Ohio Grape-Wine Electronic Newsletter

Editor: Imed Dami, PhD
Assistant Professor, Viticulture Specialist
Department of Horticulture and Crop Science
Ohio Agricultural Research and Development Center
1680 Madison Avenue
Wooster, OH 44691-4096
Phone: (330)-263-3882
Fax: (330)-263-3887
E-mail: dami.1@osu.edu
www.oardc.ohio-state.edu/grapeweb/

18 August 2006

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Content:

2007 Ohio Grape-Wine Short Course
Petiole Analysis
Growing Degree Days
Upcoming Events
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2007 Short course -- Mark Your Calendar!

The 2007 Ohio Grape-Wine Short Course will be held on 12-13 February at the Shisler Conference Center at OARDC in Wooster, OH. Please mark your calendar. More information later.

Time for Petiole Collection
by Imed Dami, HCS-OARDC

Fertilizer needs can be determined by 3 ways: observing visual symptoms, using soil tests, and using tissue (petiole) analysis. Because each method had advantages and limitations, all 3 should be checked on a regular basis. Petiole analysis is one of the best tools available to monitor the nutrient status of your grape varieties. Unfortunately, grape producers do not often use it. Tissue analysis serves two purposes: determine the nutrient status of the vine; and identify a suspected nutrient deficiency observed in the vineyard. By using tissue analysis, growers have a better handle on their fertilizer program and usually end up cutting costs since fertilizers are applied only as needed. Here are answers to commonly asked questions about petiole analysis:

Why petiole test if I did the soil test?

Soil testing is important, before planting and for established vineyards, to determine soil pH and monitor the overall balance of major nutrients. However, there is a poor relationship between soil and plant nutrient levels. Simply put, a soil may be high on a nutrient, but the same nutrient is deficient in the vine; or the vine may show sufficient level of another nutrient while the soil test indicates a deficiency. For these reasons, petiole tests are generally more useful and more reliable for judging nutrient status of the plant than soil tests.

When should I do the test?

“Trouble-shooting”: If you observe leaf symptoms and suspect a nutrient deficiency, collect petiole samples from vines showing leaf symptoms and from vines without symptoms (healthy or normal). The two samples are sent and analyzed separately for comparison purposes. This will allow you to diagnose whether or not the problem is related to nutrient status of the vine. In case of trouble-shooting, samples are collected anytime leaf symptoms “show up” during the growing season.

“Routine assessment”: In our region, veraison (Mid July – Mid August) is the ideal time for petiole sampling for several reasons. Veraison sampling gives a better measure of Potassium (K). Potassium levels are especially critical for wine grapes since they are correlated with wine quality (high fruit K leads to high pH and thus unstable wines); there is less vineyard activity (if there is such a thing!) near veraison and more time for petiole sampling; most important is the standard optimum level of each nutrient is determined at veraison. It is recommended collecting petioles about 10 weeks after bloom but before harvest.

What are the most common nutrient deficiencies in Ohio vineyards?

During the past two years, potassium (K) and magnesium (Mg) are the most common nutrient deficiencies I have observed either visually or by petiole analysis. Other nutrient problems occur occasionally and include nitrogen (N), boron (B), zinc (Zn), and iron (Fe).
Which vines should I sample?

If you grow more than one variety, sample each variety separately.
It is not necessary to sample non-bearing vines (1^st and 2^nd year of establishment), unless you observe foliar symptoms.
Begin tissue analysis when vines are producing (usually 3^rd year) and repeat every year until yields are stable and yearly fertilizer needs are determined.
For mature vines, tissue analysis is done every 2 to 3 years. Don’t forget that once in a while (3 to 5 years) you should take a soil test as well to monitor pH changes and correct as needed. Remember that nutrient availability in the soil is pH dependent. Also, the combination of soil and plant analysis provides an excellent assessment of fertility status.

What should I sample?

Collect a representative sample of 60 to 80 leaf petioles (more for small-sized petiole, less for large-sized petioles); one or two petioles per vine for each variety. A petiole is the stem that attaches the leaf blade to the shoot. Take petioles from mature, fully expanded leaves located 5 to 7 leaves from the shoot tip. Detach each petiole from the leaf blade immediately. Place petioles in a paper bag not a plastic Ziploc bag. Label each sample and keep your own record of the following: varieties sampled, vineyard block where the samples are collected, sampling date, and conditions of vineyard. Prior to shipping, allow samples to dry for a day in a warm, dry, well-ventilated place.

Where do I send the samples?

The following is a list of labs that perform tissue analysis for a fee. Petiole analysis is usually performed for nitrogen, phosphorus, potassium, magnesium, calcium, manganese, iron, zinc, boron, and copper. Laboratory results will show that each nutrient is “adequate”, “deficient” or “excessive”. Adequate or normal nutrient ranges are shown in the following table.

