Issue link: http://winesandvines.uberflip.com/i/573907
October 2015 WINES&VINES 79 to mitigate damage as best as possible, we should also keep in mind the following season and its crop as well as the effect our choices during pruning and re-training will have on it. Beyond our earlier discussion of the merits of spare-parts viticulture and graft-union pro- tection, there are several additional viticultural strategies that can mitigate the impact of win- ter cold, particularly seasonal quality assess- ment, crop estimation and crop adjustment as required. All are focused on achieving vine balance, where the goal is to produce a crop at the level that will allow desired fruit ripening to occur while reducing neither the next sea- son's cropping potential nor the cold hardiness of the vine. When effectively applied, this ap- proach can also contribute significantly to the diminution of crop losses due to spring freeze and the resulting conditions of poor fruit set. Grapevine balance has been reviewed at length previously (Gladstones, 1992; Howell, 2001) and begins with the contribution of L. Ravaz (1911), who calculated a ratio of vine yield to the weight of annual cane prunings to give us the Ravaz Index. The efforts of Newton L. Partridge in Michigan (1931) and Nelson Shaulis in New York (Kimball and Shaulis, 1958) provided a basis to make the Ravaz Index proactive by using the weight of cane prunings in year one as an indicator of the ability of a vine to ripen a crop in year two. This was ac- complished by allocating a specific number of nodes per vine at pruning based on winter prun- ing weight, and was called "balanced pruning." Richard Smart (1985, 1991) has demonstrated that the ratio of the exposed leaf area to the weight of the vine's crop was a more accurate way of expressing balance, and this has been shown frequently. Several published reports support the idea that excess cropping in the climate of culture for the cultivar reduced the cold hardiness of primary buds both during the late autumn (after leaf loss) and early spring (three weeks prior to bud break), and in general the negative impact on fruit ripening is less than on either vine size or hardiness. Achieving vine balance allows vines to fully express the complex sys- tem of genetic controls of cold hardiness at the metabolic, cellular, tissue and morphological levels that combine to yield the characteristic resistance to freezing stresses for that cultivar. It is our goal as viticulturists to minimize limits to this full genetic expression. Though logical, this speculation must be subjected to rigorous critical evaluation because the potential for producing useful grapevine culture informa- tion is considerable. WE Paolo Sabbatini is an associate professor of viticulture and extension specialist in the Department of Horti- culture at Michigan State University in East Lansing. G. Stanley Howell is professor of viticulture emeritus in the Department of Horticulture at MSU. Wine Packaging by Packaging Designed & Manufactured by a Wine Maker, for a Wine Maker 4138 Vineyard Road Stewartstown, PA 17363 Tel: 800-292-3370 Fax: 717-993-9460 Phone: 717-993-2431 Naylor Wine Cellars is a lifetime member of Wine America, Pennsylvania Wine Assoc, Ohio Wine Producers and NY Wine & Grape Foundation WPN is a premier supplier to over 2,000 wineries and wine & spirits shops. Our auto bottom carriers & shippers are the perfect sturdy solution for your retail & online sales! www.NaylorPackaging.com Features & Benefits - Extra sturdy construction for the most protection - Quick & easy to pack & set up - Folds to conform to many different bottles - Trademarked design - Bio-degradable - Quick delivery from our stock - Lies flat for easy storage - Takes up half the space of comparative packages - Tested & approved by UPS and Federal Express as a preferred method of shipping bottles - Custom imprinting and packaging is available to display your logo, enhancing your brand image WINE EAST GRAPEGROWING