Upcoming regional meetings with winemakers to meet Molly Kelly, Penn State Enology Extension Educator
There will be a series of state-wide meetings to provide winegrowers an opportunity to meet the new enology extension educator, Molly Kelly. These sessions will include wine faults sensory training, a question and answer period and a tour of the host winery (if applicable). Attendees are also invited to bring one bottle of cellared wine to be assessed blindly by the group.
All sessions will be from 1:00 pm-4:00 pm.
Sessions in Biglerville and Erie will include an additional optional sensory session with researchers from Penn State. They will be running a short sensory exercise after the meet and greet. They are studying the sensory characteristics of white wines in Pennsylvania and hope to survey wine professionals in order to compare responses with wine consumers. Your input will assist with important research that will directly impact the Pennsylvania wine industry.
Please see locations and dates below. Please register by clicking on the link. https://extension.psu.edu/wine-faults-sensory-training-meetings
These meetings are FREE!
We hope that you can join us and I look forward to meeting all of you!
Northeast: April 5, 2018 Nimble Hill Winery, 219 Windswept Lane, Mehoopany, PA 18629
Southwest: April 25, 2018, Glades Pike Winery, 2208 Glades Pike (Rt. 31), Somerset, PA 15501
South Central: April 26, 2018, Penn State Fruit Research and Extension Center, 290 University Dr., Biglerville, PA 17307
Northwest: May 3, 2018, Lake Erie Regional Grape Research and Extension Center, 662 N. Cemetery Rd., North East, PA 16428-2999
Southeast: May 2018, Location and date TBA
By Molly Kelly
There are a number of spoilage microorganisms and yeasts that we are concerned with as winemakers. Two of the most common spoilage yeasts include Kloeckera apiculata and Brettanomyces bruxellensis. The most common form of yeast spoilage is due to Brettanomyces bruxellensis. Although mature grapes may harbor this spoilage yeast, the bigger problem can occur when winery equipment is infected due to poor sanitation practices. This yeast produces volatile phenols and acetic acid. Examples of wine flaws include aromas described as “medicinal” in white wines and “leather” or “horse sweat” in red wines. Other aromas descriptors include barnyard, wet dog, tar, tobacco, creosote, plastic and band aids.
The two major groups of wine spoilage bacteria can be placed in either the acetic acid bacteria (AAB) group or the lactic acid bacteria (LAB) group. The AAB includes the genera Acetobacter and Gluconobacter. Both have aerobic (requiring oxygen) metabolisms and thus their growth generally occurs on wine surfaces as a translucent film that tends to separate into a patchy appearance. In contrast, the LAB require low oxygen conditions for growth (i.e. they are microaerophilic to facultative anaerobic micro-organisms). The LAB includes the genera Lactobacillus, Pediococcus and Oenococcus.
During fermentation the presence of such microbes may be indicated by a spontaneous or sluggish fermentation, or a spontaneous malolactic fermentation (MLF); or the presence of ethyl acetate, volatile acidity (VA) or other off-odors.
Winery Microbiology Laboratory
Because of these possible faults arising due to the presence of spoilage organisms, some wineries have incorporated sanitation monitoring and microbiological techniques into their production practices. Some considerations when planning a winery microbiology laboratory are: space considerations, availability of trained staff to perform testing, willingness to maintain adequate record-keeping, equipment costs as well as the cost of consumables.
A microscope capable of 1000x magnification is needed to view bacteria and yeast. These can cost anywhere from $1000-$3000 or more but bargains can be found on used microscopes. A phase-contrast microscope requires no staining of slides due to enhanced differences in refractive index between the microorganisms and surrounding medium. This feature also allows for rapid detection and response. The staff in the microbiology lab should have training in the proper use of a microscope as well as identification of microorganisms.
In addition to identifying spoilage organisms, a microscope can be used to monitor yeast populations. By using a simple methylene blue stain, yeast viability can be determined.
Bacterial culture media is available for the growth of spoilage organisms for identification. This requires additional equipment including an incubator. This also requires further training in sterile technique and organism identification techniques. Several types of culture media exist for the detection of the organism of interest. For example, media used to plate for Brettanomyces contains chloramphenicol (200 mg/L) to prevent bacterial growth while others may contain cyclohexamide to prevent Saccharomyces growth. Common media used in culturing juice, wine and environmental samples include WL and WL-differential agar.
Membrane Filter Method
The membrane filter method can be used to isolate small numbers of microbes from a liquid sample. A sterile cellulose nitrate membrane (0.45 microns for bacteria, 0.65-8 microns for yeasts) is placed on a vacuum flask and filtered. Using sterile technique, the membrane is placed on the culture plate and monitored for growth. This method could be used to check bottle sterility.
