RESEARCH SPOTLIGHT

Midwest Grape & Industry Institute

Research focuses on cold-hardy grape cultivars

By Ted Rieger, senior feature editor

valuating cold-hardy cul- and extension at Southwest Mis- statewide vineyard and wine pro- tivars in vineyard trials, souri State University. He has also duction and sales activities at $234 identifying quality wine char- worked in the commercial sector, million. The industry accounted acteristics of these cultivars, and helping to establish wineries in for 1,773 jobs and $50 million in providing analytical services for the Ohio and Indiana. wages. Wine production in 2008 Iowa wine industry are major goals Although ISU does not have reached a total of 187,000 gallons of and enology research specific academic programs for and retail sales totaled $7.6 million. and extension at Iowa State Uni- viticulture and enology, the MGWII In 2008, there were 74 licensed versity (ISU) in Ames, Iowa. ISU is has partnered with two community wineries and approximately 1,000 home to the Midwest Grape and colleges – Des Moines Area Com- acres of vineyards. Most Iowa Wine Industry Institute (MGWII), munity College and Kirkwood Com- which includes faculty from the munity College in Cedar Rapids – to Department of Horticulture and the develop and offer certificate pro- Department of Food Science and grams in viticulture and enology. AT A GLANCE Human Nutrition.  The Midwest Grape and Wine The MGWII was established Iowa’s Wine Industry Industry Institute was established in 2006 as a cooperative effort by to perform research and provide ISU Extension and the Iowa Wine In the early 20th century, prior extension services for the Iowa Growers Association (IWGA). Iowa to Prohibition, Iowa was the sixth- wine industry. wine sales are taxed at a rate of largest grape production state in $1.75 per gallon, with 5% of this the United States. A modern resur-  MGWII’s research focus is on revenue designated to fund the gence in Iowa grape and wine pro- vineyard field trials and quality institute. MCWII is also supported duction began in the 1990s, and wine production with cold-hardy by ISU Extension, federal research the state’s wine industry has grown cultivars. grants, IWGA and regional winery significantly in less than 15 years.  Cultivars that produce aromatic associations. Today it is home to more than 90 white and sparkling wines Dr. Murli Dharmadhikari, direc- bonded wineries and 1,200 bearing offer good promise in Iowa. tor of the MGWII, came to ISU in acres of vineyards.  The MGWII and the Iowa Wine 2005 as the extension enologist in The Iowa Wine Industry Eco- Growers Association plan to the Department of Food Science nomic Impact Study, conducted by launch an Iowa Vintners Quality and Human Nutrition. He previ- MKF Research of St. Helena, Calif., Alliance certification program. ously provided enology research for 2008, calculated the value of

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wine is consumed within the state. is operating a wine laboratory for and wine, is produced by plants in Production estimates for 2010 by the Iowa wine industry, which is response to fungal infection, and MGWII project coordinator Craig used by commercial wineries on a has been shown to have human Tordsen were 283,000 gallons of fee-for-service basis. “Part of our health benefits as an antioxidant. wine with sales of 231,000 gallons. service is to provide basic wine Dharmadhikari was co-author Although vineyards are distrib- analysis, both chemical and sen- of a paper on this new analysis in uted throughout Iowa, more acre- sory, and to make recommenda- the Journal of Chromotography, age is planted in the southern half tions to winemakers on what to do published in 2009. He said he is of the state, which tends to have prior to bottling the wine,” Dhar- interested in doing further analy- slightly warmer temperatures. madhikari said. MGWII staff ses of cold-hardy red-grape variet- Dharmadhikari said the northern includes research associates Dr. ies to see if there is a relationship part of the state must primarily Jun Dang, who manages the lab, between resveratrol levels and grow cold-hardy varieties (where and Jennifer Hansen, who assists grape resistance to fungal diseases. winter temperatures dip as low with research, outreach, education Dharmadhikari listed three major minus 35°F), whereas southern and lab analysis. enological research areas of MGWII areas can accommodate a wider On the research side, Dharmad- that address Iowa wine industry range of hybrids and Native Ameri- hikari worked with colleagues in needs: can cultivars. One of the largest the food science department to concentrations of vineyards and develop a new rapid-determination 1. Imbalance in fruit chemistry: wineries is in Warren County, south method for trace analysis of trans- Iowa wines tend to be high in pH of Des Moines. resveratrol in red wines, using sol- and acidity, particularly with malic id-phase microextraction (SPME), acid. Researchers are looking at Enological Services and with on-fiber derivitization and wine deacidification methods, Research multidimensional gas chromatogra- the use of different yeast strains, phy-mass spectrometry (GC-MS). and filtration technologies to A major function of the MGWII Resveratrol, found in red grapes reduce acidity.

