Viticulture and Enology Extension News Washington State University

Spring 2014

CONTENTS Note from the Editor Spring is finally here! Irrigation is set for full allotment this summer, buds are swelling, vines are bleeding, and the inevitable vineyard-tripping-due-to-badger-holes has com- VITICULTURE menced. It is good to shake off that winter dormancy. Quarantines...... Page 2 This issue of VEEN is an eclectic mix of rules and research, theory and practice. Washing- ton’s grape quarantines are explained, and a highlight of how the Clean Plant Center - Fruit-Zone Leaf Removal...... Page 3 Northwest is keeping our Foundation Grapes clean is presented. Canopy management and mite resistance management research by two recent graduates are discussed, as 2013 Weather Review...... Page 6 well as ground-breaking information on how “native” yeasts can be put to good use in the vineyard. Weather from 2013 is explained, and questions on irrigating different Indigenous Yeasts...... Page 7 soils are answered. We also have part one of a two-part series on fruit and wine acidity. Mites ...... Page 8 Click print, or download to your smart device and begin reading---just watch out for Virus Detection...... Page 9 those badger holes! Irrigation Mgmt...... Page 11 Michelle Moyer Viticulture Extension Specialist WSU-IAREC

ENOLOGY High pH / High TA...... Page 12

OTHER NEWS Find us on the web: Extension Publications...... Page 14 www.wine.wsu.edu/research-extension Calendar of Events ...... Page 14 Information when you need it. That is the power of the internet! Visit the WSU Viticulture and Enology Research and Extension website for valuable information regarding research programs at WSU, timely news releases on topics that are important to your business, as well as information regarding upcoming workshops Editor and meetings. Michelle M. Moyer, PhD It is also a valuable site for downloading our most recent Extension publications, in addition to archived articles and newsletters you can print on demand. Find quick WSU Extension programs and em- links to AgWeatherNet, the Viticulture and Enology Degree and Certificate programs, ployment are available to all without as well as to other Viticulture and Enology related resources. discrimination. Evidence of noncompli- Find us on Facebook ance may be reported through your local WSU Extension office. Go to: www.facebook.com/WSU.Vit.Enol.Ext and “Like” the page!

1 Understanding WA Grapevine Quarantines By Michelle Moyer, WSU-IAREC Washington has several unique factors that truly make it the perfect climate Quarantine Information for wine. Low rainfall east of the Cascades allows growers to control Information on plant quarantines can be found at the Washington State De- water; variable growing season lengths partment of Agriculture’s website : and heat accumulation across the state allow for the production of nearly every http://agr.wa.gov/PlantsInsects/PlantQuarantines/PlantQuarantines.aspx kind of variety and wine style. One of the biggest advantages to commercial grape production in Washington, these quarantines is simple: don’t bring a Washington-recognized certification however, is the relatively low disease in infested or diseased plant material program. The “certified” stamp and pest pressure. from out of the state/country. indicates that the original source plant material came from a grape Foundation Lack of established phylloxera Specifically, Washington has twoProgram (has been “cleaned up” of populations allows Washington quarantines in place for grapes. The potential diseases) and was propagated producers to grow Vitis vinifera on its first quarantine (WAC-16-481) is and grown at a certified nursery that own roots; a substantial advantage in directed at reducing the introduction met strict standards in routine testing regions where cold damage is a threat. of insect pests, specifically phylloxera of the plant material and vineyard The lack of native grape species reduces (Daktulosphaira vitifoliae) and vine maintenance to maintain the disease- the likelihood of field-infection of the mealybug (Planococcus ficus). The free status of the plant materials. Crown Gall bacterium (Agrobacterium second quarantine (WAC-16-483) is Washington currently only recognizes vitis). The warm, dry growing season directed at reducing the introduction certification programs from California, conditions in eastern Washington of three different virus diseases: Oregon, Canada, and of course, itself. make it the envy of other regions; Fanleaf, Leafroll, and Corky Bark. Interestingly, the nursery certification these conditions allow for substantially These quarantines require grapevine program in Washington tests for and reduced spray programs for powdery materials from outside of the state to excludes the viruses that cause Stem mildew and Botrytis bunch rot. Due show proof that they are free of these Pitting and Red Blotch diseases; the to these reduced pesticide inputs, pests and diseases before being allowed California certification program does Washington producers are able to into the state. This proof is typically a not. What this means is that certified sustain high populations of beneficial “phytosanitary certificate” issued by plant material from California that meet insects, which keep pest insects (mites, the state of origin’s plant regulatory Washington quarantine regulations, leafhoppers) at manageable levels. agency. may harbor these viruses since they are not specified in the Washington The best defense, however, in Under the insect quarantine, both quarantines. Washington’s pest and disease vineyard equipment and grapevine management routine is the relative materials are regulated. Equipment All out-of-state materials are subject to isolation of the state due to the originating from out of the state both quarantines. It is the purchaser’s bordering mountain ranges and ocean, must be thoroughly cleaned of soil responsibility to make sure all proper and lack of exposure to, and build up and debris before entering the state. notifications are made to the WSDA. of, other diseases due to the relatively Plant materials, however, must either: Most reputable, certified nurseries will young age of the industry. These (1) Be grown in an area that is free either do this documentation for you, factors have protected Washington of phylloxera and vine mealybug; (2) or help you with the process. This producers from a range of pests and Be grown in sterile media and pass a translates to: the only way to legally diseases that threaten the grape visual inspection that they are free of bring in grape material from outside industries around the world. The big the quarantine pests (if the shipment of Washington is if it is “certified” from question is, with the world becoming is small, <500 cuttings, the visual California, Oregon or Canada, and it an increasingly smaller place, how can inspection is the only requirement comes with a phytosanitary certificate Washington keep this “isolation” while needed), if they are from an area that showing it is pest free. expanding the industry? The answer: is not free of the quarantined pests; plant quarantines. or (3) Be subjected to one of two Think “clean” plants. Never plant different treatments that reduce or material from out of state, unless it In order to protect its large agricultural eliminate the quarantine pests. The was certified; it’s the law. Those vine industry, Washington has very strict different treatments that are approved cuttings collected while on a recent out- laws on what kinds of plant materials are: Dormant hot water treatment of of-state trip? They are illegal to bring can come into the state. These laws are cuttings or methyl bromide fumigation in, plant, or distribute in Washington. designed to prevent the introduction of dormant cuttings. Knowledge and experience from other of unwanted pests and diseases that regions can help continue to propel the could result in collapse of any one of Under the virus quarantine, the only Washington grape and wine industries our major crop systems. From a grape legal way grape materials can enter the forward, but not all legacies are worth standpoint, the general idea behind state is if they are “certified” through sharing.