The swab test method is used for semi-quantitative analysis. Moist sterile cotton swabs are used to monitor dry areas (moistened with sterile saline or water). Dry swabs can be used to test moist areas. The swabs can then be used to inoculate the proper agar medium, depending on the organism of interest. Agar plates can also be used to detect airborne organisms at critical winery locations. Plates are left open for 30 minutes to 2 hours and then incubated. Airborne organisms that settle on the plate will grow and can be further identified.
Monitoring systems exist that utilize bioluminescence technology to measure adenosine triphosphate (ATP). ATP is found in all plant, animal and microbial cells and is the prime energy currency that fuels metabolic processes. It is therefore possible to detect and measure biological matter that should not be present if proper sanitation practices are followed. One system by Hygiena™ uses an enzyme found in fireflies (luciferase). In the presence of ATP, an oxidation reaction occurs that results in light formation that is directly proportional to the amount of ATP present. Results are numeric and expressed as relative light units (RLU).
It should be stressed that cellar hygiene is critical in maintaining wine integrity and quality. Poor wine quality is usually due to poor sanitation practices. Areas of spoilage organism build-up include: the vineyard, second-hand barrels, imported bulk wine and areas of the winery that are difficult to reach.
There are commercial enology laboratories that provide all of the microbiological services discussed here. For more information please contact Molly Kelly at firstname.lastname@example.org.
Crowe, A. August 2007. Avoiding Stuck Ferments. Wine Business Monthly
Just, E. and H. Regnery. 2008. Microbiology and wine preventive care and monitoring in the wine industry. Sartorius Stedim Biotech.
Margalit, Y. 1996. Winery Technology and Operations. The Wine Appreciation Guild, San Francisco.
Ritchie, G. 2006. Stuck Fermentations. Fundamentals of Wine Chemistry and Microbiology. Napa Valley College.
Specht, G. Sept/Oct 2003. Overcoming Stuck and Sluggish Fermentations. Practical Winery and Vineyard Journal.
Van de Water, L. Sept/Oct 2009. Monitoring microbes during fermentation. Practical Winery and Vineyard Journal.
Zoecklein, B., Fugelsang, K.C., Gump, B.H. and Nury, F.S. 1999. Wine Analysis and Production, Kluwer Academic/Plenum Publishers, New York.
Zoecklein, B. 2002. Enology Notes #65, Enology-Grape Chemistry Group, Virginia Tech.
Please join us in welcoming Dr. Molly Kelly as our new Penn State Enology Extension Educator. In this role, Molly will support the technical needs of the Pennsylvania wine industry and lead educational programming focusing on wine quality. She has lead workshops, including winery sanitation, filtration, microscopy, wine analysis and berry sensory analysis. Molly’s research has focused on the effect of nitrogen and sulfur applications on Petit Manseng wine aroma and flavor. Her current research includes a pre-harvest, on-the-vine dehydration study in collaboration with Virginia Tech University.
Prior to this position, Molly was the Enology Extension Specialist at Virginia Polytechnic Institute and State University in Blacksburg, Virginia. She also held the position of enology instructor at Surry Community College in Dobson, N.C., where she developed the enology curriculum and managed all aspects of the college’s 1,000-case bonded winery. Under her direction, Surry produced numerous international award-winning wines. Prior to her position at Surry, she was a biodefense team microbiologist with the New York State Department of Health.
By Bryan Hed
Since the new year was ushered in we have had several scary moments when Mother Nature unleashed an “excess of personality.” I’m referring to the cold weather events we experienced around January 1, 7, and 14, when temperatures slipped down below zero in many places across Pennsylvania, even in some south central parts of the state. As many of you might remember, the last time we saw below zero temperatures that far south (February from hell, 2015) primary bud damage was widespread and grapevine trunks in vineyards all over Pennsylvania (and certainly other parts of the Northeast) exploded in crown gall the following spring. This generated a two-year trunk renewal process that we’ve only just recovered from. Therefore, this may be a good time to review grapevine winter hardiness and the factors that affect it, as well as how we can prepare for possible remediation pruning and renewal this spring.
Now I don’t want to raise alarm bells just yet, as the conditions we’ve experienced this January haven’t been as horrific as February of 2015. But it’s always good to be prepared for any potential consequences, like bud loss and trunk damage, so we can anticipate altering our winter pruning plans and production practices this season.
Let’s start with a review of the temperature stats available to everyone on the NEWA website (newa.cornell.edu) and see just how cold it got in various places across the state during the first half of January. In the table below, I’ve listed low temperatures for January 1, 7, and 14 for many of the NEWA locations. Starting at northeastern PA and moving counterclockwise to swing back up into northern New Jersey and finally western New York, we get the following data (Table 1).
