Extension Bulletin E-2643 • New • February 1998 Wine Grape Varieties for Michigan SAMPLE PAGES Purchase a complete version of E2643 from the MSU Bulletin Office website. G. Stanley Howell, David P . Miller and Thomas J Department of Horticulture . Zabadal Table of Contents Introduction . 3 Varieties . 5 Labrusca varieties . 5 Environmental Limitations . 3 Winter cold . 3 Mixed-species resistant varieties . 6 White wine varieties . 7 Spring frost . 3 Red wine varieties. 10 Growing season length. 3 Heat unit accumulation . 4 Vinifera varieties . 13 White wine varieties . 14 What is a Variety? A Clone?. 4 Red wine varieties. 17 Michigan's Climate. 4 Rejected Varieties. 20 Grape Rootstock Varieties . 21 Variety Trials and Selection . 5 Additional Reading. 21 Tables . 22 Cover photo: Merlot grown on a Scott Henry training system at the Mike and Sandy Nitz farm near Baroda, Mich. 22 2 Introduction he past 25 years have been marked by major and acceptance by Michigan's wine industry will con- Tgrowth and major changes in grape production for tinue to be a major factor in the industry's improve- wine in Michigan. There has been change in the geo- ment in wine quality, production economics, and graphic area involved in commercial wine production respect in the national and international wine com- and a revolution in the grape varieties chosen for munity. It is crucial that both new and traditional vari- wine production. That revolution continues. Twenty- eties be carefully evaluated under Michigan condi- five years ago, the most important wine varieties tions. grown in Michigan were Concord, Niagara and The grape varieties that perform best under Michigan Delaware, and the wine style was heavily weighted to conditions must possess a range of desirable charac- dessert types. In 1990, less than 5 percent of Michigan teristics. First and foremost, a variety must produce wines were made from these varieties, and the pre- quality wine. Second, it must possess the genetic abili- dominant wine styles were dry white and dry red table ty to adapt to the climate and soils of the state and, wines. This revolution was the result of planting a while doing so, produce consistent commercial levels range of new varieties, and new variety evaluation of economically realistic production. Environmental Limitations Winter cold Spring frost Varieties vary considerably in their ability to withstand Varieties with adequate hardiness may be susceptible cold winter temperatures. Hardiness is a complex to spring frost. Varieties that begin growth early in the genetic characteristic of each variety that is influenced spring are particularly susceptible to frost and may by vine conditions during the previous growing sea- prove unacceptable commercially because of the high son — crop load, canopy management, pest control, probability of crop loss due to frost. date of harvest and leaf loss, general vine health, etc. Vine hardiness level is also influenced by the weather during the dormant season. Successful viticulture Growing season length requires that the variety be adapted to the variable Some hardy, frost-tolerant or late-bursting varieties conditions of freeze and thaw unique to the region cannot be grown in a particular area because they (macroclimate) as well as the site (mesoclimate). require a long and/or warm growing season to achieve the desired level of fruit quality and/or pro- duction. Therefore, some important later ripening varieties are limited to the warmest regions of the state. Careful matching of variety to macroclimate and mesoclimate is crucial. 22 3 Michigan’s Climate the most critical factor in achieving varietal character. most recent data that may be found in the annual The varieties listed below are those with which the reports of the Michigan Grape and Wine Industry authors have had direct experience in Michigan. Other Council (MGWIC), the Southwest Michigan Research varieties are being currently evaluated or evaluation is and Extension Center (SWMREC), the Northwest planned. Our goal here is to provide the reader with Horticultural Research Station (NHRS) and the an up-to-date statement of our current understanding Clarksville Horticultural Experiment Station (CHES). and to encourage readers to avail themselves of the Variety Trials and Selection ariety evaluation plots have been maintained by deemed unsuitable for Michigan as a result of mal- Vthe Michigan State University Agricultural adaptation or poor wine quality. It is easy to quantify Experiment Station over the past 28 years. The goal the benefit of a newly selected variety for the industry. has been to assess genotypic adaptation to the climate One can measure increased acres, increased gallons and soils, susceptibility to pests (see Table 1, p. 22), of wine, improved market share or industry profitabili- vine yield, fruit composition, ease of culture and, most ty. It is much more difficult to quantify the value of importantly, wine quality. Nearly every variety that has data that say do not plant that variety. We include