2 Early Fruit-Zone Leaf Removal in Washington By Brittany Komm, Graduate Student, and Michelle Moyer, WSU-IAREC Early fruit-zone leaf removal (FZLR), the the canopy. The same exact of removing all or varying degrees perimental design was car- of all, the leaves within the fruiting zone ried out in 2012 and 2013; in winegrape canopies, has gained re- that is, the vines received search interest in recent years. Studies the same leaf removal done around the globe have focused treatments in both years. on how the timing and severity of FZLR impact vine growth and development, Impacts of FZLR on Vine and fruit quality. Many of these stud- Development and Yield. In ies have demonstrated that early FZLR 2013, total leaf area (TLA) can reduce fruit set, which is beneficial that was removed during in some situations where yields need to each FZLR treatment was be controlled but laws prohibit vine- evaluated. In Riesling, pre- yard activities. bloom, bloom and 4 weeks post-bloom FZLR resulted Figure 1- Water-sensitive cards post-chemical application Eastern WA’s unique climate offers in 60%, 50% and 22% during bloom in Riesling.’Cards were placed directly in the growers opportunities to optimize TLA removed, respectively. fruit-zone. At the time of assessment, only the pre-bloom and bloom treatments had undergone fruit-zone leaf re- both horticulture and pathology goals In Sauvignon blanc, pre- moval. Average coverage for both cultivars are indicated in in vineyard management. Can early bloom, bloom and 4 weeks the image. Photo by Brittany Komm. FZLR be implemented as a part of these post-bloom FZLR resulted goals in our climate? This question has in 53%, 35% and 18% TLA Clusters per shoot, was influenced by been investigated over two growing removed, respectively. early FZLR. Pre-bloom and bloom FZLR seasons (2012 and 2013) in commer- resulted in significantly more clusters cial blocks of V. vinifera ‘Sauvignon Total fruit set was also evaluated, and than later leaf removal or no leaf re- blanc’ and ‘Riesling’ located in Prosser, no significant reductions were seen moval in Riesling (p = 0.0005). This in- WA. between treatments in either year (p = crease in clusters per shoot is likely due 0.60, 0.05; Riesling 2012 and 2013, re- to increased bud surface temperatures How we evaluated early FZLR. In this spectively) (p = 0.67, 0.30; Sauvignon experienced in the 2012 growing sea- study, early FZLR was evaluated at: (i) blanc 2012 and 2013, respectively). son during the critical time of cluster pre-bloom (rachis elongation and in- In 2013, however although not sig- differentiation in buds. Increased bud dividual flowers separating), (ii) bloom nificantly different, Riesling pre-bloom exposure to sunlight along with in- (50% of the clusters had 50% of the and 4 weeks post-bloom leaf removal creased temperatures (86-95ºF) from flower caps removed), and (iii) 4 weeks had higher total fruit set relative to budbreak to bloom, promotes cluster post-bloom. Fruit-zone leaf removal bloom leaf removal (p = 0.06 and 0.09, over tendril formation for the following consisted of removing all leaves from respectively). Yield components, such growing season [1]. the second cluster down on all count as cluster and berry weights were not shoots in the canopy, on both sides of impacted by early FZLR. One of the key champions of early FZLR is improved disease management. Spray penetration was evaluated in 2013 at bloom and again at pre-véraison. During bloom, canopies that had undergone FZLR (i.e., the pre- bloom and bloom treatments) had significantly improved spray penetration (Fig. 1). In some cases, spray penetration doubled compared to canopies that had not undergone leaf removal. At véraison, there were no differences in spray penetration, although the 4 weeks post-bloom leaf-removed canopies trended towards higher spray penetration. This lack of difference at vérai- son shows that canopy refill can occur late in the season (Fig. 2).

Cold hardiness acclimation was tracked in both years of the study as well. Over- all, there were no differences between Figure 2- As the season progresses, the canopy in the fruit-zone can refill. This is an image in 2013 of Sauvignon blanc taken 2 days before harvest. Photo by Brittany Komm. continued on page 4

3 Fruit-Zone Leaf Removal, con’t continued from page 3 treatments for overall cold acclimation rates in both years of the study, indicat- ing that early FZLR does not detrimen- tally impact the various tracks that lead to cold hardiness.

Impact of early FZLR on Fruit Quality. The severity of disease and sunburn of fruit was evaluated in both years of the study. In 2012, no differences in Botrytis bunch rot severity were found in either cultivar at harvest. In 2013, no differences were seen at harvest in Riesling (Fig. 3). In Sauvignon blanc, however, pre-bloom leaf removal resulted in a significant reduction in Botrytis bunch rot relative to the control and 4 weeks post-bloom treatments (p = 0.02, 0.03, respectively, Tukey’s HSD) (Fig. 3). In both years of the study and in both cultivars, implementation of complete, early FZLR, regardless of timing, did not increase severity of sunburn.

Fruit juice was analyzed at harvest for differences in ºBrix, TA and pH (Table 1), but no differences between treatments were seen.

Juice nitrogen analysis was conducted both years of this study. In 2012, the Riesling control had a significantly higher free ammonia concentration relative to both the bloom and 4 weeks post-bloom treatments (p = 0.003, 0.0006, respectively, Tukey’s HSD); the pre-bloom treatment also had a significantly higher concentration relative to 4 weeks post-bloom (p = 0.02, Tukey’s HSD). No differences were seen in 2013. In 2012, both the control and pre-bloom treatments in Sauvignon blanc had a significantly higher concentration of free ammonia relative to the bloom and 4 weeks post- bloom treatments (p = 0.0002, and <0.0001,respectively Tukey’s HSD). In Figure 3- Vitis vinifera ‘Riesling’ Botrytis bunch rot severity ratings were conducted on 19 September 2012 and 16 September 2013 (top); ‘Sauvignon blanc’ ratings were conducted 2013, the 4 weeks post-bloom treat- on 6 September 2012 and 5 September 2013 (bottom). Significant differences were seen at ment had a significantly higher con- α=0.05 (Tukey HSD). Bars denote standard error. centration of free ammonia relative to the bloom treatment (p = 0.02; Tukey’s the bloom treatment (p = 0.04; Tukey’s HSD). In 2013, the pre-bloom treat- HSD). Even though significant differ- HSD). In addition, the pre-bloom treatment had significantly higher terpene ences were seen, all concentrations fell ment had significantly more acid vola- concentration relative to the control (p into the lower range of Washington’s tiles relative to the 4 weeks post-bloom = 0.02; Tukey’s HSD). When terpenes typical free ammonia levels. treatment (p = 0.03; Tukey’s HSD). were analyzed on specific compound, When aldehydes were analyzed on a the pre-bloom and 4 weeks post- Aromatic volatiles were analyzed in specific compound basis, the control bloom treatment had a significantly both years of this study. In 2012, alde- treatment had a significantly higher higher concentration of nerol oxide hydes were significantly higher in the concentration of hexanol relative to control treatment of Riesling relative to the bloom treatment (p = 0.03; Tukey’s continued on page 5

