Vineyard and Winery Information Series:
Vol. 18 No. 5, September-October 2003
Dr. Tony K. Wolf, Viticulture Extension Specialist
Temperature-wise, the 2003 season was cooler than average, and cooler than the previous "cold" year of 1996. The figure to the right shows the accumulated heat units for 1 April through October (mid-September for 2003). Accumulated rainfall is shown below for the same period (1 April - 31 October).
The precipitation data does not include the 3 to 8 inches of rain produced by TS Isabel. What has been the effect of this cooler and wetter season? It's always a bit hazardous to make generalizations about fruit quality or crop conditions across the state, but some features were common across a wide geographic area. For starters, we noted a 10- to 14-day delay in average harvest date for a given variety, with the extent of delay depending on location within the state. Titratable acidity levels were elevated (e.g., 9 to 10 g/L for Chardonnay at 21° Brix), but did begin to come down in October. Fruit rots were common on whites. Traminette and Chardonnay had 10 to 15% rot severity at harvest in our research vineyard. Viognier had less rot, but the Viognier flavors never really developed in the fruit. Among the varieties currently grown here at Winchester, our Viognier canopies looked most ragged by season's end. I am not sure what to attribute the poor canopy condition to, but I sense that Viognier is particularly sensitive to chemical spray injury. Traminette canopies, by comparison, looked great well into October.
As summer wound down and we headed into September, we hoped for a change in weather and a warm, dry fall. That was not the case in September, with tropical storm Isabel (18 September) setting the tone for the month. Despite the fact that the path of Isabel was straight up the eastern Piedmont, the fast-moving speed of the storm spared us much of the rain that might otherwise have fallen. Speaking with growers shortly after Isabel, it was apparent that relatively little damage was done to vineyards (fruit-laden apple trees were another story - trees were pushed over and many bushels of apples were lost to the storm). October has been somewhat drier, but October offered up its own insult with a very early frost on 2 October that fried the canopies of low-sited vineyards from the Charlottesville area north and west into the Shenandoah Valley. We recorded 25°F in the lowest part of our vineyard, and the tops of the vines located at the site were blackened. Fifty feet up the hill the vines were essentially unaffected.
At this writing (20 October) we are picking Cabernet franc. The fruit is clean and flavors are good, but like all fruit that we've harvested this season, the sugars are lower (about 21°Brix) than what we normally harvest at. We will be happy to see an end to the 2003 season and can only hope that the 2004 season will be a little more forgiving.
Compost in the Vineyard
Contributed by Pat Peacock, Viticulture Extension Assistant, Virginia Tech
On October 14, the Penn State Fruit Research and Extension Center held a one-day seminar for commercial grape growers at their research station in Biglerville, Pennsylvania. Dr. James Travis and his research team presented preliminary results from their research on compost made from yard trimmings, animal manure, poultry litter and mushroom substrate, and vermicompost (earth worm castings). The surprises in their research were that a little compost goes a long way and the effects are cumulative after repeated applications. Seven tons per acre had many of the benefits of 20 tons per acre. Dr. Travis and the research team have written a handbook called, "A Practical Guide to the Application of Compost in Vineyards", which is worthwhile for anyone considering applying compost to their vineyard. The manual has formulas for calculating the cumulative effect of composts with known chemical compositions. To get a copy contact Dr. Travis at P.O. Box 309, Biglerville, PA 17307-0209 or (717) 667-6116.
The research center is also studying Tomato Ringspot Virus, which is fairly prevalent in Vidal Blanc and Chambourcin plantings in Pennsylvania, New York, and in Virginia, at least with older, nongrafted Vidal). Dagger nematodes carry the virus from infected broadleaf plants (such as dandelions) to grapevines. The disease is particularly important for those growers planting vineyards that were previously apple orchards. If you are considering replanting a vineyard that failed or planting a vineyard where apples were recently grown, get your soil checked first for dagger nematodes before removing the vines or trees. Virginia Tech's plant disease clinic offers predictive nematode soil tests (http://oak.ppws.vt.edu/~clinic/). Those interested in this service should contact their local Cooperative Extension office to determine how samples should be collected and packaged for submission. One treatment that Dr. John Halbrendt recommended if nematode populations were high was growing the winter rapeseed varieties Dwarf Essex or Humus, and tilling them under as a green manure before planting grapevines. These rapeseed varieties produce isothiocyanates, which suppress nematode populations.
