PROCEEDINGS

SHO

Horticulture Department Series 491 January 1980

OHIO AGRICULTURAL RESEARCH ~~W' WOOSTER, 0 CONTENTS Page No. The Effective Use of Fungicides for Controlling Grape Diseases 1 by M. A. Ell is The Grape Industry in Virginia 4 by E.L. Phillips , Developing a Wine Industry in Mississippi...... 8 by R.P. Vine, B.J. Stojanovic, C.P. Hegwood, Jr., J.P. Overcash and F.L. Shuman, Jr. Use of Methiocarb in Ohio Grapes •...... 12 by R.N. Williams Maintaining Correct Levels of Free Sulfur Dioxide in Wines 14 by J.F. Ga11ander and J.R. Liu Centrifugation of Musts and Wines 18 by F. Krampe Microbiological Testing for Predicting Wine Stability 24 by A. Haffenreffer Importance of Determining Volatile Acidity in Wines 26 by J.F. Gallander Preliminary Observations of Cluster-Thinning and Shoot-Tip Removal On 'Seyval' Grapevines, by G.R. Nonnecke 29 Concepts of Making Red Table Wines 32 by R.P. Vine Environment and the Variety...... 38 by E. L. Ph i 11 i ps Integrated Pest Management and You ~...... 44 by F. R. Ha 11 A Progress Report on the Effects of Rootstocks on Five Grape Cultivars.. 49 by G.A. Cahoon and D.A. Chandler

PREFACE Approximately 150 persons attended the 1980 Ohio Grape-Wine Short Course, which was held at the Fawcett Center for Tomorrow, The Ohio State University, Columbus, Ohio, on January 29-30. Those attending were from 9 states not including Ohio and represented many areas of the grape and wine industry. This course was sponsored by the Department of Horticulture, The Ohio State University, in coopera­ tion with Ohio Agricultural Research and Development Center, Ohio Cooperative Ex­ tension Service and Ohio Wine Producers Association. 1/80-1200 THE EFFECTIVE USE OF FUNGICIDES FOR CONTROLLING GRAPE DISEASES M. A. Ellis Department of Plant Pathology Ohio Agricultural Research and Development Center

In 1859, Ohio led the nation in grape production. Most production was center­ ed around Cincinnati and eastward along the Ohio River. By 1870, diseases (pri­ marily downy mildew and black rot) eliminated much of the grape industry. At pre­ sent, the grape industry is growing in Ohio; however, disease is still one of the major factors limiting production. The most common and economically important di­ s~a~es of grape in Ohio are caus~d by f~ngi: Dow~~ mildew, caused by Plasmopara vltlcola; black rot, caused by Glugnardla bldwellll; powdery mildew, caused by Uncinula necator; bunch rot, caused by Botrytis cinerea; and bitter rot, caused by Melanconium fuligineum, are diseases that remain a constant threat to the commer­ cial production of grapes in Ohio. All commercial varieties grown in Ohio are sus­ ceptible to most or all of the above diseases. The introduction and acceptance of resistant varieties is highly unlikely within the next 10 years. Therefore, the use of fungicides for controlling these diseases is essential for the continued de­ velopment of the Ohio grape industry. Fungicides for control of most grape diseases are presently available. Whereas some fungicides may be more effective than others for controlling a specific disease, it must be remembered that the effectiveness of any fungicide is largely dependent upon how and when it is used. To use any fungicide effectively, the following points must be considered: 1) correct disease identification, 2) selection of the proper fungicide, 3) proper timing of application, and 4) thorough coverage of all suscepti­ ble plant parts. Correct Disease Identification It is essential to know what specific disease or diseases are present in order to choose the proper fungicide and determine the proper timing of application. Sev­ eral diseases commonly occur together in the same vineyard and can be easily con­ fused, especially on the fruit. One of the best examples is black rot and bitter rot. These two diseases cause similar symptoms on fruit and are often confused; however, differences in disease control practices make it essential for growers to correctly identify them. Black rot infects only young green berries. As berries begin to ripen (change color), they become resistant to black rot. Bitter rot is a disease of ripe berries and does not appear until fruit is about full size and be­ ginning to ripen. Fungicide sprays for black rot control are generally started early in the season and are terminated as berries begin to mature. If bitter rot is present and preharvest weather is warm and wet, the termination of fungicide sprays too early could result in serious losses. For help in disease identification it is recommended that growers contact their county extension agent. In many cases the agent can identify the disease. If the agent cannot identify the disease, he can send samples to the Plant Disease Clinic at The Ohio State University for diagnosis. Selection of the Proper Fungicide Correct disease identification leads to the selection of the correct fungicide. The most effective fungicides currently available have been developed for specific

-1- situations and specific diseases. Usually, there are several fungicides that are effective for a specific disease but it is unlikely that a specific fungicide will control all diseases. For this reason fungicide combinations may be needed. In southern Ohio, black rot and downy mildew must be controlled at the same time throughout the growing season. The most effective fungicide for black rot may not be the most effective fungicide for downy mildew. In situations such as this, a combination of the most effective fungicide for each disease (provided the fungi­ cides are compatible) may result in more effective control. Read the label before selecting any fungicide. It is a violation of the federal pesticide law to use a chemical in any manner inconsistent with the label. For current fungicide recom­ mendations and information on compatibility for mixing, Ohio growers should obtain a copy of the Ohio Commercial Fruit Spray Guide from their county extension agent. Proper Timing of Application Proper timing means consideration of when and how frequently the fungicide must be applied to effectively control the disease. Most fungicides currently available for grape disease control are protectants. They function by forming a protective barrier on plant surfaces and must be applied before the fungus arrives on the plant surface and enters the plant. The black rot and downy mildew fungi can enter a susceptible plant within a few hours under favorable environmental conditions. Once fungi are inside the plant tissues, protectant fungicides will not stop infec­ tion. Therefore, proper timing of spray applications is critical. After the first application, the fungicide barrier is established on the plant surfaces. Effective fungicide use involves keeping this barrier active throughout the time that the fungus can arrive on and infect the plant. For control of black rot and downy mildew the fungicide barrier needs to be present throughout most of the growing season. r10dern fungicides are developed so that they do not persist in the environment for very long. Some of the factors that affect fungicide degradation include: rain water, microbial action, oxidation, and sunlight. Due to degradation and washing away of the fungicide by rain, proper timing of additional applications are impor­ ant. Plant growth also affects the completeness of the protective fungicide barrier. As new leaves and shoots are produced, they must be covered with the fungicide bar­ rier. Reapplication guidelines are given on the fungicide label. The guidelines usually are in ranges, such as "spray at 7-14 day intervals." If excessive rainfall or excessive growth of the crop is occurring, the shorter interval should be used. Thorough Coverage of all Susceptible Plant Parts

Regardless of what type of equipment is used to apply fungicides, thorough CQV­ eraqe of all susceptible plant parts must be obtained. Any portion of the plant sur­ face not covered by fungicide is open to attack by disease-causing fungi G The black rot fungus can penetrate grape leaves through the upper and lower surface. The downy mildew fungus penetrates leaves through the lower surface. No matter how many times a plant has been sprayed, if the lower surface of the leaf is not covered with fungicide, it is still subject to attack by these fungi. Completeness of the pro­ tective barrier of fungicide is essential for effective disease control. The com­ pleteness of the barrier is partly dependent upon how well the spray spreads and sticks to the plant surfaces. For this reason, spreader-stickers or spray adjuvants are often added to fungicide sprays. Careful consideration of proper disease identification, selection of the proper fungicide or fungicides to do the job, proper timing of applications, and thorough coverage of all plant parts will go a long way towards increasing the effectiveness -2- of fungicide spray programs for controlling grape diseases.

-3- THE GRAPE INDUSTRY IN VIRGINIA

E. L. Ph i 11 i ps Department of Horticulture Virginia Polytechnic Institute &State University

Virginia has the "wine fever ll again. For the tenth time since the founding of Jamestown in 1607, a serious attempt is being made to establish a viable grape in­ dustry in the Old Dominion. With no less than eight distinct species of the genus Vitis growing wild within its borders, it is difficult to understand why the indus­ try is so little developed at the present time. The Past From the very earliest days of lJamestown, the colonists cultivated lithe vine". Lord Delaware, governor of the colony in 1610, persuaded the London Company to sub­ sidize the culture of the grape as a possible source of revenue. French vine dres­ sers were brought over for this purpose, but the results were disappointing. The vine grew profusely and the yields were good, but the wine from the native American grapes was "strong and heddy". In 1619 cuttings of the best of the European varieties were imported from France. The Colonial Assembly enacted a law requiring every land owner to plant ten cut­ tings and care for them. A reward was offered to those who would plant more than ten. This stimulated many large plantings, a few with as many as 10,000 vines. Within five years most of the vines were dead, having succumbed to mildew, black rot, and phylloxera. Tobacco was more profitable and the colonists had to be forced ll b.y legislation to replant even a few vines. These, too, soon "sickened and died •

A premium of 10,000 pounds of tobacco for "eac h two tunne ll of wine made in the colony was offered in 1660. Again the effort failed. Each succeeding generation of Virginians had to learn the same lesson--the Old World grape varieties were not adapted to Virginia's climatic conditions, diseases, and insect pests. In 1710 a colony of Germans from the Rhine country was established on the Rapidan River in Spottsylvania county. They grew a large acreage of European var­ ieties and were soon marketing "red and white Rapidan wine". Within a few years the enterprise had failed. The "sickness" took these vines, too. A fund of 500 pounds was offered in 1760 to anyone who could within eight years "make ten hogsheads of wine from the vintage of a single season". The reward was never claimed. In 1769 the Virginia Assembly subsidized a Frenchman in the culti­ vation of the European grape for wine on a tract of land near Williamsburg. By 1780 the planting had been abandoned as another failure. Native American varieties were the basis for the brief success of a grape ven­ ture in 1830, but the wine was too "foxy" for the taste of most. Wine from European grapes was preferred. Not until the discovery of Norton's Virginia in 1835 was wine from any American grape considered acceptable. A chance seedling of Vitis aestivalis, Norton's Virginia revived interest in grape growing in Virginia. One enthusiastic authority in 1865 stated that "it is one of the greatest blessings an all merciful God has ever bestowed upon suffering humanity". He predicted there would soon be thousands of acres in Virginia and

-4- wine would be one of the state1s chief exports to Europe. Grape production began in earnest immediately after the Civil War. Acreage in Virginia increased from less than 100 in 1865 to over 3,000 by 1869. Norton was the major wine variety. Some Catawba, Clinton, and ryes were also grown for wine; Con­ cord and Delaware for dessert use. Although production was statewide, planting was heaviest in Albemarle county. Albermarle1s Rivanna river was christened the IIRhine of America ll and Charlottesville, the county seat, was designated the IICapital of the ll Wine Belt of Virginia • In 1878 Virginia ranked eleventh in wine production in the United States, with over 230,000 gallons. Virginia's IINorton Claret ll was awarded a medal at the Paris Exposition for the best American wine. Efforts were then made to organize a Virginia Wine Growers' Association with branches in all centers of production. The venture failed, however, for hard times had come and it was considered a hazardous undertaking. The country was entering a depression, there was increasing competition from California, it was difficult to obtain a standard grade of wine in quantity, and disease was taking its toll. Black rot and mildew had depleted many plantings and growers were becoming discouraged. The discovery in 1882 of Bordeaux mixture for disease control came too late, and by 1895 only a remnant remained of what was once a flourishing grape industry. Soon after the repeal of National Prohibition in 1933, the Monticello Grape Growers' Cooperative Association was formed in Charlottesville to revive the wine industry in Virginia. Plans failed to materialize, however. Less than 150 acres of wine grapes were planted. Few growers were interested, and most of these had given up by 1950. The Present A survey by the Virginia Department of Agriculture and Commerce in 1969 found 15 Virginia farmers growing grapes commercially, with a total of only slightly over 50 acres. One grower operated his own winery; the others sold on the fresh market. Concord was the major variety, with some Fredonia, Niagara, and a few other American hybrids. There were no commercial plantings of muscadines or vinifera in the state, and only two acres of French-American hybrids. Commercial wineries in Virginia im­ ported grapes and juice from other states to satisfy their needs. Today, at the beginning of the 1980's, Virginia has 58 commercial growers with over 350 acres of grapes and 8 bonded estate wineries. Only 6 growers have plant­ ings in excess of 20 acres. Approximately 60 acres of American hybrids go to the fresh market, with 190 acres of French-American hybrids and 100 acres of vinifera for wine. There is only one small commercial planting of muscadines in the state. Although most of the wine grape acreage is in central and northern Virginia, plant­ ings are scattered throughout the state with the exception of the extreme south- western mountain area. The Concord variety comprises 90 percent of the current American hybrid acreage. Of the many French-American hybrids that have been tried, Seyval (5V-5276), Vidal Blanc (V-256), and Villard Blanc (SV-12375), are the most popular for white wine; Chancellor (5-7053), Chambourcin (JS-26205), Villard Noir (SV-183l5), and DeChaunac (5-9549) for red wine. r~ost growers of vinifera have planted Pinot Chardonnay, White Riesling, and Cabernet Sauvignon, with S04 and 5SB as the most common rootstocks.

