The latest newsletter put out by Mark Chien at Penn State. Always informative and a lot of material that is applicable across the eastern U.S. The link for the article on Vine Size and Balance is worth looking at as well as the new Grape IPM website from OMAFRA.
WINE GRAPE INFORMATION FOR PENNSYLVANIA AND THE REGION
From Penn State Cooperative Extension
Table of Contents
- Notes from the Finger Lakes: fine wines and great people
- Vine Size and Balance: the viticultural balancing act
- Viticulture information from Hershey: a report from the grape section of MAFVC
- PA pruning workshops, new grower workshop and other events around the region
- Ontario grape diseases website
FLX Notes: I took a quick tour of the Finger Lakes recently and discovered just how much this wine region has grown up. After visits to Long Island, and knowing what I do of Ontario and other wine areas in the East, I’m convinced that serious professional wine makers and grape growers, along with skilled help in the cellar and fields, is what is necessary to push an industry forward. We are all somewhere on this continuum, some further along than others. If you are interested in the production of fine aromatic white wines, then a visit the lakes is an essential learning experience, but any wine grower or maker would benefit from interaction with these professionals and tasting their wines. My notes try to highlight their significant contributions and challenges yet to come.
Vine Size and Balance: John Santos, the outstanding wine grower in the Finger Lakes, recently reminded me of the importance of establishing vine balance in vineyards. Vine balance is not an accident of nature. It is achieved by thorough site assessment, vineyard design and development, followed by careful management. I wrote an article called Vine Size and Balance a few years ago and updated it. These concepts are the foundation upon which fine wines are made.
Practical Viticulture Information from Hershey: The grape section at the Mid-Atlantic Fruit and Vegetable Convention is always a good blend of practical information and research.
Bunch rot and Phomopsis (Bryan Hed, Penn State): Late season conditions contribute to bunch rots, that can be caused by a variety of organisms, including botrytis. Rots can severely affect juice and wine quality. Cluster compactness determines the susceptibility and spread of the diseases within clusters from berry to berry contact. This is really important to remember!! Opportunities for control are at bloom, especially if the weather is wet to manage latent infections; pre-close is the last opportunity to get fungicides into the cluster; at veraison the cluster can be protected from the outside; and at pre-harvest, especially in wet conditions it is necessary to control the spread of fruit rots. Fungicides for botrytis include Vanguard, Scala, Elevate, Roval, Ronilan, Strobilurins (Flint, Pristine), Endura (boscalid), and Switch. Rotate between FRAC group (see Noemi’s talk, next). Cultural practices to mitigate fruit rots include variety selection, improving aeration, spray deposition and light penetration into the canopy and clusters (leaf removal, shoot thinning and positioning). Avoid excess nitrogen and water, and try to manage berry wounding (birds, deer, insects,etc) as much as possible – an intact berry skin is the best barrier to opportunistic fungal pathogens. Loosen the clusters! Bryan showed a great slide of a fully formed, very compacted Vignoles cluster that was sprayed with orange paint – removing outer berries revealed how little of the actual berry surface area was covered by the paint. He said that one berry/cm change is compactness = 2.8% change in coverage. His cluster zone leaf removal at trace bloom has given good results opening up cluster architecture by reducing fruit set. Phomopsis can be a problem in wet and cool years like 2011. Captan, mancozeb and ziram are good materials to control phomopsis. If it was a problem last year then overwintering spores are likely to exacerbate the disease this spring. Start spraying early (1”) and get good coverage. Dormant sprays of lime sulfur (10g/ac) or fixed copper (3lb/ac) are thought to have some efficacy on overwintering phomopsis.
Grape diseases and FRAC groups (Noemi Halbrendt, Penn State): Noemi tracks grape disease infection periods at the Fruit Research and Extension Center in Adams County. Many months have more days with infection periods than not, it’s a challenging situation for wine grape growers, especially for vinifera wine grapes. She offered these tips: be sure to have the correct timing/application interval, most effective material and rates, optimal spray coverage, a good sprayer, proper tractor speed, gallons of water per acre and nozzle direction. Like Bryan, she emphasizes the need for high quality canopy management. Resistance is a major threat to the continued viability of fungicides and Noemi highlighted with some excellent tables the fungicide choices for powdery and downy mildews and their Fungicide Resistance Action Committee (FRAC) group numbers that can help growers to properly rotate materials to avoid resistance. Each fungicide material should have FRAC number prominently displayed on the product label. This system was designed to help applicators to understand which products are in the same chemical class and how to avoid overuse that leads to resistance problems. In addition to Bryan’s suggestions about IPM, Noemi adds “poor spray coverage=low rates on susceptible tissues=poor control and increased resistance development”; fungicide weaknesses are magnified when weather favors the pathogen (often in the East), spray every row, every time!; use high volumes of water and be proactive by focusing on effective control early. In all cases, good vineyard sanitation practices will improve any disease management program.
I will place my talk on bird management, and some slides from Noemi and Bryan’s presentations on the PWGN website – http://pawinegrape.com/
New Grape IPM Website: Ontario may be the best place for wine grape growers and makers to find useful production information. The Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA) has one of the best informational websites I have ever found: Ontario Grape IPM. Dr. Wendy McFadden-Smith, the grape pathologist for OMAFRA, has launched a grape integrated pest management site that is loaded with great photos, biology, scouting methods, and management recommendations. The information is divided between new and advanced growers. There’s even a cool visual identification quiz so you can test your scouting knowledge. This is an excellent complement to the NY-PA Pest Management Guidelines for Grapes.
Upcoming Meetings: Pruning workshops are coming up: TOMORROW @ Blair Vineyard (Berks County), February 8th and Naylor Vineyard (York) on February 18th. A New Grape Grower Workshop in Lancaster, PA on March 9th after the Eastern Winery Exposition (3/7-8). The next few weeks are packed with events. Here are some regional listings (go to the 2012 Events Calendar for a full calendar and event website registration and information):
Ohio Grape Producers Conference – February 20 and 21
Ontario Fruit and Vegetable Convention – February 22 and 23
Maryland Wine and Grape Industry Annual Meeting – February 24 and 25
New Jersey Grape Expectations – February 25
Finger Lakes Grape Growers Convention and NY Wine Industry Workshop – March 1-3
Pennsylvania Winery Association Annual Meeting – March 6
Eastern Winery Exposition – March 7-8
Lake Erie Grape Growers Conference – March 8
New Grape Grower Workshop – March 9