Extension Bulletin E-2642 • New • December 1997 Table Grape Varieties for Michigan SAMPLE PAGES Purchase a complete version of E2642 from the MSU Bulletin Office website. Thomas J . Zabadal, G. Stanley Howell and David P Department of Horticulture . Miller Table of Contents Introduction . 3 Einset Seedless . 10 Reliance. 11 I. Seedless Varieties . 5 Saturn . 11 White . 5 Suffolk Red . 11 Himrod . 5 Vanessa . 11 Interlaken Seedless . 5 Lakemont . 6 II. Seeded Varieties . 12 Marquis . 6 White . 12 Remaily Seedless . 6 Seneca. 12 Romulus . 7 Kay Gray . 12 NY65.479.2 . 7 Edelweiss . 12 V64023 . 7 Golden Muscat . 13 Blue . 7 Blue . 13 Concord Seedless . 7 Buffalo . 13 Glenora . 7 Alden . 13 Mars. 8 Steuben . 13 Venus. 8 Sheridan . 13 ES3-22-18 . 8 Red . 13 NY46.290 . 8 Swenson Red . 13 NY65.479.1 . 9 Yates . 13 NY65.483.2 . 9 III. Sources of Vines . 14 Red . 10 Canadice . 10 Appendix A. 15 Challenger . 10 Cover photo: Clusters of Romulus grapes that were manipu- lated with giberellic acid sprays, cane girdling and cluster thinning. MSU Southwest Michigan Research and Extension Center, 1990. 22 2 Introduction able grapes are an important food category in the Vine hardiness is critically important to Michigan TUnited States. Per capita consumption of table growers. Descriptions used in this publication may be grapes has quadrupled over the past 25 years, with interpreted as follows: slightly hardy = significant win- annual consumption now exceeding 7 pounds. Table ter injury to vines occurs at -5 to -10 degrees F; mod- grapes now rank fourth in fresh fruit per capita con- erately winter hardy = significant winter injury to vines sumption after bananas, apples and oranges. at -10 to -15 degrees F; hardy = significant winter injury to vines at -15 to -20 degrees F; very winter Portions of Michigan are conducive to commercial hardy = significant winter injury to vines at tempera- table grape production because they have a favorable tures from -20 to -35 degrees F. Winter minimum tem- growing season, well drained soils, an extensive infra- perature data for several locations in Michigan (Fig. 1) structure for fresh marketing of horticultural crops and indicate regional trends for suitability of table grape proximity to a large portion of the U.S. population. production. Areas along the Great Lakes shoreline are Other areas of Michigan will support successful back- generally good to excellent for table grapes. Areas yard table grape vineyards. inland in the lower one-third of the Lower Peninsula Over the past 50 years, a large number of table grape are generally acceptable for varieties that are at least varieties with potential in Michigan have been moderately hardy, and the Upper Peninsula and inland released from several grape breeding programs. portions of the upper two-thirds of the Lower Reports and nursery catalogs often suggest that many Peninsula are generally unacceptable for grapes. varieties are excellent and worthy of culture. In reality, There are exceptions to these generalizations. however, only a small percentage of them are actually Furthermore, even if a regional climate favors grape worth planting in Michigan. This publication identifies production, the characteristics of a specific vineyard varieties with potential in Michigan by summarizing site must be evaluated. years of evaluation of numerous named and unnamed Time of fruit ripening in this publication is for grapes table grape varieties. at the Southwest Michigan Research and Extension Large quantities of the native American grape vari- Center at Benton Harbor, which has a growing season eties Concord, Niagara, Delaware and Catawba were of approximately 2,600 growing degree-days (base 50 grown years ago in Michigan for table grapes. These degrees F) from April 1 to September 30. Fruit maturi- and other seeded table grape varieties have become ty classes are: early = fruit ripens from August 15 to less important with consumers, who now tend to pre- September 7; midseason = fruit ripens from September fer seedless table grapes. Therefore, this publication 8 to September 22; late season = fruit ripens emphasizes seedless table grape varieties. September 23 or later. Presentation of seeded table grape varieties is limited Fruit appearance — cluster compactness, berry size, to a list of "top 10" choices. berry color and fruit maturity — greatly influences Descriptions of varieties include not only their physi- table grape marketability. Those characteristics that cal characteristics but also their major strengths and influence fruit appearance are highly influenced by weaknesses. There are no perfect table grape vari- cultural practices, which often must be uniquely tai- eties! Fortunately, a weakness does not eliminate a lored to each variety. Therefore, successful cultivation variety from consideration for planting. of table grapes involves not only choosing a good 22 3 Introduction