-5- Grape training systems in Virginia are quite varied. Although most growers follow methods typically American, such as the 4-Arm, 6-Arm and Umbrella Kniffin systems, many are using the Single Curtain Cordon and some have converted to the Geneva Double Curtain. The European and California influence can be seen in central Virginia, with several vineyards trained to the Italian "Casarse ll system. Some growers, who have already encountered labor difficulties, are adjusting their train­ ing systems to accommodate mechanical harvesting. The use of herbicides in the row, with a closely clipped sod between rows, is the usual practice in Virginia vineyards. Where soil erosion is not a problem, clean culture is maintained either by disking or with the grape hoe. Over-fertili­ zation, particularly with nitrogen, is all to common with new growers. This is re­ flected in excessive vine vigor and poor fruit quality. Pest control practices are as varied as the training systems. They range from no control measures at all to excessive applications of numerous pesticides. The larger commercial operations use modern low volume sprayers, with properly timed sprays of the recommended materials only as needed. Results in recent years in­ dicate most grape diseases and insects can be controlled rather effectively under adverse weather conditions and on some of the most susceptible varieties. Grape harvest in Virginia extends over a period of more than two months. Ripen­ ing of anyone variety varies by as much as 10 days or more, depending upon the sea­ son and area where grown. Early varieties may be harvested the first week of August in the southeastern part of the state; late varieties may not be ready until late October in northern Virginia or the higher elevations. Although most of Virginia's grapes are grown for wine, a high percentage of both wine and table grapes are harvested on a pick-your-own basis. This may change, however, as more estate wineries develop and acreage increases. Mechanical harvest­ ing of wine grapes is planned for the larger vineyards. The Future What lies ahead for the grape industry in Virginia? Will the present effort fail or succeed? Is the industry to flourish briefly, then fade, as it has done so many times in the past? Or, will it become a permanent and prominent part of the agriculture of the Old Dominion? Only time will tell. A limited degree of success has already been attained in the few short years since the revival of interest in grape production began in the early 1970's. ~ward­ winning wines have been made by northern Virginia wineries from Virginia grown grapes, and table grape production has been successful at several locations. Vine­ yards have recently been established by out-af-state and foreign investors attracted by Virginia's climate, soil, and market potential. This is due in large measure to the promotional activities of the Vinifera Wine Growers I Association and the Virginia Department of Agriculture and Consumer Services. Both organizations have been very active in encouraging grape planting, particularly for wine production. Attention is currently being directed toward changing Virginia's wine laws so that local winer­ ies can compete more favorably with other wine producing states. Passage of such legislation will encourage further investment in the state's budding grape industry. Production problems have not changed since the early efforts to grow grapes in Virginia. Climate and soil are the same; insect and disease problems are the same. Cultural practices have been improved, however, and pest control has been made

-6- easier and more certain by the use of newer and better pesticides. The introduction of French-American hybrids and improved rootstocks for vinifera has given present growers an advantage over their predecessors. High quality wine grapes can now be successfully grown in areas where it was previously impossible. Many of the new varieties of a11 types are being planted for evaluation under Virginia1s soil and climatic conditions. The success of the grape industry depends upon the use of the best management practices, from the initial planning stage through the sale of the finished product. Only the serious grower who operates his vineyard as a business enterprise can ex­ pect to be successful. A study of the history of the industry in Virginia reveals that most failures were a result of lack of careful planning, poor cultural practices, and poor marketing techniques. These same mistakes have been repeated in recent years. In light of the revival of interest in commercial production and the need for information on grape growing in Virginia, an annual grape production short course has been conducted each year since 1976. This course, sponsored by the Department of Horticulture and the Virginia Cooperative Extension Service at Virginia Tech, is designed to acquaint both amateur and commercial growers with up-to-date informa­ tion on all phases of the grape industry--site and variety selection, cultural prac­ tices, pest control, harvesting, processing, and marketing. -A study of the topography, soils, and climate of Virginia reveals thousands of acres of land suitable for grape production. There are few areas within the state where some type of grape cannot be grown. Under good management and with the right varieties in the right location, viticulture in Virginia can be commercially profit­ able. With favorable soil and climatic conditions more extensive than in most areas of Eastern United States, Virginia could be a leader in grape production before the turn of the century.

-7- DEVELOPING A WINE INDUSTRY IN MISSISSIPPI' Richard P. Vine, B. J. Stojanovic, C. P. Hegwood, Jr., J. P. Overcash, and F. L. Shuman, Jr. A. B. McKay Food and Enology Laboratory Mississippi Agricultural and Forestry Experiment Station

Dr. Dunbar Rowland (3), in a history of Mississippi, stated in 1925 that there were 31 wineries operating in Mississippi prior to prohibition becoming the law of the land via the Volstead Act by the U.S. Congress in 1920. Perhaps one should thus say that the r~ississippi wine industry is re-developing, rather than developing. In any event, Mississippi was the last state to vote for repeal--not until 1966--while most other states voted for repeal following the national decree in 1934. This resulted in a total of 46 years that ~1ississippi "The Magnolia Statell was "dry" and two full generations of time was lost to the great experiment. Nevertheless, grape research continued at Mississippi State University during many of these years under the direction of Dr. J. P. Overcash (2), Professor of Horticulture. Mississippians consumed approximately 1,449,000 gallons of wine in 1977, according to the 1979 Wines and Vines Directory Issue (5). This was an annual per capita consumption of only .607 gallons by a population of about 2,389,000. Mississippi is an alcohol monopoly state and all wholesale operations are con­ ducted by the Alcoholic Beverage Control Division of the State Tax Commission. Obviously, these conditions are not the most encouraging one might design for the resurrection of a wine industry. Despite the apparent shortcomings in the marketplace for new wine products, several rather dynamic ideas existed--each of which brought forth a number of pertinent questions. Perhaps the low per capita wine consumption has been the result of an in­ ordinate number of people who did not drink any wine. Was there a tacit market segment existing for native Mississippi wines? If so, how large was this market? What are its demographics and how was it to be reached? What characteristics would native Mississippi wines need to exhibit in comparison to the out-ot-state wines already on the shelves? How much would IIhome-grown" really mean in this II might-be" marketplace?

Perhaps some of the crop yields observed by Dr. Overcash (2), particularly trom some of the rather new Vitis rotundifolia cultivars being tested from the University of Georgia and North Carolina State University, could be considered for potentially lower unit production costs. Could these grapes yield wines that would satisfy the hypothetical demand? Would accepted basic vineyard practices and methods apply to Vitis rotundifolia in Mississippi or will new procedures need to be developed to achieve top quality, quantity, efficiency and profitability? Should cultivars of Vitis vinitera, Vitis labrusca and other species be consider­ ed despite the poor reputations for disease resistance? What about the French-

Mississippi Agricultural and Forestry Experiment Station Paper No. 4465.

-8- American hybrids and the Vitis vinifera--Vitis rotundifolia crosses developed by Dr. H. P. Olmo at the University of California at Davis? Legislation for a specially reduced state excise tax rate and an open availability to utilize the state-operated monopoly wholesale facility may provide an adequate framework for native Mississippi wines to compete. How can an excise tax be reduced for products in an industry that does not exist? Just how much will Mississippians care about home-grown wines? What price levels will this prospective market accept? None of the basic reasoning behind these ideas and questions is new to the industry. However, much of the existing data cannot be applied directly in Mississ­ ippi. A different product from a rather new raw material was to be designed for an unknown market segment in a shy consumption area. The first order of business was the establishment of legal foundations upon which to form a native wine industry. The primary energy behind Senate Bill No. 2172 (passed in 1976) in the Mississippi legislature was from Senator William G. Burgin, Jr., of Columbus, Mississippi. The new law made it possible for wineries to operate once more in Mississippi. The tax rate adopted for native wines was $.05 per gallon, while out-of-state still wines remained at $.35 per gallon. Some counties elected to remain "d ry ". Wineries are directed to produce wines primarily from fruit grown within the state, although there is relief from this regulation during the first three years of operation for each new winery established. The covenants of the Mississippi native wine law are comprehensive and thorough to the extent that a creditable re­ birth of its wine industry is insured. A research program needed to be developed. Dr. Louis N. Wise, Vice President, Division of Agriculture, Forestry and Veterinary Medicine at Mississippi State Uni­ versity, began to develop his long ambition of bringing grape and wine academics to the College of Agriculture. Leadership of the project was assigned to Dr. Boris J. Stojanovic, a micro­ biologist of Yugoslavian descent whose family owned an estate winery prior to World War II. Stojanovic was transferred from the Department of Agronomy to the Horticulture Department and, with the cooperation of Dr. Clyde C. Singletary, the enology and viticulture project was initially housed in the Department of Horticul­ ture (4). Dr. J.P. Overcash established in 1973 four research vineyards in various soii and climatic areas in Mississippi. Muscadines received primary emphasis because of previous success with this species in studies at Mississippi State University and from a USDA grape breeding program at Meridian, Mississippi. Research at Meridian showed poor success with American bunch grapes and French-American hybrids. Plot yields from muscadine cultivars have been from 150 to 200 pounds per vine (2"18 per acre) in the current vineyards. A grant by the Mississippi State University Development Foundation provided funds for Dr. Stojanovic·s initial travel and study in order to bring profiles up to date upon the state of the art. Plans for the new enology laboratory facilities were drawn, evaluated, amend­ ed as necessary and, finally, approved. However, only a portion of the 8,000 square

-9- foot laboratory could be funded at the beginning. ~1eanwhile, Dr. Stojanovic set forth with the extensive administrative and legal legwork required to commence his task.

In 1977, Mr. Richard P. Vine joined the project as Cellarmaster and Research Assistant, bringing 17 years experience from the eastern wine industry. Shortly thereafter, Dr. C.P. Hegwood, Jr., joined the team as Viticulturist, with several years of viticultural research experience having been responsible for the vineyard at the Mississippi Agricultural and Forestry Experiment Station--Delta Branch at Stoneville, Mississippi. Dr. Fred L. Shuman, Jr., a Senior Engineer from the Department of Agricultural and Biological Engineering at ~1ississippi State, also joined the project on a part­ time basis, providing the expertise necessary to adapt small industrial winery machinery and equipment to research requirements. The enology laboratory is now virtually completed and is properly addressed as the A.B. McKay Food and Enology Laboratory. The "food" portion of the facility will eventually research and instruct in the field of food preparation and catering. Viticulture and enology research functions are now carried on autonomously within the structures of the t1ississippi Agricultural and Forestry Experiment Sta­ tion which is directed by Dr. R. Rodney Foil. Four branch experiment stations maintain research vineyards from which many of the grapes originate for experimen­ tation. In addition to the Stoneville (Delta) station, the others are at the Beaumont, Crystal Springs, and Verona locations. Two new vineyard plots have also been established near the laboratory facility. Within this overall system, more than 40 cultivars and breeding lines of Vitis rotundifolia are currently being evaluated. Cultivars of Vitis vinifera, Vitis labrusca and French-American hybrids, and other germplasm materials are rap­ idly increasing the collection. It did not take long for the research program to encounter several major pro­ blems. One of the largest threats to Mississippi viticulture is the infamous Pierce1s Disease which attacks the xylem of most Vitis vinifera, Vitis labt~usca, and French-American hybrid vines and other species. Anthracnose and Black Rot are also significant diseases found in the pathway of the grape grower. An average rainfall of 55 inches per year is accompanied by very high humidity--both of which provide adequate moisture for downy mildew. Low juice yields from the muscadine cultivars continue to perplex vintners and, in a major effort, we are finding sound solutions difficult to formulate. Muscadine wines have a rather high potential for oxidation--to the extent that sulfur dioxide cannot be used in red muscadine wine preservation. When it is used, immediate browning of the diglucoside (usually delphinidin or petunidin) takes place. Other areas of attention include acid synthesis during primary fermentation and stabilization techniques. Of course, a good new native wine law with an attractive excise tax rate and a comprehensive research program do not make a wine industry. There rernains Jl1any other considerations--not the least of which are some answers to how the potential markets in r1ississippi are to be analyzed, scrutinized and theorized. Most of this must continue to be done by the new commercial wineries. This is the area that

-10- any industry is likely to find the most difficult and can get the least help to solve. One of the more tangible problems that faces the young Mississippi wine in­ dustry is a state law that prohibits the advertising of wine. This is a real handi­ cap in the promotion of tours at the new wineries and ultimately, retail sales. An­ other difficulty is shipping. Retail shops are not prone to buying large stocks of unproven brands which results in high unit costs for delivery. Despite the difficulties and problems, the young Mississippi wine industry is very much alive and well. At present, four wineries operate in the Magnolia State, with yet another on the drawing boards. Of these, two have bottled goods for sale and proudly display their eleven awards won at Wineries Unlimited last year in Lancaster, Pennsylvania. Dr. Alex Mathers, retired Bureau of Alcohol, Tobacco and Firearms Chief Chemist, is President of the Mississippi Grape Growers Association. It was char­ tered in 1979 and is nearly 100 members strong. Dr. Richard Mullenax, Horticulturist with the Mississippi Cooperative Exten­ sion Service (1) is quick to caution growers about overproduction but concludes that, IIWith the interest we have in growing muscadine grapes, this young industry could explode into prominence in the next few years. II The current analysis of the Mississippi ventures into viticulture and enology results in profiles that are encouraging. It will be interesting to see how solu­ tions to important problems and answers to significant questions affect the growth curve over the span of this new decade. Literature Cited 1. Anonymous. 1979. More processing markets hold key to Mississippi's grape industry...growers told. Fruit South 4:24. 2. Overcash, J.P. and B.J. Stojanovic. 1977. Viticulture and enology in Mississippi: grape production research. Miss. Bus. Rev. 39(1):3-7. 3. Rowland, Dunbar. 1925. History of Mississippi. S.J. Clark Pub. Co., Chicago, Jackson. Rep. 1978. 4. Stojanovic, B.J. and J.P. Overcash. 1977. Viticulture and enology in Mississippi: II. enological research. Miss. Bus. Rev. 39(6):3-7. 5. Wines and Vines. 1978. Directory of the wine industry in North America 1979. Vol. 59, No. 12-A. The Hiaring Co., San Francisco.

-11- USE OF r1ETH IOCARB ON OH 10 GRAPES Roger N. Williams Department of Entomology Ohio Agricultural Research and Development Center

. Many devices have been used in an attempt to keep birds out of ripening grapes; flre crackers, carbide cannons, distress call recordings, various types of netting, even shotguns, but none have been completely satisfactory. There have been problems with such methods. Recently, Methiocarb (Mesurol R) was registered for use on cher­ ries as a bird repellent and this may have revolutionized bird control for other crops as well. Mesurol is a carbamate insecticide, acaricide, and molluscicide which kills by contact and by stomach poison action. It is labelled as a 75% WP and a 50% Hopper­ Box Treater by Mobay Chemical Corp., and 2% Bait known as "Snail and Slug Pellets ~1-2" by Hopkin Agricultural Chemical Co.