4 Fruit-Zone Leaf Removal, con’t continued from page 4 significantly improved during bloom, Table 1- No significant differences were seen in ˚Brix, TA or pH. Values in parentheses indicate standard error. Riesling analyses were conducted 7 days prior to commercial when critical preventive tactics are de- harvest. Sauvignon blanc analyses in 2012 were conducted 1 day prior to commercial ployed to prevent various diseases. harvest, and 2 days prior to commercial harvest in 2013. Leaf It appears that the hot and arid climate Removal °Brix TA (g/L) pH of eastern WA is conducive to imple- Treatment menting FZLR prior to or even during bloom, without seeing any negative Riesling side effects on vine development and 2012 2013 2012 2013 2012 2013 fruit quality. However, implementing FZLR prior to or during bloom would 19.83 21.88 10.37 6.91 2.91 3.24 Control have to be done manually. Current me- (0.50) (0.48) (0.89) (0.16) (0.05) (0.04) chanical leaf removal devices are not 19.58 22.28 9.71 6.43 2.88 3.29 engineered to be deployed this early in Pre-Bloom (0.23) (0.13) (0.44) (0.08) (0.07) (0.05) canopy and fruit development. How- ever, this earlier timing of FZLR may 19.98 21.45 9.21 7.17 2.91 3.2 Bloom coincide with vineyard activities such (0.13) (0.27) (0.38) (0.41) (0.06) (0.07) as shoot thinning. 4 Weeks Post- 19.55 20.93 9.19 7.09 2.95 3.09 Bloom (0.27) (0.45) (0.30) (0.37) (0.07) (0.02) References SAUVIGNON BLANC 2012 2013 2012 2013 2012 2013 1. Butrosse, M.S. 1970. Fruitfulness in grape-vines: the response of different Control 21.63 21.75 7.49 6.89 3.65 3.33 cultivars to light, temperature and day- (0.29) (0.60) (0.30) (0.33) (0.07) (0.03) length. Vitis. 9: p. 121-125. Pre-Bloom 21.85 21.88 7.16 6.45 3.57 3.32 (0.71) (1.41) (1.06) (0.34) (0.06) (0.05) 2. Ristic, R. et al. 2007. Exclusion of sunlight 21.58 22.75 7.63 6.99 3.57 3.29 from Shiraz grapes alters wine colour, Bloom (0.77) (0.53) (0.99) (0.10) (0.02) (0.03) tannin and sensory properties. Australian 4 Weeks Post- 21.43 20.98 6.83 6.74 3.56 3.27 Journal of Grape and Wine Research. 13 Bloom (0.58) (0.83) (0.44) (0.43) (0.06) (0.04) (2): p. 53-65. relative to the control (p = 0.01, 0.01; Skin and seed tannins and phenolics 3. Marais, J. 1983. Terpenes in the aroma of respectively, Tukey’s HSD). Significant were also analyzed. Statistically, skin grapes and wines: a review. South African differences in the compound α-ionone tannins and phenolics were lower in Journal of Enology and Viticulture. 4 (2): were also seen; the pre-bloom treat- the control treatment relative to all oth- p. 49-58. ment had a significantly higher con- er treatments. This was not a surprise, centration relative to both the bloom as past research has shown that when and control treatments (p = 0.003, clusters are shaded, total tannins and 0.05; respectively, Tukey’s HSD). The phenolics tend to be lower then sun- most prominent aromatic volatiles in exposed compared to fruit from vines Riesling are terpenes [3], suggesting where FZLR was implemented [2]. that early fruit-zone leaf removal may enhance this Riesling character. No sig- Early FZLR: Adoption in WA. Early FZLR nificant differences were seen between did not result in reduction in fruit set or treatments for aromatic volatiles in ei- increased sunburn, as past studies may ther year for Sauvignon blanc. have suggested. Spray penetration was Not Receiving WSU V&E Extension emails? Go to our website: http://irrigatedag.wsu.edu/subscribe-to-email-lists/

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5 2013: A Changeable (and Warm) Weather Year By Nic Loyd, WSU-AgWeatherNet

Although annual mean temperatures There were numer- 2013 Monthly Temperatures in Washington were only slightly above ous significant me- Prosser average, the 2013 weather was any- teorological events in 95 90 Tmaximum thing but normal. Below average tem- 2013. An early May 85 Average Tmax peratures in January and again from heat wave sent tem- 80 Taverage Average Tavg 75 October to December served to bal- peratures soaring into Tminimum 70 Average Tmin ance out a very warm interim period. the 90s across eastern F) o 65 Washington, while 60 Prosser, WA’s warm season (April to cool and wet weather 55 September) temperatures were 1.7 de- later in the month 50 kept high tempera- 45 grees above average, and 2.4 degrees ( Temperature 40 above average at night (Fig. 1). The tures at some of the 35 April 1 to October 31 accumulated same locations below 30 Growing Degree Day (GDD; ˚F) value 50˚F on 22 May. An- 25 other major heat wave 20 was 2851, 297 units above the 5-year 15 average (Table 1). In fact, Prosser ex- on 1 and 2 July sent April May June July temperatures east of March August perienced several notable monthly cli- January February October September NovemberDecember mate occurrences last year, including the Cascades soaring Month the warmest monthly mean high tem- into the 100s. Like perature on record for any month (July, its May predecessor, Central Washington 2013 Monthly Rainfall 92.1˚F), the warmest monthly mean the July hot spell was 2.00 the earliest heat wave low temperatures on record in August Prosser 1.75 and September, the warmest August of such magnitude Tri-Cities since 1992. Other- Walla Walla since 1991, and the second warmest 1.50 summer on record (1990 to present). wise, July was hot and By contrast, the December mean low dry, with record heat 1.25 temperature was 7.2 degrees below av- in the east and record erage. That is the largest (positive or dryness in the west. 1.00 negative) monthly temperature anom- August was unusually 0.75 aly since December 2009. humid, which aided Rainfall(Inches) in the development 0.50 of several episodes of The seasonal distribution of eventful 0.25 weather was also highly variable in thunderstorms. Sep- tember was warm 2013. Conditions were relatively be- 0.00 and stormy. On 15 April May June July nign during the normally active and March August JanuaryFebruary October September, a line of NovemberDecember wet months like January/February and September October to December (Fig. 1). Mean- strong thunderstorms 2013 while, most of the active weather oc- raged through central Washington, with 60 Figure 1- Temperature (top) and rainfall (bottom) records. Data curred during unlikely times, such as from http://weather.wsu.edu . August and September. It is notewor- mph winds and heavy thy that several west-side locations rain squalls. The high temperature of 101˚F heavy snow to the mountains, and like Vancouver and Seattle, which winds of over 70 mph to Huntsville. experienced more precipitation (P) at College Place was the latest occur- rence of a +100˚F temperature in the Finally, an early December arctic out- than evapotranspiration (ET) in 2012, break was responsible for some of the recorded net negative (P – ET) values history of AgWeatherNet. September ended with an epic 3-day storm that coldest temperatures since late No- in 2013. At Vancouver, (P – ET) was vember of 2010. Although the annual +7.53 in 2012, but -12.24 in 2013. dropped more than 5 inches of rain at East Olympia, while also bringing average conditions paint a dull picture, a closer inspection of last year reveals a diverse array of anomalous weather Table 1- Seasonal heat accumulation in selected eastern WA locations. events that combined to make 2013 a Accumulated Growing Degree Days* year to remember. Location 2013 5 Year Average Difference Further details about Washington’s Prosser 2851 2554 +297 weather and climate are available at (WSU-IAREC) AgWeatherNet: weather.wsu.edu. TriCities 3332 3097 +235 Send questions or suggestions to Nic Loyd, [email protected], or Gerrit Walla Walla 3046 2769 +277 Hoogenboom, gerrit.hoogenboom@ * Growing Degree Days are calculated from 1 April to 31 October using 50˚F as a base tempera- wsu.edu. ture.