The Penn State researchers also reviewed their grape disease research. They had good results with the alternative fungicides Prophyt and Phostrol for controlling downy mildew and JMS Stylet Oil for powdery mildew. One interesting result was that pulling the first four leaves nearest the cordon at the first hint of bloom was the most effective means of controlling Botrytis in Vignoles clusters. Note that there are severe drawbacks with this method -- The fruitfulness of buds in the following year is severely reduced, and the method should NOT be used with spur-pruned vines.
For more information about the seminar, contact Dr. Travis at the previously mentioned address.
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Mounding or "hilling" of soil over graft unions of grafted, cold-tender varieties is one means of avoiding potential vine loss due to cold injury. In practice, soil is plowed up against the trunks of vines with a tractor-mounted blade in the fall, before the advent of severe cold weather. In lieu of soil, finely milled bark mulch can be used. We've hilled trunks as late as mid-December, but it's important to provide the protection before the advent of potentially damaging low temperatures. The soil must be mounded high enough to protect a 6- to 12-inch portion of the vines' trunks. This soil conducts heat from the earth and insulates the covered portion of the trunks. In the event of catastrophic cold damage to the above-ground structure, the vine can be retrained using buds that had been protected by the layer of soil. The fall hilling operation is followed in the spring by a "de-hilling" of the trunks to prevent scion rooting. I had wondered what would happen if the scion roots were allowed to persist and this year I learned of two vineyards that lost vines due to scion rooting. The original rootstock did not persist where the scion (Cabernet franc in one case) rooted, and the scion roots were, in turn, infested with phylloxera. Take-home message: be sure to remove soil or de-hill from the graft union in the spring following the hilling operation.
Benefits of hilling include the protection offered in the event of extreme weather. Vinifera trunks, depending upon variety and time of season, can be injured by temperatures above 0°F, although injury is more common at temperatures below -10°F. Symptoms of cold injury can include poor shoot growth in the following season, development of crown gall, and death and splitting of affected trunks. Another possible benefit of hilling and dehilling is the destruction of weeds, overwintering insect pests, and reduction of certain disease inoculum caused by the mechanical cultivation. The costs of hilling and dehilling must also be considered. First is the capital cost of equipment and annual operating costs. Grape hoes can cost from $1,500 to over $5,000, while operating (machinery and labor) costs run from $20 to $25 per acre. Annual hilling and dehilling has led to severe soil erosion problems in some older vineyards. The soil in some of these vineyards has eroded many inches below the graft union and the practice of hilling is no longer effective. Furthermore, the loss of top soil is associated with reduced vine vigor, lack of trellis fill, and unprofitable crop yields. One means of reducing soil erosion on hilly sites (aside from keeping rows oriented perpendicular to the prevailing slope) is to leave undisturbed soil "dams" every 30 feet or so along the row. Simply pull the plow out of the soil at regular intervals to avoid creating a continuous channel or trench down a row.
Another potential negative consequence of hilling and dehilling is the mechanical damage to vines. This can range from the obvious collisions with trunks to the less obvious damage to roots near the soil surface. Each grower must weigh the pros and cons of hilling and decide for one's self if this is a justifiable practice. Your own experience will determine whether hilling of graft unions is good insurance or a wasteful practice. A grower may conclude, after 5 to 10 years without trunk cold injury, that the "insurance" is unnecessary. The most recent severe cold event in Virginia (February 1996) would have been much more destructive had it not been for the snow cover that blanketed most of the Piedmont vineyards. The snow did essentially the same thing that our mounding of soil did - it provided a thermal continuum between the earth and vine trunks. What about sawdust, grow tubes, white paint, etc? Sawdust and finely milled bark mulch would work, provided it retained sufficient moisture to conduct heat; however, the mechanics and cost of application must also be considered. We have also noticed that organic mulches can lead to increased climbing cut-worm populations in the subsequent spring. Grow tubes provide no cold protection, and can even cause increased winter injury. Painting of trunks with white paint is intended to reflect sunlight and limit radiational warming of the trunks. I am unaware of this practice being used successfully in Virginia vineyards. Nurserymen generally recommend the hilling-up of young vines for the first few years in the vineyard, even with excellent sites. The occasional observation that trunks of young vines sustain greater cold injury than do the trunks of older, established vines probably relates more to cropping stress on the young vines, rather than direct age effects on cold hardiness. I do, however, recommend that you follow the advice of your grapevine supplier with respect to hilling of graft unions. It's usually easier to obtain recompense from a nursery for failed vines if you've followed the nursery's planting and care recommendations. Be careful when mounding soil against young vines. The young trunks and graft unions may not withstand the impact of heavy clods of soil. For first-year vines, we find that it's safer to turn the soil near the trunk with a grape-hoe and then use a hand-hoe to move the loosened soil against the trunks.