~1esurol was first labelled as an insecticide for control of plum curculio on cherries and peaches and as an acaricide on these same fruits for control of European red mite and the ~1cDaniel mite. This material has also been shown to have activity as a bird repellent and has been labelled for this use on cherries. The 75% WP formulation used as a bird re­ pellent material is of interest to us on grapes.

r~esurol has worked quite effectively as a deterrent to bird depredation. For this reason it was decided at the last GrapeWine Short Course (in early 1979) to ini"ciate a request for the use of Mesurol on grapes in Ohio under an Emergency Use Permit (Section 18 of the Federal Insecticide, Fungicide and Rodenticide Act as Amended). This request was prepared by the Ohio Wine Producers Association in the person of Mr. Ed Boas following preliminary ground work by Dr. Tom Quilter. The required information was compiled and forwarded to the Ohio Department of Agriculture (GOA) at Reynoldsburg. Oren W. Spilker, in charge of the Pesticide Regulation sec­ tion of ODA was instrumental in getting the request approved within Ohio and for- warded to the Environmental Protection Agency (EPA) in Washington, D.C. The request was accompanied by a list of counties with total acreages in grapes, a list of growers that were expected to use Mesurol as a bird repellent, and the estimated acreage to be treated. The application was submitted to EPA on May 24, 1979. The mlnlmum time required for action on a request of this type is generally 90 days. Thus, it was realized that approval, if it came, would likely be too late for use in the southern part of the State. In mid-July, an EPA representative contacted me to ask a few general questions. At that time he indicated that everything in the request seemed to be in order. On August 24, 1979, EPA granted approval for the use of Mesurol as a bird repellent on grapes in Ohio. aDA prepared a sheet of procedures for the use of Mesurol under Section 18 and a form to be used by growers in record keeping (Exhibit A). Later Mobay Chemical Corp. prepared an Information Bulletin (Exhibit B) indicating how Mesurol 75% WP should be used. This Bulletin was accompanied by a sheet from ODA (Exhibit C) re-

-12- stating the stipulations and providing the growers with a form to keep the necessary records of Mesurol applications. This Section 18 label is similar to the label for use of Mesurol on cherries ex­ cept that a l-day application to harvest interval is allowed on grapes, whereas, on cherries a 7-day period between last application and harvest is required. The final report on the Section 18 for use of Methiocarb (Mesurol) on grapes in Ohio for 1979 was sent to EPA by ODA in mid-January 1980. The contents of the writ­ ten portion of the report were: "From the 1978 bird problem, the grape growers expected a greater number of birds in 1979, thus resulting in more damage to their vineyards. The bird problem, des­ cribed in our request for the Section 18, did not develop as expected. In addition, some growers felt that approval arrived too late and had not made any provisions for obtaining Mesurol for the Section 18 intended use. Only eight growers participated in the program. The U.S. Fish and Wildlife Ser­ vice was interested in the program and were requested by the Ohio Department of Agriculture to participate by making observations in the treated areas to determine any possible adverse effects to non-target species. The date of initial bird attacks ranged from July 25, 1979 to September 25, 1979. Application dates in the eight vineyards ranged from September 2, 1979 to October 3, 1979. Rates of Mesurol applied ranged from 2 pounds to 2.67 pounds per acre. A total of 453 lbs. of product was used in 219 total acres. Twelve different grape varieties were involved, and there appeared to be some variation in control within the varieties ranging from fair to excellent. The U.S. Fish and Wildlife field staff reported that there were no adverse ef­ fects observed in non-target areas surrounding the treated vineyards. Attached is a record form that was supplied to and used by the cooperators. In­ formation in the columns is the totals of all cooperators. II EPA is not acting very fast in the area of pesticide registration and thus there is not a great amount of optimism that Mesurol will receive a national label on grapes before the 1980 bird season. One of the 1st steps in obtaining a label for a new crop is a permanent tolerance, which is the amount of residue that can be pre­ sent on the host crop after a specific period of time. To this point, EPA has only issued a temporary tolerance for Mesurol on grapes. Thus, it is believed that in order to use this product in 1980 that another Section 18 will be required. It should be easier to obtain this year with the precedent already worked Qut. However, in order for it to be used over the entire State it will be desirable to get the request and information to support the emergency to the Ohio Department of Agricul­ ture as soon as possible.

-13- MAINTAINING CORRECT LEVELS OF FREE SULFUR DIOXIDE IN WINES James F. Gallander and Jim-Wen R. Liu Department of Horticulture Ohio Agricultural Research and Development Center

The use of sulfur dioxide in making wines has been known for many centuries. In solution, sulfur dioxide is rather unique, because it has both antimicrobial and antioxidative activity. In general, 100 ppm sulfur dioxide is added at the time of crushing, and 20 to 30 ppm free sulfur dioxide is maintained during wine production. This level of sulfur dioxide will inhibit the growth of spoilage microorganisms and prevent discoloration in the wines. Therefore, it is important that both the total and free sulfur dioxide be analyzed after fermentation, periodically throughout the aging period, and prior to bottling. This is basic to a good winery quality control program. It is also important to avoid an excessive amount of sulfur dioxide in wines. If too much sulfur dioxide is added to a must, fermentation may be delayed, and the resulting wine will have a high bound sulfur dioxide content. In wine, excessive amounts of sulfur dioxide may bleach the color and cause an objectionable, pungent odor. In addition, the maximum amount of total sulfur dioxide permissable in wines in the United States is 350 ppm. Chemistry of Sulfur Dioxide Sulfur dioxide may be added to a must or wine as a gas, salt, or aqueous solu­ tion. For the small winery, the preferred method is usually adding salts of sulfur dioxide, such as potassium metabisulfite. This salt is approximately 57.6% sulfur dioxide and is easy to handle by a small-scale operation. When sulfur dioxide is added to water, the general reactions that occur are as follows:

S02 + H20~ H2 S03 (sulfurous acid) H2S03 ~ HS03- + H+ (bisulfite) HS03- ~ 503= + H+ (sulfite) From the above, it is seen that several ionic species are formed and their concen­ trations are influenced by the level of H+ ions (pH). The effectiveness of sulfur dioxide depends primarily on the concentrations of these ionic species. The portion of these ionic species that are not bound to other compounds in musts and wines is known as free sulfur dioxide. It is this form that contributes most to the activity of sulfur dioxide in preventing spoilage and discoloration. For the other form, fixed or bound, the ability of sulfur dioxide, mainly the bisulfite ion, to combine with acetaldehyde, pyruvic acid, glucose, or other compounds is known to decrease the action of sulfur dioxide. Therefore, the effectiveness of sulfur dioxide is related to those factors which influence the formation of sulfur dioxide binding compounds. Some of the most important factors include: yeast strain, temperature, aeration, and must composition. Another prime factor is pH, which not only affects the formation of binding compounds such as pyruvic acid, but also the ionic form of sulfur dioxide. Since these factors are not the same for all wines, it is essen­ tial to routinely measure the free sulfur dioxide. This will aid in determining

-14- the correct amount of sulfur dioxide to add and when to treat the wines. Experiment and Discussion To illustrate the fact that each wine binds sulfur dioxide in different pro­ portions of free to bound, five varietal musts were treated with 100 ppm of sulfur dioxide at the time of crushing. Each wine was fermented by a standard procedure using the wine yeast, Montrachet #522. About five days after dryness (-1.50 Brix), each wine was analyzed for free and total sulfur dioxide by the Ripper procedure (1). The amounts of free sulfur dioxide covered a range of 11 to 15 ppm with the variety Aurore having the lowest content (Table 1). These results indicate that the must composition has a significant effect upon the proportion of sulfur dioxide which is free. Even though 100 ppm of sulfur dioxide was added, the total was found to vary between 61 and 115 ppm. It is well known that sulfur dioxide may be produced during yeast fermentation. This would account for the high total sulfur dioxide contents in some of the wines. For the other wines, volatilization and entrapment of sulfur dioxide by must particles may have been the causes for the loss of sulfur dioxide. TABLE 1. Free and Total Sulfur Dioxide of Five Varietal Wines Immediately After Fermentation Sulfur Dioxide, ppm Variety Free Total Aurore 11 84 Villard Blanc 13 115 Vidal 12 61 Seyval 15 114 Catawba 14 86

The next step in treating wines with sulfur dioxide is to bring the free sulfur dioxide content to 20 to 30 ppm. To obtain this level by calculation is rather dif­ ficult, because the ratio of free to total varies widely from one wine to another. The common method is to add various levels of sulfur dioxide to a series of wine samples and determine their free sulfur dioxide content. For the five varietal wines in this study, various amounts of sulfur dioxide were added to a series of samples. These samples were treated with an additional 20, 40, 60, and 80 ppm sulfur dioxide. After the samples were sealed and stored for five days, each sample was analyzed for its free sulfur dioxide content. The data were plotted on graph paper, ppm of sulfur dioxide added versus ppm of free sulfur dioxide found. After drawing a line between the points, the amount of sulfur dioxide to be added to obtain 20 ppm free sulfur dioxide was determined for each wine. This is illustrated in Fig. 1 by using the data of Vidal wine samples.

-15- 60

\j c ~ 0 W-

E CL CL 40

~ \j x 0

~

~ ~ 4- 20 r-- ~ V1

~ ~ ~ w- 25 ppm

o 20 40 60 80 Sulfur Dioxide (ppm) Added Fig. 1. Effect of Adding Sulfur Dioxide on the Free Sulfur Dioxide Content in Vidal Wine. It is estimated that approximately 25 ppm of sulfur dioxide must be added to the Vidal wines to obtain an additional 8 ppm free sulfur dioxide. The resulting Vidal wine will then contain about 20 ppm free sulfur dioxide. The results for the other varietal wines including the Vidal wine are summarized in Table 2. These re­ sults indicate that when a subsequent addition of sulfur dioxide was made the amount of free depended upon the variety. An additional 35 ppm sulfur dioxide was required for Aurore, but Villard Blanc required only 22 ppm to obtain 20 ppm free sulfur dio­ xide. TABLE 2. Amount of Sulfur Dioxide to be Added to Several Wines for the Purpose of Obtaining 20 ppm Free Sulfur Dioxide.

l Original 5°2 Free S02 To Be Free S02 Content Added Increase Variety (ppm) (ppm) (ppm)

Aurore 11 35 9 Villard Blanc 13 22 7 Vidal 12 25 8 Seyval 15 30 5 Catawba 14 30 6

Approximately 5 days after dryness.

-16- SUMMARY Since the ratio of free to total sulfur dioxide depends upon so many factors, it is important to analyze each wine on a regular basis. This will aid in deter­ mining the correct amount of sulfur dioxide necessary to produce the required free sulfur dioxide in a particular wine. In general, the free sulfur dioxide content of a wine should be kept within 20 to 30 ppm. This range is usually sufficient to prevent spoilage by oxidation and growth of microorganisms.

LITERATURE CITED 1. Amerine, M.A. and C.5. Ough. Wine and ~1ust Analysis, John Wiley and Sons, N.Y., 1974.

-17- CENTRIFUGATION OF MUSTS AND WINES Fred Krampe Centrico, Inc., Northvale, New Jersey

The clarification of wine and juice is required during various stages leading to the final polished product. In general, clarification can be accomplished by settling, filtering, or centrifugation. Each of these procedures has advantages and disadvantages. Settling

The two main advantages of settling are (1) that it only needs the natural force of gravity to accomplish the goal; and (2) it does not require the inter­ posing or intermixing of foreign matter with the product. Negative factors in­ clude the need for large tanks and considerable time to complete the process. In addition, for highest quality, it is frequently desirable to remove the solids from the liquid more rapidly than settling allows. Finally, clarification and solids concentration efficiency may be insufficient. Filtering Filtering provides the highest degree of clarity and is definitely necessary for final polishing. On the other hand it is relatively slow, occupies a relatively large amount of space, and requires frequent replacement and/or cleaning of the filter medium, adding to material and labor costs. Where filter aid is needed, this material may find its way into the filtrate. Finally, filtering is also not readily adaptable to continuous as opposed to batch processing. Centrifugation Basically, a centrifuge is a mechanical means of speeding nature1s work. The higher g-force, in combination with the internal centrifuge configuration, makes clarification with a centrifuge especially efficient, by far the fastest of all three processes. Unlike filtering, the liquid is not forced through a layer of solids; instead the solids are removed from the product stream with minimum contact time. Furthermore, solids are not intermixed with foreign matter, such as filter aid. However, centrifugation entails greater system complexity than settling, and cannot quite achieve the degree of clarity obtainable by filtration. In summary, clarification by centrifuge offers four significant advantages:

1) Less space is required than for any of the other methods. 2) Clarification is accomplished within a shorter time than settling. 3) Any desired degree of clarity can be obtained by increasing or de­ creasing the feed to the centrifuge. 4) Concentrated solids are not intermixed with foreign matter. The centrifuge most widely used in the United States wine industry is the disc type or automatic desludger (fig. 1). The feed is brought into the rotating bowl through a central feed tube, and enters the disc stack. As clarification proceeds, the clarified liquid is discharged under pressure from the bowl, and the solids chamber fills with solids. The bowl opens periodically to eject the solids in­ stantaneously, and immediately closes again. The discharged solids are collected

-18- in the sludge catcher and carried out into a collecting tank.

Feed ---':;.:·~}::::{5:::::··~"{\ :::. ~.: :. :::

Fig. 1. Disc Type or Automatic Desludger

Opening and closing of the bowl are accomplished b:1 a sliding piston, actuated by water that is permitted to enter chambers of varying sizes. The centrifugal forces of the different volumes of water cause alternate pressure below and above the sliding piston, thus creating the up-and-down motion of the piston. The entire desludging process takes only a fevJ seconds and is usually initiat­ ed automatically by means of a timing unit or monitoring system. Manual initiation is also possible. Frame designs are of two basic types. One is the gear drive type, with power transmission via turbo-clutch between drive motor and rotating bowl spindle. This system is mostly used on small and medium-size centrifuges. The second type is the V-belt drive system, with power transmission via V-belts between drive motor and rotating bowl. The Uses of Centrifuges in Wineries The wine centrifuge is finding application in three stages of winemaking: juice clarification, clarification of "young" \-!ine, and clarification after benton­ iting and fining. With regard to juice, the v/ine centrifuge offers the flexibility of attaining various levels of clarity. Only juices being clarified for further concentration require a high degree of clarity. Generally, juices are clarified to a level not below 1 1/2% by volume in order to achieve the best uniform fermen­ tation and maintain identity of the juice. Undesirable particles, including soil, skins, seeds, stems, and even fertilizer and pesticides, are removed, together with most of the natural yeast. Remaining in the juice are principally fruit pulr and particles with a density closest to the liquid part of the juice. The degree of achieved clarity is simply adjusted by increasing or decreasing flowrate. The immediate advantages include the following: better quality juice; higher yield by elimination of most lees right from the beginning; better control"led and uniform fermentation; stroger influence of quality-forming ingredients; sreed-up of operation; and savings in tank storage. It has been our experience that the

-19- centrifuge affects the style of a wine--centrifuged wines seem to be cleaner, fruitier, and have different balance than their "racked" counterparts. This qual­ ity cannot be achieved through settling because larger, undesirable solids tend to carry down with them the same solids that contain much of the bouquet of the grape juice. For the clarification of freshly fermented wines, applications range from re­ moval of solids to pre-clarification. With increased usage of stainless steel tanks, valves, and other contact parts, the formation of hydrogen sulfite after fermenta­ tion appears to increase significantly. Dead yeast cells and their subsequent de­ terioration are known to cause this problem. Centrifugation immediately after fer­ mentation is considered an important factor in preventing the formation of hydrogen sulfite and the possible pickup of flavors. The clarification of the total tank volume also results in higher yield. In­ creased gallonage of wine per tank can be achieved by reduction and compaction of lees. The centrifuge is also employed in stopping fermentation to maintain a desired sugar level. If, for instance, a winemaker would like to leave a fraction of sweet­ ness in the wine for a more pronounced, distinct bouquet, he could wait for settling time to run its course, or control the process by means of a centrifuge. Again, expensive tanks are not tied up unnecessarily. The third application of wine centrifuges is the clarification of wine after bentoniting and fining. Most of the rough filtration can be eliminated, and a fol­ lowing polishing step can operate with up to four times the volumes before recoating is necessary. By running at relatively low centrifuge capacities, it is possible to discharge a wine with brilliant appearance. Centrifugation will make is possible to have the finished wine available for marketing several weeks earlier, than other­ wise. All automatic Westfalia wine clarifiers are equipped for operation with inert gas injection to prevent contact by air. (This is required only during the desludging interval.) The flexibility of a modern wine centrifuge offers such a wide scope of applications that the machine is typically in use nine or more months a year. In summary, the basic advantages of centrifuges are: 1. Increase in quality, because multiple filtration can be replaced by centrifugation; applications range from juice clarification to polishing of still or sparkling wines. 2. Higher yield because there are fewer lees throughout the entire winemaking process. The result is an increased gallonage of quality wine per ton of grapes. 3. Speed-up of the winemaking process because centrifugation replaces multiple racking. The finished wine can be bottled weeks earlier. An important side benefit is saving in tank storage. 4. Reduction in labor and material costs. Although a relatively high capital investment, a centrifuge in year-round use affords sufficient reduction in filtration and filter aid, plus subsequent savings in labor, to provide overall cost economies. The price