6 Can Indigenous Yeasts Help Control Grapevine Diseases? By Leslie Holland and Elizabeth Kramer, Graduate Students; Dean Glawe, WSU-Pullman; and Gary Grove, WSU-IAREC

Each year grape growers and winemakers in Washington State and around Eutypa Dieback Survey the world contend with reductions in yield and quality caused by powdery Researchers in the WSU Plant mildew (caused by Erysiphe necator) Pathology department are con- and Botrytis bunch rot (caused by Botrytis cinerea). Proven management ducting a survey to determine strategies include the use of fungicides the distribution of Eutypa die- and managing canopy vigor. While ef- back in WA. fective, these activities are costly and fungicides can reduce populations of More information on the Eutypa beneficial vineyard organisms. New dieback symptoms that could be management strategies that maintain effective levels of disease control while present at your vineyard can be reducing production costs and the found in the Eutypa Dieback: Di- non-target effects of fungicides would agnostic Guide at http://www. benefit the industry. plantmanagementnetwork.org/ Figure 2- Growth of Botrytis cinerea with pub/php/diagnosticguide/die- In the search for alternative options yeasts. Examples of inhibition gap (left) and back/ for managing these diseases, research- no inhibition (right) In each Petri plate. Yeast ers at Washington State University are species: 1-Wickerhamomyces anomalus, studying the possible effectiveness of 2- Pseudozyma sp., 3- Metschnikowia pul- If you believe that you are seeing cherrima, and 4- Cryptococcus carnescens. naturally-occurring yeasts as biological symptoms of Eutypa dieback in control agents (Fig. 1). Scientists esti- your vineyard, and are interest- mate that there may be as many as 1.5 In laboratory tests several of these B. ed in participating in this study, cinerea-inhibiting yeast strains were million species of yeasts in the world; please contact Leslie Holland at: only 1% of which have been studied. insensitive to fungicides used in vine- Yeasts are ubiquitous—they can be yards, which raises interesting ques- [email protected] or found on plants, in soil, on machinery, tions for further research. For example, 937-768-2089. on and inside insects and other ani- would it be possible to apply one or mals, and in the air. more of these fungicide-resistant yeasts along with a fungicide in a tank mix? Over the past several years we and our Such a combination could provide coworkers have identified more than initial pathogen knock-down by the 60 species of yeasts occurring on grape fungicide as well as longer term sup- leaves or berries in Washington. Many pression of pathogens by the yeasts. of the species were unknown in North Alternatively, knowing more about the America, and several are new. biology of these yeasts could enable growers to manage vineyards in ways that enhance the biocontrol activity of Ten of these newly-isolated strains limit yeasts already present in vineyards. growth of B. cinerea in laboratory assays (Fig. 2) and now are being evaluated for reduction of Botrytis bunch We also have isolated a number of rot. yeasts from powdery mildew colonies on grape leaves. Leaves are the primary source of powdery mildew inoculum Figure 3- Powdery mildew (Erysiphe neca- (Fig. 3). While no research on interac- tor) infection on a White Riesling leaf. tions of yeasts and E. necator has been done previously in our region, researchers in other regions have found yeasts yeasts likely interact with foliar and that parasitize or suppress powdery fruit pathogens in ways that, if we can mildews. This year we will conduct learn to manage them, may offer new our first tests to determine if locally- tools for Washington grape growers occurring yeasts can reduce E. necator and winemakers in their quest to make growth or spore production. unique, highly-valued premium wines.

We are only beginning to understand the roles of these previously ignored Figure 1- Budding cells of the yeast, Crypto- fungi in Washington vineyards. Our coccus victoriae. results so far suggest that indigenous

7 Spider Mites and Acaricide Resistance in Vineyards By Tara Piraneo, former Graduate Student, and Douglas Walsh, WSU-IAREC

Wine grapes are periodically attacked of the field rate, one population experi- by a suite of arthropod pests, and dam- enced 95% mortality, and another was age from feeding or contamination of recorded at 98% mortality. Addition- fruit can result in economic loss. His- ally, vineyard field observations dem- torically, spider mites were damaging onstrated that Acramite was highly ef- in Washington State vineyards, but the fective at suppressing mite outbreaks. industry-wide shift away from applying organophosphates in the early 2000s These results directly contrasted with has resulted in an improved balance of spider mite populations from hop- natural enemies in our vineyards. As a yards, where we observed increased result, spider mite abundance has re- levels of tolerance of the two-spotted mained low over the past decade. spider mite to exposure to Acramite.

