Viticulture Notes

Vineyard and Winery Information Series:
Vol. 20 No. 5, September-October 2005

Dr. Tony K. Wolf, Viticulture Extension Specialist

Table of Contents

I. Current situation

Please contact the VA Agricultural Statistics Service (804-771-2493) if you grow one or more acres of grapes (bearing or non-bearing) and you do not receive a grape crop acreage-production survey questionnaire by 15 December 2005.

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II. Grape cultivar evaluation in the Eastern Piedmont of Virginia (SPAREC)

Virginia Tech began a formal evaluation of 19 wine grape varieties at the Southern Piedmont Agricultural Research and Extension Center (SPAREC) in Blackstone, Virginia (30 miles east of Farmville) in 2000, with some of the planting occurring in 2001. The unique climate of the eastern/southern piedmont warrants a separate evaluation of varieties - day and night temperatures are typically warmer than those of northern Virginia, and the threat of winter injury is lessened; however, bud break is earlier and the region experiences a strong continental climate, which increases the threat of spring frost damage.

The varieties under evaluation at the SPAREC (Table 1) were chosen on the basis of their performance elsewhere in the state (i.e., Winchester), have late bud break (e.g., Mourvedre, Cabernet Sauvignon, Tannat), have pronounced aromas that might persist under less than optimal ripening conditions (e.g., Traminette and Petit Manseng), or have established commercial merit in hot climates (e.g., Norton, Tinta Cao, Touriga Nacionale.

Generally, our goal with variety evaluations such as that at the SPAREC is to evaluate the material over a 5- to 10-year fruiting period. Our previous variety evaluation at Winchester was maintained from 1988 through 1998, with harvest and wine data collected over eight years. We are interested in both the viticultural (yield components, pest issues, vine size/vigor, adaptation to local climate) and enological performance of varieties (see, http://www.ext.vt.edu/pubs/viticulture/463-019/463-019.pdf). The day-to-day management of the Blackstone vineyard is carried out by staff of the SPAREC with assistance and oversight by Dr. Jeremy Pattison. We also acknowledge the excellent support provided by Ned Jones, Margaret Coates, Mac Tilson and other staff at the SPAREC in this effort. Wine-making is done within the Department of Food Science and Technology on the main campus by Dr. Bruce Zoecklein, Sandy Birkenmaier and others. Staff from the Winchester AREC (Kay Miller, Fritz Westover, T. Wolf and occasionally others) visit the SPAREC for pruning, shoot-thinning, crop thinning, and harvest, with harvest comprising many visits due to the period over which the varieties ripen. My point here is that many people are involved with the conduct of this project. On that note, we also gratefully acknowledge the generous, sustaining financial support of the Virginia Wine Board, the Viticulture Consortium:East (USDA/CSREES) and, in the establishment phase, the North Carolina Grape Council.

The vines at SPAREC are planted in three-vine plots (8 feet between plants) in rows that are 11 feet wide (to accommodate the equipment available at the SPAREC). Plots are replicated 6 times in a completely randomized design for a total of 18 vines per variety. The exception to this is for Norton which, due to its sensitivity to sulfur and copper fungicides, is planted separately and trained to Geneva Double Curtain. The vineyard has drip irrigation and a deer exclusion fence. Vines (except Norton) are trained to Smart-Dyson. Typically, shoot density is set by dormant pruning and shoot-thinning to result in about 5 shoots per foot of canopy for the upper canopy and about 3 shoots/foot for the lower canopy. Crops are regulated somewhat to target between 3 and 6 tons/acre, with part of our research being to determine what a tolerable crop level is from a wine quality standpoint.

General observations to-date: Initial harvest data were collected in 2004, with more detailed data collected during the 2005 harvest. While it is preliminary, some trends are appearing. Wildlife has been troublesome at the vineyard: Raccoons have been attracted to the ripening grapes and have taken a toll on yields. We are retrofitting the deer fence this winter with a band of wire-mesh around the base of the fence to exclude small mammals. Green June bugs are more abundant at Blackstone than at Winchester (photo), and their feeding in 2004 appeared to aggravate rot problems. Assail insecticide appeared to help with green June bug management in 2005. Birds have also been a problem and we are currently pricing the cost and feasibility of an overhead net for the 2006 season.

Primary fruit chemistry at harvest in 2005 is shown in Table 1. Several varieties appear to be promising: Petit Manseng, the white-fruited variety from the Jurancon, retained its distinctive flavors and exhibited a good balance of sugar and acidity at harvest. Cabernet Sauvignon #337, Rousanne, Tinta cao, and Norton also tasted very good at harvest. Generally, the grapes at the SPAREC have had higher pH values at harvest, for a corresponding sugar concentration, than what we have seen at the cooler Winchester site (example here with Viognier and Vidal, both of which have been grown at Winchester and Blackstone). This is likely due to the higher heat summations at Blackstone, compared to Winchester. The Cabernet Sauvignon clone #337 is of particular interest in that it ripens much earlier than either of the Cabernet franc clones at Blackstone - we harvested clone #337 at the same date that we harvested Chardonnay in 2005. Clone #337 is noted for its relatively small berries and deep color. Clone #337 is also known to be virus-infected (Rupestris stem-pitting and type-2 leafroll), but the consequences of this infection are not certain. The clone #337 at Blackstone is grafted to C-3309, which some advise against for this particular clone; however we have not seen obvious virus problems with the vines after 5 years in the ground.