-20- of a new automatic centrifuge ranges from $20,000 for the smallest up to $160,000 for the largest model available. Westfalia, continuing to assist the winemaking process through technological advances, has recently introduced two additional centrifuges, the decanter and the IISuper-Clarifierll. The decanter is basically designed to meet the requirements for high solids clarification--primarily sediment of tank bottoms from juice and wine tanks. Various installations have proven that the Decanter can also handle efficiently and continuously juice lees from free run or press juice, as well as fermented lees for additional recovery of valuable material without using rotary or vacuum filters. The decanter is a horizontal unit, with solid bowl wall, a cylindrical section for efficient clarification of the liquid and a shallow- or steep-angled section for drying of solids (fig. 2). The material enters the decanter through the feed tube and is fed by distributor to the centrifugation space. Solid particles are deposited on the wall due to the effect of centrifugal force and are conveyed by conveyor screw, rotating at a slightly higher speed than the bowl, to the solids outlet. The clari­ fied liquid is discharged from the bowl at the large diameter end of the bowl. The decanter can be blanketed with gas to eliminate undesirable air entrainment and its accompanying oxidation, and can be equipped with built-in centripetal pump system for pressurized, clarified liquid discharge. The Super-Clarifier or polishing centrifuge is the newest centrifuge available (fig. 3). In comparison to the automatic desludger/clarifier, the Super Clarifier develops a g-force approximately 15,000 gas, double that of the conventional disc .centrifuge. The Super-Clarifier has been developed to replace conventional filtra- tion of wines. Depending on the amount of solids present, the Super-Clarifier has been developed to replace conventional filtration of wines. Depending on the amount of solids present, the Super-Clarifier can handle pre-filtration, polishing filtra­ tion, fine filtration and removal of bacteria to a certain degree, although it does not replace final filtration. The wine in the hermetically sealed bowl does not come into contact with the atmosphere. The clarified liquid is thus discharged without air and foam. In the Super-Clarifier, the wine to be clarified enters the bowl through the feed line and is clarified in the disc set. The clarified wine is discharged with­ out foam by discharge pump. The solids settle in the sediment space from where they are intermittently ejected through ports. Solids ejection is triggered by a timing unit. Specific numerical data have been eliminated from this presentation because operations vary at every winery. A centrifuge is only a tool to aid the winemaker; his skills and personal touch still make a bottle of wine. Westfalia centrifuges are built with this thought in mind.

-21- The decanter is driven by a three-phase AC motor which is started by a star­ delta starter. Power transmission is via V-belts. The conveyor screw is driven via V-belts and a rotating cam disc gear (Cyclo-gear). The decanter and motor are mounted on a common base plate resting on bonded metal/rubber cushions for minimizing transmission of vibrations to the foundation. A shear pin (preset breaking point) fitted in the motor p~lley protects the screw and gear from overloading.

V-belt pulley 6 Conveyor screw 11 Main bowl bearing (conveyor screw drive) (scroll) 12 Feed 2 Cyclo Gear 7 Separation chamber 13 Solids discharge 3 V-belt pulley (bowl drive) 8 Distributor 14 Clarified liquid 4 r1a in bOY-/l bea ri ng 9 Bowl discharge 5 Housing 10 Regulating ring 15 Centripetal pump

Fig. 2. A Decanter with Pressure Discharge of the Clarified Liquid

-22- 7

Operating principle of the CSA 160 The product flows through inlet 1 into the bowl, where it is clarified in disc set 4 and conveyed by discharge pump 13 to discharge line 2. The separated solids collect in sediment holding space 5, from where they are periodically ejected through ports 6. Bowl de-sludgings are initiated by timing unit 12. The operating water, which does not come in contact with the product, is only used to initiate de-sludgings. Automatic ejection of solids Depending on the solids, the timing unit 12 can be preset for: partial or full de-sludgings combined partial and full de-sludgings bowl flushing after every full de-sludging. 1 Feed 6 Sediment ejection ports 10 Closing chamber 2 Discharge 7 Operating-water valve 11 Annular piston 3 Photo-electric cell 8 Drain hole 12 Timing unit 4 Discs 9 Opening chamber 13 Discharge pump 5 Sediment holding space Fig. 3. Cross-section of a super-clarifier

-23- t1ICROBIOLOGICAL TESTING FOR PREDICTING WINE STABILITY Augie Haffenreffer Millipore Corporation, Bedford, Massachusetts

People drinking wine have now become conscious and critical of the appearance and taste. Granted that taste may be an individual preference the stability char­ acteristics apply to most all wines. Whether we are thinking of physical, chemical or biological stability, we want to know before shipping the bottled product what the degree of success will be as to these characteristics. Certainly the biological conditions at the time of packaging can affect the wine1s future materially. How­ ever, this is the one area where we can predetermine very precisely our degree of microbiological stability. Here we are dealing with numbers of yeast and bacteria which can be pinpointed by simple monitoring. Yeast and mold presence in the wine can be controlled by pasteurization--addition of inhibitors--long storage--sterile filtration. Even so, the effectiveness of these methods needs to be monitored such that we bring the microbial numbers to 0 or near o. The membrane filter provides for sampling of relatively large volumes of the wine when contrasted to multiple tube and plate methods where we are limited to 1 to a few milliliters of sample. The membrane is a screen with rigid pores in a con­ tinuous sheet of plastic of such uniformity and precision of hole size that we can get high flow rates as well as absolute removal of all troublesome microorganisms. Its use is now standard in 48 states for separating out one coliform bacteria for detection in 100 mls of drinking water. If we look at the monitoring of our wine process at the filtration stages, we have a good indicator of just how well the filters are doing their job of clarification. It should be remembered that every stnge of filtration should be thought of as though it were the last filtration. Never say, "I can coast on this prefiltration because the next stage will cure the errors of carelessness made at this step". In this way, if we have a series of two or three filtrations, we can arrive at 0 or near zero microbial presence in the finished wine and attain higher thruputs on the final sterilizing or membrane fil­ tration. In practice we like to check the wine after the first prefiltration to hold the count as low as possible consistent with using a filter finess that still gives practical thruputs. After the second filtration which utilizes pads in a press or diatomite, we should expect to bring the microbial counts to one per 10 mls. This is not a required count but is designed to illustrate what at the same time is ef­ fective in reducing particles to achieve fine brilliance. Naturally, counts near zero will permit much longer sterilizing membrane life and hence lower costs. To monitor the filtrate at each stage, we suggest 20 mls after the first filter, 100 mls after the second and their (sterilizing) filtrations. Small plants will find the 3-piece beverage monitor to be the easiest test­ ing device because there is no preparation of apparatus to run the test and several tests can be run in a 15 minute period. This is the method most soft drink plants use and requires very little training to run easily. The beverage monitor MHWG037HO is a self-contained filtration device and culturing dish, sterile and ready to use on a moments notice. Larger plants with laboratory facilities may prefer the HAWG047S0 or 47mm membrane method. Here we insert the membrane filter into a holder that must be sterilized each time used. The filter after filtration is then put into a Petri dish for growing the cells collected into visible colonies. This requires hot water sanitizing of the funnels and more time even though the cost per test materials is -24- less. As further follow-up on monitoring the process, we strongly recommend a swab tester (MYSK200020) for checking the filling heads and tubes. One yeast and mold swab tester is used to check 5 filling valves which tells how effectively the clean­ ing or sanitizing of the filling machine was done. Naturally, the testing of 100 mls of the bottled product for yeast as well as for bacteria tells the real story of the biological stability. Remember the attain­ ment of good biological shelf life also achieves a polish and particle removal that gives exceptional brilliance to the product and vivid color appeal.

-25- IMPORTANCE OF DETERMINING VOLATILE ACIDITY IN WINES James F. Gallander Department of Horticulture Ohio Agricultural Research and Development Center

Determining volatile acidity is basic to a winery quality control program. Federal and State laws have established legal limits for the amount of volatile acidity that can be permitted in wines. For example, the maximum volatile acidi­ ties established by the Federal requlations in white and red table wines are 0.120 and 0.140 g/lOO ml, respectively. The amount is expressed as g of acetic acid per 100 ml of wine, exclusive of sulfur dioxide. A high volatile acidity content is an indication of acetic acid spoilage, particularly from the bacteria named Aceto- bacter. If this microorganism is not controlled by such means as sulfur dioxide and the elimination of air, the wine may turn to vinegar. Formation of Acetic Acid The overall equation for alcoholic fermentation which shows the conversion of sugar in grape juice to alcohol plus carbon dioxide is as follows: 2CH3-CH20H + Sugar Alcohol Carbon Dioxide 180g 929 88g From a theoretical standpoint, the wine yeast, Saccharomyces cerevisiae, yields about 51% alcohol and 49% carbon dioxide. However, these percentages are never rea1; zed, because the amounts of these two .products are governed by a variety of factors. One important factor is that a number of by-products are also produced during the metabolic processes of alcoholic fermentation. Some of the common by­ products include: acetaldehyde, glycerol, lactic acid, and succinic ac·id. Another major by-product is acetic acid and is usually formed during the early stages of alcoholic fermentation. Sound table wines contain about 0.04 9/100 ml, well below the Federal limits.

The other major source of acetic acid or vinegar in wine is brought about by bacterial fermentation. This fermentation is caused by Acetobacter which secures its energy by oxidation of ethanol to acetic acid. If these acetic acid bacteria are allowed to grow, sufficient quantities of acetic acid including ethyl acetate will be produced to cause the wine to develop a vinegary type character. This bacterial action may occur during and after alcoholic fermentation and concentrations near 0.070 g/lOO ml become detectable by taste. Wines approaching this level of acetic acid must be treated to prevent a further increase in volatile acidity. Factors Influencing Volatile Acid Formation

Sulfur dioxide: In the wine industry, sulfur dioxide is widely used to inhibit microbial spoilage and undesirable discoloration. Since acetic acid bacteria are sensitive to sulfur dioxide, it is important to add and maintain proper amounts of sulfur dioxide during vinification. It is well known that wines are uniformly low­ er in volatile acidity when adequate levels are used in making wines. In general, 100 ppm sulfur dioxide is added at the time of crushing~ and 25 to 35 ppm free sulfur dioxide is maintained during wine production.

-26- Yeast strain: One purpose for using a selected yeast culture in making wine is to minimize the production of volatile acidity. Authorities agree that differ­ ences exists among yeasts in their ability to produce different amounts of by­ products including acetic acid. Therefore, wine yeasts with proper winemaking practices will produce a clean fermentation without yielding excessive amounts of volatile acidity. This fact was emphasized by Cruess (2), who reported that sul­ fur dioxide in conjunction with pure yeast prevented high volatile acidity in wines. Sulfited musts provided a favorable condition for the wine yeasts, but unfavorable for the growth of undesirable microorganisms. Fermentation temperature: In general, the higher the fermentation temperature the greater the amount of volatile acidity is produced in the finished wine (1). The basis for this is that the growth of acetic acid bacteria is favored by high temperatures, 30° to 40 0 C (86 0 to 104 0 F). Also, a high fermentation temperature tends to increase the formation of acetic acid by yeasts during alcoholic fermenta­ tion. Therefore, maintaining fermentation temperatures at the recommended levels, reds about 24°C (75 0 F) and whites about l60 C (60oF), together with good winemaking practices result in wines with low volatile acidity. The high fermentation temper­ ature for red wines is one reason why these wines are usually greater in volatile acidity than whites. Aeration: Since the growth of acetic acid bacteria is favored by aerobic con­ ditions, it is important to minimize aeration during each step of the winemaking process. Under aerobic conditions, Acetobacter are capable of producing relatively large amounts of acetic acid by oxidizing the ethanol in the wine. One of the main sources of high volatile acidity in wines is not keeping barrels, casks, and other cooperage filled to capacity. If this is not done on a regular basis, acetifica­ tion will occur, and the wine will exceed the legal limit for volatile acidity. It is also important to avoid excessive aeration during other winemaking operations, such as in racking and filtering wines. After wine has been handled, a good prac­ tice is to determine its volatile acidity content. Fermenting-on-the-skins: In general, red wines usually contain higher levels of volatile acidity than white wines. This is due, in part, to the method of color extraction employed in making most red wines, fermenting-on-the-skins. During this practice, pomace of the cap is mixed with the fermenting juice several times a day. This is also done for several days, about 3 to 5 days, depending upon the amount of color desired. Since mixing the pomace of the cap causes aeration and acetic acid bacteria requires oxygen for growth, acetification may occur during this color ex­ traction process. Also, the temperature of the cap may rise to a level well above the temperature of the fermenting must. If this temperature is elevated to n cer­ tain level, it will promote growth of acetic acid bacteria while inhibiting yeast fermentation. Therefore, to minimize high levels of volatile acidity in red wines, it is important on a regular basis to frequently mix the cap during color extraction. This will prevent a "dried out" cap with an elevated temperature. The use of sulfur dioxide during crushing in moderate amounts is also necessary to avoid acetification. Fruit condition: Another important factor that affects the volatile acidity content in wines is fruit condition. Grapes for wine should be in good condition free from rotten and moldy berries. Overripe and unsound berries contain many undesirable microorganisms including acetic acid bacteria. Using such fruit to make wines provide a source of microbial infection and increase the potential for wine spoilage. Also, diseased and overripe berries often experience acetification in the vineyard and possess a vinegar-sour smell. These fruit contain acetic acid and should not be used in order to minimize the level of volatile acidity in wines.

-27- Malo-lactic fermentation: One effect of malo-lactic fermentation is an in­ crease in volatile acidity. This increase is illustrated in Table 1 which lists the volatile acidities of two varietal wines. The results indicate that malo-lactic wines contained a higher level of volatile acidity than the control samples, with out malo-lactic fermentation. One possible reason for this high volatile acidity is that malo-lactic bacteria produce some acetic acid, as a by-product, during fermentation. Also, winemakers wishing to induce malo-lactic fermentation often use minimal amounts of sulfur dioxide, less than 50 ppm at the time of crushing. At these levels, wines are not only susceptible to malo-lactic fermentation, but to some acetification. A high volatile acidity may occur, especially if malo­ lactic fermentation is delayed for an extended period of time. TABLE l.--Changes in volatile acidity resulting from malo-lactic fermentation, 1978. g volatile acidity/lOa ml Treatment DeChaunac Chancellor Control 0.030 0.031 t1alo-lactic Fermentation 0.060 0.054

SUMMARY Volatile acidity is a good indication of the soundness of wine and should be measured on a regular basis during the winemaking process. In order to prevent a high volatile acidity, winemakers should be knowledgeable about the many factors that influence acetification in wines. This would assist the winemaker in making a better wine with a lower amount of volatile acidity.