Areas of southeastern and northwestern Pennsylvania, at opposite corners of the state, appear to have escaped the below-zero temperatures for the most part, but some areas of south central Pennsylvania took a hit (look at York Springs). Areas of southwestern Pennsylvania experienced some of the most extended periods of below-zero weather, and parts of northeastern and central Pennsylvania also got quite cold. The temperature low is the most important bit to consider when sizing up vine bud damage, but the duration of those lows can affect the extent of trunk damage, especially in big old trunks where it may take longer for the core to reach ambient temperatures. Up in the northwestern corner of the state, the buffering effect of Lake Erie probably played a role in our relatively mild temperatures during that period, and we expect little to no damage to most of our vines as our wine industry there is heavily invested in tougher hybrids. The Erie area was also blessed (?) with a heap of snow (10 feet!) before the cold snap that provided added protection to bud unions of grafted vines.
If you’re anticipating primary bud damage, here’s a review of the ranges of temperatures for the LT50 (low temperature at which 50% of primary buds fail to survive) for the cultivars you’re growing. For Vitis vinifera, the LT50 range of the most winter sensitive cultivars falls between 5o and -5oF. This includes cultivars like Merlot and Syrah. But for most cultivars of V. vinifera, LT50 values fall more in the 0o to -8oF range (Chardonnay, Cabernet Sauvignon, Pinot gris, Pinot noir, Gewurztraminer). And finally, there’s the tougher V. vinifera and sensitive hybrids that have buds with LT50 values of -5o to -10oF. This includes cultivars like Riesling, Cabernet franc, Lemberger, and Chambourcin. On the flip side, most hybrids fall into the -10o to -15oF range (which is why Northeastern U.S. vineyards are perhaps still more invested in hybrids than V. vinifera). Then there are the V. labrusca (Concord) and the Minnesota hybrids that range from -15o down to -30oF for cultivars like Frontenac and LaCrescent. Unfortunately, we don’t have such helpful ranges for determining trunk damage, which often comes with more profound consequences and is costlier to address.
Rapid temperature drops are often the most devastating in terms of the extent of damage. Fortunately, December temperatures this winter descended very gradually giving vines time to fully acclimate to cold weather extremes. In fact, recent data from the Cornell research group in the Finger Lakes region of New York shows that LT50 values for primary buds of several cultivars were close to, or at, maximum hardiness. Therefore, it is hoped that many Northeastern U.S. vineyards were well prepped and close to their hardiest when these cold events occurred. On the other hand, any given cultivar in central New York is likely to be a bit more cold hardy than that same cultivar growing in southern Pennsylvania, simply because vines farther north will have accumulated more cooling units than those farther south. So there is the possibility of bud and—worse yet—trunk damage in parts of PA, to the more sensitive cultivars of V. vinifera.
We also had a balmy warm period during the second week in January that pumped temperatures up into the 60s in some places before plunging back down into single digits. However, it’s unlikely the brief warm period was long enough to cause any deacclimation of vines before cold temperatures resumed, and little, if any harm, is expected from that event.
The capacity for cold hardiness is mostly determined by genetics. As I alluded to above, V. vinifera cultivars are generally the most sensitive to cold winter temperature extremes, French hybrids are generally hardier, and native V. labrusca cultivars are often the toughest. Nevertheless, other site specific factors can come into play to affect cold hardiness, and this is often the reason for the range in the LT50 values. For example, there’s vine health to consider; vines that finished the season with relatively disease-free canopies and balanced crop levels can be expected to be hardier (within their genetic range) than vines that were over-cropped and/or heavily diseased. At times like these, we can’t emphasize enough how important it is to maintain your vines and production strategy with a view to optimizing their chances of surviving every winter. Other stresses like drought or flooded soils (during the growing season) that we can’t do much to control, and infection by leafroll viruses, can also play a significant role in reducing vine cold hardiness.
If you suspect damage, you should delay winter pruning of your vines, according to Dr. Michela Centinari. Feel free to revisit her previous blog posts and others at psuwineandgrapes.wordpress.com. Type “cold hardiness” or “winter injury” into the search box, and you’ll quickly and easily gain access to several timely blogs.
Bud damage can be estimated from 100 nodes collected from each potentially compromised vineyard block. Typically, gather ten, 10-node canes from each area, but do not sample from blocks randomly, unless the block is relatively uniform. If a block is made up of pronounced low and high areas (or some other site feature that would affect vine health and bud survival) make sure you sample from those areas separately as they will likely have experienced different temperature lows (Zabadal et al. 2007). You may find that vines in high areas need no or less special pruning consideration than vines in low areas that suffered more primary bud damage and will require increased remediation.