Viognier and Traminette, which are also grown at Winchester, have not expressed as intense flavors or aromas at harvest at Blackstone as they do at the Winchester site. Again, that may reflect the greater heat experienced at Blackstone. As with many of the varieties grown at Blackstone, Viognier fruit has a relatively high pH (Figure 1), at the point when soluble solids exceed 20 or 21 °Brix.

We've lost several of the Tempranillo vines to vascular pathogens (e.g., crown gall) and/or winter injury. I'm not certain at this point whether we simply started with poor nursery stock or whether the vines are not adapted to the Blackstone environment. The fruit matures early and has had mediocre quality. NY73.0136.17, an unnamed red from the Cornell breeding program, similarly colors early, but does not acquire perceptible flavors or aromas or soluble solids levels greater than about 18° Brix. Aleatico and Muscat blanc also mature early. These are both aromatic varieties and (consequently) suffered significant depredation by raccoons and green June bugs this year. I'm hopeful that if we can eliminate the wildlife problems, these might find an interesting niche in the eastern/southern piedmont, perhaps as used in conjunction with fruit drying. Tannat and Norton looked reasonably good at harvest. We have been able to achieve much lower acid levels at Blackstone than at Winchester with Norton, a reflection of the lower vigor and more open canopies at the Blackstone site.

Again, this is a very preliminary progress report and no firm conclusions can be made to recommend one variety over another. Yield and pruning weight data are being collected - generally, crops have required thinning with all varieties and pruning weights are acceptable (> 0.3 pounds per foot of row) or supra-optimal. The wines being made from the Blackstone fruit will be subjected to chemistry and sensory evaluations and will help identify varieties that are relatively superior performers in the relatively warm part of the state.

Table 1. Harvest date and primary fruit chemistry of varieties/clones being evaluated at the Southern Piedmont Agricultural Research and Extension Center, Blackstone, Virginia, in 2005.

Variety (clone)	Harvest date	Brix	pH	TA (g/L)
Aleatico	Not harvested
Cabernet franc ( "#313")	26 Sept-05	18.3	3.85	5.01
Cabernet franc (#1)	26 Sept-05	20.5	3.87	4.60
Cabernet Sauvignon (#337)	12 Sept-05	20.3	3.74	5.42
Chardonnay (#96)	12 Sept-05	21.8	3.81	4.85
Mourvedre	19 Sept-05	20.8	3.92	4.32
Muscat blanc	12 Sept-05	19.1	3.73	4.70
Norton	26 Sept-05	22.2	3.88	6.11
NY73.0136.17	7 Sept-05	17.3	3.46	5.18
Petit Manseng	12 Sept-05	25.2	3.28	8.08
Petit Verdot	20 Sept-05	21.7	3.92	5.26
Rousanne	12 Sept-05	21.8	3.75	5.45
Tannat	19 Sept-05	21.5	3.43	6.08
Tempranillo	7 Sept-05	19.5	3.80	5.56
Tinta cao	19 Sept-05	20.5	3.64	4.38
Touriga nacionale	19 Sept-05	18.9	3.61	4.42
Traminette	19 Sept-05	19.8	3.51	4.53
Vidal	19 Sept-05	21.7	3.51	5.38
Viognier	12 Sept-05	22.9	3.97	5.04

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III. Upcoming meetings

A. Winchester

When: Wednesday, 7 December 2005; 2:00 pm - 5:00 pm
Where: Virginia Tech's AHS Jr. Agricultural Research and Extension Center, Virginia Tech, Winchester, VA.
Information: Fritz Westover, 540-869-2560 Ext. 11, westover@vt.edu
Program: Basic pruning workshop. Learn the basics of pruning grapevines including training of young vines, balanced pruning, assessment of and compensation for cold injury and bud necrosis, cordon vs. head training, pathogens of pruning wounds, demonstrations of Geneva Double Curtain (GDC), Vertical Shoot Position (VSP), Smart-Dyson, and open-lyre training systems. No fees or registration required. Bring pruning shears, and dress appropriately for the day's weather.
Directions: Virginia Tech's AHS Jr. Agricultural Research and Extension Center is located at 595 Laurel Grove Road, about 7 miles southwest of Winchester, VA in Frederick County. From Interstate-81, take the Stephens City exit on the south side of Winchester. Go west into Stephens City (200 yards off of I-81) and proceed straight through traffic light onto Rt 631. Continue west on Rt 631 approximately 3.5 miles. Turn right (north) onto Rt 628 at "T". Go 1.5 miles north on Rt 628 and turn left (west) onto Rt 629 (Laurel Grove Road). Go 0.8 miles to the Center on left. Meet in main conference room.