Unfortunately, in 2013 many Washing- Figure 2- Bronzing of leaves is a common symptom of spider mite infestations. Photo In a separate laboratory-based experi- ton State winegrape growers experi- by Tora Brooks. ment, populations of susceptible acari- enced outbreaks of Willamette spider cide spider mites were exposed to re- mite (Eotetranychus willamettei) and When spider mite infestations result peated doses of Acramite and Agri-mek McDaniel spider mite (Tetranychus mc- in visible plant injury (Fig. 2) growers (abamectin). In these studies, we con- danieli). Two-spotted spider mite (Tet- will often apply an acaricide to control cluded that spider mites could gradu- ranychus urticae; Fig. 1) was sometimes these outbreaks. Spider mites as pests ally increase tolerance to the acaricid- observed, but at lower population are well documented for rapidly devel- es. After a series of ten exposures of densities. We speculate that the hot oping resistance to the acaricides. Sum- Agri-mek and Acramite, spider mites summer in 2013 contributed to the mer 2013 provided us with an oppor- outbreak of spider mites. Outbreaks tunity to assess spider mite resistance are intensified by warmer tempera- levels in Washington State vineyards. tures and extreme diurnal fluctuations in humidity; conditions were prevalent in 2013. Increased temperatures up To monitor for acaricide resistance in to a threshold of ~95°F increases spi- Washington wine grapes, spider mites der mite development and mites can were collected from several vineyards mature from egg to adult in as little as that experienced outbreaks. We fo- 7-8 days. Fungicides, insecticides and cused specifically on the toxicity of Ac- fertilizers applied in the vineyard can ramite (bifenazate), as it is a commonly also disrupt the interactions between used acaricide in vineyards. The toxicity spider mites and their natural enemies. testing consisted of a leaf-disc bioassay, We speculate that the increase in insec- which is a frequently used method to ticides applied for grape mealybug in assess the susceptibility of spider mites Figure 3- Ten adult female mites are the past several years has contributed to various insecticides/ acaricides. transferred to each leaf disc. Spider mites to spider mite outbreaks. were then exposed to different concentra- In our studies, cohorts of 10 adult fe- tions of an acaricide to determine the level male spider mites were placed on leaf of resistance in that population. Photo by Tara Piraneo. discs (Fig. 3). The cohorts of spider mites placed on these leaf discs were exposed to a range of concentrations increased resistance by 27-fold and 14- of Acramite in a topical mist applica- fold, respectively. tion using a Potter Spray Tower. Mor- tality was evaluated at 24 hours post Conclusion. Caution should be taken spray application. This allowed for suf- when applying acaricides to control ficient exposure time to kill those mites spider mites. Our data suggests that susceptible to the acaricide at that repeated acaricide treatments in the concentration, and allowed those that vineyards could result in increased tol- were resistant to survive. erance by spider mites, thus making them harder to control. Fortunately, Results of the bioassays revealed high our data demonstrates that spider mortalities to Acramite, suggesting mites in vineyards are not currently re- Figure 1- Two-spotted spider mite (Tetrany- that spider mites in Washington vine- sistant to acaricides. However, we do chus urticae) immature and eggs on a leaf. yards are highly susceptible to this recommend the prudent and judicious Spider mites feed on leaves using special- acaricide. All the spider mites exposed use of acaricides in the future to pre- ized mouthparts, which deplete the plant of to the recommended field rate or 50% nutrients and chlorophyll (note the patchy vent the establishment of resistance. discoloration). Photo by Tora Brooks. of field rate of Acramite died. At 25%

8 Deep Sequencing: A New Strategy for Virus Detection By Dan E. Villamor, Gary Ballard, and Kenneth Eastwell, WSU-IAREC and Clean Plant Center Northwest

When a vine becomes infected by a Since these viruses are different than virus, it remains infected throughout 3. Biological assays: These tests are the viruses that are already being test- its lifetime. Unlike fungal and bacterial based on directly infecting specif- ed for, new protocols were needed in pathogens, which can often be con- ic herbaceous and woody plants, order to detect them. trolled by fungicides and bactericides, which are known to produce very chemicals effective in combating plant specific disease symptoms when The testing protocols for these DNA viruses have yet to be commercial- infected with virus-like agents. Ex- viruses were obtained from leading re- ized. For this reason, the use of virus- tracts from the grapevine source is searchers; all of the vines in the CPC- free planting materials (clean plants) used to inoculate four different her- NW Foundation vineyard were tested has long been the first line of defense baceous plant species in environ- to determine if any of them were in- against viruses in a vineyard. mentally-controlled greenhouses. fected. One recently introduced cul- The plants are carefully watched tivar was positive for GVCV; this vine The grapevine Foundation Program for the appearance of virus-induced was promptly removed from the Foun- of the Clean Plant Center Northwest symptoms. Woody indexing in- dation Program. Tests for these viruses (CPCNW) produces grapevines free cludes the establishment and main- are now incorporated into the standard of economically important pathogens tenance of field plantings through- testing protocols at the CPCNW. from which certified grapevines are out the growing season. They are produced. The entire Foundation col- observed for two years. For some The next step forward. Although there lection is screened routinely for new viruses, the two-year old vines are are some exceptions, molecular and and known pathogens. This vigilance harvested and the bark stripped to serological assays generally depend on is essential to protect the prized collec- look for underlying damage to the knowledge of already-described virus- tion of grape cultivars that is the back- wood. es, and they rely on this information to bone of the wine industry in Washing- test for specific viruses that are likely to ton State and the Pacific Northwest. For more than 20 years, these assays be present in a sample. Since each mo- have been the cornerstone in ensur- lecular assay targets a unique genetic Freedom from pathogens is verified ing the production and release of certi- sequence of the pathogen, the speci- through molecular, serological and fied planting materials. The success of ficity and sensitivity of these assays biological assays: these assays are attributed to the ability have made PCR an important compo- of the assays to detect pathogens even nent in the detection method toolbox. 1. Molecular assays: This type of test when the original grapevine seemingly detects the presence or absence of expresses no visible symptoms. However, new methods of genetic test- a pathogen-specific genetic frag- ing, termed deep sequencing (also ment within the vine. Reverse tran- The CPCNW program is constantly re- known as Next Generation Sequenc- scription polymerase chain reaction viewing and updating its procedures to ing), have been developed and can (RT-PCR) is currently used to detect provide the best security possible for now provide a snapshot of ALL of the 19 RNA-based viruses. Since RNA maintaining virus-free planting materi- genetic information in a plant, includ- viruses can have genomes that vary, als. For example, two viruses with DNA ing pathogens known and unknown, several of the viruses are tested by genomes were recently described in based on its general approach rather more than one RT-PCR test. Thus, a the literature: Grapevine red blotch as- than the specific approaches in past total of 27 RT-PCR reactions are per- sociated virus (GRBaV) and Grapevine molecular assays. formed for each grapevine in the vein clearing virus (GVCV) (Fig. 1). Foundation Program. PCR tests are continued on page 10 also performed for Agrobacterium vitis (bacterial that causes Crown gall), Xylella fastidiosa (bacteria that causes Pierce’s disease) and phyto- plasmas (which cause diseases such as Bois noir, Flavescence dorée, and grapevine yellows).