Once you have your sample, bring the canes inside to warm up a bit and make cuts (with a razor blade) through the cross section of the bud to reveal the health (bright green) or death (brown) of primary, secondary, and tertiary buds. You’ll need a magnifying glass to make this determination as you examine each bud. You should figure that primaries will contribute two thirds of your crop and secondaries, one third when considering how many “extra” buds to leave during pruning. And remember that some bud damage, up to 15% or so, is normal. If you’ve lost a third of your primaries, leave a third more nodes as you do your dormant pruning. If you’ve lost half your primaries, double the nodes you leave, and so on. However, when bud mortality is very high (more than half the primary buds are dead), it may not be cost effective to do any dormant pruning as it is likely there are more sinister consequences afoot, like severe trunk damage that is much harder to quantify. A “wait and see” strategy, or at least very minimal pruning, may be best for severely injured vines (Figure 1) and trunk damage will manifest itself in spring by generating excessive sucker growth (Figure 2). And one more thing: Secondary buds are often more hardy than primaries, may have survived to a larger extent, and in some cultivars, can be incredibly fruitful. This is especially true of some hybrid varieties like DeChaunac. So, to make more informed decisions when winter damage is suspected, you have to know the fruitful potential of your cultivar; and in cases where primary bud mortality is high, it’s therefore important to also assess the mortality of secondary buds.
Another great fear is the appearance of crown gall, mainly at the base of trunks. This disease is caused by a bacterium that lives in the vine. However, the bacterium generally doesn’t cause gall formation on trunks until some injury occurs, usually from severe winter cold damage near the soil line or just above grafts on grafted vines (if you hilled over the grafts last fall). Another search at psuwineandgrapes.wordpress.com will bring up information on how to deal with this disease. You can also visit What we have learned about crown gall for an update on research into this disease from Dr. Tom Burr and his research group at Cornell University. Tom has devoted a lifetime to researching grape crown gall and many advances have been made over the years. But it’s still a huge problem for Northeastern U.S. grape growers; and crown gall problems will likely increase as our industry becomes more and more heavily invested in the most susceptible cultivars of V. vinifera.
With more sensitive detection methods, Tom’s group is getting us closer and closer to crown gall-free mother vines and planting stock, but they’re also discovering that the crown gall bacterium is everywhere grapevines are located. Not restricted to internal grapevine tissues; it’s also found on external surfaces of cultivated and wild grapevines. So, clean planting stock may still acquire the pathogen internally down the road and management of crown gall, once vines are infected, will continue to be an important part of life in any vineyard that experiences cold winter temperature extremes. However, there is potential for a commercial product that inhibits gall formation, which can be applied to infected vines. The product is actually a non-gall-forming, non-root-necrotizing version of the crown gall bacterium that is applied to grape wounds and inhibits the gall-forming characteristic of the pathogenic strains of the bacterium. This product is still under development in lab and greenhouse tests, awaiting field nursery trials soon.
If you do happen to meet up with some crown gall development this spring, galled trunks can be nursed through the 2018 season to produce at least a partial crop while you train up suckers (from below the galls) as renewal trunks. When our Chancellor vineyard was struck with widespread crown gall in the 2015 season, we were able to harvest a couple of decent sized crops while trunk renewal was taking place (Figure 2), and we never went a single season without some crop. There’s also the issue of crop insurance to think of; adjusters may want you to leave damaged trunks in place so they can more accurately document the economic damage from winter cold.
Lastly, a great guide to grapevine winter cold damage was published about 10 years ago by several experts. In fact, information from that guide was used in composing large parts of this blog and I highly recommend you read it. It’s an excellent publication, the result of many years of outstanding research by a number of leading scientists and extension specialists from all over the Northeastern U.S. The details of that publication are found below and you can purchase a hard copy for 15 bucksby clicking here: Winter Injury to Grapevines and Methods of Protection (E2930).
For those of you who can spend hours reading off of a computer screen without going blind, you can also access a web version of the document at msue.anr.msu.edu/uploads/files/e2930.pdf.
Zabadal, TJ, Dami, IE, Goiffinet, MC, Martinson, TE, and Chien, ML. 2007. Winter injury to grapevines and methods of protection. Extension Bulletin E2930. Michigan University Extension
By Michela Centinari, Bryan Hed, Kathy Kelley, and Jody Timer
The 2017 growing season was a rewarding one for many Pennsylvania (PA) grape growers; crop quality and yields generally met or exceeded expectations. However, this season was not without its challenges. Before we start planning for next year, let’s review this past season and discuss the important issues and concerns PA growers faced in 2017. In November a link to a 10-minute Internet survey was sent via email to 110 members of a PA wine grape grower extension mailing list. The survey was designed to solicit their feedback with regards to the 2017 growing and harvest season. Fifty participants completed the survey* and their responses form the basis of this blog article. So that we have a complete accounting for growers throughout the Commonwealth, we encourage PA wine grape growers who may not have received the email to contact us (Michela Centinari; Bryan Hed) and provide their contact information so that they can be included in future surveys.
First, some information about participant demographics
Of those who provided the region where they grew grapes (44 participants), the majority (16) were located in the Southeast region, followed by South Central (9), Northwest (8), Northeast (5), North Central (3), and Southwest (3) regions. Species of grapes survey participants grew are listed in Table 1.
What did we ask the survey participants?
