Anthracnose of Grape in Ohio
Insect Pests
Setting Up a Laboratory for Quality Wine Analysis
Loss of Free Sulfur Dioxide During Bottle Storage
ATF Announcement
OSU Viticulture and Enology Program
Winter Grape School
Pesticide Container Recycling Collection Sites
Web Site Listings
Upcoming Meetings

Anthracnose or bird’s-eye rot is a disease of European origin, and is caused by the fungus Elsinoe ampelina. Before the introduction of powdery mildew and downy mildew, anthracnose was the most damaging grape disease in Europe. Anthracnose has been reported from all grape-growing countries, and it was probably carried from Europe to the United States on propagation material. Anthracnose is a disease of rainy, humid regions, where some grape cultivars are practically impossible to grow because of the disease. Because of this environmental requirement, anthracnose does not occur on the West Coast of the United States, although it can be a serious problem east of the Rocky Mountains. Anthracnose is generally a problem in the southern portion of the eastern U.S., where conditions during the growing season are usually humid (wet) and warm. In areas like Arkansas and Missouri, anthracnose is a common disease that occurs nearly every year, and generally requires the annual use of fungicides to provide effective control.

The disease is not common in Ohio; however, it was observed in a central Ohio vineyard where it caused severe damage on Vidal grapes in 1993. Due to the abnormally wet and warm spring in 1998 (El Nino), anthracnose developed in several states across the Midwest including: Iowa, Indiana, Kentucky, Missouri and Ohio. In 1998, the disease was observed in a commercial vineyard in southwest Ohio where it caused serious damage on the cultivars Vidal and Reliance. It is possible that the disease was present in other vineyards as well and was not recognized by growers or was misidentified as another disease. The purpose of this article is to familiarize Ohio growers with the symptoms of Anthracnose and provide current recommendations for its control.

Anthracnose produces circular (1-5 mm in diameter) leaf lesions, with brown to black margins and round or angular edges. The lesions are often quite numerous and may coalesce or remain isolated. The center of the lesion becomes grayish white and dry. The necrotic (dead) tissue in the center of the lesion eventually drops, leaving a "shot-hole" appearance. Young leaves are most susceptible to infection. Lesions may cover the entire leaf blade or appear mainly along the veins. When the veins are affected, especially on young leaves, the lesions prevent normal development, resulting in malformation or complete drying of the leaf. Because the youngest leaves are the most susceptible, the malformations are most obvious at the tips of the shoots, which may appear burned.

Young, green, succulent parts of the shoot are most susceptible to anthracnose. Lesions on shoots are small and isolated, with round or angular edges. Lesions have a violet brown margin, which gradually becomes violet-black. Lesions may coalesce. The center of the lesions may extend into the pith of the shoot. Callus tissue forms a slightly raised area around the edge of the lesions. These lesions on the shoots may crack, causing the shoots to become brittle. Anthracnose lesions on the shoots may be confused with hail injury; however, unlike hail damage, the edges of the wounds caused by the anthracnose fungus are raised and black. Anthracnose on petioles appears similar to that on the shoots.

Clusters are susceptible to infection before flowering and until véraison. Lesions on the rachis and pedicels appear similar to those on shoots. If the rachis is girdled, the distal portion of the cluster may shrivel. Lesions on berries are round to irregular and are surrounded by a narrow, dark brown to black margin. The center of the lesion is violet in the early stages of development but gradually becomes velvety and whitish-gray. The light colored center surrounded by a dark margin give the lesions on fruit an eye-like appearance. Thus, the common name for the disease "birds-eye rot". Lesions on berries may extend into the pulp, which induces cracking. Fruit infection generally results in a dry rot that should have little effect on juice quality when clusters with a few infected berries are pressed. However, if fruit cracking occurs, many secondary microorganisms can infect the berries resulting in undesirable sour rots and poor juice quality.

