About Us

Extension Programs

My extension responsibilities are to educate commercial grape growers and train Cooperative Extension agents in interdisciplinary measures that improve grape quality and vineyard productivity. I use workshops, shortcourses, field meetings, and a variety of written media to disseminate information. To the extent possible, I also address individual requests for information and assistance. I directly assist Virginia Cooperative Extension (VCE) faculty-agents with grape-related problems and provide in-service agent training. Some of this activity is of a regional nature with colleagues in Pennsylvania and Maryland. The publication of the Wine Grape Production Guide for Eastern North America in 2008 is a recent example of an extension deliverable.

Current Extension programs include:
- Cooperation with local VCE agents with seasonal vineyard meetings
- Cooperation with the Virginia Vineyards Association on technical summer meeting and winter shortcourse
- Development of a "Sustainable Vineyard Practices" workbook for Virginia grape producers.

Research Programs

My research interests are broad and reflect the multi-disciplinary challenges faced by the Virginia wine grape industry. Previous research focused on methods of grapevine canopy management that affected grape and wine quality, cold hardiness investigations, and inter-disciplinary collaboration with entomologists and plant pathologists to reduce pest problems. Current research includes wine grape variety evaluations at our Blackstone, VA AREC, collaborative studies of grape root borer effects on grapevines, regulation of vine vegetative growth to enhance grape and wine quality, and collaborative efforts to develop a new generation of vineyard suitablity maps for Virginia. Brief descriptions of principal, current research efforts follow:

Grape variety evaluations

A 19-cultivar wine grape evaluation planting was established at the Southern Piedmont AREC in 2001. This planting has yielded data that supports our cultivar recommendations for growers in the southern and eastern Piedmont of Virginia and the Pierce's Disease-free areas of North Carolina's Piedmont.
Our preliminary findings, based on harvests to-date are as follows:
- Disease pressure has been greater in this environment than our experience at Winchester. Chardonnay, for example, is very difficult to keep free of powdery mildew.
- Aleatico and Tempranillo performed poorly, but for different reasons. Aleatico ripens unevenly and is highly susceptible to bee and green June bug injury, perhaps owing to its aroma. Many of the Tempranillo vines were lost within the first several years of planting to crown gall or other causes. While this might have been due to poor nursery stock, the fruit of apparently healthy vines was susceptible to rot. For these reasons, we have removed Aleatico and Tempranillo from the planting. The recently named variety, Noiret (NY73.0136.17) has also performed poorly from the standpoint of primary fruit chemistry. At full ripeness (about 19 degrees Brix) the fruit lack flavor.
- Varieties that have performed well from a viticultural standpoint include Petit Manseng, Norton, Cabernet Sauvignon, Rousanne and Viognier. Others may perform well if we continue to manage crops, including Petit Verdot, Tannat, Traminette, and Mourvedre.
- With the exception of Norton, all varieties have expressed some incidence of Pierces Disease (PD) and this will continue to be a threat in the southern Piedmont as winter temperatures remain above average.
- Wines have been made by colleague Dr. Bruce Zoecklein, but have not been formally evaluated from this effort.
- Our last fruit harvest was in 2008. Our current goal with the vineyard is to apply a minimal, maintenance fungicide management program with the intention of rating the relative tolerance of the varieties to our major fungal diseases.

Training System Comparisons

Vines are trained to different training systems due to varietal differences in growth habit, vigor or vine size differences, ease of vineyard mechanization, and grower's opinion about potential effects on fruit/wine quality. Consequently, many types of grape training systems have been devised and are in use worldwide. No two systems have had formal evaluation in Virginia. Research commenced in 1998 to address that deficiency by way of multi-year field comparisons of two divided canopy systems (Geneva Double Curtain and Smart-Dyson) and a "standard", non-divided, vertically shoot-positioned system. (An example of Smart-Dyson-trained vines is shown in the image here).

An additional factor of variety (Traminette, Cabernet franc, and Viognier) was included in the treatment design. Data collection began with the 2000 growing season and will continue ca. 10 years. Vine vigor, ease of canopy management, crop components of yield, and fruit chemistry will be major response variables. Collaboration with Dr. Bruce Zoecklein (enologist) will allow examination of wine quality as well.

Significance: Basic trellis systems cost from $1,500 to $2,000 per acre, while more elaborate, divided canopy structures cost as much as $3,500 per acre. Virginia and other mid-Atlantic winegrape producers will benefit from this research by better understanding the costs, as well as the potential returns from several training system options. Our monitoring of time involved with seasonal management of the different systems will ultimately permit a detailed examination of the economics of the different system.

Publication:
Zoecklein, B.W., T.K. Wolf, L. Pelanne, M.K. Miller, and S.S.Birkenmaier. 2008. Effect of vertical shoot-positioned, Smart-Dyson, and Geneva Double-Curtain training systems on Viognier grape and wine composition. Amer. J. Enol. Vitic. 59:11-21.

Alson H Smith Jr AREC
595 Laurel Grove Road
Winchester, VA   22602
E-mail: emcintir@vt.edu
Phone: 540-869-2560
Fax: 540-869-0862