Participants were asked to indicate the average yield of the grapes they grew in 2017 by selecting the appropriate category: “poor,” “below average,” “average,” “above average,” or “record crop.” Although growers often adjust crop load to meet a desired level, environmental or other unexpected factors may cause final yield to differ from expected, “average” values.
Participants were also asked to rank the overall quality of the fruit from “poor” to “excellent,” and the insect and disease pressure from “below average” to “above average.” Respondents were then directed to open-ended questions where they indicated what cultivars performed “below,” “average,” or “above average” and why.
Weather conditions during the growing season
A look at the weather conditions throughout the growing season can help to explain participants’ answers. In Figures 1 and 2, we reported monthly, seasonal (April 1 through October 31) growing degree days (GDD; index of heat accumulation), and precipitation collected by weather stations (http://newa.cornell.edu/) at two locations: Lake Erie Regional Grape Research and Extension center (LERGREC) in North East (Erie County, northwestern PA) and in Reading (Berks County, southeast PA). We compared the 2017 data to the previous 18-year (1999-2016) average.
We recognize that weather conditions might vary greatly from site to site, but some general trends were observed. For example, April GDDs were above-average in many regions of the Commonwealth. On the other hand, May was slightly cooler than the average in both the Southeast and Northwest (Figure 1). Additionally, below freezing temperatures were recorded during the early morning hours of May 8 and May 9 at the agricultural experiment station located near the Penn State main campus in State College. Some of the grape cultivars grown at this research farm, especially those that typically break bud early like Marquette and Concord, sustained crop loss due to frost damage. Fortunately, spring frost affected relatively few growers in PA and only two survey participants, one from the Southwest and another from the Northeast, reported reduced crop yield due to early May frost damage.
Growing degree day accumulations were slightly above the long-term average in June and July. However, August was noticeably cooler than the average in the Southeast and many other regions of the state, but not in Erie which remained warmer than average nearly all season (Figure 1). As the season came to a close, temperatures in September and especially October were warmer than average at both locations (Figure 1).
In most regions of the state, precipitation was abundant, particularly in June, July, and August (Figure 2 and Table 2). The one exception to this trend was in the far Northwest corner of the state where rainfall along the Lake Erie shore was well below average in July and August. September was relatively dry statewide, which was a big relief for many growers after facing a wet summer. As the season came to an end, October saw a return to higher amounts of rainfall in some areas of the state.
Survey participants’ responses
Yield: Twenty-two respondents (44% of the participants) indicated that overall crop yield was “average,” which was close to the target values (Figure 3). Sixteen percent of the participants indicated that overall yield was “above average,” or “record crop,” while for 40% was “below average” or “poor.”
“Poor” or “below average” yield was attributed to several factors, including poor or reduced fruit set, herbicide drift damage from a nearby field (for more information please refer to the newsletter article: Growth regulator herbicides negatively affect grapevine development) and/or disease issues (e.g., downy mildew, bunch rot). Two participants reported crop yield losses due to late spring freeze damage. One respondent indicated that “above average” yield was likely related to bigger berry size.
Fruit quality: Participants were asked to rate fruit quality, with the majority of the respondents (82%) rating fruit quality as “average,” “above average” or “excellent.” Only 18% of the respondents indicated that overall quality was “below average” or “poor,” although in some cases the rating varied depending on the cultivars grown as specified in a follow-up question.
With the exception of the Northwest region, several participants across the state pointed out that despite the wet summer conditions the warm and dry fall weather favorably influenced fruit ripening, especially for late ripening cultivars.
For example, some of them commented:
- “Early cultivars were of lower quality than later cultivars due to the cold, wet weather in the August and early September time frame. The warm and dry later half of September and most of October benefited the later.”
- “Pinot Gris, Sauvignon Blanc, Viognier, Chardonnay all had excellent sugar levels and good pH and acidity. Flavors were well concentrated. Reds were average to good. Some like Merlot had low sugar levels while later varieties had better sugars like Cabernet franc and Cabernet sauvignon. The late reds seemed to ripen more quickly than normal.”
- “Later varieties were above average due to smaller crop size and better weather conditions.”
Disease pressure: Half of the growers who participated in the survey experienced “above average” disease pressure during the 2017 growing season, while 41% reported “average” disease pressure and only 9% reported that the disease pressure was “below average.” This contrasts markedly with results obtained in 2016 when 47% of survey participants experienced “below average” disease pressure (Looking back at the 2016 season).
The major disease problem identified by the growers was downy mildew followed by bunch rot. A few respondents indicated that downy mildew pressure was particularly high in August. This is not surprising; downy mildew pressure is very dependent on rainfall and the threat of this disease would be particularly high in areas where recorded rainfall had been above average for most of the season (for example, Berks County).