The fungus overwinters in the vineyard primarily in lesions on infected shoots in specialized survival structures called sclerotia. Therefore, pruning out and removing infected canes during the dormant season (sanitation) is an important cultural practice for control. In the spring, the fungus produces numerous spores (conidia) on the surface of infected canes when they are wet for 24 hours or more, and the temperature is above 36^oF. The infective spores are spread by splashing rain and are not carried by the wind alone. As little as 2 mm (2/25 inch) of rain can disseminate the spores to susceptible green tissue, where they germinate to cause primary infections when free water is present for at least 12 hours. Spores can germinate and infect at temperatures, ranging from 36 to 90^oF. The higher the temperature, the faster disease develops. The incubation period (the time from infection until symptoms develop) varies from 13 days at 36^oF to four days at 90^oF. The optimal temperatures for disease development are 75 to 79^oF. Temperature and moisture are the main environmental factors influencing disease develop. Heavy rainfall and warm temperatures are ideal for disease development and spread.

The fungus can also overwinter on infected berries left in the trellis or on the vineyard floor. The fungus produces splash-dispersed spores (conidia) as well as another type of spore (ascospore) on infected fruit in the spring. Ascospores are discharged into the air and may be disseminated over longer distances by wind currents to susceptible tissues where the cause primary infections. The importance of ascospores in disease development is not clearly understood. Spores (conidia) from overwintered cane lesions are considered the most important source of primary inoculum in the spring.

1. Avoid highly susceptible cultivars. In Ohio, Vidal and Reliance are the two cultivars that have been severely infected: Although other cultivars are susceptible, it should be noted that other cultivars in close proximity to infected Vidal and Reliance were not affected by the disease in 1998. I am not suggesting that growers do not plant Vidal (an important winegrape) and Reliance (an important seedless table grape); however, it is important to remember their high degree of susceptibility.

2. Sanitation is very important. Prune out and destroy as much infected wood and possible during the dormant season. This includes infected cluster stems and berries.

3. Canopy Management. Any practice that opens the canopy to improve air circulation and reduce drying time of susceptible tissue is beneficial for disease control. These practices include selection of the proper training system, shoot positioning and leaf removal.

4. Eliminate wild hosts (grapes) near the vineyard. The disease has been observed on wild grapes in southern Ohio and was present on wild grapes near the vineyard in southern Ohio where the disease was a problem in 1998. Wild grapes provide an excellent place for the disease to develop, and serve as an excellent reservoir for the disease near the vineyard. It is probably impossible to eradicate wild grapes from the woods, but a serious effort should be made to at least remove them from the fence rows and as far from the vineyard as possible (create a buffer zone). Remember the spores are spread over relatively short distances by splashing rain and should not be able to move over long distances into the vineyard.

5. Use of Fungicides. Where the disease is a problem, the use of fungicides is highly recommended. Fungicide recommendations for anthracnose control consist of a dormant application of Liquid Lime Sulfur in the early spring, followed by the applications of foliar fungicides during the growing season.

a Liquid Lime Sulfur is applied as a dormant application in early spring at the rate of 10 gallons/acre. The application should be delayed as late in the spring as possible, but should be made before the buds swell. Lime sulfur is very caustic and can cause vine damage if applied after bud swell and green tissue is present. This spray is directed at eradicating (burning out) the fungus on infected tissue that was missed during dormant pruning, and is considered to be very important for obtaining effective control.

Lime sulfur has a bad smell (rotten eggs) and is caustic to wires and sprayers. Special care should be taken when using it to avoid drift to non-target plants and objects, and to thoroughly clean the sprayer after use. Once the disease is "cleaned up" in the vineyard, it may not be necessary to use Lime sulfur every year.

