetramat (‘Movento’). Das Deutsche Weinmagazin 18, 32–33; 2019.

[German] Abstract not available for reproduction

244.55 Brito, V., Achimón, F., Peschiutta, M., Borau, G.D., Zygadlo, J. Botanical products for vine mealybug control in organic vineyards. Wine & Viticulture Journal 34(4), 30–34; 2019.

While vine mealybug has not been recorded in Australia, it is a principal pest of vineyards in many parts of the world including Argentina, Brazil, California and South Africa. As a safer, more organically friendly alternative to synthetic insecticides in controlling vine mealybug, researchers from Argentina have been exploring the potential of bioactive products derived from plants.

© Reproduced with permission Brito, V., Achimón, F., Peschiutta, M., Borau, G.D., Zygadlo, J. Botanical products for vine mealybug control in organic vineyards. Wine & Viticulture Journal 34(4), 30–34; 2019. Copyright 2019 Winetitles Media Pty Ltd.

244.56 Casanova-Gascón, J., Ferrer-Martín, C., Bernad-Eustaquio, A., Elbaile-Mur, A., Ayuso-Rodríguez, J.M., Torres-Sánchez, S., Jarne-Casasús, A., Martín-Ramos, P. Behavior of vine varieties resistant to fungal diseases in the Somontano region. Agronomy 9(11):738; 2019.

The vine is highly susceptible to numerous fungal diseases, the incidence and severity of which are increasing because of climate change. To fight them, large amounts of phytosanitary products are generally used, although they entail important economic and environmental costs. The new fungus resistant vine varieties (PIWI) constitute one of the most active lines of research on plant material in viticulture and are regarded as a viable solution to respond to the requirements of European Directive 2009/128/EC. In the present work, the evolution and impact of the three main fungal diseases (powdery mildew, downy mildew and botrytis bunch rot) were monitored in plots in the Somontano region (Huesca, Spain), comparing three PIWI varieties (Sauvignon Kretos, Souvignier Gris and Muscaris) with a susceptible control variety (Sauvignon Blanc) in real field growing conditions over three successive years (2016–2018). The main ampelographic characters C

February 2020 Technical Review No. 244 27 L of each variety were studied and a weekly follow-up was carried out to track the development of each disease, relating it to climatic variables. Regardless of the climatic conditions (one of the growing seasons was rainy and the other two corresponded to dry years, with differences in the distribution of rainfall), the three PIWI varieties hardly presented any symptoms, demonstrating a high resistance to downy mildew and powdery mildew and even to Botrytis. Principal component analysis results pointed to a differential behavior versus the control and treated Sauvignon Blanc plants in terms of disease resistance. Based on production results, despite the youth of the plantation, the excellent potential of Sauvignon Kretos variety was observed. However, from the analysis of the quality of wine obtained in microvinifications from these fungus resistant varieties in the second and third year, the one obtained from Muscaris seemed to have the best organoleptic properties. Apart from environmental considerations, given that these fungus resistant varieties can significantly contribute to the sustainability of wineries, they may also respond to the demand of consumers who want zero-pesticide products or of the supporters of ecological products adjusted to European regulations.

Full text available online at http://doi.org/dgws

244.57 Elliott, C. Lessons from the USA to help Australia prepare for Xylella. Wine & Viticulture Journal 34(4), 10; 2019.

For Australia’s plant-based agricultural industries, there is no bigger threat than bacteria Xylella fastidiosa (Xylella), which causes Pierce’s Disease in grapevines and a range of other diseases in other plants. While Australia is currently free from Xylella, it is rapidly spreading around the world with catastrophic consequences; infecting more than 200 million citrus trees in Brazil, seeing the destruction of over 1 million olive trees in Italy and causing annual losses in excess of US$100 million for the Californian grape sector.