B. Ivy, Virginia

When: Tuesday, 13 December 2005; 10:00 am - 1:00 pm
Where: Ivy Creek Vineyard, Ivy, VA (Albemarle County)
Information: Fritz Westover, 540-869-2560 Ext. 11, westover@vt.edu
(Contact on day of workshop: 434-979-4905)
Program: Basic pruning workshop. Learn the basics of pruning grapevines including training of young vines, balanced pruning, assessment of and compensation for cold injury and bud necrosis, cordon vs. head training, pathogens of pruning wounds, demonstrations of Geneva Double Curtain (GDC), Vertical Shoot Position (VSP), Scott Henry, and open-lyre training systems. No fees or registration required. Bring pruning shears, and dress appropriately for the day's weather.
Directions: From interstate 81, travel east on I-64 to exit 114, left toward Ivy. Turn right onto Bloomfield Road, about 0.5 mile from I-64. Go up hill and Ivy Creek sign will be on the left, about 1.0 mile. (Contact at vineyard on day of workshop: 434-979-4905).
From Charlottesville take U.S. 250 West towards Ivy. Turn left onto Bloomsfield road. Follow Bloomsfield road and look for the Ivy Creek sign on the right. (Contact at vineyard on day of workshop: 434-979-4905)

C. Blackstone, Virginia

When: Wednesday, 11 January 2006; 1:00 pm - 4:00 pm
Where: Southern Piedmont Agricultural Research and Extension Center, Virginia Tech, Blackstone, VA.
Information: Fritz Westover, 540-869-2560 Ext. 11, westover@vt.edu
Program: Basic pruning workshop. Learn the basics of pruning grapevines including training of young vines, balanced pruning, assessment of and compensation for cold injury and bud necrosis, cordon vs. head training, pathogens of pruning wounds, demonstrations of Geneva Double Curtain (GDC), Vertical Shoot Position (VSP), Smart-Dyson training systems. No fees or registration required. Bring pruning shears, and dress appropriately for the day's weather.
Directions: Virginia Tech's Southern Piedmont Agricultural Research and Extension Center is located on 2375 Darvills Road near Blackstone, VA. In Blackstone, take Dinwiddie Ave. (also Highway 40 East), travel approximately 1.5 miles east on Highway 40 past the Fort Pickett main gate. Keep straight approximately 0.5 mile crossing two railroad tracks. Just past the second railroad track, turn left. The Center is immediately on the right. Meet in Center parking lot.

2006 Seminars at Linden Vineyards
A series of seminars geared towards commercial winegrowers will be taught at Linden Vineyards by Jim Law. These are practical courses on small-scale, high quality vineyard and wine production. Seminars will be held at Linden Vineyards from 10:30 a.m. to 4:00 p.m. The cost is $150 per person, per session. Winemaking classes will have an additional tasting fee of $25. Seating is very limited, please reserve well in advance. Bread, cheese and sausage are available for purchase at Linden for lunch, or bring your own. To register by phone call 540-364-1997. MasterCard and Visa are accepted. More information is available at www.lindenvineyards.com

Getting a Vineyard Started: Saturday, January 28 and Saturday, June 24: This seminar is designed for those new to grape growing or contemplating starting a vineyard. It is geared towards the quality-conscious commercial operation. Emphasis is on site and variety selection, planting, trellis construction, first year care and economics.

Vineyard Management: Sunday, June 25: The focus on this session is the finer points of day to day management of a producing vineyard. Canopy management to enhance quality and flavors is the main emphasis. Horticultural decisions such as pruning, training, pest management and vine nutrition are also covered.

Winemaking Basics: Sunday, January 29 and Saturday, August 12: The nuts and bolts of both red and white commercial winemaking, this seminar is geared towards the novice, but moves quickly with classroom, cellar and tasting sessions. High end artisan winemaking is the focus.

Advanced Winemaking: Sunday, August 13: The finer points of artisan winemaking are covered is this seminar with time spent in the vineyard, cellar, classroom and tasting. Style and quality issues are the focus. Participants should have some winemaking experience or have taken the Winemaking Basics Seminar.

Virginia Vineyards Association Annual Technical meeting
When: 9 - 11 February 2006
Where: Omni Hotel, Charlottesville, VA
Program: In development. Thursday, 9 February will be geared towards beginning or novice grapegrowers, with program of 10 and 11 February at more advanced level. Details will follow in subsequent newsletter and at VVA web site (http://www.virginiavineyardsassociation.com/).

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"Viticulture Notes" is a bi-monthly newsletter issued by Dr. Tony K. Wolf, Viticulture Extension Specialist with Virginia Tech's Alson H. Smith, Agricultural Research and Extension Center in Winchester, Virginia. If you would like to receive "Viticulture Notes" as well as Dr. Bruce Zoecklein's "Vinter's Corner" by mail, contact Dr. Wolf at:

Dr. Tony K. Wolf
AHS Agricultural Research and Extension Center
595 Laurel Grove Road
Winchester, VA 22602

or e-mail: vitis@vt.edu

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