Some growers have found that hilling does not guarantee vine renewal in the event of trunk injury. Repeated episodes of vine kill generally dictate the need for more radical measures. If the problem is confined to a small area of the vineyard, study the area to see if it's associated with poor soil conditions, lower topography, or other features that may be contributing to vine failure. It may be best to remove these "problem" areas from production if there are site-specific limitations.
Timing: Fall hilling can be done at any time before the ground freezes, typically after harvest and before mid-December in VA. De-hilling in the late-winter or spring occurs after the threat of extreme weather, and before the application of pre-emergence herbicides; the period from late-February until mid-March is convenient.
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Table 1. Fungicides and insecticides, and stage of growth at each application, used in the AHS AREC research vineyard during 2003. "Precip." Is the amount of rainfall that was recorded since the last spray (e.g., 1.66 inches of rain was measured between 6 and 13 May).
|Date||Pesticides used||Growth stage||Precip.|
|6-May||Penncozeb 75DF, Nova 40W||8-10" shoots|
|13-May||Nova 40W, Ridomil Gold MZ||12-16" shoots||1.66"|
|20-May||Elite 45DF, Ridomil Gold MZ||16-24" shoots||1.74|
|27-May||Abound, Microthiol Disperss (sulfur)||pre-bloom||0.9|
|5-Jun||Elite 45DF, Pro-phyt||pre-bloom||1.97|
|10-Jun||Ridomil Gold MZ, Flint, |
Microthiol Disperss (sulfur)
|18-Jun||Penncozeb 75DF, Rubigan EC, Microthiol Disperss (sulfur)||post bloom||2.68|
|27-Jun||Captan 50W, Rubigan EC, Intrepid 2F||pea-size berries||1.37|
|4-Jul||Abound, Intrepid 2F, Elevate 50WDG||beg. bunch closure||0.86|
|11-Jul||Nova 40W, Tenn-Cop 5E, Imidan 70W||berries hard & green||2.48|
|25-Jul||Elite 45DF, Tenn-Cop 5E, Pro-phyt, |
|berries hard & green||0.74|
|5 Aug||Pro-phyt, Microthiol Disperss (sulfur), Imidan 70W||Berries hard and green||2.62|
|15 Aug||Pro-phyt, Elite 45DF, Imidan 70W||Start of veraison||1.09|
|12 Sep||Flint, Pro-phyt||Ripening (sort of)||2.83|
Compared to "normal" years, our 2003 program relied less on mancozeb, and more on Ridomil for downy mildew, because this was a wetter than normal year. We "normally" apply around 13 sprays/year compared to 15 this season. Given the wet weather of late-August and September, coupled with a concern for effects of sulfur on winemaking, we chose to use an additional spray of Elite and one additional spray each of Abound and Flint in August and September. The total of 5 sprays of strobilurins (Abound and Flint) was at least 2 more than we would have preferred to make from a disease resistance management standpoint, but we felt that we had few viable alternatives given the frequency and amounts of rain occurring and forecast. The program was expensive but effective; we were free of powdery mildew, downy, and black rot up until 26 September when we noticed some powdery mildew lesions beginning to appear on some of the Chardonnay. No additional sprays were made after 12 September and the sporadic powdery mildew observed in late-September made very little progress.
