Fruit of the Vine

Fruit of the Vine

by Melissa Lutz Blouin

The next time you sip some wine or gulp grape juice reflect a moment on the long, winding, torturous route the wine or juice took to end up on your table. First, the vines the grapes grow on must be carefully pruned and trimmed for maximum fruit yield. Then, the fruit must be thinned to ensure the grapes reach their maximum flavor and sweetness. After that, someone has to pick the grapes.

To make wine, all that must happen before the crushing, fermenting and other processes that finally bring the drink to your dining room table.

Wine cultivation is a process with roots that began growing almost 8,000 years ago. Archeologists have found ancient clay vessels containing wine residues at a site in Hajji Firuz Tepe, Iran, that date back to 5400 B.C. Some of the techniques used 1,000 years ago still are used today. But modern-day wine growers have new concerns in today’s global market, and University of Arkansas researchers have created a system that may revolutionize the labor practices used in the production of grapes.

Justin Morris, Distinguished Professor of food science and director of the Institute of Food Science and Engineering, grew up on a fruit farm. So it seemed natural for his career path to lead to research on making fruit production less labor-intensive. Although mechanical harvesting of grapes has existed for years, Morris envisioned a system that would allow mechanization of almost all of the hand-labor operations in a vineyard.

People might imagine that the harvest draws the most workers to the field to pluck the juicy orbs from the vine, but it turns out that the grape picking proves to be the last in a long line of tasks required to grow and maintain a successful vineyard. The neat, even-looking rows of vines are sculpted and maintained several times a year by workers, who might hand-prune the vines, trim back shoots and thin fruit, depending upon the season. The workers painstakingly perform all of these operations to achieve one goal: to maximize fruit quality and production.

About 35 years ago, Morris teamed up with a local grape grower and inventor, Tom Oldridge, and began to experiment with machines that might help reduce the labor-intensive nature of growing and harvesting wine and juice grapes. They assembled different types of equipment from old parts on Oldridge’s farm outside of Lowell in hopes of developing a machine or machines useful throughout the whole process of growing and harvesting grapes.

“We both had been working with grapes all of our lives,” Morris said. “Pretty soon you start thinking like a grape.”

Through the years, they tried different types of machines and attachments and various techniques, evaluating the results by the quantity of harvest in the field and the quality of the product through sensory evaluations at the University of Arkansas.

“If we decreased the quality, we would take another approach,” Morris said.

After more than 35 years of research, the University obtained a patent in 2002 for the Morris-Oldridge System, a vineyard mechanization system that uses more than 40 different machines and attachments that allow for the total mechanization of operations for the major trellising systems used throughout the world. The patent contains 98 pages of detailed illustrations and explanations of the equipment and its uses. The equipment has made it possible to do dormant pruning, canopy management, shoot and fruit thinning, shoot positioning, summer shoot pruning and leaf removal faster and with fewer people in the field than before.

OXBO International Corporation has acquired the license to manufacture the patented system under the name vMech®.

“Looking at the vineyard industry, there’s a real need to begin supplying a complete mechanized system,” said Andy Talbott, vice president for marketing and sales at OXBO. Labor costs continue to rise, but two-thirds of the wine grapes grown in California end up in bottles of wine that sell for seven dollars or less. With foreign wines selling at similar prices, California wineries can’t afford to increase the price. They also can’t afford to employ large numbers of laborers as costs continue to rise.

In 2002 and 2003, Morris worked with OXBO and French Camp Vineyards in Paso Robles, Calif., to conduct research comparing hand-farmed and machine-farmed grapes at the vineyard. French Camp Vineyards has 1,725 acres of grapes on the central coast of California. The mechanized system was used on 475 acres in 2003 and, this year, they have about 905 acres of grapes being raised using the vineyard mechanization system.

The researchers compared yields, grape weight and the quality parameters ­ flavor and color — for these two methods using six heavy-hitter varieties in the grape industry: Chardonnay, Sauvignon Blanc, Merlot, Sangiovese, Syrah and Zinfandel. They found that in most cases, the two methods proved comparable in yields and quality. With Merlot, the machine-farmed grapes yielded a better-tasting wine than the hand-farmed grapes.

In 2004, the vineyard will produce about 7,000 tons of grapes using the mechanized system and sell them to 10 or so wineries.

“The idea is to produce grapes of just as high quality as hand-farmed using the mechanized system,” said Hank Ashby of French Camp Vineyards.

The difference should show up in the cost of doing business. Ashby estimates that the mechanized method could save the vineyard about 50-70 percent per acre in labor costs. This could translate into a savings of as much as $1,500 per acre. A mechanized system would require skilled employees who can operate the machinery and could reduce the number of people laboring in the fields. These cost savings could be passed on to consumers, who could see less expensive grape juice and wine as a result.

This would be welcome news to American wine producers.

