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80 W i n e s & V i n e s A U G U s T 2 0 1 4 WineEast Grapegrowing spring frosts. Cold-hardy varieties should be planted on mid-slopes for warmer tem- peratures, with high fruiting wire training and multiple trunks. Viticultural practices may include delayed pruning or double pruning, the use of wind machines, careful balancing of the crop load, canopy manage- ment for light exposure, water management to encourage early acclimation and field and/or winery sorting of fruit to increase uniformity. Insufficient water obviously has an im- pact on both grapevines and their grapes. Grapevines may have reduced shoot growth and leaf size, reduced carbohydrate re- serves and earlier shoot maturation. The fruit will have smaller berry size, lower yield, incomplete ripeness and a higher concentration of phenolics. Vineyard design will have to include developing a water source (or finding a different site), use drought-tolerant rootstocks and a low-vigor trellis system. In contrast, regions with excessive water can have too much vine vigor, with con- comitant shade problems. Acclimation may be delayed, with reduced cold hardiness resulting. Berry size may be larger, clusters tighter, and fruit may be prone to berry cracking, increasing the po- tential for bunch rot diseases. Measures must be taken within the vineyard to reduce vine vigor through wider vine spac- ing, the use of permanent competitive cover crops and training systems to accommo- date high vigor. Disease and canopy management are most important. In summary, Hellman noted that environmental factors interact (light exposure, temperature and water), and growers must integrate the man- agement of the whole system. Variety development for challenging environments Peter Hemstad, grape breeder at the Hor- ticulture Research Center at the University of Minnesota, has experienced some of the most challenging of environments for grow- ing grapes. According to Hemstad, Minne- sota had 53 days with temperatures below 0° F during the winter of 2013-14, and to compound the difficult growing conditions, some regions received more than 13 inches of rain in June 2014. Given a climate with those challenges, Hemstad has specific goals he is looking for when breeding grapes: cold hardiness, disease resistance, growth habit, productivity and (of course) wine quality. Or course, Hemstad is not the first grape Waterloo_Nov10.qxp 8/26/10 11:36 AM Page 1 Viticulturist Ed Hellman discussed the use of trellising systems to control vine vigor at the ASEV national meeting. ED HELLMAN