244.58 Nicholson, T. The insidiousness of trunk disease. New Zealand Winegrower 117, 38–40; 2019.

Ignore trunk disease at your peril, is the message that came from Mark Sosnowski at the recent NZW Grape Days. With the stats to back his assertion up, he highlighted how quickly a few diseased vines can turn into economic disaster if nothing is done.

Full text available online at https://bit.ly/34EPWTf

28 Technical Review No. 244 February 2020 244.59 Sosnowski, M., Mundy, D. Prevalence of grapevine trunk disease in New Zealand – observations from vineyard surveys. New Zealand Winegrower 117, 116–121; 2019.

Eutypa and botryosphaeria dieback (ED and BD) are major grapevine trunk diseases (GTD) worldwide, causing significant yield and quality reduction. They threaten the sustainability of the New Zealand wine industry, with total exports valued at $1.7 billion, and are becoming more prevalent as vineyards age. Trunk pathogens infect vines through pruning wounds, colonise woody tissue and cause dieback of cordons and trunks, observed as dark wedge-shaped tissue in cross- section. The Eutypa lata fungus produces toxic metabolites which are translocated to the foliage, causing stunted shoots, necrotic and distorted leaves, reduced bunch size and uneven ripening.

Full text available online at https://bit.ly/34EPWTf

© Reprinted with permission Sosnowski, M., Mundy, D. Prevalence of grapevine trunk disease in New Zealand – observations from vineyard surveys. New Zealand Winegrower 117, 116–121; 2019. Copyright 2019 New Zealand Winegrowers Inc. and New Zealand Winegrowers Research Centre Ltd.

244.60 Sosnowski, M., Mundy, D., van Zijll de Jong, E. Grapevine trunk disease research update. New Zealand Winegrower 115, 79–80; 2019.

Current research aims to optimise pruning wound protection strategies by determining the duration of susceptibility of pruning wounds, validating the curative and preventative properties of fungicides, and monitoring disease progress and spore inoculum in vineyards.

Full text available online at https://bit.ly/33EEoOt

© Reprinted with permission Sosnowski, M., Mundy, D., van Zijll de Jong, E. Grapevine trunk disease research update. New Zealand Winegrower 115, 79–80; 2019. Copyright 2019 New Zealand Winegrowers Inc. and New Zealand Winegrowers Research Centre Ltd.

244.61 Vinehealth. Xylella: the front line. Australian & New Zealand Grapegrower & Winemaker 670, 41–44; 2019.

As Xylella continues to plague horticultural sectors overseas, work is under way in Australia to prepare for what many fear could be its inevitable arrival.

February 2020 Technical Review No. 244 29 L Vine improvement and varieties

244.62 Dunlevy, J., Blackmore, D., Edwards, E., Walker, R., Berger, B., Walker, M. Developing a smart, rapid screening method for desirable grapevine rootstock traits. Wine & Viticulture Journal 34(4), 55–57; 2019.

The CSIRO rootstock breeding program is trialling the Australian Plant Phenomics Facility’s Plant Accelerator®, a state-of-the-art facility designed to quantify the growth and water use of a large number of plants on a daily basis. We are utilising the phenotyping capacity of the Plant Accelerator as a pre-screening tool to assess new selections for their tolerance to abiotic stresses including salinity. It is anticipated that this rapid screening tool will allow the quick and cost- effective identification of new stress tolerant rootstock genotypes, which will reduce the number of plants in field-grown trials. This represents a positive step forward in our attempts to help future proof the Australian wine industry in the face of unfavourable climate change scenarios.

© Reprinted with permission Dunlevy, J., Blackmore, D., Edwards, E., Walker, R., Berger, B., Walker, M. Developing a smart, rapid screening method for desirable grapevine rootstock traits. Wine & Viticulture Journal 34(4), 55–57; 2019. Copyright 2019 Winetitles Media Pty Ltd.