“We’re in a challenging grape market. Imports are killing us,” Ashby said. Low shipping costs allow countries such as Australia and Chile to export their wines to the United States, yet keep costs low. He recently heard an Australian wine exporter comment that it costs more to move grapes across Australia in a truck than it does to ship them to England.

Indeed, countries in the southern hemisphere have exploded onto the wine export market, with Australia, Argentina, Chile and South Africa among the top six exporters of wine worldwide.

These matters weigh heavily in California, where grapes — destined for wine and juice ­ are the state’s second-leading farm product. The annual economic impact of the wine industry in California totals $45 billion, according to the Wine Institute, the public policy advocacy association of California wineries. Although California accounts for about 90 percent of the wines produced in the United States, vineyards flourish in other places, including Washington, Oregon, New York, Colorado, Michigan, Missouri and Arkansas, so the interest in staying competitive extends throughout the country.

“We need to cut costs to try to compete with foreign wineries,” Ashby said.

While the mechanization results look promising, the technology is still new. OXBO has test blocks in other vineyards. Talbott said the producers will make their own determination as to the quality of the grapes grown with mechanical manipulation.

“This will be adapted. It will just take time,” Talbott said.

The machines vary greatly in their uses, but the basic outline of most resembles a go-cart with large, mechanical wings flanking it. The “go-cart” portion must be narrow enough to fit between rows, while the “wings” contain the machinery that performs the task at hand: pruning, shoot thinning, fruit thinning, leaf cutting ­ all designed to create the proper balance of sugar in the fruit necessary to produce a fine wine.

Grape leaves need light for photosynthesis, which creates the energy required to produce sugar in the grapes. In addition, the developing canes that produce the next year’s fruit need light as well. However, too many competing canes and leaves produce lesser-quality fruit, so careful pruning ensures quality. Too dense a canopy creates too much shade and not enough air circulation around the grapes. Too thin a canopy means not enough leaves for photosynthesis to produce healthy fruit.

To bathe the plants in sun, grape growers have created trellis systems that use posts and wires in various combinations. The systems vary from simple vertical poles to a lyre system that features a U-shaped trellis, allowing the grapes to fan out to each side of a row. These systems share the same objective: to maximize the plant’s exposure to the sun.

The majority of vineyard owners worldwide use one of 12 different types of trellising systems. Morris and Oldridge designed their machinery to work with these different types of trellises.

Using the Morris-Oldridge system, which has more than 40 machines and attachments, grape growers should be able to prune, thin, pluck and cut on the different types of standard trellises.

Now that Morris has created a successful mechanization system, his thoughts have turned to timing. In grape production, timing is everything, and timing vineyard operations is complicated by nature. A hot spring, a late frost, a rainy summer…all of these variations change
the timing of the procedures required to bring a grape from blossom to fruit.

“Even the time of day can make a big difference,” Ashby said. In the morning, the small shoots retain more water and are more easily thinned by machine. But as the plant loses water in the midday sun, the shoots become rubbery and harder to thin.

Despite the challenges, Ashby said the vineyard mechanization system is viable.

“There’s a lot of interest in the grape-growing community,” he said.

Justin Morris, Distinguished Professor of food science, examines grapes grown on a farm at the University of Arkansas campus. Morris has worked for more than 30 years to develop a vineyard mechanization system for total care of grapes, from pruning and shoot positioning to grape harvesting.

The University’s enology program grew from a history of grape growing in the region. Arkansas is the oldest and largest grape growing and wine producing state in the South. A colony of German-Swiss immigrants settled in a community near Altus in the 1870s, and today the area’s four wineries produce more than 1.2 million gallons of wine a year.

Grape production also began in the University’s back yard in the 1800s. A group of Italian immigrants, led by a Catholic priest from New York, founded Tontitown in the late 1800s and began to grow Concord grapes as well as hardy wine grapes. Welch’s Food built a grape juice production plant in nearby Springdale in 1922.

While developing the system, Morris and his colleagues worked with the National Grape Cooperative in New York and with the Arkansas Agricultural Experiment Station in Fayetteville to test differences in yield and grape quality using machine-farming versus hand-farming techniques. They found that grape quality and quantity were nearly identical for both methods.

During his career, Morris has examined almost every aspect of grape cultivation imaginable. He has written papers on rootstock, cultivars and irrigation. He has looked at thinning, pruning, harvest timing, transportation and storage. He has contemplated grape yield and quality. He has pondered the acidity, color and maturity of wine and juice grapes.

Morris has published more than 340 articles during the course of his career. His work has been recognized by numerous groups, including the American Wine Society and the American Society for Enology and Viticulture, and he earned the University of Arkansas Faculty Distinguished Achievement Award for Research and Public Service. Some of the awards line the walls of his office. A glance around his office also reveals grapes everywhere ­ grape stained glass, a grape frieze and some wine magnets. More prominent still are bottles and jars displayed near his desk, samples that former students bring him when they visit.

About The Author

University Relations Science and Research Team

University Relations Science and Research Team

Matt McGowan
science and research writer

Robert Whitby
science and research writer

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