LITERATURE CITED 1. Amerine, M.A. and M.A. Joslyn. Table Wines, The Technology of Wine Making. Univ. of California Press, Berkeley and Los Angeles, Calif., 1970. 2. Cruess, W.V. Notes on producing and keeping wines low in volatile acidity. Fruit Prod. J. 15:76-77 (1935).

-28- PRELIMINARY OBSERVATIONS OF CLUSTER-THINNING AND SHOOT-TIP REMOVAL ON ISEYVAL 1 GRAPEVINES Gail Romberger Nonnecke Department of Horticulture Ohio Agricultural Research and Development Center Historically, crop control of the traditional American (V. labruscana, Bailey) and American hybrid cultivars in Ohio has been regulated by balanced pruning. How­ ever, pruning dormant vines alone cannot regulate the crop produced by the inter­ specific (French) hybrids. The practice of fruit-thinning has been shown to prevent overcropping in other fruit crops. Shoot-tip removal has been shown to improve cul­ tural practices, grape quality and vine condition in several viticultural areas of the world. However, little information is available regarding the effects of shoot­ tip removal in interspecific hybrids. Therefore, field experiments were initiated in 1978 to evaluate the effects of both shoot-tip removal time and shoot-tip re­ moval length together with cluster-thinning. By conducting the two studies concur­ rently (shoot-tip removal and cluster thinning) it was possible to determine the interaction as well as individual value of these two cultural practices. The trials were conducted during 1978, 1979 and 1980 in two commercial vineyards in northern and southern Ohio with the popular, widely planted, interspecific (French) hybrid ·Seyval I (Seyve Villard 5276). Cluster-Thinning Grapevines were cluster-thinned by physically removing flower clusters before bloom. Three thinning treatments were included. Treatment 1 involved no cluster removal (control). Treatment 2 removed all clusters except the two clusters closest to the base of the shoot (2 cl/shoot). Treatment 3 removed all clusters except the basal cluster of the shoot (1 cl/shoot). A given vine received the same cluster­ thinning treatment for both years. Shoot-Tip Removal Shoot-tip removal treatments were separated into two experiments. Both experi­ ments included the three cluster-thinning treatments previously described. Also, designated vines received the same cluster-thinning and shoot-tip removal treat­ ments both years. Experiment I included treatments which removed 50% of the shoot length on each vine at four different times during the growing season. Treatments were as follows: 1) no shoot-tip removal (control), shoot-tip removal at 2) prebloom, 3) shatter, 4) midseason, and 5) late season. Experiment II evaluated the effect of removing either 0% (control), 25%, 50%, or 75% of the shoot length. The four application treatments were applied in the middle of the growing season. Observations Cluster-thinning x Shoot-tip Removal. Significant interactions did not occur between cluster-thinning and shoot-tip removal treatments. Therefore, these treat­ ments are discussed independently.

-29- Cluster-thinning. Although were removed prior to bloom, decreases in yield were not observed in the field experiments, due primarily to increased cluster weights. In two experiments, the second year cluster-thinning increased yield. The 2 cl/shoot treatment did not appear to remove sufficient clusters and the observed effect on yield and other variables was similar to the control. Cluster number on the vines at harvest was significantly lower the first year on vines thinned to 1 cl/shoot compared to the other treatments. However, in the second year the cluster numbers were the same for all three cluster-thinning treat­ ments. Although a significantly higher cluster number was removed on vines thinned to 1 cl/shoot the second year, the cluster number present on the vine was similar to the other cluster-thinning treatments. Hence, the highest total cluster number was obtained on vines thinned to 1 cl/shoot. In addition, cluster and berry weights were the highest on vines thinned to 1 cl/shoot. f10re compact clusters were observed on vines receiving the 1 cllshoot treatment. However, only in one instance did the 1 cl/shoot treatment show a higher incidence of disease. Few differences were found between cluster-thinning treatments for the variables, total soluble solids (TSS), pH, and total acid (TA). In two experiments, thinning to 1 cl/shoot produced significantly higher TSS values. TA and pH were unaffected. The greatest pruning weights were obtained in response to the 1 cl/shoot treat­ ment. In addition, the highest number of buds retained and best cane condition were observed with thinning to 1 cl/shoot. Overall, the optimal yield, cluster and berry weight, pruning weights, number of buds retained, and cane condition occurred on vines thinned to 1 cl/shoot. Thin­ ning vines to 2 cl/shoot did not remove sufficient clusters to create the beneficial effects listed above which were found when thinning to 1 cl/shoot. Thinning to 2 cll shoot was often similar in its effect to the no thinning (control) on the variables studied, such as lower yield, cluster number, cluster weight, pruning weights, number of buds retained, and poorer cane condition. From these studies it is possible to conclude that cluster-thinning 'Seyval' to 1 cl/shoot is a desirable cultural practice and should be recommended to 'Seyval' growers in Ohio. Vine vigor, fruitfulness, and yield are maintained with thinning to 1 cl/shoot. Shoot-tip Removal. Shoot-tip removal at different times during the growing season decreased yield in the field experiments. Decreased yields due to lower berry weights were observed ~,;th shoot-tip removal at shatter the first year. In the second year, decreased yields were obtained with most shoot-tip removal times because of lower cluster numbers. Lower cluster numbers were possibly due to poor­ er fruit bud development in the previous season when shoot-tipping occurred. TSS levels were decreased by shoot-tip removal treatments regardless of the time applied. Pruning weights and number of buds retained were lower and the cane con­ dition rating was poorer following shoot-tip removal, regardless of time of appli­ cation. Overall, shoot-tip removal at any time resulted in reduced yield, lower grape quality, and poorer dormant vine status.

-30- During the first year, yield was reduced only with the severe, -75% shoot-tip length removal. The decrease was primarily to lower cluster weights. In the second year, any amount of shoot-tip removal caused a decrease in yield. The lower yield in the second year was due primarily to reduced cluster number. Reduction in clus­ ter number occurred from shoot-tip removal during the prior season when fruit bud development occurred. In three of the four experiments investigating length of shoot-tip removal, TSS was reduced regardless of severity of shoot-tip removal. The least desirable pruning weights, the fewest number of buds retained and poorest cane condition were found with any length of shoot-tip removal. Overall, it appears any length or time of shoot-tip removal lowered production, quality and dormant vine condition of 'Seyval I grapevines. Therefore, shoot-tip removal on 'Seyval' grapevines grown in Ohio cannot be recommended.

-31- CONCEPTS OF MAKING RED TABLE WINES l Richard P. Vine A.B. McKay Food and Enology Laboratory Mississippi Agricultural and Forestry Experiment Station

The heritage of red table wines in our western civilization is a most inter­ esting topic to pursue. One might commence in Italy, the largest producer of red wines in the world. The most expensive wine one could find in ancient Rome was Falernian, a dry red reputed to be a hundred years old. Apparently it was heavy and rich--aged in ceramic jars, of one type or another, sealed with a material similar to plaster of Paris. H. Warner Allen has judged the wine to be comparable in most respects to a Rhone, only with a more powerful nose (5)~ Some 2,000 years later, the most expensive wine in Rome is still a red of the same basic type as the old Falernian--but, nowadays, from Brunello di Montalcino. It might be termed as a IIsuperll Chianti, made from the Brunello strain of the great Sangiovese grape--used only sparingly in ordinary Chianti blends. The wine remains very dark and full with the most noteworthy vintners holding their bottlings of Brunello in excess of 50 years before release to the market (5)~ The Romans quarried the chalk in what is now the Province of Champagne in France--making both roads and cellars at the same time. Centuries before the pop and sparkle in the late 1600 ls which would make the "stars" of Dom Pierre Perignonls "Champagne" so very famous, red table wines were grown in Champagne. These wines were often great--enough to compete with those of Burgundy for the favor of King Louis XIV, who apparently preferred the delicate beauty and elegance of Pinot nair (6). Speaking of Pinot noir and Burgundy, one will find difficulty finding any wine authority who will not offer highest praise for La Romanee Conti--"the centre pearl of the Burgundian necklace", as it was so well put by an unknown poet. The Cote OIOr sparkles with more pearls, Fixin, Gevrey, Chambertain, Echezeaux and Vougeot, among others, that now approach a millenium of classic red wine vintages. One cannot leave this province without mention of the fine red wines produced from Gamay in the Maconnais and the Beaujolais, particularly at Fluerie, Morgan, and Julienas. Pinot noir and Gamay are not the heaviest cultivars known to man, either in yield, pigment or body and have, necessarily, caused the wines of Burgundy to be rather delicate--yet bone dry and very complicated (3). Farther south in France one encounters the incomparable Rhone and its Syrah-­ grown in such dark and heavy proportions long before and since the Popes lived at Avignon, the Chateauneuf-du-Pape, some five centuries ago (8). If one were to ac­ curately describe the concepts for making Beaujolais Nouveau, there would be, save the dryness, a totally different and opposite profile for the Syrah of the Rhone Valley. In more modern times, however, the Syrah is blended with Grenache and other lighter wines. No walk down the boulevard of great red wines can be made without passing

Mississippi Agricultural and Forestry Experiment Station Paper No. 4464

-32- the great growth of Bordeaux. One has but to name only a few, Chateaux Lafite and Mouton in the House of Rothschild, Chateau Margaux, Chateau Haut-Brion and Chateau Cheval Blanc, to label some of the most coveted wines of all time (4). In the New World, if one were to ask most any person familiar with wine just what kinds of wines were the very best in California, the answer would most likely be in the direction of Cabernet Sauvignon and Zinfandel. Perhaps this is best evidenced by the remarkable performance of Stag's Leap Cabernet Sauvignon at the famous blind tasting in France in 1976. This, as we all remember, included as competition some of the great names from the previous paragraph. Yet, for all of the regality and superiority red wines are rather stagnated in our national marketplace. Wines and Vines (2) statistics relate in the last six years that, while red table wine shipments have increased 1,705,000 gallons, white table wines have grown an astounding 55,082,000 gallons~ This amounts to a loss of red wines in the table wine market share of more than 35%. In 1978, Italian table wine shipments to America accounted for some 39,422,000 gallons--more than the imports of like wines from all other countries combined~ An equally startling statistic is that during the past decade, the growth of Italian table wines in our nation has increased more than 1,000% (1). It is obvious to any­ one that the tremendous movement of Lambrusco has been the influential single item in this set of numbers. There is no paradox. Red wines continue to grow along a consumption curve every bit as dynamic as white wines in our country, it is just that most of this growth is enjoyed by Italian winegrowers. What is Lambrusco? What can we learn from this amazing product? Can we ana­ lYle the particulars of this wine and teach ourselves some lessons in winemaking and wine marketing? One authority describes Lambrusco as "a fruity, slightly sweet and spritzy red grape table wine, generally with less alcohol than other red table wines ... (1 )." The great foresight of Andre Simon is evident in his untimely statement that, "Italian wines are different--some of them, such as Lambrusco, very different--from anything grown in France, and should be treated as such, judged by their own stand­ ards, not condemned for not being what they do not pretend to be. Nevertheless, they have character, and with the growing demand for wines in Britain, especially for wines of modest price ... (7)." Just which of these characteristics account for such magnanimous consumer acceptance in our marketplace? What has happened in America for such a wine to have such great appeal? I want to quickly rebuke any interference or suggestion that we foresake trad­ itional red table wine generics and varietals in favor of Lambrusco types. We sim­ ply must remember that the old red standards now represent a very limited area for market penetration. Realistically, the magic names of Vitis vinifera dominate and will continue to do so. The entrance of French-American hybrid wines, even in the most favorable demographics, have had only limited success. On the other hand, it may be contemptuous of our own self-preservation not to examine item-by-item the implications of Lambrusco-style products.

-33- Lambrusco is fruity. Apparently Americans are turning to the more delicate and simple values of fruit aromas and flavors. The cost of red meat may have been instrumental in driving food budgets to white meats--fish and fowl. In turn, the "red wine with red meat ll syndrome has been greatly relaxed. We have suspected this right along, of course, as we watch the boom of delicate and simple white wines grow and prosper. Comparing some of these whites with Lambrusco may be quite dif­ ficult behind a blindfold. Come to think of it, doesn't one often hear terms like IIbig fruit" and "blackberry" and IIcurrantll in the midst of experts judging entries of Cabernet Sauvignon and Zinfandel? This probably does not mean that, at last, we have found an honest-to-goodness place for Concord. It may well mean that such heavy fruitiness, of course, is over­ bearing. t10re important, we may be guilty of making our eastern red wines, especially those from the better French-American cultivars, more complex than our consumers can understand. Specifically, this could be the result from leaving our wines to ferment too long on the skins. I have witnessed fermenters of fine wine grapes fermented to, literally, the bitter end--to -2° Balling and beyond~ It may go without saying that hot-pressing, particularly at higher temperatures and longer exposures can yield even heavier results than excessive skin contact. Another detractor from light wines can be found with wood aging programs that are a far cry from simpli­ city. There is further evidence for the popularity of light wines as we see some of the larger vintners developing significant programs of advertising, point-of­ sale and packaging in order to grasp some of the red wine market currently owned by Lambrusco. This is especially evident in the promotion of chilled light red wines. Lambrusco is slightly sweet. It has always been interesting to me during the vintage season to watch how delighted people are when they sample the red grapes arriving at a winery. Yet, in the tasting cellar, things are much less ecstatic when dry red wines from similar grapes are tasted--and in the retail shop, they buy white wine, or worse yet, nothing at all. Many of the French-American hybrids have a delicious fruit--not over-power­ ing and reminiscent enough of Lambrusco values to be competitive. My list includes Baco Noir, Chelois, DeChaunac, r1arechal Foch and Rougeon. A Virginia winegrower comes to mind who makes annually a light, fruity, vintage Rougeon--the first wine in his line to sellout each year. I feel that we often make too much of the word "sweet" in our industry; that it causes confusion, fear, even shame sometimes, when red wines are the topic of consideration. This becomes even more distinct when we realize that sweet, and residually sweet, white wines, and roses are commonplace, often nobel and a few, great. I submit that there is nothing wrong with a little residual sweetness add­ ing a pleasant touch to a light red wine. Lambrusco is spritzy. A little "tingle" can be an attractive dash in the quest for new red wine concepts. It is difficult, however, for some vintners to embrace the technical control of petillant wines, and may not find this aspect especially interesting to pursue. I am not personnally convinced that the presence of a few bubbles in the Lambrusco wines makes up very much of the success pattern.