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2. Red-wine quality: Low tannin gris, La Crescent, La content and tannin stabilization Crosse and St. Pepin. For reds, he are issues for red wines. listed frontenac, , sabre- vois, St. Croix and Swenson red. 3. Flavor chemistry: The industry Dharmadhikari said brianna and La does not have a good under- Crescent have good potential for standing of the flavor profiles sparkling wine. of new varieties being planted. Therefore, research is needed to Viticulture Focus on identify flavor components and Cold-Climate Cultivars marker compounds to determine optimal harvest dates, and to A significant focus of the viti- improve viticultural and enologi- culture program has been on field cal practices to enhance flavor trials to evaluate the suitability of profiles. cold-climate cultivars for Iowa and the upper Midwest states. “We have the challenges of Cultivars that can tolerate winter high acidity, a short growing sea- freeze periods and undergo late- son and high humidity,” Dharmad- spring bud break to avoid spring hikari said. “At the present time, frost damage are needed to reliably aromatic white-wine varieties and produce annual crops. In addition, sparkling wines seem to have the successful cultivars should have greatest potential for quality wine good pest and disease resistance production.” He said he believes and be able to mature fruit during a the more promising white variet- short growing season. ies being grown include brianna, Dr. Paul Domoto of the Depart-

Trials are conducted in various locations with different soil and climatic condi- tion. This trial block at Tabor Home Vineyards and Winery near Baldwin is planted to MN-1220.

ment of Horticulture and the MGWII staff have been involved in cultivar research trials since 2002. ISU has four research facili- ties where trials are conducted: the ISU Horticulture Research Sta- tion at Ames, the ISU Armstrong Research and Demonstration Farm in Lewis, the ISU Southeast R & D Farm in Crawfordsville, and the ISU Northeast R & D Farm in Nashua. These sites represent three differ- ent climatic and four different soil conditions. Trials are also conduct- ed in cooperation with Tabor Home Vineyards and Winery at its prop- erty near Baldwin. A cultivar trial was established in 2002 at the Ames and Armstrong Farm stations, with a grant from the Leopold Center of Sustainable Agriculture, to study grape culti- vars by management system. Ten are being evaluated: marechal foch, frontenac, , St. Croix, cham-