It is important to note that areas of the state that experienced “above average” disease pressure may have a relatively high overwintering population of the pathogen(s), particularly if a fair amount of disease was actually observed in the vineyard. This can easily translate into higher disease pressure in 2018, especially if conditions remain wet.
In contrast to the majority of grape growing areas in PA, growers in the Lake Erie region experienced a second consecutive dry season, and disease development in many of the region’s vineyards was limited to powdery mildew in 2017. Therefore vineyards in the Lake Erie region will generally carry relatively low overwintering pathogen levels into 2018, with the exception of powdery mildew (a disease that is only dependent on rainfall for the first primary infections in early spring).
Despite the above-average wet conditions, respondents pointed out that fruit was clean from major diseases: “low fruit disease despite wet season,” and “given the weather conditions during the growing season overall our grapes were kept almost disease free.”
Several of them attributed their ability to keep disease pressure under control to a “persistent spray program,” “solid spray program and very good protective materials available,” and that “rainy season required that growers stay on top of their disease management program. Botrytis, downy and powdery mildew could have been rampant.”
A respondent pointed out that in addition to a solid spray program new canopy management implemented likely helped to reduce Botrytis infection in susceptible varieties: “I also started to leaf pull pre-bloom which I believe has loosened our clusters up and has allowed for better spray penetration and overall less rot.”
Insect pressure: Twenty-two participants (45% of the respondents) experienced “average” insect pressure during the 2017 growing season, while 31% answered “above average” and 24 % “below average.”
The majority of the growers who experienced “average” or “above average” insect pressure indicated problems with late-season insect pests, such as Spotted Wing Drosophila (SWD), wasps and hornets (for more information on those insect pests and how to manage them please refer to: Is Spotted Wing Drosophila a problem in my wine grapes?; Late season insect management)
Some of them commented:
“SWD seems to be more present at the end of the season,” “Drosophila was the primary insect,” “SWD was above normal.”
Japanese Beetles were also named, although answers were divided: some respondents indicated “Japanese beetle pressure was lower than in previous years” while others answered that “Japanese beetles were the most prevalent insect” and they were “very aggressive in the vineyard.” A respondent observed a new insect in the vineyard, the grape leafhopper. Grapevines can tolerate fairly high populations of leaf hoppers and Japanese beetles without harm to the crop. Populations of fewer than 20 leafhopper nymphs/leaf usually does not require spraying (Japanese Beetle: A common pest in the vineyard).
In the Lake Erie region the grape berry moth was once again the most destructive insect present. The unusually dry summer kept a potentially large population to average numbers. Brown Marmorated stink bug damage is beginning to be noticeable in some Lake Erie vineyards (Will the Brown Marmorated stink bug be a problem in wine and juice?)
Unfortunately, the insect who made its big entry this season into southeastern PA vineyards was the Spotted Lanternfly (Lycorma delicatula). Spotted Lanternfly (SLF) is an invasive insect first discovered in Berks County in 2014 and is now threatening parts of southeastern PA and Southern New York (Invasive insect confirmed in New York). Half of the respondents from the Southeast region (8 participants) observed the Spotted Lanternfly in their vineyards, and this was the first year for many of them.
Some of them commented:
- “At the end of the season I started seeing Spotted Lanternfly.”
- “Lantern fly moved into my vineyard this year. Some of us believe honeydew from lantern fly is attracting yellow jackets and other bees, which were really bad.”
- “The Spotted Lanternfly in our vineyard continues to put pressure on the crop; we estimated that we killed 1/2 million adults in September.”
- “The significant increase in the adult Spotted Lantern Fly population this season in our area causes significant concern for our vineyard longevity. While many of the sprays were able to knock the populations back quickly only so many applications could be made. Within a few days of spraying and killing the adults, new adults migrated into the vineyards.”
The quarantined area for SLF at the beginning of the season included three counties of southeastern PA, but by the end of the season, SLF populations had decidedly increased causing the quarantine area to be markedly expanded. The PA Department of Agriculture does not have the quarantine map completely updated at this time, however, they do have a search quarantine map where you can put in your location to check to see if you are included in the quarantine. (https://www.agriculture.pa.gov/spottedlanternfly; http://www.agriculture.pa.gov/plants_land_water/plantindustry/entomology/spotted_lanternfly/pages/default.aspx)
Information on SLF and measures that can be taken to stop its spread can be found at: https://extension.psu.edu/spotted-lanternfly, additional resources are listed on the Penn State Extension website. As stated in the article: “Penn State is at the forefront of education and research aimed at stopping the spread of this exotic species.” Penn State is seeking to hire an entomologist extension associate to coordinate outreach and response efforts for the SLF.
We are also planning to discuss Spotted Lanternfly management options at the Penn State Grape Disease & Insect Management Workshop, soon to be announced through the Penn State extension website and our listserv.
