/AnMtgsAbsts2009.55849 Terroir of Southeastern Pennsylvania Viticulture: An Analytical Hierarchy in a Udic Soil Moisture Regime.

Wednesday, November 4, 2009: 1:10 PM
Convention Center, Room 413, Fourth Floor

James Fisher, Soil Solutions, LLC, Malvern, PA
Growing wine grapes in a humid climate poses many challenges to the viticulturist. The inherent difficulties are overcome with innovative methods to combat disease, reduce plant vigor, and enhance soil fertility in order to achieve balanced growth in the vineyard. By choosing an optimal site in a udic soil moisture regime, the grape grower can alleviate multiple problems at the outset.
Development of an analytical hierarchy assists the grower in site selection (Itami et al., 2000). Assignment of values to parameters of soils, terrain, and micro-meteorology results in a rating which can be used by the viticulturist to determine a suitable variety of grape to grow. An expansive scoring key designates three levels of suitability for the site, specifically Vitis vinifera varieties, hybrid and native North American varieties, or using the site for another crop.
Once a site has been determined as suitable for V. vinifera, the specific varieties must be chosen. Evaluation of specific criteria is necessary to assign the optimal variety to the site. For example, V. vinifera ‘Chardonnay’ is highly susceptible to the fungal disease known as powdery mildew, which is caused by Erysiphe necator. In this situation a slope shape of convex/convex would increase the micro-meteorological component known in viticulture as “air-drainage.” A site with this surface morphometry would be more suitable for Chardonnay than a site with a linear or concave slope shape.
In addition to providing guidelines for suitable varieties, the analytical hierarchy assists the grower in choosing cultural practices to modify an existing site. The analytical hierarchy uses a percentage system, which can be immediately applied to a budget designed for site development.