-34- Lambrusco is generally made with less alochol. It is no secret that most grapes grown in the eastern part of our country mature to less sugar content than those grown in California or Italy. Yet, many of us continue to forge ahead adding sugar to our must in order to reach that magic plateau of 12% alcohol by volume. There is no real need for this practice, it is an old concept that should be care­ fully examined. In 1978, West Germany shipped nearly as much wine to America as did France (1). Again, look at the trend set by our consumers, fruity, light, residually sweet, low alcohol wines in greater demand. Title 27, Code of Federal Regulations, 4.36 provides for us the omission of alcoholic content upon our labels as long as we state the term "table wine" or "light wine". This ruling all but eliminates any further need for the 12% alcohol habit. The fact is that some of us seem to be fermenting ethanol that our market doesn1t seem to want and our government doesn1t seem to distinguish. Lower alcohol content may also lead to some instant nobility gained byeast­ ern vintners as our 18 and 19-degree Brix grapes can suddenly generate some un­ ameliorated products. More important, of course, are the reduced requirements for energy, time and sugar. Lambrusco is different. There are few wineries in the world, let alone America, that can afford to make wines designed for connoisseurs. The late Frank Schoonrnaker termed Lambrusco, lias nearly undrinkable as a well known wine could be." Whether or not we agree may be academic. We can be well advised to continue making the grand dry red wines of tradition--full of complex bouquet, oak and tannin--for ourselves and any others who may continue to enjoy them. We should fully understand, though, that the lion1s share of the American red table wine demand lays in a dif­ ferent direction. The most dangerous assessment one might make of his wines is that based upon input from the pseudo-experts. How many times have we listened to the faint praise of those who talk dry but leave their glass of good old dry red in favor of some­ thing a little more mellow. Yet, we are prone to turn a deaf ear to the honest ll neophyte who exclailns of "sour" and "bitter •

Lambrusco is moderately priced. ~le have just considered that there are few wineries in the world that can afford to make wines only for connoisseurs. There must be even fewer vintners who can exist marketing only to the wealthy enophile. To be sure, lighter, younger and lower alcohol red wines should be less expensive to produce but several other ideas need examination and review if we are to look at generating the most dynamic red wine concepts for today1s new market. Basic viticultural economics can tell us that the easiest cultivar to grow may not be the most profitable. We have a tendency to plant and maintain the most disease-resistant, the most hardy, the earliest-ripening, the most productive, the vigorous, etc. Perhaps something should be said for planting what the consumer thinks is good and then figuring out how to grow this selection most effect~vely. What good does it do to harvest 8 tons per acre if it takes three years in lnven­ tory to make a wine that has to be posted-off to deplete? Aren't we better off if, we grow 6 tons per acre, take a one-year inventory and make wines that people really want and will buy?

-35- Each vintner, of course, has a different market than every other and the de­ velopment of those individual parameters of new light red wine types will neces­ sarily require considerable research. One may find his market demographics so segmented that more than one light red wine type will be needed in order to parti­ cipate. The basic cost consideration, however, is depletion. As Diamond Jim Brady so aptly put it, IIYou can have the finest product in the world, but if ~ don't sell it, ~ still have it! II A decade ago a red table wine bottle without a cork closure was tantamount to hypocrisy and its vintner subjected to several choice terms of ridicule. Decidedly, big old red wines may still be best kept under cork and capsule. However, many con­ sumers of light red wines are likely to scorn cork closures. As we are all well aware, corks require a corkscrew, which is still not necessarily a household item in America. More important, corks are expensive, and becoming very expensive. Much the same can be considered for back labels and some of the custom metal cap­ sules. Not only are all of these items costly to buy, but are, of course, also becoming very costly to apply. Why then such cost factors? We are talking about delicate and simple light red wines, there is no reason to depart from this basic philosophy when designing packaging inputs. Despite the idea that all of this may be pointing towards the suggestion that we lower standards and commence making cheap red wines, I most emphatically assure you that such a suggestion is totally not intended. On the contrary, I urge that we upgrade our standards and commence making profitable wines that people really want. I recommend that we carefully review our concepts of red wine philosophy and production keeping in mind whether or not the realism of market demand is being ad­ equately met. I suggest experimentation with the ideas outlined herein, but, more important, those of your own generation. I urge that we listen to our own best judgement in red wine design rather than that of those who don1t have a nickel in­ vested. Is a bitter, dark, dry Concord at 12% alcohol more noble and pure than a light Rougeon at 1 Balling and 9% alcohol? I offer that light, residually sweet, fruity, low alcohol red table wines can be honest---again to quote Simon, IIjudged by their own standards, not condemned for not being what they do not pretend to be. 1I Literature Cited

1. Anonymous. 1979. Imports of table wine and all wine, by major countries of origin. Wines and Vines 60(5). San Francisco. 2. Anonymous. 1979. The first color breakdown of table wine marketings. Wines and Vines 60(12). San Francisco. 3. Jacquelin, Louis and Rene Poulain. 1962. The wines and vineyards of France. Drury House, London. 4. Johnson, Hugh. 1971. The world atlas of wine. Simon and Schuster, New York. 5. Ray, Cyril. 1966. The wines of Italy. McGraw-Hill, New York. 6. Simon, Andre. 1962. Champagne. McGraw-Hill. New York. 7. Simon, Andre. 1962. Wines of the world. McGraw-Hill, New York.

-36- Literature Cited (cont.) 8. Simon, Andre. 1968. The noble grapes and great wines of France. McGraw­ Hill, New York.

-37- ENVIRONMENT AND THE VARIETY E.l. Phillips Department of Horticulture Virginia Polytechnic Institute &State University

Grape quality is a product of the total environment and the genetic make-up of the variety. The ultimate in quality can be achieved only with a perfect variety in a flawless environment. Neither is available. By careful selection of site and variety, however, superior quality can be produced with a yield sufficient to make production commercially profitable. This requires a thorough knowledge of the en­ vironmental conditions under which the grapes will be grown, and selection of the varieties adapted to those conditions. Environment Although there are few locations in Virginia where some type of grape cannot be grown, each is specific in its environmental requirements. These should be con­ sidered in the selection of varieties to be planted on any particular site within the state. Both the above-ground and below-ground environmental conditions must be taken into account. In addition to a favorable climate, a good vineyard site should have a soil of moderate fertility with a structure that allows good moisture drainage and root penetration, few insect and disease problems, and be free of man-made soil, water and air pollution. Local climate, is in most cases, the factor limiting grape production in Virginia. The phases of climate involved are: length of growing season; extreme low tempera­ tures and frequency of occurrence; growing season temperatures; solar radiation and hours of sunshine; and, rainfall and humidity. Although anyone phase can be a limit­ ing factor, they are all interrelated and must be considered as a unit (Figure 1 and Table 1). The ideal climate for grape production has a growing season of 170 to 180 days or more, mild winter temperatures with no false springs, warm growing season temper­ atures with a narrow daily range, maximum light intensity and hours of sunshine, and no rainfall during the fruit set and ripening periods. A site having good air cir­ culation without strong prevailing winds aids in disease control and reduced vine damage and trellising problems. As the climate is beyond human control, it is essential that the most favor­ able site be sleeted for the grape planting. The microclimate within a vineyard frequently varies greatly with even a slight change in elevation, soil conditions, or cultural practices. Some adjustments can be made in management techniques, however, which will on a small scale partially compensate for less than ideal conditions for quality grape production. To survive winter cold, the wood of the vine must be sufficiently matured. Practices which stimulate vegetative growth after harvest are to be avoided. Cluster thinning to prevent overbearing and control of insects and diseases are essential for vine vigor and winter hardiness. With vinifera and other tender varieties, train­ ing to a double trunk and mounding around the vines in the fall helps to insure maxi­ mum winter survival.

-38- As grapes have a relatively short chilling requirement, they are subject to injury by fluctuating mid-winter temperatures. Planting on a northern exposure, maintaining a ground cover as long as possible, and late or double pruning will help delay growth and premature bud break. Injury by spring frost can be kept to a mini­ mum by planting on a slope to allow good air drainage, avoiding frost pockets, high trellising, and maintaining a firm, clean cultivated area under the vines. Arti­ ficial means of frost control such as heaters, wind machines, and sprinklers are frequently used, with varying degrees of success. This is expensive, however, and no substitute for good site selection. A high, wide trellising system allows better air circulation and exposure of a maximum amount of foliage to sunlight. The benefits are a reduction in fungal in­ fection and increased fruit yield and quality. Select early maturing varieties for areas with a short growing season to assure fruit and wood maturation before frost. Late maturing varieties in areas with a long growing season will avoid having fruit ripen during the heat of summer. The soil is an important phase in vineyard site selection. It is an intimate mixture of mineral materials, organic matter, water, air, and various living organ­ isms ranging from bacteria and fungi to worms, insects, rodents, and plant roots. Each contributes to the total soil environment. A change in either has an overall effect on the entire system. When the environment in the root zone is altered, there is a resulting effect on the growth, vigor, and productivity of the vine and quality of the fruit. The mineral element in a soil is composed of small rock fragments of various sizes whose physical and chemical properties are determined by climate and parent material. Organic matter is the partially decomposed residue of plants and animals, usually comprising 1 to 5 percent of the total topsoil volume. It has a great in­ fluence on soil properties, having a high water holding capacity and supplying ad­ ditional nutrients upon decomposition. Water is essential for mineral absorption by the vine roots and for normal growth and fruiting of the plant. Oxygen in the soil air is required in respiration by roots and micro-organisms. Proper balance between soil air and soil water is necessary for optimum growth. Too much water and the plant suffers from oxygen deficiency; too little water and the plant suffers from nutritional deficiency and dehydration. Living organisms in the soil disintegrate and decompose organic matter, thereby making nutrients available to the plant. Unfortunately a soil environment favorable for grapes is also favorable for the growth of harmful organisms. Nematodes, insects, bacteria, and fungi in a soil create a number of problems in the roots, stems, foliage, and fruit of plants. Sel­ ect a site for a vineyard that has not recently been used for the production of any plant susceptible to the same soil borne problems. Fumigation can render a site suitable for planting, but this is expensive and should be used only when necessary. Grapes do best on a sandy loam soil of moderate fertility and organic matter content, with a pH range of 5.5 to 6.5. It should allow deep root penetration and be well drained. Deep sands or heavy clays may be used if provisions are made for adequate fertilization, moisture, and soil drainage. Any deviation from the most desirable soil and soil environment, however, will result in increased mangement problems and possible decreased yield or quality, or both.

-39- The Variety Proper selection of varieties ;s essential to the success of a commercial grape planting. In addition to fruit and vine characteristics such as quality, vigor, and productivity, season of ripening, hardiness, and resistance to common disease and insect pests, the market outlet and requirements of the processor or consumer must be considered. A market for the grapes should be determined before the vines are planted. Seasonal conditions, particularly temperature, have a great influence on the time of ripening of all grape varieties. Development is slow in a cool season and rapid in a warm season. Varieties requiring a long season for maturation should not be planted where the growing season is short. Few varieties will mature fruit and wood where the growing season is less than 150 days. Vineyard management also influences the time of ripening. Trellising systems that increase the amount of leaf exposure to full sunlight will usually hasten fruit maturation. Overcropping delays maturity, as does overstimulation of vegetative growth with excess nitrogen or moisture. Severe disease and insect injury to the foliage reduces the rate of fruit ripening and maturity of the wood. Most American grapes and French-American hybrids can withstand humid summers and cold winters better than the vinifera varieties. Variations exist, however, among varieties of the same type with regard to climatic adaptation. Length of growing season for a given area of the state~ winter hardiness, and susceptibility to such diseases as black rot and mildew should be considered in the selection of varieties of either type. The European grape, Vitis vinifera, grows best under long, warm, dry summers and cool winters. It is extremely susceptible to fungal diseases and insect pests that flourish under humid conditions. Neither does it withstand intense winter cold without grotection. Few varieties are successful when temperatures frequently drop below 10 F. It requires a long growing season, with a minimum of rainfall during the blossoming and ripening season. Any commercial planting of vinifera in Eastern United States should be on phylloxera resistant rootstock. The muscadine grape, Vitis rotundifolia, cannot be successfully grown where temperatures fall below 10°F. It will thrive, however, in warm, humid areas where othere types of grapes fail.

-40- rl TABLE 1. Climate at Selected Stations in Virginia 1941-1970 ...-.... u: -f-J 0 U LO r-- r-- 0 I ttS ttS C C I ..IJ ..IJ 0 0 . ""0 OJ 0 0 (/) er- s- o > ,..... I- 1-...-.... ttS...-.... -f-J c.. ~ er- 0 ttS ...-.... (/) QJ(/) ttSc::( 0 s- ..c -f-J (/) QJ(/) ·OJ c (/')~ E .....J OJ ...-.... c::( ...... OOJ C OJ -f-J ..c: 0---.. ttS E (/) O-(/) (/) I- -'= :::J -'= c..u er-f-J oro :::J >, OJ s- s->, u r-::> u OJc ..IJQJ c ...... (/) ttS E ...... cttS OttS ,..... C I C (/') er- ttSOJ er- 0 QJLJ.. S-QJ -0 ttSer- r-- er- I ...... ~ ~ of-> I s-o =S>, LJ...... :::::s ...... er- ...... >, ~ 0 ttSlL. ..IJ ...... of-> ...... 0 c S- r-- r-- S- OJo X QJ 0 C c.. :::J L..LJ <.!) ::c ...... LLJ ~ (j) TIDEWATER Back Bay 5 250 4231 8 15 46.13 8.60 16.75 Diamond Springs 25 236 4361 8 37 46.99 10.21 16.67 Fredericksburg 100 179 3762 -7 9 47 39.85 9.67 14.85 Hopewe 11 40 203 4416 -5 NA 54 42. 12 10.63 13.44 Newport News 50 243 4588 7 44 44.38 10.14 13.80 Painter 30 206 3930 -5 NA 25 42.25 9.78 12 .19 Suffolk 22 210 4125 5 37 46.91 10.33 15.99 Urbanna 25 213 4123 1 34 42.22 10.18 13.37 Walkerton 50 180 3985 -10 8 45 43.90 10.64 13.93 Warsaw 140 193 4028 -4 44 41 .26 9.66 13.38 Williamsburg 70 193 4086 -3 39 43.76 10.85 13.68

EASTERN PIED~10NT Ashland 220 180 3689 -7 14 35 40.44 10.00 12.34 Columbia 300 172 3765 -7 14 47 38.12 9.22 11 .70 Farmville 450 165 3823 -16 7 47 43.20 10.64 12.39 John Kerr Dam 323 189 4016 -1 40 40.12 9.48 11 .60 Lawrenceville 300 180 4028 -2 39 45 43.33 10.74 12.52 Louisa 420 174 3719 -9 5 39 41 .62 9.67 12.56 Partlow 250 156 3551 -16 10 47 42.24 9.41 13.08 Richmond 164 206 4007 -12 41 42 44.21 9.71 14.27