Houghton (10,8,6,4) Grand Marais (10,8,3,1) Sault Ste. Marie (10,10,10,8) Herman (10,10,10,9) Ironwood Chatham (10,10,10,10) (10,10,8,7) Iron Newberry Mountain (10,9,7,3) (10,10,10,8) Stephenson (10,10,8,8) Vanderbilt Maple City (10,10,10,10) Alpena (8,4,1,1) (10,10,8,4) Grayling (10,10,10,8) East Tawas Manistee (10,8,5,1) (6,3,2,1) Gladwin (10,9,7,3) Big Rapids (10,9,7,3) Muskegon (8,3,0,0) Saginaw (9,4,1,0) Holland (9,4,1,0) Lansing (10,8,4,2) Detroit South Haven (8,4,1,0) (5,1,0,0) Bloomingdale (9,6,2,0) Benton Harbor Adrian (6,3,1,0) Dowagiac (10,6,2,1) Monroe (9,7,4,1) (7,3,1,0) Eau Claire (7,4,2,0) Fig. 1. The values in parentheses indicate the number of years per 10-year period when the location experienced -5, -10, -15 or -20 degree F temperatures. Values are averaged for the 30-year period from 1961 to 1990. Data courtesy of J. Andresen, Michigan State University Department of Geography. 22 4 I. Seedless Varieties variety but also applying appropriate cultural prac- ty. Detailed information on planting, pruning, training, tices. For this reason, comments on the culture of the pest management, harvesting, storage, packaging, most desirable varieties are included with their etc., for table grapes is available in publications listed descriptions whenever possible. in Appendix A. Common cultural practices in the production of seed- Storage life is another important characteristic of table less table grapes are: applying gibberellic acid (GA) grapes. A typical farm storage kept near 32 degrees F sprays, which can reduce berry number per cluster will allow at least fair storage of most varieties for two and/or increase berry size; girdling canes or trunk, weeks if efforts are made to maintain high humidity. which can increase berry number per cluster and/or Some varieties are capable of good or excellent stor- increase berry size; and thinning, which reduces the age under such conditions and will maintain quality crop level on the vine to ensure acceptable fruit quali- for 3 to 4 weeks or longer. I. Seedless Varieties White Major strengths: High fruit quality; reli- able responses to gibberellic acid Himrod (N.Y.) Vines are moderately sprays and girdling. hardy and moderately vigorous. Recommendations: Commercial pro- Berries are round and small with an duction and home production on good adherent skin. Flesh is soft with good sites if girdling is used and gibberellic flavor. Seeds are very small and soft. acid sprays will be practiced. Clusters in their natural condition are long and loose. Fruit responds very Interlaken Seedless (N.Y.) Vines are well to gibberellic acid (GA) applica- slightly hardy and moderately vigor- tions and girdling (Fig. 2). Necrosis of ous. Berries are oval and medium- the terminal portion of the cluster sized with an adherent skin. Flesh is rachis becomes more prevalent with soft with a strong flavor. Seeds are increasing cluster size. Berry thinning, soft and small. Clusters are medium- which involves removing the bottom sized and compact. The fruit ripens half of the cluster, counteracts this very early. fault. Himrod has moderate suscepti- Major weakness: Low hardiness. bility to berry cracking and fruit rot. Fig. 2. A 'Himrod' cluster from a vine that was manipulated with Major strengths: Very early ripening; The fruit is early ripening and stores gibberellic acid sprays at bloom strong flavor. fairly well. and fruit set, cane girdling at fruit set and cluster thinning of Recommendations: Home plantings Major weakness: Postharvest berry the vine. only if very early fruit production is shatter. desired on good sites and if gibberellic acid sprays will be applied. 22 5 I. Seedless Varieties Lakemont (N.Y.) Vines are medium hardy and mod- to large and soft. Clusters are long, large and loose. erately vigorous. Berries are round and small to medi- Fruit ripens midseason and stores fair. Vine is suscep- um-sized with an adherent skin. Flesh is firm and tible to downy mildew. Gibberellic acid applications mild-flavored. are phytotoxic to vines and cause crop failure. Vines Seeds are small respond well to flower cluster (Fig. 4) and berry thin- and fleshy but ning. Fruit is resistant to cracking during rainy harvest become larger and periods. Skin thick- occasionally woody ness becomes less with vine manipu- noticeable as fruit lation. Clusters are ripens. Vines tend long, medium to to overbear. Berry large and moder- thinning is the pre- ately compact. ferred crop adjust- Vines are moder- ment practice. ately to highly sus- Major weaknesses: ceptible to downy Thick skin; seed mildew. Fruit is size; fruit storage subject to cracking limitation; downy and rot during rainy mildew harvest periods. susceptibility. Vines tend to over- Major strengths: Fig. 3. A well filled, large cluster bear and should be of 'Lakemont' from a vine that thinned after fruit Thick skin affords was manipulated with gibberellic set.