2. Foliar fungicides. Many of the fungicides used in our "normal" disease management

program for control of Phomopsis cane and leaf spot, black rot and downy mildew should be beneficial for anthracnose control. After the dormant application of lime sulfur, foliar fungicide applications should be started at 4 to 10 inch shoot growth and continued at 7 - 14 day intervals. Please note that this is the "normal" timing for our currently recommended fungicide program. Mancozeb and Captan are both recommended for early season control of Phomopsis cane and leaf spot and should have activity against anthracnose. Benlate is reported to have good activity against anthracnose, but is not generally used in our "normal" early season disease control program. If anthracnose is a serious problem in the vineyard, incorporation of Benlate into the spray program could be considered. Although I have not seen any data for control of grape anthracnose, Abound fungicide is reported to have good activity against similar anthracnose diseases on other crops and should have good activity on grape anthracnose. Copper fungicides have also been reported to have good activity against grape anthracnose.

Insect Pests by Dan Fickle and Roger Williams

The grape root borer (GRB) is a clear-wing moth whose appearance mimics that of a brown wasp. It is a major pest of grapes in central and southern Ohio where the larval stage inflicts severe damage to the roots of cultivated grapes. Adult GRB’s begin to emerge in late June and are active up to the first week of September. During the adult activity period eggs are deposited on the vine trunks and weeds under the trellis. After hatching newly emerged larvae travel down the plant to the soil surface where they tunnel into the soil and begin feeding on the vines root system. They will feed within the root system for about 22 months at which time they will leave the roots and tunnel to just under the soil surface where they will pupate, and emerge as new adults. The presence of this pest within a vineyard is difficult to detect due to its subterranean nature. Often it goes unnoticed until vines are stressed to the point that canes begin to wilt and die. Fortunately a synthetic sex pheromone is available for monitoring of this pest. One trap is usually sufficient for this purpose since the pheromone is quite powerful. If you are currently growing or thinking of establishing grapes within the range of this pest, you should determine if GRB’s are present in your area. If you wish to make this determination, we will be glad to furnish growers with a rubber septa impregnated with the pheromone. The septa should be placed in a sticky trap and hung from the trellis in late June. It should be checked on a weekly basis throughout the season.

If borers are detected, control measures should be considered. Unfortunately current control methods may only provide marginal control, but some control is better than no control at all. Current methods to be considered are (1) establish new plantings in polyethylene mulch (2) monitor the population annually with pheromone traps to determine if it is increasing, and (3) isomate pheromone ties for confusion technique are available. The rate is 100 ties to the acre. Pheromone ties are more effective in areas where the external population of GRB is minimal (isolated vineyards that are surrounded by only a few trees and undeveloped land). (4) Maintain good weed control within the vineyard, especially under the trellis. This reduces the number of oviposition sites and provides an area under the trellis suitable for applying an insecticide. (5) An application of chlorpyrifos in late summer to the ground immediately under the trellis. This will help to prevent newly hatched larvae from reaching the vine’s root system.

If you have additional questions or would like to obtain the pheromone for this pest please contact us at the department of Entomology, OARDC, 1680 Madison Ave., Wooster, OH 44691, phone: 330-263-3725, e-mail: fickle.1@osu.edu or williams.14@osu.edu.

Japanese beetles are present throughout Ohio with population size varying within local areas. The immature stage of this insect is spent as a grub in the soil feeding primarily on grass roots. Adult beetles, which are metallic green and copper colored, begin emerging in late June and early July. They feed on a wide range of host plants of which grape is favorite, especially thin-leafed French hybrid and vinifera cultivars. Vineyards that have turf growing between the vine rows or have large areas of turf in the immediate vicinity will usually tend to have the greatest pressure from this pest. Severe damage will result in leaves becoming skeletonized and prematurely dropping from the vine. There is no economic threshold on the number of beetles present or the amount of damage that requires treatment. If a susceptible cultivar is being grown and growers have observed high populations of Japanese beetles, an insecticide should be applied when beetles emerge and thereafter as needed. A Japanese beetle lure and trap is available as an alternative to applying insecticide. If traps are utilized they should be placed a good distance away from the plants you are trying to protect. Traps will provide some benefit by reducing the number of beetles in your area, but they may not provide adequate protection under severe conditions and an application of insecticide may be needed.

