Characterization of Winegrowing Regions in Texas

Eight wine grape production regions are officially recognized as American Viticultural Areas (AVAs) in Texas. Improved understanding of the growing conditions within each AVA facilitates selection of well-adapted cultivars that is critical for continued success and expansion of the wine industry. The Texas AVA project developed and utilized a geographic information system to characterize the climatic, topographic, geologic, and edaphic conditions of eight AVAs in the State, and produced an interactive website, the Winegrowing Regions of Texas, for public access to the system.

Hellman, E.W., E.A. Takow, M.D. Tchakerian, and R.N. Coulson. 2011. Geographic Information system characterization of four appellations in west Texas, USA. Geoscience Canada 38(1):6-20.

2009 Texas Viticulture & Enology Research Symposium

The first Texas Viticulture & Enology Research Symposium, sponsored by Texas AgriLife Extension and Research and Texas Tech University, featured recent and ongoing research by a dozen Texas scientists. Two invited keynote speakers provided a national perspective: Dr. Peter Cousins, USDA-ARS grape rootstock breeder and geneticist described his research program to develop rootstocks for viticulture nationwide with a particular emphasis on pest and disease resistance; Patricia Howe, owner of 16019 Winery in Napa, California, shared her expertise in oxidation and other wine quality problems. A total of nineteen research reports were presented on a diversity of viticulture and enology topics ranging from pest management, deficit irrigation strategies, and economics, to wine stability, anti?cancer effects of Texas wines, and U.S. wine consumption trends. All proceedings papers are available for viewing or printing at: Proceedings of the 2009 Texas Viticulture & Enology Research Symposium.

Evaluation of Regulated Deficit Irrigation in Texas

Basinger, A.R. and E.W. Hellman. 2006. Evaluation of regulated deficit irrigation on grape in Texas and implications for acclimation and cold hardiness. International Journal of Fruit Science 6(2):3-22.

ABSTRACT. Deficit irrigation is used increasingly as a vigor management tool and to conserve water in grape vineyards. Several strategies including regulated deficit irrigation (RDI) have emerged, but none has been evaluated in Texas. Deficit irrigation has also been observed to influence vine acclimation and presumably vine cold hardiness. Experiments were established in a commercial 'Cabernet Sauvignon' (Vitis vinifera) vineyard in west Texas to evaluate RDI under local conditions and to study the potential for deficit irrigation to induce earlier shoot acclimation and influence cold hardiness. RDI significantly reduced pruning weights by as much as 46% and increased applied water-use efficiency up to 72%, but had little or no effect on yield components or fruit composition, indicating that these strategies could be useful in west Texas. Deficit irrigation was consistently associated with earlier and more rapid development of periderm on shoots, but had no effect on bud cold hardiness.

Evaluation of Abscisic Acid to Delay bud break of grapevines

Hellman, E.W., S. Shelby, and C. Lowery. 2006. Exogenously applied abscisic acid did not consistently delay budburst of deacclimating grapevine. Journal of the American Pomological Society 60:178-186.

ABSTRACT. An experimental formulation of abscisic acid (ABA; Valent Biosciences VBC-30025) was evaluated for potential to delay budburst of (Vitis vinifera L. winegrapes. Five experiments were conducted during 2004 and 2005 on dormant grapevine cuttings, container-grown vines, and field-grown vines to evaluate rates and/or timing of ABA applications. Two application methods were tested - spray application to buds or soil application. Spray application of ABA solutions to unopened buds increased the number of days to budburst by 3.5 days in one of four laboratory trials on single-bud cuttings, and delayed budburst by one day in established field-grown vines in one of two years. Further study to enhance the efficacy of ABA spray applications should examine materials or methods to improve penetration of ABA through bud scales. Soil applications of ABA to container-grown vines provided the greatest delay in budburst (up to 7 days) and gave the most consistent response. Soil application of ABA to established field-grown vines, however, produced no response and this may not be a practical or economical application method for commercial vineyards.