Wine grapes have high economic value because of their combined farm gate price, associated agribusiness revenue, and attraction to tourists. Retail wine in the United States has an estimated value of ≈$30 billion and the state of California accounts for ≈90% of domestic wine production (U.S. Department of Commerce, 2011). The high economic potential of the wine industry has stimulated the expansion of wine grape acreage into climatic regions previously considered unsuitable for commercial production. Grape acreage in Idaho is second only to apple (Malus ×domestica) in percentage of total fruit acreage and it increased by 86% from 1999 to 2007 [U.S. Department of Agriculture (USDA), 2007]. Winery revenue in Idaho increased from $15 to 52 million from 2002 to 2008 (Bierle et al., 2008; Foltz et al., 2007). The estimated economic impact of the Idaho wine grape industry to the state of Idaho in 2008 was $73 million (Bierle et al., 2008).
The majority of vineyards in Idaho are located in the western Snake River Plain at elevations between 2280 and 2919 ft (Gillerman et al., 2006; Jones et al., 2010). Cold is a major factor that limits wine grape production in this region. Annual cold events in the spring and fall delimit the length of the growing season. Seasonal differences in growing season duration influence the ability of the vine to ripen fruit to maturity and to cold acclimate in the fall. Bud viability and vine vigor in the upcoming growing season are influenced by tolerance to midwinter cold and warming events as well as cold events that occur during deacclimation in the spring. Despite limitations imposed by cold temperature, other climatic features, such as the Mediterranean type pattern of precipitation, readily available supply of water for irrigation, high incidence of cloudless days, and high solar radiation offer major advantages for growing wine grapes in this region. The low humidity and high elevation of this region creates large diurnal temperature differences that facilitates fruit maturity by conserving respiratory substrates in the vine and berry. Cultivars of wine grape suitable for production in the western Snake River Plain of Idaho must be able to produce and ripen fruit at a commercially competitive quantity and quality during growing seasons of variable length and to survive exposure to winter cold.
Despite the large heterogeneity available among cultivars of wine grape, global wine grape production remains dominated by a few leading cultivars of European origin, with ‘Cabernet Sauvignon’ and ‘Merlot’ being the most widely planted red-skinned cultivars and ‘Thompson Seedless’ and ‘Airen’ being the most widely planted white-skinned cultivars (Fegan, 2003). Many leading white- and red-skinned wine grape cultivars have been found to produce commercially acceptable quantities of high-quality fruit with sustainable tolerance to cold (Fallahi et al., 2004; Shellie, 2007). The leading red-skinned cultivars Cabernet Sauvignon and Merlot comprise about a third of the commercial producing acreage in Idaho with the white-skinned cultivars Riesling, Chardonnay, and Gewürztraminer making up the rest (Gillerman et al., 2006). Fruit produced in Idaho must compete for winery contracts against fruit grown in more established, well-known production regions. Wine grape cultivars of European origin, not currently being grown commercially in well-established, competing production regions, may offer an economic alternative for growers in nontraditional growing regions. However, little information is available about how these alternative cultivars perform in regions where the growing season is delimited by winter cold.
The objective of this study was to evaluate the viticulture performance of some alternative wine grape cultivars under the growing conditions of southwestern Idaho and compare their yield, fruit maturity, and cold tolerance to that of leading cultivars already in commercial production in this region. A field trial was established in a commercial vineyard in southwestern Idaho where the performance of ‘Cabernet Sauvignon’ and ‘Merlot’ was compared with wine grape cultivars from production regions in Portugal, Spain, Italy, Austria, Chile, and France. The practical goal of this research was to identify novel planting material with potential to enhance the competitiveness of wine grape production in less traditional production regions with climatic conditions similar to southwestern Idaho.
BierleK.HolleyD.BlackG.2008The economic impact of the wine industry on Idaho’s Economy. Boise State Univ. Ctr. Business Econ. Res. Boise ID
EhlenfeldtM.K.AroraR.2008Cold tolerance of blueberry genotypes throughout the dormant period from acclimation to deacclimationHortScience4319701974
FallahiE.ShafiiB.FallahiB.StarkJ.C.EbgelA.L.2004Yield, quality attributes, and degree day requirements of various wine grapes under the climatic conditions of Intermountain West regionJ. Amer. Pomol. Soc.58156652
FeganP.W.2003The vineyard handbook: Appellations maps and statistics. Chicago Wine School Chicago IL
FergusonJ.C.TararaJ.M.MillsL.J.GroveG.G.KellerM.2011Dynamic thermal time model of cold hardiness for dormant grapevine budsAnn. Bot. (Lond.)107389396
FoltzJ.C.WoodallS.WandschneiderP.R.TaylorR.G.2007The contribution of the grape and wine industry to Idaho’s economy: Agribusiness and tourism impactsJ. Agribusiness257791
GillermanV.S.WilkinsD.ShellieK.C.BitnerR.2006Geology and wine 11: Terroir of the western Snake River Plain, IdahoGeoScience Can.333748
HammanR.A.JrDamiI.E.WalshT.M.StushnoffC.1996Seasonal carbohydrate changes and cold hardiness of Chardonnay and Riesling grapevinesAmer. J. Enol. Viticult.73136
IlandP.N.BruerN.EdwardsG.WeeksS.WilkesE.2004Chemical analysis of grapes and wine: Techniques and concepts. Patrick Iland Campbelltown Australia
JonesG.V.DuffA.A.HallA.MyersJ.W.2010Spatial analysis of climate in wine grape growing regions in the western United StatesAmer. J. Enol. Viticult.61313326
KalbererS.R.WisniewskiM.AroraR.2006Deacclimation and reacclimation of cold-hardy plants: Current understanding and emerging conceptsPlant Sci.171316
LittleT.M.HillsF.J.1978Agricultural experimentation design and analysis. Wiley New York NY
U.S. Department of Agriculture1972Soil survey of Canyon Area Idaho. U.S. Govt. Printing Office Washington DC
U.S. Department of Agriculture2007Census of agriculture. 28 Dec. 2012. <http://www.agcensus.usda.gov/Publications/2007/Full_Report/Volume_1,_Chapter_2_US_State_Level/st99_2_032_032.pdf>
U.S. Department of Agriculture2013Web soil survey. 21 Nov. 2013. <http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx>
U.S. Department of Commerce2011U.S. wine industry: 2011. 22 Jan. 2013. <http://www.ita.doc.gov/td/ocg/wine2011.pdf>
U.S. Department of the Interior2013Agrimet: The Pacific Northwest cooperative agricultural network. 3 Jan. 2013. <http://www.usbr.gov/pn/agrimet/wxdata.html>
WatsonJ.1999Washington viticulture: The basics p. 13–20. In: J. Watson (ed.). Growing grapes in eastern Washington. Good Fruit Grower Yakima WA
WinklerA.J.CookJ.A.KliewerW.M.LiderL.A.1974Climate and soils p. 61–71. In: A.J. Winkler J.A. Cook W.M. Kliewer and L.A. Lider (eds.). General viticulture. 2nd ed. University of California Press Berkley CA
WolfT.K.PoolR.M.1987Factors affecting exotherm detection in differential thermal analysis of grapevine dormant budsJ. Amer. Soc. Hort. Sci.112520552