244.63 Freeman, B. Corvina thrives in the NSW Hilltops. Wine & Viticulture Journal 34(4), 58–59; 2019.

Australia’s only true expression of Amarone comes from a family vineyard established in 1999 from just six cuttings of each variety by Dr Brian Freeman. Formerly Professor of Wine Science at Charles Sturt University, Brian talks about the progress of his unique Australian wine venture that is now 17 vintages old.

244.64 Howlett, R. Behind the top drops: Cloudy Bay Sauvignon Blanc. Australian & New Zealand Grapegrower & Winemaker 669, 70–73; 2019.

This year marks the 35th vintage of Cloudy Bay Sauvignon Blanc - Marlborough’s most renowned Sauvignon Blanc. Established in the mid-1980s by David Hohnen of Cape Mentelle in Western Australia, Cloudy Bay immediately launched its first Sauvignon Blanc which today is still widely regarded as the benchmark for Marlborough. The author caught up with Cloudy Bay’s technical director Jim White to find out more about this iconic New Zealand white.

30 Technical Review No. 244 February 2020 244.65 Logan, S. Making marvellous Malbec. Wine & Viticulture Journal 34(4), 66–68; 2019.

Australian Malbecs were the focus of this issue’s tasting. It was the first time these wines had featured in a Wine & Viticulture Journal tasting, with tasting panellists judging wines with fruit sourced from Langhorne Creek, McLaren Vale and Kangaroo Island as their top three. In this report Malbec producers reveal what goes into making them.

244.66 Logan, S. Diverse and complex Australian Malbec. Wine & Viticulture Journal 34(4), 69–76; 2019.

Far from being an alternative variety on the sidelines of Australian winemaking, it seems that Malbec is growing in both popularity and stature. In this tasting report panellists were offered a broad selection of Malbec wines that showed just how diverse and complex the variety has become. Not only were there wines representing almost every state but interpretations of the wine, and approaches to producing it, also varied widely. Interestingly, versions of the wine came from both cooler and warmer regions, indicating the variety’s newfound appeal among more adventurous winemakers across the country.

244.67 Morris, M. Stars of the South. Decanter 45(2), 20–30; 2019.

With its plethora of native and local grape varieties and an increasing number of skilled and dedicated winemakers, Southern Italy’s wine future is looking bright. This article showcases some of its leading lights.

244.68 Tapia, P. The new Carménère. Decanter 45(1), 68–75; 2019.

Armed with a better understanding of how to get the best out of the variety, Chilean winemakers have created a fresher, fruitier style of Carménère.

February 2020 Technical Review No. 244 31 L 244.69 Williams, D. Beyond the sea. Decanter Spain, 36–40; 2019.

Look past the Spanish mainland, to the Canaries and Balearics, and you’ll find a wide range of wines in diverse styles, many made from fascinating local grape varieties.

244.70 Wine Australia. Elite phylloxera and root knot nematode breeding lines ‘in the pipeline’. R&D at Work October, 1; 2019.

Abstract available online at https://bit.ly/38ctBif

Water and nutrition

244.71 Heßdörfer, D. Irrigation management during extended drought: a comparison of dry grown vines with moderate and early season irrigation. Das Deutsche Weinmagazin 22, 29–31; 2019.

[German] Abstract not available for reproduction

244.72 Pagay, V., Kidman, C.M. Evaluating remotely-sensed grapevine (Vitis vinifera L.) water stress responses across a viticultural region. Agronomy 9(11):682; 2019.

