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WineEast The Potential of Hybrid Grapes Hybrids offer an element of consistency in cold-climate wine regions By Paolo Sabbatini and G. Stanley Howell I n "Vitis Hybrids: History and Current Status" (see the January 2014 issue of Wines & Vines), we explored the necessity that led to hybridization of wine grapes in Michigan and the Great Lakes region of the eastern United States. But once hybrid cultivars are developed, what challenges and opportunities do growers face? • Experience in Michigan and the Great Lakes region suggests that mixed viticulture—growing both vinifera and hybrid cultivars—is necessary to maintain economic viability of wineries in cool or cold climates. • ll wine regions, including those with cool A or cold climates, need to be able to produce two types of wine grapes: Those that will give the region a positive reputation, and those that can produce reliably every year. • In the future, the development of hybrid cultivars may help growers manage vine pests with fewer chemical inputs and allow for greater sustainability at lower cost. 74 W in es & V i ne s F E B R UARY 20 14 devito Wine East HIGHLIGHTS carlo The Michigan experience, 1970 to date Michigan soils are commonly sandy loams or loamy sands, and those soils are deep and well drained due to the state's glacial history. Michigan's climate is characterized by a short growing season (150 to 175 days) with cool-climate conditions (2,932 growing degree-days with standard deviation of ± sd 297) base 50°F. Yield and quality are often limited by several factors, namely spring freeze (50% chance of spring frost as late as May 15), early fall frost, high humidity and rainfall during the harvest season that promotes bunch rot. Hybrid cultivars used for wine in Michigan typically lack the strong flavors associated with Vitis labrusca and have a range of parental complexity from a simple crossing in Baco Noir to the very complex Traminette (see parentage on page 76). Baco Noir is the signature red wine grape variety at Hudson-Chatham Winery in Ghent, N.Y. Most hybrids are cultured as own-rooted (OR) vines, although there are exceptions. Chambourcin, Seyval Blanc and Valvin Muscat maintain vine size better when grafted. Because of the danger of winter freeze damage, graft unions require winter protection, and soil is mechanically mounded to cover the union while short spurs are maintained just above. That soil is mechanically removed the following spring to prevent scion rooting. Plant spacing is typically 8 feet within row and 10 feet between rows; own-rooted vines with less capacity to maintain vine size may be planted at closer within-row spacing, e.g., 6 feet. Training systems (see illustrations on page 76) are based on growth habit. Most hybrids produce a sessile, pendulous shoot habit resulting from larger leaves and longer internodes than typical for vinifera, and are trained to high systems as either cane-pruned, head-trained vines or as bilateral cordon-trained vines Baco Noir Folle blanche V. riparia Unlike some hybrid grape varieties, the parentage of Baco Noir is quite simple. at the top wire. These systems employ canes as bearers (five to eight nodes per cane for cordon, and 12-15 nodes per cane for head). In both cases, the height of the head or cordon is 6 feet. Most hybrids employ minimal canopy manipulation other than shoot positioning as described by Nelson Shaulis et al. (1966) for cultivars with similar shoot growth characteristics. Many hybrids possess the ability to produce fruitful shoots from "non-count" (Howell et al. 1987; Wolpert et al. 1983) base buds, giving them superior cropping ability, especially in years following severe winter cold, spring freezes or insect predation. This means cropping is different from the technique employed with most