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bourcin, , , ters to observe fruit characteristics. cialist Mike White publishes a free , and edelweiss. Marquette and MN-1220 showed newsletter called the “Wine Grow- Results and data from the 2010 susceptibility to anthracnose. Fron- er News,” which includes updates growing season showed differing tenac, MN-1200 and MN-1235 during the growing season. White effects of the 2009-2010 winter show susceptibility to black rot. listed several areas of focus for that had significant freeze periods in December and January (down to minus 21°F) and a spring frost in May 2010, down to 29°F. At both sites, injury was greatest to the cultivars classified as “slightly” or “moderately” cold hardy, while those classified as “very” cold- hardy had the least bud injury. At the Ames site, , trami- nette and vignoles failed to produce a crop and were among the lowest- producing cultivars at Armstrong Farm. The highest-yielding cultivars at each site were frontenac and La Crosse; St. Croix, marechal foch, seyval blanc and edelweiss also produced a usable crop. Among the red varieties, frontenac and mare- chal foch showed better overall fruit chemistry in terms of percent of soluble solids and pH. Seyval blanc and La Crosse showed better among the white varieties. As part of the Northeast regional research project, NE 1020 “Multi- ISU researchers conducted trials of cold-hardy cultivars at Tabor Home Vineyards as state Evaluation of Wine Grape Cul- part of the larger NE 1020 research project. tivars and Clones,” Domoto and Dr. Gail Nonnecke of the Department A list of more than 70 cold-cli- the future: canopy management of Horticulture began ISU trials in mate cultivars with links to more and fruit loads for optimum quality 2008 at the Ames station and at information on each can be found and yields, vineyard mechanization, Tabor Home Vineyards on cold-har- at http://viticulture.hort.iastate.edu/ and better methods for controlling dy grape cultivars. These include cultivars/cultivars.html anthracnose, black rot, downy mil- several from the University of Min- dew, phomopsis and powdery mil- nesota Cold-Hardy Grape Breeding V&E Extension dew. Program: La Crescent, Marquette, MGWII staff members have writ- MN-1189, MN-1200, MN-1220, Proper site selection is being ten several publications and short MN-1235, MN-1258 and petite promoted through extension pro- guides for grapegrowing and wine- amie, in addition to corot noir and grams and publications designed making operations, which are post- NY 95-0301-01 developed at Cor- to match cultivars to vineyard sites. ed on the Institute’s website. The nell University. Frontenac and St. The coldest temperatures occur MGWII also conducts educational Croix are planted as controls. under radiation freeze conditions workshops and field days for the Some initial information was when there is little air movement industry and is involved with the gathered following the 2010 sea- and cold air settles in low-lying IWGA annual conference. son that put the young vines to areas. It is recommended that vine- the test with winter freezes and yards be planted in locations that Iowa Vintners Quality a May 2010 frost. MN-1189 broke are 50 feet or more above a valley Alliance bud later than the other Minnesota floor. It is also recommended that selections, and MN-1200, MN-1235 soils be tested before planting. The Since 2008, the MGWII has been and Marquette showed some tol- ISU Soil and Plant Analysis Labora- working with the IWGA to estab- erance to spring frost. Few vines tory provides such testing to grow- lish an Iowa Vintners Quality Alli- carried any crop at the Ames sta- ers to assist with vineyard design ance (IVQA) program similar to VQA tion, and vines at Tabor Home were and cultivar selection. programs that exist in Canada. This allowed to carry one or two clus- Viticulture extension field spe- would be a voluntary, fee-based

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certification and labeling program eries do well with direct sales in traits and flavor characteristics in for wineries to submit samples to their tasting rooms; the IVQA seal cold-hardy cultivars. “People are the MWGII lab for chemical and is expected to help Iowa wines interested in looking at grape and sensory testing, using standards gain better acceptance and place wine quality from a genetic stand- established by the industry. Dhar- more wines in Iowa restaurants, point. For example, identifying the madhikari said the Alcohol and and eventually help expand sales genes and mechanisms that cause Tobacco Tax and Trade Bureau has beyond the state’s borders. the expression or non-expression been contacted about the program of malic acid in cultivars grown here and sample certification seals have Future Directions would be of great interest,” he been designed. Two are planned: said. “Iowa Quality Wine,” for wines For future projects, Dharmad- For more information, see the certified under the program made hikari said he hopes to test “flash ISU Department of Horticulture from 100% Iowa-grown grapes; dentente” technology (featured in website at http://viticulture.hort. and “Quality Wine,” for wines pro- the September-October issue of iastate.edu, or the MGWII web- duced in Iowa that may have wine V&WM) on red-grape varieties dur- site at www.extension.iastate.edu/ blended in from grapes grown out- ing the 2012 crush to assist with wine.  side the state. under-ripeness issues. “If this is a Dharmadhikari is optimistic the good technology that can reduce Ted Rieger, CSW, is a writer and program can be launched in the grassy and herbaceous notes in red photographer based in Sacramento, near future with a consumer infor- wines and enhance fruit compo- Calif., and has been a contributing mation campaign. He said about 20 nents, it’s something we should be editor for V&WM since 1990. IWGA winery members, represent- using,” he said. ing most of the state’s larger winer- Noting that grape genetics are Comments? Please e-mail us at ies and a significant percentage of a focus of research in Minnesota [email protected]. total production, have expressed and South Dakota, Dharmadhikari interest in participating in the IVQA said he wants to see more research program. Most of the state’s win- to determine how genes express

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