The evolving spatial and temporal knowledge about vineyard performance through the use of remote sensing offers new perspectives for vine water status studies. This paper describes the application of aerial thermal imaging to evaluate vine water status to improve irrigation scheduling decisions, water use efficiency, and overall winegrape quality in the Coonawarra viticultural region of South Australia. Airborne infrared images were acquired during the 2016 and 2017 growing seasons in the region of Coonawarra, South Australia. Several thermal indices of crop water status

(CWSI, Ig, (Tc-Ta)) were calculated that correlated with conventional soil and vine water status measures (Ψpd, Ψs, gs). CWSI and Ig could discriminate between the two cultivars used in this study, Cabernet Sauvignon (CAS) and Shiraz (SHI), as did the conventional water stress measures. The relationship between conventional vine water status measures appeared stronger with CWSI in the warmer and drier season (2016) compared to the cooler and wetter season (2017), where Ig and (Tc-Ta) showed stronger correlations. The study identified CWSI, Ig and (Tc-Ta) to be reliable indicators of vine water status under a variety of environmental conditions. This is the first study to report on high resolution vine water status at a regional scale in Australia using a combination

32 Technical Review No. 244 February 2020 of remote and direct sensing methods. This methodology is promising for aerial surveillance of vine water status across multiple blocks and cultivars to inform irrigation scheduling.

Full text available online at http://doi.org/dgwt

244.73 Rienth, M., Scholasch, T. State-of-the-art of tools and methods to assess vine water status. OENO one 53(4), 619–637; 2019.

Rising global air temperatures will lead to an increased evapotranspiration and altered precipitation pattern. In many regions this may result in a negative water balance during the vegetative cycle, which can augment the risk of drought and will require mitigation strategies. These strategies, ultimately, will mean the installation of irrigation systems in some winegrowing regions where vines were cultivated historically under rain-fed conditions and growers do not have many years of experience with vine water management. This review aims to provide a state-of-the-art summary of the recent and most important literature on vine water assessment for monitoring and adapting vineyard management strategies to production goals in view of global warming. Plant, soil and atmospheric methods are reviewed, and their advantages and drawbacks are discussed. Recent advances in plant water status measurement reveal the limitation of traditional techniques such as water potential, particularly in the context of drought and high vapor pressure deficit and the discoveries regarding hydraulic and stomatal regulation. New technologies can integrate heterogeneous sources of information collected in the vineyard at different spatial and temporal resolutions. Such new approaches offer new synergies to overcome limitations inherent to plant water status measurement techniques obtained directly or indirectly from proxy measurements.

Full text available online at http://doi.org/dgw8

February 2020 Technical Review No. 244 33 L AWRI publications

2118 Romanini, E., McRae, J.M, Colangelo, D., Lambri, M. First trials to assess the feasibility of grape seed powder (GSP) as a novel and sustainable bentonite alternative. Food Chemistry 305:125484; 2019.

Grape pathogenesis-related proteins can cause haze in wine that is undesirable for consumers. Bentonite is used to remove these proteins but is a non-renewable natural material and reduces wine volume due to poor settling. As a potential bentonite alternative, grape seeds powder (GSP) was added to four wines and two grape juice varieties. Addition to wine required high doses (25–32 g/L) for protein removal and haze prevention and this induced changes to wine composition. By contrast, addition to grape juice prior to fermentation required substantially lower doses of GSP (5 g/L) to prevent haze formation. Further 20 g/L of GSP added to the must induced less changes to wine composition than direct addition of GSP to the wine. No changes were recorded in the efficacy of protein removal by changing the GSP source (red or white grape marc), or by using grape seed roasting. Despite the need for additional trials, these preliminary results suggest that GSP may be considered as a viable alternative to bentonite especially when added to juice prior to fermentation.

Abstract available online at http://doi.org/ddnw

© Reprinted with permission Romanini, E., McRae, J.M, Colangelo, D., Lambri, M. First trials to assess the feasibility of grape seed powder (GSP) as a novel and sustainable bentonite alternative. Food Chemistry 305, 1–8; 2019. Copyright 2019 Elsevier.

2119 Longbottom, M. Ask the AWRI: Sustainable Winegrowing Australia. Supporting the nation’s growers and winemakers in demonstrating and improving their sustainability. Australian & New Zealand Grapegrower & Winemaker 670, 45–46; 2019.

The Australian wine industry’s unified sustainability program, Sustainable Winegrowing Australia, was launched in July 2019. This article addresses some of the most common questions about the program.