WESTERN PIED~10NT Bedford 975 181 3752 -3 42 38 43.05 11 .21 12.55 Charlotte C.H. 560 189 3762 -1 NA 33 40.39 10.54 11 .27 Charlottesville 870 211 3915 1 44 35 44.34 10.62 14.18 Danville 410 196 4205 -4 72 57 42.62 10.91 12.62 Lynchburg AP 916 208 3675 -4 28 20 38.27 9.38 11 .40 Martinsville 760 172 3667 -5 37 41 43.90 11 .09 13.07 Rocky Mount 1232 178 3202 -2 32 42.98 10.81 13.42 Stuart 1455 196 3682 -17 38 15 49.31 13.35 14.97 NORTHERN Berryville 580 157 3157 -13 NA 30 36.89 9.90 10.93 Bi 9 t'1eadows 3535 145 1914 -14 3 0 48.62 12.05 14.58 Cul peper 420 182 3722 -14 6 38 40.98 10.78 12.52 Elkwood 300 166 3517 -14 5 37 39.79 10.33 11 .97 Falls Church 320 184 3582 -13 NA 31 41 .57 10.90 12.55 Lincoln 500 187 3735 -5 NA 40 41 .05 10.82 11 .95 Luray 1200 155 3208 -10 5 32 38.63 9.74 11 .80 ~~anassas 330 184 3640 -8 NA 38 39.27 9.65 12.52 ~1t. Weather 1720 179 2794 -8 8 5 39.66 11 . 13 11 .80 Orange Res. Sta. 515 189 3680 -9 15 37 38.68 9.72 11 .37

-42- TABLE 1. Climate at Selected Stations in Virginia 1941-1970 (cont.) u: ...... -.. 0 r-- r-- .f.J LO re re c cu I .f.J .f.J 0 00 -0 ID 0 0 V) ..... I 0 > r-- I-- I-- re .f.JS- 3 .,... 0 re ID .....-.. rae. 0 S- ...... -.. .c .f.J ...... -.. IDV) • V) C (/) V) Eet: -J QJV) « OV) CID .f.JID 0 >, E o..S- ...... -.. I--ID ::::5 ..c e...c O'>re ::::IV) ID re S-V) ..c -::> U QJU .f.J .f.J S::-C (/)>, E...... -.. CQJ 0>, r- U IS:: (/) C reID ..... ""--" ttS IDlL. S->, ttS ttSS::::: r- - .... I .,... >ID 3: .f.J Q S-O ::::1""'-" lL. -c ~ ...... ,... ""'-" >,""--" ID4- 0 ttSl .f.J ""'-" ~ o ""'-" c""'-" S- r-- r-- "-"" S- IDlL. X ID 0 c: c.. :::s L.LJ c.!J :r:o w 0:: m c::( c::( r-::> ""'-" NORTHERN (cont.) Washington Natl. 10 220 4202 3 39 38.89 10.02 11 .87 Winchester 760 185 3426 -10 NA 30 37.31 10.35 11 .02 Woodstock 887 170 3395 -10 4 36 33.80 9.53 10.42 CENTRAL MOUNTAIN Buchanan 870 170 3716 -4 17 43 41 .78 10.55 12.45 Catawba 1890 178 3150 -8 15 9 40.86 10.77 11 .86 Dale Enterprise 1400 167 3114 -12 4 19 34.01 9.52 11 .31 Hot Springs 2238 158 2567 -11 NA 3 40.70 10.60 11 .78 Lexington 1060 169 3532 -8 8 29 37.73 9.39 10.98 r~onterey 2910 143 2095 -14 3 0 38.73 10.74 11 .05 Roanoke 1149 193 3598 -1 75 21 39.03 9.78 11 .31 Staunton 1385 175 3206 -10 9 18 35.34 9.49 10.39 SOUTHWEST MOUNTAIN Blacksburg 2000 160 2820 -12 8 8 38.17 10.28 10.66 Burkes Garden 3300 135 2071 -24 2 0 42.42 10.91 11 .79 Chilhowie 2000 148 2626 -19 NA 10 41 .08 9.88 11 .52 Floyd 2600 153 2802 -13 5 7 43.10 11 .21 13.02 Galax 2385 149 2679 -7 NA 3 41 .47 10.82 12.43 Glen Lyn 1524 175 3272 -9 10 29 35.15 9.32 10.36 Pennington Gap 1510 165 3044 -15 4 16 50.29 11 .71 12.75 Pul ask; 1850 162 2851 -5 15 6 36.90 9.10 11 .39 Saltville 1735 189 3239 -10 11 21 43.10 11 .13 11 .71 Wise 2570 158 2657 -23 NA 0 46.30 11 .22 13.99 Wytheville 2450 163 2730 -10 9 5 36.97 9.48 11 .33

-43- INTEGRATED PEST MANAGEMENT AND YOU Franklin R. Hall Department of Entomology Ohio Agricultural Research &Development Center Integrated pest management or IPM are words you·l1 become familiar with in the 1980·s. Already you feel the pinch of labor, rising costs of all production fac­ tors, energy problems, increased federal regulations and the ever present weather problems always associated with agriculture. Recently, agricultural economists have identified the most important factors affecting profit to the farmer in the next 25 years. In summary, these factors include prices, cost control and finan­ cial management. Integrated pest management is the manipulation of pest populations by utili­ zing all suitable techniques including chemical, cultural, physical and biological methods, in a compatible manner to hold crop damage below economic loss levels. Pests in this case include insects, mites, nematodes, plant pathogens, and weeds which adversely affect crop quality and yield. In 1976, a pilot program for pest management on grapes was established in Erie County, Pa. The following information on this program is presented for your en­ lightenment courtesy of Dr. G.l. (Skip) Jubb, Department of Entomology, Penn State University, the original coordinator of this research effort (1,2). The objectives of the grape pest management program were to make pest popula­ tion assessments through regular vineyard checking ("scouting"), to apply insecti­ cides and miticides only when needed, to improve the timing of fungicide applica­ tions, and to refine pest scouting techniques.

The program started in 1976 with 6 growers and 335 acres, and expanded in 1979 to 33 growers with 1850 acres (ca. 14% Erie Co. grape acreage). Concord was the predominant cultivar grown by the participants. Pest monitoring stations were established in each vineyard. Weekly visits were made by scouts who accumulated seasonal data on insects (by visual and phero­ mone trap counts), mites, diseases and weeds. Scout reports were left with the growers that day and weekly summaries mailed to each participant. Provisional thresholds for foliar feeding pests were set at greater than 15%, and greater than 4% for flower/berry feeders. Action was suggested for control of grape berry moth when 25 moths/trapping period were found in traps. Controls were suggested for leafhoppers at greater than 8 nymphs/leaf and for European red mite (ERM) at greater than lO/leaf. Participants were encouraged to follow a preventative program for diseases and treat as needed for insects and mites. No fees were charged in 1976, $3.00/acre in 1977, and $4.75/acre in 1978. The Lake Shore Crop Management Cooperative officially came into existence in February of 1979 and is believed to be one of the first of its type in northeastern U.S. The co-op is operated by a Board of Directors, all 5 of whom are commercial grape producers. There were 32 members with over 1850 acres total included in the program.

Presented at the Ohio Grape-Wine Short Course, January 29-30, 1980, Columbus, Ohio.

-44- The Cooperative personnel include a manager, secretary, and sufficient scouts to monitor member acreage. The manager is a grape producer with a college degree in Horticulture and 5 years of experience in grape pest management. Training of scouts is provided by the entomologist and pomologist of the Erie County Field Re­ search Lab and by the Erie County Cooperative Extension Service. Scout activity begins in late May and continues until mid-September. The manager notifies the grower when pest and cultural problems arise and assists the grower in control decision-making. The role of the University is supportive in nature supplying the technological knowledge for the program. Fees included $l/acre membership; if a farm was less than 25 acres or larger than 175 acres, then flat fees of $25 and $175 were assessed, respectively. Pesticide expenditures for 1976-1978 are shown in Tables 1-4. Insecticide applications for IPM programs averaged ca. 40% less than conventional, while little difference was noted in fungicide and miticide applications. In most cases, the number of acres treated was less in IPM vineyards because of the use of spot treat­ ments rather than overall vineyard sprays. In 1977, total spray costs in the IPM vineyard averaged $9/acre less than non-IPM vineyards (Table 4). According to Jubb (2), grower opinion of the pest management was quite favor­ able. Participants were satisfied with the program, wanted to see it continued, would recommend the program to their neighbor, and found the weekly pest reports helpful. Growers indicated a willingness to pay a higher seasonal fee for pest management services. They also indicated that they would revert back to preventive spraying if pest management services were not available. The pilot program on grapes in Erie County demonstrated the value of utilizing pest scouting information and applying insecticides and miticides based on need rather than on calendar date. Fundamental prerequisites for growers not in a concentrated grape-growing area such as Erie County might include the following: 1) Be able to identify and count both pests and natural enemies at frequent intervals and reasonable cost. 2) Be able to understand major influences on population dynamics of pests and natural enemies. 3) Be able to know within a fairly close range the economic injury levels or potentials at any given time. 4) Be able to have chemicals and/or methods that will check or reduce pest populations at any level that threatens crop loss. Fortunately we do not have to satisfy all of these and other requirements to make a beginning in use of pest management principles. It is clear that a number of you are recognizing the first principle--to know as much as possible about what is happening in your vineyard. Increased Crop Management -A Prerequisite to IPM In general, IPM programs (1) may use less pesticide than conventional programs (although the opposite may also be true in certain years), (2) make more effective use of time and labor, (3) use or develop predators for mite control, and (4) re­ quire more managment and decision making by the grower. If we look at the division

-45- TABLE 1. Insecticide use in Pennsylvania pest management program.

Average number applications Year IPM Non-IPM

1976 0.8 2.3 1977 1.1 2.3 1978 2.1 2.5

TABLE 2. Fungicide use in Pennsylvania pest management program.

Average Number Applications Year IPM Non-IPM

1976 3.1 2.6 1977 2.1 2.4 1978 2.4 2.5

TABLE 3. Miticide use in Pennsylvania pest management program.

Average Number Applications Year IPM Non-IPM

1976 0.7 0.4 1977 0 0.2 1978 0.1 0.2

TABLE 4. Spray costs in 1977 for Pennsylvania pest management program.

Materials and Applications

$33-48 Non-IPM $26-36 IPM

-46- of production costs over the last 10 years, we see that management has traditionally only occupied a fraction of your total costs. Materials, including pesticides and fertilizers, still only require about 10-15% of total costs. If you are going to pinch pennies, then we must be sure that we are squeezing the right costs. This means that you have to establish goals for your vineyard operation. In addition, you have to evaluate how successful you·ve been in attaining those goals (history).

Why the rhetoric? If you've set your sights on cutting costs via IPr1, then it's important to realize that you have to have a correct assessment of your manage­ ment skills. In other words, accurate records of sprays, estimates of success of treatments, crop losses and pack-outs are essential. If your "house is not in order" now, then management of delicate balances of IPM strategies and techniques will get you into more difficulty. v!e, as scientists, frequently recomlTlend strategies and techniques which require optimum timing of events and precise selection and use of both compounds and rates. In actuality, only a few managers today have been able fl to cope with the increasing strain of IIdoing everything right •

Pesticide Application Process -A Maj~r Key to rPM Success

There are factors that you deal with today that can be improved~ One of them is the spra~ application process which has been noted to account for 70% of pest control efflciency~ Of course, you all know that "even ll distribution of material is essential for good pest control. The main problem is that "even u or II good coverage" is not easy to obtain in some vineyards .

.Factors Affecting liGand Coverage il 1. Ground speed - 2-3 mph for most plantings. 2. Nozzles - new and checked periodically. 3. Pressure functional gauges. 4. Air velocity/air volume - airways clean and rpms at correct rates. ll 5. Dosage - lI a little more for good measure is wasteful. 6. Wind - below 10 mph or do it later. 7. Temperature and Relative Humidity - high T and RH will diminish low volume deposition 8. Cultivar and Pruning - dense foliage will reduce spray penetration. Other factors incl ing your sprayers clean and functional, properly operating pressure gauges, and speedometers. Inadequate attention to proper cali­ bration techniques and worn nozzles are probably the most common problems encoun­ tered by private consultants throughout the country. Air velocity is important along with droplet sizes because large drops deposit at low velocities whereas small drops require higher velocities to impinge on leaf surfaces. Small drops also move more easily with natural wind forces if the air velocity of the sprayer drops too low. We know that the faster you drive, the less you are able to take advantage of air shear type nozzles for droplet break and the faster the air velocity diminishes as the spray departs from the sprayer. Al­ ternate row spraying is helpful for both energy savings and rPM programs. But the distance between rows, vine and foliage density and sprayer capacity are the deter­ mining factors in the success or failure of this technique. Well, you say, live heard this before. You're right ....many folks have told you the same story but it appears from experiences allover the country that, in order to prepare you for dealing with low volume spraying problems, weather conditions and new pesticides ll (effective at very low rates of use), that itls "back to basics • If we are to ~--- -47- select certain pesticides, to use at precise rates, at specific times in order to enhance IPM strategies then the process of spray calibration, upkeep and care, and the application itself, just has to be made more precise. In a recent study by IISuccessful Farming Magazine", 2 out of 3 pesticide ap­ plicators were making significant application errors. You can expect "calibra­ tion wi'l be increasingly important as concern is focused on the biggest problem ll with agricultural chemicals--the people who apply them • Inflation, labor and re­ gulatory problems, and increasing energy costs should cause you to look carefully at your management skills in 1980. Accurate records of spray applications, pest activity, crop losses, and assessment of yield and quality results by block will play an increasingly important role in how successful you·" be in the 80·s. LITERATURE CITED 1. Jubb, G., T. Obourn, and D. Peterson. 1978. Pilot pest management program for grapes in Erie County, Pennsylvania. J. Econ. Entomol. Vol. 71 :913­ 16. 2. Jubb, G. and T. Obourn. 1979. Pest management: its development and appli­ cation in Pennsylvania vineyards. Proc. 11th Pa. Wine Conf., Univ. Park, Pa. Feb. 6-7, 197 9. 58 P.

-48- A PROGRESS REPORT ON THE EFFECTS OF ROOTSTOCKS ON FIVE GRAPE CULTIVARS G.A. Cahoon and Donald A. Chandler Ohio Agricultural Research and Development Center Wooster, Ohio 44691

The role of rootstocks in the propagation of most types of fruit crops is well known. They are not only a means of propagating and maintaining the clonal proper­ ties of a variety, but also to gain certain beneficial effects from the rootstocks themselves. Traditionally, most of the grapevines propagated and planted in Ohio are as "own-rooted" cuttings. This has been primarily because of the type of grape grown (Concord, Catawba, Niagara). The fact that the predominant cultivars are of Ameri­ can origin (Vitis labruscana) and thus presumably somewhat resistant to grape phyl­ loxera (a root pest, which nearly destroyed the Fr·ench grape industry some years ago) has allowed them to be grown on their own roots with good success. Other fac­ tors are the cost, time and effort involved in propagating vines on rootstocks, plus the doubtful benefit to be derived.