2. Serological assays: This test detects pathogen-specific proteins within the vine using specific antibod- ies. CPCNW currently adopts the method known as enzyme linked immunosorbent assay (ELISA) to complement molecular assays. This test is useful for annual screening of Figure 1- Grapevine disease symptoms associated with infection by Grapevine red blotch the Foundation vineyard for viruses associated virus, GRBaV, (left, photo courtesy of M.R. Sudarshana, USDA-ARS) and Grapevine such as the Grapevine leafroll associ- vein clearing virus, GVCV, (right, A. Zuroweste, Missouri State University). These two viruses ated viruses 1 through 9. are the latest additions to the list of pathogens screened at CPCNW.

9 Deep Sequencing, con’t continued from page 9

The cost for deep sequencing is de- evaluated for use as a routine diag- creasing rapidly, and the technology nostic tool. As part of this evaluation, Deep Sequencing Explained is now being employed routinely. The thirty grapevine selections from the expanding use of this technology is Foundation vineyard were subjected Deep sequencing data consists of revolutionizing the science of patho- to deep sequencing. In most cases, the short “reads” of genetic segments; gen detection. Deep sequencing offers result confirmed the virus-free status one can think of them as individual many advantages over existing meth- of the vines (Table 1). However, deep words. These short read segments are odologies: the sensitivity of deep se- sequencing also detected the presence assembled by a computer into longer quencing exceeds that of PCR or ELISA of an isolate of Rupestris stem pitting as- sequences known as contigs, by care- and, because deep sequencing is not sociated virus (RSPaV) that had escaped fully matching and aligning overlap- limited to knowledge of known agents, detection in prior testing. Additionally, ping small sequences. This is akin to it is capable of detecting unanticipat- it confirmed the presence of the DNA- taking a scrambled sentence and re- ording the words to form a coherent ed pathogens, even in an apparently virus GVCV that was detected by PCR. one. healthy vine. In grapevine virus re- Without additional RT-PCR tests, deep search, deep sequencing has revealed sequencing also revealed the status of The resulting contigs from a sample previously uncharacterized plant virus- viroids (virus-like organisms) in grape- are then compared to a public data- es in seemingly healthy vines [1,2], and vines. Viroids are considered latent in base of genetic information. In some viruses associated with Syrah decline grapevines but awareness of their pres- cases, contigs will show a significant [3], grapevine vein clearing, and red ence could be used to promote higher match to a virus sequence (or any blotch diseases of grapevines [4-6]. phytosanitary standards in the future. plant pathogen); this is then consid- Preliminary assessments indicate that ered a “positive” identification that Deep sequencing is available in dif- deep sequencing may also work for de- the plant source was infected by that virus (or other pathogen). In other ferent platforms [7-8], but the overall tection of pathogenic bacteria. cases, contigs may be similar, but not procedure can be summarized in three an exact match. In those cases, closer steps: (i) nucleic acid (total RNA, total These results are promising; deep se- examination is needed, and additional DNA, double stranded RNA and/or quencing technology is now being tests, such as PCR or RT-PCR for the small RNAs) is purified from the source evaluated at CPCNW on a larger scale. particular sequence revealed by the organism (i.e., the grapevine); (ii) these It appears that deep sequencing will deep sequencing contig is needed. purified nucleic acids are converted provide more reliable detection of These extra measures are taken to into a form appropriate for statistical pathogens than existing technologies make sure there are no “false posi- analysis; and (iii) the results from these allow, and will aid in the provision of tives” which can result in unnecessary analyses are used to develop a patho- healthier grapevine clones for propa- alarm and plant destruction. gen diagnosis. gation at certified nurseries. Once the reliability of the technology is verified, To increase the reliability of pathogen acceptance by the regulatory commu- REFERENCES detection at the Clean Plant Center nity is needed before full implementa- Northwest, deep sequencing is being tion of the new technology can occur. 1. Sabanadzovic, S., Ghanem-Sa- banadzovic, N.A. and Gorbalenya, A.E. 2009. Virology 394:1-7. Table 1- A comparison of pathogens detected by deep sequencing (next generation 2. Giampetruzzi, A., Roumi, V., Roberto, sequencing) versus the current testing standards. R., Malossini, U., Yoshikawa, N., La Notte, P., Terlizzi, F., Credi, R. and Grapevine pATHOGENS dETECTED BY pATHOGENS dETECTED BY Saldarelli P. 2012. Virus Res. 163:262- 1 Selection cURRENT pROCEEDURE dEEP sEQUENCING 268. 00gr11 none HSVd 3. Al Rwahnih, M., Daubert, S., Golino, D. and Rowhani, A. 2009. Virology 00gr23 none HSVd, GYSVd-1 387:395-401. 03gr03 none HSVd, GYSVd-1 4. Al Rwahnih, M., Dave, A., Anderson, M.M., Rowhani, A., Uyemoto, J.K. and 00gr29 none HSVd Sudarshana, M.R. 2013. Phytopathol- ogy 103:1069-1076. 00gr21 none HSVd, GYSVd-1 5. Poojari, S., Alabi, O. J., Fofanov, V. Y., 00gr19 none HSVd, GYSVd-1 Naidu and R. N. 2013. PLoS One 8:e64194. 00gr17 none HSVd, GYSVd-1 6. Zhang, Y., Singh, K., Kaur, R. and Qiu, 00gr05 none HSVd, GYSVd-1, GYSVd-2, AGVd W. 2011. Phytopathology 101:1081- 1090. 00gr22 none RSPaV, HSVd, GYSVd-1 7. Glenn, T. 2011. Mol. Ecol. Resources 07gr21 GVCV GVCV 11:759-769. 8. Radford, A.D., Chapman, D., Dixon, L., 1 The viroids Hop stunt viroid (HSVd), Grapevine yellow speckle viroid 1 or 2 (GYSVd-1 or 2 ) and Chantrey, J., Darby, A.C. and Hall, N. Australian grapevine viroid (AGVd ) are not considered economically important pathogens and not 2012. J. Gen. Virol. 93:1853-1868. tested by current protocols. RSPaV = Rupestris stem pitting-associated virus; GVCV = Grapevine vein clearing virus.