SETTING UP A LABORATORY FOR QUALITY WINE ANALYSIS by Todd Steiner

When setting up a wine laboratory, one must not underestimate the importance of a proper equipped laboratory. The wine laboratory is one of the most important places in the winery. To produce an "award winning wine" it is essential that you utilize the wine laboratory to its fullest potential. This means that detailed data analysis should be done from harvest to the bottling line. There are several important factors to consider when setting up a well-equipped laboratory.

I. SIZE

Make sure that you have enough space for your routine analysis.

Make sure that you have enough proper storage space on shelves, in cabinets and drawers for equipment and chemicals.

The laboratory should be large enough to accommodate several people at once.

Size recommendation: no smaller than 11' wide x 16' long.

Include future expansion in your planning.

II. LOCATION

A. Should be centrally located between crushing, fermentation, cold storage and

bottling areas.

B. Should be enclosed with a separate intake and exhaust vent.

C. Should be located in relation to utilities: water, natural gas, heating and cooling.

III. ROUTINE ANALYSIS

A. Determine what is essential to your routine analysis for quality wine production:

1. Brix/Balling

2. pH

3. Titratable acidity

4. Sulfur dioxide

5. Alcohol content

6. Tartrate stability

7. Protein stability

8. Degree of malolactic fermentation: paper chromatography

9. Volatile acidity

IV. LABORATORY EQUIPMENT

A. See attachment listing the essential equipment.

V. CHEMICALS

Store chemicals according to the specific manufacturer directions which are on the label. Keep all acids, bases, solvents and oxidizers in their own designated area. Keep them separate from each other and in enclosed cabinets approved for that use.

Label all incoming chemicals with receiving date and laboratory supervisor’s initials.

See attached list of laboratory analytical chemicals.

VI. ORGANIZATION

A. Laboratory

1. Design specific areas for each analytical procedure.

2. Procedures requiring gas, water, vacuum or a sink should be located close to the

source. (Recommendation of two sinks with hot and cold water in laboratory.)

3. Label all drawers, cabinets, shelves, etc. with the contents they contain.

4. Have laboratory analytical procedures written up and accessible in the lab.

B. Paperwork

It is extremely important to keep good and organized records of laboratory

analysis. This will enable you to trace your analytical data for any given sample

back to the specific date when the procedure was performed.

a) Keep a logbook with the standardization of chemicals which includes their

concentration and date of analysis.

3. See attached handout of a suggested laboratory analysis sheet.

4. Keep all laboratory equipment and chemical purchases listed in a file or

notebook for future reference.

C. Personnel

1. Appoint a laboratory supervisor that is in charge of all laboratory activities

including purchases and procedures.

LOSS OF FREE SULFUR DIOXIDE DURING BOTTLE STORAGE by Jim Gallander

In general, 50-80 ppm sulfur dioxide (SO₂) is added at the time of crushing, and 20-40 ppm free SO₂ is maintained during wine production. At the time of bottling, winemakers should adjust the free SO₂ level depending upon the wine pH. Often, a molecular SO₂ level of 0.8 ppm has been suggested to be an acceptable concentration for most wines. The table below offers those free SO₂ levels to obtain 0.8 ppm molecular SO₂ at various pH levels.

Source: C. Smith, Enology Briefs, Feb/March, 1982, Univ. of CA, Davis.

These levels will inhibit the growth of spoilage microorganisms and prevent discoloration in wines. To ensure biological and browning stability, winemakers should be interested in knowing the amount of free SO₂ retained during bottle storage.

The purpose of this study was to illustrate the loss of free SO₂ in sweet table wines at 6 months storage (65^oF). Finished wines (Catawba and Vidal) were sweetened with sucrose and juice reserve to 4^oBrix. Also, wines without sweetening were used as "controls" for each variety. The results indicated that the level of free SO₂ was reduced during bottle storage. The average percentage loss in free SO₂ was about 20% for the sweet table wines and approximately 15% for the "control" wines. Similar results were obtained by Ough et al. (1) with dry table wines. They also reported that low storage temperature generally resulted in higher wine quality and usually reduced the decline in free SO₂. Therefore, to protect wines in storage, a winemaker may consider adding a small amount of SO₂ over the recommended level.