© Reprinted with permission Longbottom, M. Ask the AWRI: Sustainable Winegrowing Australia. Supporting the nation’s growers and winemakers in demonstrating and improving their sustainability. Australian & New Zealand Grapegrower & Winemaker 670, 45–46; 2019. Copyright 2019 Winetitles Media Pty Ltd.

34 Technical Review No. 244 February 2020 2120 Scrimgeour, N., Wilkes, E., Bartowsky, E. Making sense of yeast assimilable nitrogen (YAN). Australian & New Zealand Grapegrower & Winemaker 670, 47–50; 2019.

Yeast assimilable nitrogen provides an indication of the nitrogen status of fruit, must or juice. Low YAN levels can directly affect yeast vitality and ferment dynamics and increase the risk of sluggish or stuck ferments. The free alpha-amino nitrogen (FAN) component of YAN is a direct measure of the concentration of organic nitrogen which can be utilised by yeast for cell growth and metabolism of secondary metabolites which influence wine aroma and flavour. The authors explain that it is important to understand both FAN and YAN levels, especially when using targeted organic and complex nutrient supplements, so that desirable fermentation outcomes can be achieved.

© Reprinted with permission Scrimgeour, N., Wilkes, E., Bartowsky, E. Making sense of yeast assimilable nitrogen (YAN). Australian & New Zealand Grapegrower & Winemaker 670, 47–50; 2019. Copyright 2019 Winetitles Media Pty Ltd.

2121 Wilkes, E., Wheal, M. Elements of wine. Chemistry in Australia November/December, 37; 2019.

Nearly every known naturally occurring element has been found in at least some wines, at concentrations ranging from parts per trillion for some of the rarer elements, through to hundreds of grams per litre for oxygen. This article presents a periodic table highlighting the typical concentrations found in wine for each element. Ranges shown are averages across a wide selection of wines; any given wine may not contain all elements indicated.

Full text available online at https://bit.ly/2PbBxZw

2122 Pearson, W., Schmidtke, L., Francis, I.L., Blackmank J.W. An investigation of the Pivot© Profile sensory analysis method using wine experts: comparison with descriptive analysis and results from two expert panels. Food Quality & Preference DOI: 10.1016/j.foodqual.2019.103858, 1–27; 2019.

The performance of the recently developed rapid sensory descriptive method Pivot© Profile (PP) was assessed with a set of 17 Shiraz/Syrah red wines using a group of 49 sommeliers and 11 winemakers. The PP results were compared to results from descriptive analysis (DA) performed by a trained panel. The PP from the two groups of experts gave similar sample configurations, although the terms used differed, with one notable difference being less detailed information on wine colour provided by the sommeliers. The data showed that the PP results from the two panels were also closely equivalent to that obtained from descriptive analysis, with similar sample space configurations, relatively high RV coefficient values and comparable attributes discriminating the samples. PP allowed interpretation of complex terms used by the two groups of experts, and gave insight into the major sensory differences discriminating the wines. DA provided better C

February 2020 Technical Review No. 244 35 L information regarding attributes that differed more subtly among the sample set, including bitterness. This study demonstrated for the first time that PP and DA provide similar insights into the sensory properties of products, confirmed that PP with expert panellists allows a rapid understanding of the main sensory differences among samples, with some advantages over DA in obtaining a more holistic overview of each sample.

Abstract available online at https://doi.org/10.1016/j.foodqual.2019.103858

© Reprinted with permission Pearson, W., Schmidtke, L., Francis, I.L., Blackmank J.W. An investigation of the Pivot© Profile sensory analysis method using wine experts: comparison with descriptive analysis and results from two expert panels. Food Quality & Preference DOI: 10.1016/j.foodqual.2019.103858, 1–27; 2019. Copyright 2019 Elsevier Science.

2123 Hirlam, K., Scrimgeour, N., Wilkes, E. The impact of temperature fluctuations on closure performance. Australian & New Zealand Grapegrower & Winemaker 671, 59–61; 2019.