10 Irrigation in Vineyards with Different Soil Types By Troy Peters, WSU-IAREC

Vineyards are irrigated on a block-basis. However, there are often very different types of soils, and thus different levels of water-holding capacity and drain- age within these blocks. This can cause problems since the areas with lower water holding capacity (sandy, rocky, or shallow soils) will run out of water sooner than areas with higher water holding capacity (silt, clay, or deep soils). In the case of variable vineyard soils, you have the choice to: 1) irrigate to meet the needs of the sandy area, 2) irrigate to the silty soils, or 3) irrigate to some “average” condition. We used the free mobile irrigation scheduling tool on AgWeatherNet (http://weather. wsu.edu/is) to simulate these different strategies and evaluate their effects on soil moisture content in an example vineyard with both fine sand and silt Figure 1- The soil water content of a sandy soil that was irrigated for no water loss to deep loam soils. The results are below. percolation (leaching), and no water stress.

Managing for Sandy Soils. What would happen to soil moisture content if this block were managed as if it were a fine sand only? Fig. 1 shows a soil water content of the sandy soil that was irrigated for sandy soils, such that there was no water stress (soil water content remained between the full line and the first water stress line) and limited water loss to deep percolation (leaching). This includes a growing root zone which accounts for the upward sloping lines (increasing soil moisture content) in the first part of the growing season. Because the water holding capacity of sands is small, frequent irrigations of small amounts (green squares) are required to avoid water stress and losses to deep percolation. Figure 2- The soil water content for a silt loam soil managed as if it were a fine sand soil. Fig. 2 shows how the silt loam soil sec- tion of this same block would fare when • 3.4 inches MORE water is lost to the block is managed for no stress or Managing for Silt Soils. What if the wa- deep percolation. water loss as if it were a sandy soil. The ter for the whole block is managed for • There is a 17% yield reduction due applied irrigation is exactly the same the silt soils in the block? The soil wa- to water stress. on the same dates for both scenarios. ter content on the silt soils over time • The vines would use 4 inches LESS Under this management scenario, the is shown in Fig. 3. In this case, much water in the sandy areas due to following results are seen: more water can be applied at each ir- shutting down as a result of water rigation event and these events can be stress. • No water stress in either block. much less frequent. • Total vine water use and loss to Sometimes growers will put additional deep percolation in both the sandy Fig. 4 shows how the sandy areas of drip emitters into the lines in the sandy and the silt soils of the block are the block would fare if the water was spots or use higher flow drip tubing in the same. managed as if it were a silt soil. While those areas to apply more water per • Yields are the same in both areas. the same amount of water is applied irrigation event to combate potential • At the end of the season, the silt on both the silt and the sand sections, water stress. Since sandy soils do not soil will have much greater residual in the sandy areas: water available than the sand. continued on page 13

11 High pH, High TA: The Winemaker’s Conundrum By Jim Harbertson, WSU-IAREC

This is part 1 of a 2-part series on grape units is generally observed. Titrat- and wine pH and titratable acidity. able acidity, a second measure of acidity, represents the total num- Part 1: Defining Acidity ber of acids in the wine. This is done by titrating the juice or wine Wines or juice that have a high pH sample with base to a chosen pH and high titratable acidity (TA) are the endpoint; in the USA, this end- winemaker’s conundrum; even though point is 8.2 pH units. Typically, the the wine has a high concentration of value is lower than the expected titratable acids the pH of the wine in- measure from the actual organic dicates the wine is not acidic. But how acid concentrations. is this possible? The answer lays in the understanding of how acidity is deter- Under normal conditions there is mined in the grape and/or wine, and an inverse relationship between how it is measured. Acidity is a funda- the TA and pH of a juice or wine Figure 1- Under normal conditions (left) the mental aspect of grape and wine com- sample (i.e., as the TA of a juice pH and TA of a must are inversly related; as pH position. Acids are the second most or wine sample increases, the pH increases, TA should decrease. In some cases, however, WA grape musts have had both high pH and abundant component in grapes, and tends to decrease). However, this high TA (right). How is this possible? correspondingly, in wine. Sensorially general “rule” doesn’t always play acids are sour, can augment astringen- out in the vineyard and wine, thus malic acid is readily metabolized. Un- cy and their sourness is masked by sug- our pH – TA dilemma. How is it possible fortunately the absolute temperature ars. From a chemical standpoint they to have high pH and high TA simulta- differentials required for malic acid are responsible for multiple important neously, if they normally are inversely preservation are unknown, making the aspects of wine. Acids take part in es- related (Fig. 1)? To understand this we phenomenon difficult to predict. Most terification reactions, catalyze hydro- will need to first understand events that current knowledge on the subject of lytic reactions and impact red wine occur during grape ripening to gain in- malic acid preservation and abundance color. sight into this problem. in fruit assumes that the final malic acid concentration in grape juice is due to Grapes contain a mixture of organic Acid Development in Grapes. During its preservation, not to its initial synthe- acids. The two most abundant acids ripening, as the berry size increases due sized amount. present are tartaric and malic. Tartar- to water engorgement, compounds ic acid is stable to metabolism, while synthesized within the berry must also To complicate the acid situation, in- malic acid can be metabolized during be increased otherwise they become organic ions (e.g., potassium [K+], so- grape ripening and fermentation by diluted. In the case of malic and tartar- dium [Na+]) are pumped into the berry bacteria and yeast. Both tartaric acid ic acids, the synthesis of both continue via the plants vascular system. For each and malic acid have two acidic func- until véraison, where synthesis then inorganic ion pumped into the berry, tional groups, but malic acid is a sig- stops and their concentration within there is an exchange of a proton (H+) nificantly weaker acid with a difference the berry declines due to dilution. Un- out of the berry. Because of the con- of 0.5 pH units between the first acidic fortunately, dilution isn’t the only cause centrations of acid in grapes are high functional group’s disassociation con- for decline of malic acid, which is also the pH of the grapes would actually be stants. This mixture of acids plays a sig- lost due to berry respiration. During nearly pH 2.5, but because of this pro- nificant role in the buffering capacity respiration, malic acid is converted by ton exchange, the observed fruit pH is of the juice; due to the different chemi- the malic enzyme into pyruvate, car- in the range of 3.0 to 4.0. cal species available, the buffering ca- bon dioxide and the reduced co-factor pacity extends over a larger pH range, NADPH. The conversion of malic acid The most important of the inorganic reducing the likelihood of sudden pH to pyruvate consumes protons and ions is potassium (K+). The net effect changes that could be detrimental to thus increases the pH of the cell. Tar- of this is an increase in pH of the fruit yeasts. taric acid, on the other hand, is stable because of a loss of the protons. The to grape metabolism. amount of potassium or sodium ex- The basic methods by which various change that occurs is dependent on indicators of acidity are measured are Berry respiration occurs during the the concentration of potassium or so- simple. The main measure of acidity is day and night; the degree of malic dium in the soil, the vine’s ability to pH, which measures the equilibrium acid breakdown is thought to be de- uptake said nutrient, and the amount protons (H+) in the sample. pH is a log pendent on the overall sustained high of nutrient recycle that occurs after vé- scale; a change in a single unit (such as temperature. Large temperature dif- raison as the canopy nears senescence. 3.0 to 4.0), represents a ten-fold differ- ferentials between day and night can ence in proton concentration. As such, dampen respiration that occurs dur- Thus, the pH of the fruit is dependent the differences in juice or wine pHs ing the evening, which then preserves upon the concentration of organic seen are on smaller scale. For example, malic acid. In regions where there is acids, their relative strengths and the during malolactic fermentation, an in- not a large change between day and crease in pH on the order of 0.2 pH night temperatures (i.e., warm nights), continued on page 13