We would like to thank all the growers who participated in the survey. Their time spent responding to these questions provides us with valuable information that research and extension personnel can utilize to customize efforts to help the industry grow and improve. The more responses we receive, the more accurately our efforts can target the needs of our stakeholders statewide. Despite some challenges, it was a rewarding growing season for many PA wine grape growers. We are looking forward to tasting this season’s wines!
* All procedures were approved by the Office of Research Protections at The Pennsylvania State University (University Park, PA). Upon completion of the survey, each participant was entered into a raffle to win one of three $25 gift certificates that could be redeemed toward any Penn State Extension wine or grape program fee.
By Dr. Helene Hopfer
Since starting to work at Penn State last year, I am excited about all these local wines made of Austrian varieties. As a native Austrian, Grüner Veltliner, Zeigelt, and Blaufränkisch (called Lemburger in Germany and Kékfrankos in Hungary) and in particular, the (even) lesser known Rotgipfler, Zierfandler and St. Laurent, are near and dear to my heart (and my palate).
The more I learn about viticulture in Pennsylvania, the more similarities I discover: Similar to Pennsylvania, Austrian growers worry about late spring frosts, fungal pressure and fruit rot, wet summers, and damaging hail events . So it is only fitting to provide some details and insight to Austrian winegrowing and winemaking through this blog post.
Located in the heart of Middle Europe, the Austrian climate is influenced by a continental Pannonian climate from the East, a moderate Atlantic climate from the West, cooler air from the north and an Illyrian Mediterranean climate from the South. Over the past decades, the number of very hot and dry summers is increasing, leading to more interest in irrigation systems, as on average the annual average temperature in Austrian wine growing areas increased between 0.3 to 1˚C since 1990 .
Austrian wine growers also see a move towards larger operations: Similar to other wine regions in Europe, the average vineyard area per producer is increasing, from 1.28 ha / 3.16 acres in 1987 to 3.22 ha / 7.96 acres per producer in 2015. Many very small producers who often run their operations besides full-time jobs are now selling grapes or leasing their vineyards to larger wineries. A similar trend is true for wineries .
Different to other countries where widely known varieties like Chardonnay or Pinot noir make up the majority of plantings, the most commonly planted grape varieties in Austria are the indigenous Grüner Veltiner (nearly 50% of all whites) and Zweigelt (42% of all reds), followed by the white Welschriesling and the red Blaufränkisch (Lemburger). Another interesting fact is that over 80% of all planted vines are 10 years or older, with 30% of all vines being more than 30+ years old .
The Austrian wine market is very small on a global scale, with just over 45,000 hectares / ~ 112,000 acres of planted and producing vineyards by around 14,000 producers nation-wide . Nevertheless, Austrian wine exports are steadily increasing, particularly into countries outside of the European Union, such as the USA, Canada, and Hongkong, indicating a strong interest in this small wine-producing country. Austrian wines are considered high quality, attributable to one of the strictest wine law in the world, the result of the infamous wine scandal of 1985 . Today, the law regulates enological treatments (e.g., chaptalization, deacidification, and blending), levels and definitions of wine quality (e.g., the “Qualitätswein” designation requires a federal evaluation of chemical and sensory compliance), and viticultural parameters such as maximum permitted yield of 9 tons/ha or 67.5 hL/ha and permitted grape cultivars (currently 36 different varieties) .
One of the leading figures in developing the now well-established Austrian wine law was Johann Stadlmann, then president of the Austrian Wine Growers’ Association. During his 5-year tenure starting in 1985 at the peak of the wine scandal, he made sure that the wine law could be implemented in every winery and ensured strict standards; Johann Stadlmann could be called the father of the Austrian ‘Weinwunder’ (=’wine miracle’), the conversion of Austria as a mass-producing wine country to one with an emphasis on high quality.
Weingut Stadlmann – an estate with a very long history
If you ever visit Austria, you most likely fly into Vienna, the country’s capital. Vienna is one of the few cities in the world that also has producing vineyards located within city limits. Just outside of the city limits to the South, lies another important wine region in Austria, the so-called ‘Thermenregion’, named after thermal springs in the region. The region has a long wine history, dating back to the ancient Romans, and later Burgundian monks in the Middle Ages. The region is characterized by hot summers and dry falls, with a continuous breeze that reduces fungal pressure. One of the leading producers within the region is the Weingut Stadlmann, dating back to 1778 and now run by the eighth generation, Bernhard Stadlmann. He is the latest in a line of highly skilled winemakers that combine innovation with a conservative approach. His grandfather, Johann Stadlmann (yes, the same guy of the Austrian wine law), was one of the first ones in Austria to use single vineyard designations on his wine labels. Bernhard’s father, Johann Stadlmann VII, a master in creating wines from varieties only grown in this region, and named ‘winemaker of the year’ in 1994, is known for his careful approach and is now working alongside his son, Bernhard. In 2007, Bernhard started the conversion of the family-owned vineyards to certified organic. The family cultivates some of the best vineyards in Austria, including the single vineyard designations ‘Mandel-Höh’, ‘Tagelsteiner’, ‘Igeln’, and ‘Höfen’, planted with the indigenous varieties Zierfandler and Rotgipfler only grown here in the region. Wines from these vineyards are among the very best Austria can offer!