The authors report on the results of a recent trial that investigated the impact of storage orientation and temperature cycling on the oxygen transmission rate of four commercial closures.

© Reprinted with permission Hirlam, K., Scrimgeour, N., Wilkes, E. The impact of temperature fluctuations on closure performance. Australian & New Zealand Grapegrower & Winemaker 671, 59–61; 2019. Copyright 2019 Winetitles Media Pty Ltd.

2124 Godden, P. Ask the AWRI: grape solids in white winemaking. Australian & New Zealand Grapegrower & Winemaker 671, 73–74; 2019.

Since 2016, the Australian Wine Research Institute (AWRI) has made a series of wines from single batches of grapes, changing one variable in each fermentation, with the resulting wines being presented to winemakers in workshops around Australia. In 2019, the trial was conducted with Chardonnay. The author covers key questions on grape solids in white winemaking and is the first in a series that will examine winemaking variables included in the 2019 trial that have a significant influence on Chardonnay wine style.

2125 Johnson, D. 2019 Report. Australian & New Zealand Grapegrower & Winemaker 671, 1–4; 2019.

The recent positive trajectory for the Australian grape and wine community has continued in the past year. Wine exports and grape prices are continuing to increase, with China the stand-out market. Challenges are, however, ever present. The place of alcohol in society and the terms of trade among industry participants continue to attract external scrutiny. Water access, climate variability, regulatory changes and biosecurity threats are among the issues that are keeping growers and winemakers up at night. As our industry works towards a new long-term strategy, the need for

36 Technical Review No. 244 February 2020 innovation – both collectively and within individual companies – is paramount. The AWRI provides the technical support base that is essential for such innovation and the prosperity that it delivers.

2126 Watson, F.T., Smernik, R.J., Doolette, A.L. Thermal degradation of phytate produces all four possible inositol pentakiphosphates as determined by ion chromatography and 1H and 31P NMR spectroscopy. Phosphorus, Sulfur, and Silicon, and the Related Elements 194(12), 1140–1148; 2019.

Decomposition of phytate has recently been shown to occur under mild conditions in the solid state, giving rise to a complex mixture of lower inositol phosphates. In this study, the reaction products of this thermal, abiotic degradation of phytate were separated using ion chromatography and the most highly phosphorylated products subsequently identified using 1D and 2D NMR spectroscopy. Two late eluting fractions were each shown to be a mixture of two specific inositol pentakisphosphate isomers. The peak with shorter retention time contained Ins(1,2,3,4,6)P5 and

DL-Ins(1,2,3,4,5)P5, while the later eluting fraction contained Ins(1,3,4,5,6)P5 and DL-Ins(1,2,4,5,6)

P5. The formation of all four possible inositol pentakisphosphate isomers by thermal degradation of phytate contrasts with the selective production of unique inositol pentakisphosphate isomers during enzymatic phytate degradation and therefore suggests a method for differentiating abiotic and biotic processes in environmental samples, including soils and decomposing plant biomass.

Abstract available online at http://doi.org/dgt8

© Reprinted with permission Watson, F.T., Smernik, R.J., Doolette, A.L. Thermal degradation of phytate produces all four possible inositol pentakiphosphates as determined by ion chromatography and 1H and 31P NMR spectroscopy. Phosphorus, Sulfur, and Silicon, and the Related Elements 194(12), 1140–1148; 2019. Copyright 2019 Taylor & Francis.

2127 Luo, M., Li, H., Chakraborty, S., Morbitzer, R., Rinaldo, A., Upadhyaya, N., Bhatt, D., Louis, S., Richardson, T., Lahaye, T., Ayliffe, M. Efficient TALEN-mediated gene editing in wheat. Plant Biotechnology Journal 17(11), 2026–2028; 2019.