Note: Did you have disease or other pest problems this season which you're having difficulty understanding the basis for? If you want a constructive critique of your spray schedule, please send me that schedule, along with vine developmental information and any rainfall data, if available, similar to the table outlined above. Tell me when you first noticed the disease/pest and how severe the problem was by season's end.
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The 9th Annual Mid-Atlantic Biodynamic Food and Farming Conference November 14-16, 2003 Leesburg, Virginia.
Presented with Support from The Josephine Porter Institute of Applied Biodynamics and The Loudoun County (VA) Department of Commercial Horticulture
Event Details at http://www.gardeningforthefuture.com
Background: Biodyanamics may be viewed as "the next step" in sustainable and alternative viticulture - for those who seek the highest quality wines in even the most difficult seasons. This conference offers in-depth opportunity to learn the practical applications of biodynamics from some of the worlds best-reputed practitioners. What is biodynamics? One source of info is from the biodynamic Farming and Gardening Association with a "What is biodyanamics" link on their homepage at http://www.biodynamics.com. The Annual Mid-Atlantic Biodynamic Food and Farming Conference organizers realized the profound interest of Eastern States Viticulturists to maximize wine quality and sustainable production systems. As a result, this year's conference is a focus on Biodynamic Viticulture. You will not find a better opportunity in the Eastern US to learn the applications of Biodynamics to Viticulture.
PLEASE NOTE This conference is funded entirely by registration fees. For this reason, we request that you register as early as possible to support our efforts in a very practical fashion.
CONFERENCE FEE: Currently $125 for full-paid pre-registrations received before October 15. Conference fee is $150 after October 15. Pre-registration is encouraged. Early Payment is appreciated.
LOCATION: Holiday Inn Leesburg, VA. 70mi from Washington DC and 20 min. from Dulles Airport.
RESERVATION/PAYMENT: To make reservations: Call (304) 876-3382 or email email@example.com or send your check, made out to: "MABFFC2003" to MABFFC, POB 3047, Shepherdstown, WV 25443. Payment can be by check or by credit card (credit cards only via PayPal www.paypal.com id: firstname.lastname@example.org). Checks or Cash only at the door (No credit cards at the door.) Late breaking information is at our web page: http://www.gardeningforthefuture.com QUESTIONS? Contact Allan Balliett at email@example.com Holiday Inn Leesburg, 703-771-9200, 1500 East Market Street, Leesburg, VA 20176 Rooms Blocked Until October 31 at special Rate of $69 - as Loudoun Extension Conference
From Leesburg, Take Route 7 East toward Tyson's Corner. The Hotel is on the left - 1.5 miles past interchange with Route 15 Bypass. Note: a U-turn is required to enter the conference center at River Creek Parkway, if you pass Route 659 (Bellmont Ridge Road) you passed it.
From Washington, DC, From Interstate 495 Take Route 7 West to Leesburg. The Hotel is on the right - approx. 20 miles. Hotel is just before Route 15 at Leesburg.
Tentative Agenda (subject to change) - speakers info at www.gardeningforthefuture.com
Friday Nov. 14
10:30am to 12:30pm - Dr. Michael Glenn and Dr. Jerzy Nowak
2:00pm to 5:00pm - Phillipe Armenier And Hugh Courtney
7:00pm to 9:00pm - Hugh Lovel
Saturday Nov. 15
8:30am to 4:30pm - Nicolas Joly
7:00pm to 9:00pm - Wine Reception Featuring a Selection of Biodynamic Wines (please also bring a bottle from a Winery Near you)
Sunday Nov 16
8:30am to 12:30pm - Bob Schaffer and Mark Trela
*Conference will offer Light Fare for Breakfast Daily, Coffee, Water, Juices, Sodas, Cookies. Lunch and Dinner will not be provided. Holiday Inn will offer its own Buffet for a charge, and dinning options will be handed out at the conference.
