‘Seyval Blanc’ (Seyve-Villard 5–276) is a French–American hybrid grape cultivar used in the production of white wines. Because of its cold hardiness and early ripening (Wolf, 2008), ‘Seyval Blanc’ is grown in such places as the Finger Lakes of New York, Ontario, Canada, and numerous other locations in eastern North America. However, one major detriment of ‘Seyval Blanc’ is that it has a propensity to overcrop (Reynolds et al., 1986).
Hybrid grapevines often do not respond to balanced pruning techniques like many other grape cultivars due to fruitful basal buds (Pool et al., 1978) and secondary shoots that are not accounted for in balanced pruning techniques. Consequently, severe dormant pruning generally does not balance excessive fruit production as intended. However, ST is a technique that has been reported to decrease yield and open the canopy to improve the fruit quality of several French–American hybrids including ‘Marechal Foch’ (Sun et al., 2011), ‘Seyval Blanc’ (Reynolds et al., 1986), as well as Aurore, Chancellor and Villard noir (Morris et al., 2004). It has been suggested that ‘Seyval Blanc’ vines should be thinned to a density in the range of 12–19 shoots/month of row to obtain a desirable canopy (Reynolds et al., 1986).
Reducing a crop through CL to attain an optimal leaf area to fruit ratio in hybrids has been thoroughly examined (Hummell and Ferree, 1998; Kaps and Cahoon, 1989; Mabe 1983; Morris et al., 1987, 2004; Wolpert et al., 1983). CL generally results in fewer clusters per vine and greater individual cluster weights in hybrids (Reynolds et al., 1986; Wolpert et al., 1983) and has been reported to impact various quality metrics in ‘Seyval Blanc’ (Hummell and Ferree, 1998), ‘Vidal Blanc’ (Howell et al., 1987; Wolpert et al., 1983), ‘Chambourcin’ (Prajitna et al., 2007), ‘De Chaunac’ (Fisher et al., 1977; Reynolds, 1989; Wood and Looney, 1977), and ‘Marechal Foch’ (Sun et al., 2011).
Although the literature on hybrid wine grapes indicates that crop load management techniques such as ST and CL often improve fruit quality of cultivars prone to overcropping, commercial producers must consider the economic trade-off between implementation costs and potential economic benefits (Preszler et al., 2010). Economic justification for ST and CL is complicated by the fact that grapes of ‘Seyval Blanc’ and other hybrids generally demand a relatively low price compared with vinifera (Vitis vinifera) cultivars in New York State and elsewhere. As a result, it is important for growers to maintain low production costs and to fully understand the potential economic impact of improving wines through CL and ST (Preszler et al., 2010). The objective of this study was to determine the impact of both CL and ST on yield components, fruit composition, consumer wine preference, and costs of production of ‘Seyval Blanc’.
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