Plant genome editing is a major advance in the production of novel plant genotypes. There is, however, only a single previous report of applying this technology to hexaploid wheat using TALEN-mediated gene editing to produce heritable modifications. This editorial describes highly efficient TALEN editing of a uidA transgene and a second endogenous gene, lr21Ψ, in bread wheat with efficiencies exceeding most previous TALEN and CRISPR/Cas9 reports in this species.

Full text available online at http://doi.org/dgt9

Copyright © 2019 by the authors. This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited. C

February 2020 Technical Review No. 244 37 L 2128 Robinson, S.P., Pezhmanmehr, M., Speirs, J., McDavid, D.A.J., Hooper, L.C., Rinaldo, A.R., Bogs, J., Ebadi, A., Walker, A.R. Grape and wine flavonoid composition in transgenic grapevines with altered expression of flavonoid hydroxylase genes. Australian Journal of Grape and Wine Research 25(3), 293–306; 2019.

Background and Aims: Grape flavonoids impart colour and mouthfeel to wines. This work aimed to understand how genetic manipulation of the hydroxylation of flavonoids affected grape flavonoid composition and wine properties. Methods and Results: We produced transgenic grapevines with decreased expression of flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′5′-hydroxylase (F3′5′H) to investigate how this altered the composition of flavonoids in grapes and wine. Grapes from transgenic grapevines with decreased expression of F3′5′H genes had a concentration of anthocyanin and skin tannin similar to that of Shiraz Controls but had increased seed tannin and a greatly decreased proportion of trihydroxylated anthocyanin and tannin. Lines with decreased expression of F3′H had a decreased concentration of seed tannin and an increased proportion of trihydroxylated flavonoids. When expression of both F3′H and F3′5′H was decreased, concentration of anthocyanin and tannin in the grapes was decreased to 20–30% of the Shiraz Controls. Wines made from grapes with decreased expression of F3′5′H had lower wine colour, and a lower concentration of anthocyanin, tannin and phenolic substances. Conclusions: In grapes, the flavonoid pathway does not effectively use monohydroxylated intermediates so F3′H and F3′5′H are required to produce dihydroxylated and trihydroxylated intermediates. The hydroxylation status of flavonoids in grapes determines grape and wine colour and tannin composition. Significance of the Study: The composition as well as the total amount of anthocyanin and tannin in grapes is important for wine colour and quality. The expression of genes encoding F3′H and F3′5′H in grapes is dependent on viticultural factors including temperature, light exposure and vine water stress, providing the potential to manipulate flavonoid composition of existing cultivars in the vineyard.

Abstract available online at http://doi.org/dgvb

© Reprinted with permission Robinson, S.P., Pezhmanmehr, M., Speirs, J., McDavid, D.A.J., Hooper, L.C., Rinaldo, A.R., Bogs, J., Ebadi, A., Walker, A.R. Grape and wine flavonoid composition in transgenic grapevines with altered expression of flavonoid hydroxylase genes. Australian Journal of Grape and Wine Research 25(3), 293–306; 2019. Copyright 2019 Australian Society of Viticulture and Oenology.

38 Technical Review No. 244 February 2020 AWRI events calendar

May 2020 18–21 May — Advanced Wine Assessment Course (AWAC 51), The Australian Wine Research Institute (WIC Building), Urrbrae SA

25–28 May — Advanced Wine Assessment Course (AWAC 52), The Australian Wine Research Institute (WIC Building), Urrbrae SA

* Details subject to change without notice. Please visit the AWRI website to view the current copy of this calendar at https://www.awri.com.au/industry_support/courses-seminars-workshops/events. All information was accurate at time of compilation.

February 2020 Technical Review No. 244 39 Technical Review is published bimonthly by The Australian Wine Research Institute. It is available free of charge to Australian grape and wine sector members paying a levy under the Wine Grapes Levy Act, however, other interested organisations and individuals may subscribe to Technical Review.

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40 Technical Review No. 244 February 2020