Hotels in the Area (see also www.visitloudoun.org/home.cfm)
Leesburg Holiday Inn - 703-771-9200
Leesburg Best Western - 703-777-9400
Comfort Suites Leesburg - 703-669-1650
Days Inn Leesburg - 703-777-6622
Hampton Inn & Suites Leesburg - 703-669-8640
NICOLAS JOLY is best known in the U.S. as author of the ACRES USA book, Wine from Sky to Earth: A Growers Appreciation of Biodynamic Wine. He is commonly given credit as the international popularizer of biodynamic viticulture. Wines produced under his management have consistently received rave reviews from critics like Robert Parker. Mr. Joly will be conducting a full-day workshop on Whys and Hows of biodynamic viticulture, an incredible opportunity for any viticulturist interested in consistently producing - - even in difficult years - - wines of value and character.
PHILIPPE ARMENIER grew up in a French vineyard. He made his first wine in 1973. He started growing grapes biodynamically in 1989. He has received many accolades for his work at Domaine De Marcoux, which he owned with his sister, and for the wines produced there, known as Chateauneu-du-Pape. A few years ago he sold his interest in Domaine De Marcoux and currently lives and works in Santa Rosa California where he consults for 9 vineyards in California, Oregon and Washington. Pierre came to us highly recommended by the Alan York, former president of the Biodynamic Association and the foremost US-born biodynamic vineyard consultant in the U.S.
HUGH COURTNEY, (The Josephine Porter Institute) Hugh makes most of the high quality BD preps used in America. Brewer of the Pfeiffer Field Spray and Pfeiffer Compost Starter. He will teach you how to use them!
HUGH LOVEL (Union Agricultural Institute) America's foremost teacher and demonstrator of Cosmiculture and author of A Biodynamic Farm for Growing Healthy Vegetables. Hugh will deliver an in-depth introduction to biodynamics on Friday evening. MORE INFO BOB SHAFFER is co-founder of Soil Culture Consulting, has 30 years experience as an organic farmer and is a consultant for the production of premium quality wine grapes in Sonoma and Napa Counties, as well as other high value crops in California and Hawaii. Since 1989 Soil Culture Consulting has provided practical, effective information and hands-on assistance for farms in transition to sustainable organic agriculture, on thousands of vineyard acres. Bob Shaffer is certified by the American Society of Agronomy, served as president of the North Coast Chapter of California Certified Organic Farmers from 1997-2001 and is currently instructor for cover crops for vineyards, in the Department of Viticulture and Winery Technology, at Napa Valley College. Bob will discuss cover crops from a whole-farm perspective including soil biology, soil physics and how the cover crop interrelates with wine quality.
Dr. JERZY NOWAK is a professor and Head of the Department of Horticulture, Virginia Tech, Blacksburg, VA. His research focuses on enhanced plant (including grapes) tolerance to stresses, technology development for sustainable agriculture and landscape management, based on "priming" plant propagules, the planting site, and "precision" management of the rhizosphere, is the ultimate goals of his program. He also initiated and implemented an "Organic Horticulture" program at Virginia Tech.
Dr. MICHAEL GLENN is a Soil Scientist at the USDA-ARS-Appalachian Fruit Research Station near Kearneysville, WV. Dr. Glenn's research mission is to develop technology that will make the U.S. fruit grower more efficient and competitive in both the global market and the regional market. These new technologies focus on sustainable techniques with novel or reduced inputs into the fruit production system that improve fruit quality. In Dr. Glenn's 20 years of research he has developed new irrigation technology and demonstrated the cost effectiveness of tree fruit irrigation in the humid eastern U.S. Dr. Glenn developed the killed sod system of tree establishment that is standard throughout the eastern U.S. Dr. Glenn is one of the inventors of particle film technology, of which, Surround Crop Protectant, is the first commercial product. Surround Crop Protectant is a general insect repellant and a heat reflectant that is used worldwide in horticultural production systems.
STEVE STORCH Steve is a farm advisor for JPI and is well known for the biodynamic stirring equipment he fabricates.
MARK TRELA designed and installed a 7-acre biodynamic vineyard in New Harmony, Indiana. Located on the Wabash River, his successful vineyard has been subject to the same disease pressures experience in Mid-Atlantic vineyards. Mark will share his experiences on managing this vineyard.
The Mid-Atlantic Biodynamic Food and Farming Conference
Post Office Box 3047, Shepherdstown, WV
304.876-3382 / firstname.lastname@example.org
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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: email@example.com
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