Ough, C.S., E.B. Roessler and M.A. Amerine. 1960. Effects of sulfur dioxide, temperature, time and closures on the quality of bottled dry white table wines. Food Tech. 14:1-4.

Note: Information was provided by Jerry Cajka and Kathy Kneier of the ATF Office in Cleveland.

JOHANNISPERG RIESLING PETITION; PROPOSED ADDITION OF GRAPE

VARIETY NAMES FOR AMERICAN WINES, AND REQUEST FOR

ADDITIONAL INFORMATION FOR OTHER PROPOSED GRAPE VARIETIES

In order to allow for the sufficient review and evaluation of comments received as a result of the NPRM, ATF has also published a Treasury Decision (T.D.) deferring the current compliance date with respect to the use of the term Johannisberg Riesling set forth in section 4.92(b) in T.D. ATF-370 from January 1, 1999 until September 30, 1999.

In an effort to increase our responsiveness and to improve communications both within our group and to our clientele, the folks involved with the grape and wine industry team in Horticulture and Crop Science met and proposed a job descriptions for each member of our group. We would like to share the descriptions with you so that you have an understanding of what we are doing and know who to contact if you need assistance. We will continue to work as a team with the overall goal of having a strong research and extension effort to improve Ohio wine quality. If you would like to have this report, please contact Dave Ferree (330-263-3813) or ferree.1@osu.edu, or Maurus Brown at (330-263-3681) or brown.989@osu.edu for a copy.

Coshocton TMK Farm Service Bakersville 330-897-3911 June 4, 11, 18, 25

Fairfield Fairfield Landmark Lancaster 740-653-2161 Call for time

Fairfield Rager Fertilizer Amanda 614-837-2568 Aug. 9-13

Greene Terra Industries Cedarville 937-766-3111 Aug. 23-27

Licking Granville Mill Granville Aug. 11

Lorain Town & Cntry. Coop LaGrange 216-355-5641 June-Aug., Tues.

Medina Medina Landmark Medina 330-723-3208 Call for time

Medina Marvin’s Crop Ser. Litchfield 330-725-8769 May 18, June 18

Portage Deerfield Farms Ser. Deerfield 330-584-4715 July 12-30

Trumbull W.I. Miller & Sons Farmdale 330-876-6573 July & Aug.

Tuscarawas Landmark Coop Fresno 740-545-9846 July 30 & Sept. 3

Warren Agri-Urban, Inc. Lebanon 513-932-2015 Aug. 11

Wayne Wooster Equity Wooster 330-264-9925 Aug. 11

Note: This is a partial listing of collection sites available. If you would like to receive the complete listing, contact Maurus Brown at 330-263-3681 or e-mail: brown.989@osu.edu for a copy.

___________________________________________________________________________

http://www.atf.treas.gov

http://www.atf.treas.gov/columbus

http://www.agriculture.com/agtalk/Ag_Groups.html

http://www.agworldwide.comscgi/Agtalk/discuss_user.cgi

http://www.dainet.de/genres/vitis/vitis.htm

http://www.usda.gov

http://www.state.oh.us/agr

http://www.ohiowines.org

Note: The Viticulture and Enology Extension Team web site "The Ohio Grape Web" is being relocated to a new server with a new web site address, to be published in the March issue.

Topic:Planning, Financing, Establishing and Expanding vineyards and wineries.

Disclaimer Clause

Any information provided in this newsletter regarding procedures, products or equipment are provided solely for informational purposes and are not intended for advertisement and endorsement of any procedures, products or equipment, nor criticism of procedures, products or equipment not mentioned. The authors, The Ohio State University, Ohio State University Extension, and Ohio Agricultural Research and Development Center assume no responsibility for the implementation of procedures, products or equipment mentioned in this publication. Readers should follow manufacturers label for specified directions and recommendations.