In 1968, some 37 rootstock selections were obtained for testing from the Horti­ cultural Research Institute, Vineland, Ontario, Canada (Table 1). By 1971, suf­ ficient material was available to initiate studies using 24 of these rootstocks on 5 scions. This study was conducted at the Southern Branch of the Ohio Agricultural Research and Development Center. The 5 cultivars (scions) chosen were: Concord, Catawba, DeChaunac, Aurore, and Himrod. The principal relationships that have been under study during the 71-79 period were those factors that might be affected by rootstock performance; ie., vigor, cold hardiness, productivity and quality. All vines were balanced pruned each year. The first meaningful yield was obtained in 1974. Data has been taken annually since that time, 1974-79. Within this 6-year period, considerable variability was encountered. During the winters of 1976-77, 1977-78 and 1978-79 some very adverse weather occurred. Perhaps the most severe in the last 100 years. As expected, there was some vine mortality. The discussion to follow is presented in two ways: 1) the average yield, cluster number and cluster weight (Table 2) is given as if all vines were present during the entire 6-year period; 2) the average pruning weight and soluble solids content is based upon just the living vines. This 1atter­ method is necessary in order to give some insight into the vigor and productivity of the existing vines and does not penalize a rootstock because one or more vines died during the 6-year period. Some vines died during 1972 and 1973. No replanting was done after this time. The material in Table 2 includes an average of only the 1974-79 (6-year) period.

RESULTS AND DISCUSSION Yield per Vine When considering the highest average production for each of the cultivars, the ranking was: 1) Concord, 2) Catawba, 3) DeChaunac, 4) Aurore, and 5) Himrod. As can be seen in Table 2, rootstocks did have a significant affect on yield. For Concord the highest 5 producing rootstocks during the 6-year period--1974­ 79 were as follows: 1) C3309--average production of 33.3 lbs. per vine; 2) C1616--

-49- TABLE 1. Rootstock introductions at the Southern Branch of the Ohio Agricul- tural Research and Development Center. Planted May 1968.

1. Solonis x Rip. 1616 14. Napka 26. Berlandieri x Rup. 44R 2. Vandervi11e 15. Ri p. x Rup. 3309 27. Mourvendre x Rup. 1202 3. Ridgeville #1 16. 420 A 28. Eona 4. Ridgeville #2 17 . Dogridge 29. A x R #1 5. Salt Creek 18. Castel 18815 30. CS #35 6. Rip. x Rup. 19. Rup. St. George 31 . C 40 de Massanes 225 20. Clinton 32. Azi ka 7. Toscha 21 . Te1eki 5-A 33. C 1613 8. Atkan 22. Shakoka 34. 161-49 9. SO-4 23. Rip. Glorie 35. 110 R 10. Rip. x Rup. 101-14 24. Ri p. x Rup. 3306 36. Sanoma 11 . Seibel 1000 25. Rip. x Rup. x 37. Te1eki 5-88, 12. Mandan Cord. 4453 Selection Kober 13. Berlandieri x Rup. 57R

-50- average production of 29.6 lbs. per vine; 3) 57R--average production of 26.8 lbs. per vine; 4) C5 #35--average production of 26.4 lbs. per vine; and 5) Teleki 5BB-­ average production of 24.6 lbs. per vine. Other Concord vines whose rootstocks averaged near 20 lbs. per vine included: 4453, C40, and Shakoka. Own-rooted vines averaged 11.4 lbs. per vine. For Catawba (Table 2), the 5 highest producing rootstocks were: 1) Castel 18815--26.6 lbs. per vine, 2) S04--23.1 lbs. per vine, 3) Teleki 5B8--23.0 lbs. per vine, 4) Atkan--22.4 lbs. per vine, and 5) C-40--22.2 lbs. per vine. Other Catawba vines whose rootstocks produced near 20 lbs. per vine included: 420A, Ridgeville, C3306, Eona, and Clinton. Own-rooted vines averaged 14.5 lbs. per vine. For PeChaunac (Table 2), the highest average production was as follows: 1) C1616--18.4 lbs. per vine; 2) Teleki 5BB-17.4 lbs. per vine; 3) C3309-·17.3 lbs. per vine; 4) C5 #35--16.9 lbs. per vine; and 5) 57R--15.5 lbs. per vine. Others near the 15 lb. catagory included: 420A, Ridgeville, Rip. Gloire and C3306. Own-rooted vines averaged 11.2 lbs. per vine. For Aurore (Table 2), the highest 5 producing rootstocks were: 1) Ridgevil1e-­ 17.4 lbs. per vine, 2) Castel 18815--14.9 lbs. per vine; 3) Clinton--9.5 lbs. per vine; 4) 420A--9.3 lbs. per vine; 5) C5 #35--9.0 lbs. per vine. Own-rooted vines produced only 3.8 lbs. per vine. It should be noted that on this cultivar, almost every rootstock was missing one or more vines. If the averages are retabulated and only living vines are averaged (one missing vine), the order would be: 1) Ridge­ ville--18.7 lbs.; 2) Clinton--17.8 lbs.; 3) 504--16.4 lbs.; 4) C5 #35--15.0 lbs.; and 5) Castel 18815--14.9 lbs.

For Himrod (Table 2), the six top ranking rootstocks were: 1) Shakoka--12.5 lbs. per vine; 2) C3306--11.1 lbs. per vine, 3) C3309--9.6 lbs. per vine, 4) Castel 18815--9.6 lbs. per vine, 5) M. Vendre--9.3 lbs. per vine; and 6) Atkan--9.3 lbs. per vine. Own-rooted vines averaged 4.3 lbs. per vine. Cluster Number and Cluster Weight per Vine The two components making up total yield are, the number of clusters per vine and the weight per cluster. As shown in Table 2, yield variability attributable to the various rootstocks was due to both. For Concord, yields are very strongly related to the number of clusters. Both C3309 and C1616 had 113 clusters per vine, followed by C5#35 with 104, 57R with 102, Teleki 5BB with 92 and Own-rooted vines with only 49. The highest yieldrootstocks generally produced the highest cluster weight. The only rootstock not following this trend was Teleki 5BB (.27 lbs. per cluster). Own-rooted vines not only had the lowest cluster number but also the lowest cluster weight (.23 lbs. per cluster). For Catawba, the top two producing rootstocks also had the highest cluster number, but differences were very small and not significantly different. Yield differences among the top 5 producing rootstocks were also small. Own-rooted vines yield reduction was primarily from a significantly lower cluster number not cluster weight. Throughout all five rootstocks, cluster weight varied very little (.24 to .27 lbs. per cluster). For DeChaunac, differences among the five highest producing rootstocks was the result of both cluster weight and cluster number. C1616 for example, averaged 18 less clusters per vine than Teleki 5BB, but had a higher cluster weight (.20 vs .16 -51- lbs./vine). Differences among the yields, as well as cluster weights were actually quite small. Own-rooted vines, with only 52 clusters, had the highest weight per cluster (.22 lbs.), but the lowest yield (11.2 lbs. per vine). For Aurore, yield was very strongly related to cluster weight. Ranges varied from .24 for the highest yielding rootstock (Ridgeville) to .10 for Own-rooted vines. Clinton 420A and C5 #35 also had to depend on higher cluster numbers in order to pro­ duce 9.0 and 9.5 lbs. per vine. It should be noted that a crop failure on Aurore took place at harvest in 1977 due to a bad disease problem and no yield data was taken. Since 1977 was an average production year, the comparative yields for this variety as shown in Table 2 have been reduced. For Himrod, cluster number was related rather strongly to total Yield, but some interesting differences are present with the cluster weight. For example, C3309 had an average cluster weight of .37 lbs. per vine, which was the highest for all rootstocks and cluster number of 26 tended to be low. Yields were generally low and somewhat in the category of Aurore. It should be pointed out that cluster weights averaged about 1/3 lbs. per vine and are higher than the usual Himrod cluster. This was due to the Alar that was applied at a rate of 500 ppm at first bloom every year of the study. As with the other cultivars, Own-rooted vines produced only about half as much as the 5 top rated rootstocks and the cluster weight was significantly lower. Soluble Solids Yield-soluble solids relationships produced by the various rootstocks were weak or nonexistent. In other words, the percent soluble solids produced by high yielding vines were about the same as for low yielding vines. In general, the soluble solids were quite acceptable, being the lowest for Concord and the highest for Himrod. Pruning Weight An important consideration to note in this study is that all vines were balanced pruned. For Concord, Catawba and Himrod, a 30 + 10 ratio was followed (30 buds for the first pound of wood plus 10 buds for each additional pound) and for DeChaunac and Aurore a 20 + 10 ratio was followed. In addition, the two French hybrids, DeChaunac and Aurore, which tend to overfruit, were cluster thinned every year to two clusters per shoot. This was done to avoid any severe overloading which would cause excessive weakening and mortality of the vines. Two clusters per shoot, however, would still allow for an expression of maximum yield. Vine vigor, as mea­ sured by pruning weight, was very satisfactory for most rootstock/cultivar combina­ tions shown here. The least vigorous cultivar; i.e., the cultivar with the lowest pruning weight was Aurore. Vines of Aurore could benefit from higher pruning weights and higher vigor. However, this is typical for this variety. Looking at the top 5 producing rootstocks, the relationship of pruning weight to production does exist; i.e., the greater the vigor the higher the yield. How­ ever, when all 24 rootstocks are compared, some rather interesting relationships become evident. For example, in Table 2, DeChaunac shows a very strong correlation between vigor and yield. However, when all 24 rootstocks are considered, the pruning­ yield relationship is less than on any of the other cultivars. This relationship, somewhat evident in the 5 top producing rootstocks of Aurore, was very strong when all 24 rootstocks are considered. In fact, it constitutes the least deviation from the mean of all cultivars when pruning weight and yield are correlated. As a

-52- TABLE 2. Average yield cluster number, cluster weight, soluble solids, and pruning weight of 5 grape cultivars grafted to the 5 top producing rootstocks. Yield Weight Prune vine Cluster cluster Soluble weight Rootstock lbs. no. 1bs. solids lbs. CONCORD C 3309 33.3 113 .29 16.3 3.9 C 1616 29.6 113 .26 15. 1 4.3 57R 26.8 102 .26 15. 1 2.4 C5-35 26.4 104 .25 15.9 3.4 Teleki 5BB 24.6 92 .27 16.2 3.9 Own-root 11 .4 49 .23 15.5 0.6 CATAWBA Cl1815 26.6 100 .27 17.9 4.4 504 23.1 93 .25 17.9 4.6 Teleki 5SB 23.0 84 .27 18.2 4.6 Atkan 22.4 88 .25 17.8 3.2 C-40 22.2 92 .24 17.2 3.7 Own-root 14.5 59 .25 17.4 3.9 DeCHAUNAC C 1616 18.4 90 .20 18.9 5.7 Teleki 5BB 17.4 108 .16 18.7 5.3 C 3309 17.3 104 .17 18.8 5. 1 C5-35 16.9 91 .19 17.9 3.2 57R 15.5 88 .18 18.4 2.3 Own-root 11 .2 52 .22 17.6 1.5 AURORE Ridgeville 17.4 74 .24 17.7 2.0 C 18815 14.9 68 .22 18.3 1.6 Clinton 9.5 83 .11 16.7 2.1 420A 9.3 73 .13 16.2 1.3 C5-35 9.0 68 .13 18.3 1.3 Own-root 3.8 37 .10 18.6 0.6 HIMROD Shakoka 12.5 41 .30 15.8 2.0 C 3306 11 .1 34 .33 18.9 3.4 C 3309 9.6 26 .37 19.0 2.0 C 18815 9.6 28 .34 18.5 2.3 M. Vendre 9.3 28 .33 18.7 2.6 Atkan 9.3 30 .31 18.9 1.5 Own-root 4.3 18 .24 19.0 0.6

-53- French hybrid it woul d be. ex.pected to b-ehave more like DeChaunac than the Ameri can hybrids. Concord, Cata;wba, and Himrod all showed a strong relationshi p between pruning weight and yield. This certainly is to be expected because of the crop con­ trol benefits that are to be derived by balance pruning American hybrids, such as these. Of the 3 Amertcan hybrids, Catawba shows the strongest relationship (least deviation from the mean).

SUMMARY AND CON,CLUS IONS One of the first conclusions that become obvious from this study is that no one rootstock is really outstanding for all 5 of the cultivars. In fact, the opposite is true: 15, rootstocks are represented when the 5 highest producing rootstocks in each of the 5 cultivars are selected. Rootstocks showing the greatest prominence among the 5 cultivars were: C.3309, C5 #35, Teleki 588, Castel 18815. All of these were listed in 3 of the 5 cultivars. Those appearing twice include: 57R, C1616 and Atkan. Own-rooted vines also appear to be abnormally low in productivity. It is hoped that time will be one of the best factors that will help to point up the strengths of the best rootstocks. Likewise, it should help weed out those that are the least desirable. However, this experiment only represents one set of soil and climatic conditions. As noted earlier, during this 6-year production per­ iod were three of the hardest winters that Ohio has experienced in, perhaps, 100 years. The fact that there was some vine loss should not be unexpected. One of the very difficult things to screen out from the experiment, however, was this vine loss relationship. Remaining vines that existed of some of these cultivars continue to produce at very desirable levels. Just how this can be evaluated properly will re­ quire additional years of research. There is no doubt that beneficial effects have been produced by propagating the various cultivars on rootstocks. It is also pointed up that such things as spacing and fertility experiments now need to be con­ ducted to capitalize on the benefits offered by some of these rootstock/scion combina­ tions. The present study is to be continued for several more years.

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Ohio's major soil types and climatic Muck Crops Branch, Willard, Huron Coun­ conditions are represented at the Re­ ty: 15 acres search Center's 12 locations. North Appalachian Experimental Water­ Research is conducted by 15 depart­ shed, Coshocton, Coshocton County: ments on more than 7000 acres at Center 1047 acres (Cooperative with Science headquarters in Wooster, eight branches, and Education Administration/Agri­ Pomerene Forest Laboratory, North Appa­ cultural Research, U. S. Dept. of Agri­ lachian Experimental Watershed, and culture) The Ohio State University. Northwestern Branch, Hoytville, Wood Center Headquarters, Wooster, Wayne County: 247 acres County: 1953 acres Pomerene Forest Laboratory, Coshocton Eastern Ohio Resource Development Cen­ County: 227 acres ter, Caldwell, Noble County: 2053 Southern Branch, Ripley, Brown County: acres 275 acres Jackson Branch, Jackson, Jackson Coun­ Vegetable Crops Branch, Fremont, San­ ty: 502 acres dusky County: 105 acres Mahoning County Farm, Canfield: 275 Western Branch, South Charleston, Clark acres County: 428 acres