a become important in Michigan's wine quality list of varieties at the end of the bulletin that have improvement revolution resulted from such a been evaluated and should not be planted in Michigan variety trial. Another less often considered Michigan. We submit that such data are also very benefit of such trials is the rejection of varieties valuable. Varieties he three general categories of grape varieties ease attack and increased cold hardiness (compared T being grown for wine in Michigan are: labrusca, with the V. vinifera parent). For these reasons, which are varieties with genetic and species back- European viticulturists are now more often referring to ground in Vitis labruscana; vinifera, which are derived these varieties as "resistant varieties" rather than the from Vitis vinifera, the native grapes of the Mideast and former, pejorative term "hybrids" as a result of their Europe; and mixed-species varieties, which have efforts to reduce pesticide inputs into their wine grape genetic contributions from V. vinifera and one or more culture. native American species (V. riparia, V. rupestris, V. aes- tivalis, V. lincecumii, V. longii, etc.). (V. labruscana and the strong varietal flavors associated with that species Labrusca varieties were not used in the production of the mixed-species A significant reduction has occurred in the culture of varieties.) Incorporating genes from native American V. labruscana-based varieties grown for wine in species increased varietal resistance to insect and dis- Michigan, and only two are being used. 22 5 Varieties Niagara is a white Weaknesses. variety that pro- Demand for duces wines of Concord wine is in strong varietal severe decline. aroma and flavor. It Early bud burst is also used in the results in spring production of frost hazard and dessert wines (dry puts the crop at and cream sherry). risk. The variety is It ripens about 10 not recommended to 14 days before for future wine Concord. grape plantings. Strengths. It has a long history of cul- Other Labrusca ture in Michigan varieties were and is adapted to grown for wine in the climate and Michigan's past. Niagara soils. Culture is Concord Only two, Delaware nearly 100 percent and Catawba, were mechanized, including pruning and harvest. The qual- grown to any extent. Both are now seldom seen, and ity of the cream sherry produced is excellent. planting them for wine is not recommended. Weaknesses. Strong flavor limits the market for white table wine. The market for cream sherry is low com- pared with that for table wines of similar quality. Mixed-species resistant varieties These market concerns suggest caution and a careful assessment of grape prices, production levels and pro- This second group of Michigan wine grapes has been duction costs before considering plantings of Niagara variously called "French hybrids," "French-American for wine production. hybrids," "American hybrids" and, most recently, "resistant varieties." In Michigan, we are fortunate that genes for improved cold hardiness were also incorpo- Concord is used for the narrow market of sweet, rated. The history of these varieties and market flavorful red wines often marketed as kosher wines. It response to them has been varied. Early varieties is late ripening, which limits production to southwest released by French breeders produced wines of mar- Michigan, where growing seasons exceed 165 days ginal quality and did much damage to the concept that and heat units (expressed as growing degree-days genetic improvement could be used as a means of [GDD] at base 50 degrees F) are 2,700 to 3,100. solving the inadequacies of the V. vinifera parent. Continued breeding efforts employing superior vinifera Strengths. It has been cultured in Michigan for more varieties back-crossed to first- and second-generation than 100 years and is clearly adapted to the climate interspecific varieties or selections have resulted in a and soils. It is very cold hardy. The culture is nearly number of varieties capable of producing high quality 100 percent mechanized. wines. In addition, the breeding efforts of Einset and Reisch at Cornell University and Moore at the 22 6 Varieties University of Arkansas, combined with the efforts of Cayuga White, Alleweldt, Eibach and Becker in Germany and formerly GW-3, was Hungarian breeders, continue to breed grapevines named by Cornell resistant to disease and insect attack that also possess University in the the capacity to produce fine wines. We have formal early 1970s. It is relationships with Dr. Reisch at Cornell University and similar in leaf and Drs. Alleweldt and Eibach at Geilweilerhof in the growth characteris- German Rhinepfalz that allow us to evaluate their tics to Vitis labrus- advanced selections and patented varieties in cana varieties. Michigan variety trials. Strengths. It is hardy and produc- White wine varieties tive, and the wines are pleasant and Aurore was an Germanic in style early selection when the fruit is among the inter- harvested prior to specific varieties for full ripeness.