Grape Tissue Analysis Labs

A & L Great Lakes Lab, Inc.
3505 Conestoga Drive
Fort Wayne, IN 46808
(219) 483-4759

Agricultural Analytical Services
Pennsylvania State University
University Park, PA 16802
(814) 863-6124

Brookside Farm Lab
308 South Main Street
New Knoxville, OH 45871
(419) 753-2448


Suggested “Normal” Ranges of Nutrients from Grape Leaf Petioles*

Nitrogen (N)
0.9 – 1.3 %
Phosphorus (P)
0.16 – 0.29 %
Potassium (K)
1.5 – 2.5 %
Calcium (Ca)
1.2 – 1.8 %
Magnesium (Mg)
0.26 – 0.45 %
Manganese (Mn)
31 – 150 ppm
Iron (Fe)
31 – 50 ppm
Copper (Cu)
5 – 15 ppm
Boron (B)
25 – 50 ppm
Zinc (Zn)
30 – 50 ppm
*Values are based on petioles taken between July 15 and August 15.
Source: Midwest Grape Production Guide, 2005.

Take Home Message

Be proactive not reactive: Do not wait until you see visual symptoms to correct a nutritional problem. If you see it, the problem already exists and the damage has already been done on growth, yield, and fruit quality. The goal of fertilization is to prevent nutrient deficiencies from occurring in the first place.

Growing Degree Days Across Ohio
(Source: ICM Newsletter, Editor: Dr. Shawn Wright)

Growing Degree Days Across Ohio - Data through August 17, 2006 from OSU Phenology Garden Network (not all locations) OSU Phenology Garden Network

OSU South Centers Piketon       2582 Wilmington                      2552 Chillicothe                     2517 Athens                          2500 Marietta                        2488 Washington Court House          2471 Xenia                           2453 Mt. Sterling                    2382 Columbus                        2346 Newark                          2325 Delaware                        2307 Findlay                         2254 Toledo                          2233 Coshocton                       2216 Mansfield                       2192 Wooster                         2190 Canton                          2187                                Norwalk                         2183 Shinrock                        2168                                Stow                            2147                    Canfield                        2137 Cortland                        2056                      Willoughby                      2049 Kingsville                      1943

Upcoming Events:

Aug. 9-20: Indiana State Fair, Indianapolis. (317) 927-7500.

August 17-18, Apple Crop Outlook and Marketing Conference. Four Seasons Motel, Chicago, Ill. For more information www.usapple.org.

August 22-23, North American Strawberry Growers Association Summer Tour, Portland Maine. For more information, http://www.nasga.org/

August 24, Organic Horticultural Crop Field Day, OARDC, Wooster, Ohio. For more information phone (330) 263-3878.

August 24, 2006 Bramble Field Day, 3pm – 7pm at Nourse Farms, Whately MA. Co-sponsored by UMass Extension and Penn State University, this workshop will provide an opportunity to learn about practical methods for identifying common field and postharvest bramble diseases through formal and informal activities. Please pre-register for this meeting by contacting Sonia Schloemann at 413-545-4347 or sgs@umext.umass.edu.

Aug. 30-Sept.1 North American Fruit, Explorers (NAFEX) and SFF Annual Meeting, Holiday Inn North, Lexington, KY. Contact John Strang 859-257-5685; e-mail: jstrang@uky.edu

September 19-21, Farm Science Review, Molly Caren Agricultural Center, London.      http://fsr.osu.edu/

September 21, Grape and Pawpaw Field Day KSU Research Farm, Mills Lane, Frankfort, KY. For more information contact Kirk Pomper at 502-597-5942

October 6-7, U.S. Highbush Blueberry Council Fall Meeting. Regency, Bar Harbor, Maine , Regency, Bar Harbor, Maine. For more information (207) 288-9723.

November 9-11, Southeast Strawberry Expo, Sunset Beach, NC (near Wilmington). Farm tour, intensive workshops on Strawberry Plasticulture ABCs and High Tunnel Production, tradeshow, many educational sessions on production and marketing. For more information, contact the NC Strawberry Association, 919-542-3687 or ncstrawberry@mindspring.com

December 5-7, Great Lakes Fruit, Vegetable and Farm Market EXPO. DeVos Place, Grand Rapids, Mich., www.glexpo.com..

January 7-9, 2007, Wisconsin Fresh Fruit and Vegetable Conference, Olympia Resort and Conference Center, Oconomowoc, www.wisconsinfreshproduce.org

Jan. 8-9, 2007, Kentucky Fruit and Vegetable Conference and Trade Show, Holiday Inn North, Lexington, KY. Contact John Strang 859-257-5685; e-mail jstrang@uky.edu

January 25-28, 2007, Southern Sustainable Agriculture Conference. The Galt House Hotel and Suites, Louisville, Ky. For more information (678) 494-0696

January 30-February1, 2007, Mid-Atlantic Fruit & Vegetable Convention. Hershey Lodge &. Convention Center, Hershey PA

February 9-12, 2007, North American Strawberry Growers Association Strawberry Symposium. Ventura, California. More program details (abstract deadlines, keynote speakers, etc.) and opportunities for industry, organization and agency sponsorship will be announced on the NASGA website http://www.nasga.org/.

February 12-13, 2007, Ohio Grape-Wine Short Course. Shisler Center OARDC, Wooster, OH.

February 14-15, 2007, Empire State Fruit and Vegetable Expo Syracuse, N.Y. For more information www.nysaes.cornell.edu/hort/expo.

February 16-17, 2007, North American Farmers' Direct Marketing Conference and Trade Show. Hyatt Regency Hotel, Calgary, Alberta, Canada. For more information www.nafdma.com..