12 High pH, High TA: con’t continued from page 12 extent of proton to inorganic ion ex- entials, minimal rainfall, and young change. The most common way of get- Eq. 2: vineyards, has seen more than its share ting a wine with high pH and high TA of this problem. The coupling of soils is to have a large amount of inorganic that may be high in K, with reduced ions that have exchanged into the fruit. As seen in Eqs. 1 & 2, raising the K+ degradation of malic acid, makes un- This can be numerically demonstrated concentration while maintaining tar- derstanding how to manage a high pH, with the following ratios, where K+ is taric and malic acid levels will result in high TA vintage a must for every WA the potassium concentration and H2TA an increase in pH while maintaining TA. grower and winemaker. and H2MA are tartaric and malic acids, respectively. The Washington State Conundrum. In the Fall 2014 issue of VEEN, we will High pH with high TA is a relatively rare follow up on the “The Winemaker’s problem, but frustrating because of its Conundrum” with a discussion of the Eq. 1: seemingly paradoxical nature. Eastern techniques for managing acidity in the WA, with its large temperature differ- vineyard and winery. Irrigation Management, con’t continued from page 11 have high water holding capacity, all of this additional applied water is mostly lost to deep percolation (leached). Adding more water at each irrigation event to compensate for low water holding capacity is inappropriate. To reduce water stress in sandy areas, more frequent applications of smaller amounts are needed.

Conclusion. From this we can see that on variable soils, if we want to achieve maximum growth from all of the vines, then the entire block should be managed for the soil with the lowest water holding capacity (sandy, rocky, or shallow soils). This means more frequent irrigation events of smaller amounts of water per event. Figure 3- The soil water content over time of a silt soil managed for maximum efficiency If the block is subjected to deficit irri- and yield for a silt soil. gation, then achieving the same level of deficit or water stress in the different soils will be difficult. Sandy areas will be at extreme water stress when the silty soils still have plenty of water remaining. For proper deficit irrigation management and a uniform per- formance from the field, the irrigation events for the different soils will need to be managed separately. This means re-plumbing the irrigation system to be able to control the water to the silty areas separately from the sandy areas. If done correctly approximately the same total amount of water will be applied to both areas.

More information on vineyard irrigation management can be found at: http://wine.wsu.edu/research-extension/irrigation/ Figure 4- The soil water content over time of a sandy soil managed as if it were a silt soil.

13 Building References: Vit. Extension Publications

More information, as well as links to Growing Winegrapes in Mari- additional resources, can be found at time Western Washington the WSU Viticulture and Enology Re- (EM068e) New to Viticulture? search and Extension website: http:// wine.wsu.edu/research-extension/ . There are many aspects to consider in order to be successful at growing Check out: Grape Pest Management Guide grapes in the maritime climate areas eViticulture.org for Grapes in Washington of the Pacific Northwest. Quality wine- (EB0762) grapes can be grown in western Wash- ington, provided careful consideration eViticulture.org is an Extension Containing information on registered is given to choosing the appropriate clearing house for all things viti- products for weed, insect, disease, and site, variety, rootstock, and cultural culture. Populated with resourc- nematode management in WA, this practices. This publication includes es and references produced by guide is a must-have for every grape information on site selection and university Extension specialists grower. It also has information of nutri- preparation, vineyard establishment, across the country, this resource ent management and sprayer calibra- nutrition and pest management, and provides quick factsheets on tion. vineyard management. This revision the basics of viticulture produc- of the former “Growing Winegrapes tion, with links to more in-depth publications written in practical The 2014 edition has a vastly improved in Maritime Western Washington terms. phenology calendar on which to sched- (EB2001) contains substantial updates, ule intervention strategies, as well as including a full appendix of varieties, This online resource is perfect tables discussing resistance manage- enology notes, viticulture notes, and for students, those just get- ment for weeds and diseases. cluster images. ting started, and as a refresher for those who have been in the Links on ordering or downloading this This publication is available at: http:// wine.wsu.edu/research-extension/ industry. After harvest, grab a guide will be made available at: http:// glass of wine and check it out! wine.wsu.edu/research-extension/ vineyard-management/ plant-health/ .

Calendar of Events

Date Description Wine Trial Showcase, WSU & Washington Wine Technical Group 16 April 2014 http://cahnrs.wsu.edu/event/trial-showcase-2014/ 1 May 2014 Grape Fieldman’s Breakfast, Cafe Villa, Prosser, WA 5 June 2014 Grape Fieldman’s Breakfast, Cafe Villa, Prosser, WA American Society for Enology and Viticulture Annual Meeting, Austin, TX 23-27 June 2014 http://www.asev.org/2014-national-conference 3 July 2014 Grape Fieldman’s Breakfast, Cafe Villa, Prosser, WA 7 August 2014 Grape Fieldman’s Breakfast, Cafe Villa, Prosser, WA Washington State Viticulture Field Day, WSU & Washington State Grape Society, 15 August 2014 Prosser, WA 4 September 2014 Grape Fieldman’s Breakfast, Cafe Villa, Prosser, WA

Check the website for changes and updates to the Calendar of Events. http://cahnrs.wsu.edu/events/category/grapes-wine/

The next issue of VEEN will be in mid-September and is accepting events between 15 September 2014 and 1 April 2015 Let Michelle ([email protected]) know of your events by 15 August 2014