The vineyards cultivated by the Stadlmann family also differ quite dramatically in soil composition: While the ‘Mandel-Höh’ vineyard is highly permeable to water and nutrients, with lots of ‘Muschelkalk’ (limestone soil formed of fossilized mussels shells), is the ‘Taglsteiner’ vineyard characterized by more fertile and heavier ‘Braunerde’ soil, capable of retaining more water.
The long winemaking history becomes apparent once one steps into the wine cellar, full of large barrels, made of local oak: Some of these barrels have hand-carved fronts, depicting their vineyards and Johann Stadlmann senior. All of these barrels are in use, and part of the Stadlmann philosophy of combining tradition with innovation.
Another increasing threat is the spotted wing Drosophila, Drosophila suzukii, damaging ripening grape berries from véraison onwards. Bernhard sees some varieties more affected by Drosophila suzukii than others. There is intensive research on pest control, including shielding nets, fly traps, and insecticide strategies, and the Stadlmanns currently run experiments within their organic program: They blow finest rock flour (Kaolin and Dolomite rock) into the leaf canopy and fruit zone to create unfavorable conditions for different insects, including Drosophila, wasps, which pierce sweet berries, earwigs and Asian lady beetle, both leafing residuals causing off-flavors in the wine once they’re crushed. Drosophila suzukii was first discovered in Austria a few years ago and is also an issue in the US (see also Jody Timer’s blog post).
During a recent visit at the Stadlmann estate, I had the chance to chat with Bernhard about the challenges of Austrian winegrowing and winemaking. I was interested in a young winemaker’s perspective, especially as Bernhard has been trained all around the world, including Burgundy, Germany, and California. This year, spring frost in late April threatened vineyards in many winegrowing regions in Austria, requiring the use of straw bales and paraffin torches to produce protective and warming smoke. Luckily, not too much damage was done to the Stadlmann’s vineyards, however, it caused some sleepless nights for Bernhard and his family, and shows also the importance of developing effective spring frost prevention alternatives (see also Michela Centinari’s blog post).
We also talked quite a bit about wine quality: while the Austrian ‘Qualitätswein’ designation ensures basic chemical (e.g., ethanol content, titratable and volatile acidity, residual sugar, total and free SO2, malvidin-3-glucoside content (for reds), etc.) and sensory (i.e., wine defects like volatile acidity, Brettanomyces, atypical aging, mousiness and other microbial defects) quality, this only ensures a lower limit of quality. In the recent years, the Austrian governing bodies added another layer of wine quality, based on the Romanic system of regional typicity and origin: The so-called DAC (Districtus Austriae Controllatus) wines are quality wines typical for a region, made from varieties that are best suited for that region. DAC wine producers adhere to viticultural, enological, and marketing standards, with the goal to establish themselves as famous wines of origin (think Chablis, Cote de Nuits, Barolo, Rioja or Vouvray). As this is a relatively new system for Austria, we will see how successful these DAC regions will be. Their success will also depend on the regional producers, and how stringent they set the criteria for the DAC designation, as they have to walk a fine line between establishing a recognizable regional typical wine without losing individual character that each producer brings to their wines.
If you are interested in learning more about Austrian wines, and Bernhard and his family’s wines, they were recently highlighted in a couple of US wine publications, including a great podcast episode on ‘I’ll drink to that!’ and an article in the SOMM journal about Zierfandler. Zierfandler is one of Stadlmann’s signature varieties, indigenous to the region, but tricky to grow, as it requires long and dry ripening periods and has a very thin skin, prone to botrytis. However, when done well (like the Stadlmanns do), it produces extraordinary wines with fruity, floral, and sometimes nutty notes that have a long aging potential. If you are able to get your hand on these Zierfandler wines get them while you can!
Last, a big Thank You to Bernhard Stadlmann for his help with this blog post: He took time out of his super busy harvest schedule to show me around, never getting tired of answering my questions. He also graciously provided all but one of the pictures.
 Huber K (2017) Durchschnittliche Weinernte 2017 erwartet. LKOnline. Available at (in German): https://noe.lko.at/weinbau+2500++2455141
 Austrian Wine Marketing Board (2017) Austrian Wine Statistics Report 2015. Available at (in German): http://www.austrianwine.com/facts-figures/austrian-wine-statistics-report/
 New York Times (1985) Austria’s Wine Laws Tightened in Scandal. Available at: http://www.nytimes.com/1985/08/30/world/austria-s-wine-laws-tightened-in-scandal.html
 Austrian Wine (2017) Wine Law. Available at: http://www.austrianwine.com/our-wine/wine-law/