Winemakers look to hardy hybrids for solutions to environmental challenges

After a few minutes, Professor Bruce Reisch stands up and asks what people think of wine No. 1. Dave Peterson, general manager of Swedish Hill Winery in upstate New York, volunteers: „Lots of Muscat aromas.” A few nods around the room. Someone else says it has some „citrus notes, but is a little ‘foxy.’ „ Eric Amberg, owner-winemaker of Amberg Wine Cellars, gets technical, asking about harvest dates, acidity and sugar levels.

Eventually Reisch identifies wine No. 1 as the prosaically named 76.848.03. Like the other wines at the tasting, it’s a hybrid variety developed at Cornell University’s Agricultural Experiment Station in Geneva, N.Y., where Reisch is professor of grapevine breeding and genetics. A hybrid is a cross between grapes of two different species; Reisch says his goal, and that of most hybrid grape breeders, is to bring together the flavor of Europe’s Vitis vinifera grape species with the cold-hardiness and disease resistance of American grapes.

Those native American grapes are often described as having a „foxy” aroma - something like a mix of grape juice, wild strawberry and musk. And that’s the challenge Cornell’s Reisch faces: to devise hybrids that can grow in less ideal conditions, but yield wines that taste like Vitis vinifera, the European species responsible for Chardonnay, Cabernet Sauvignon, Sangiovese and almost any other wine grape you’ve heard of. Foxiness is out. It’s easy to confuse hybrids with other crosses, especially those that stay within one species.

For example, South Africa’s Pinotage is a cross between Pinot Noir and Cinsault, and Symphony is a cross between Grenache Gris and a type of Muscat, created by the late UC Davis researcher Harold Olmo. Olmo and other scientists at Davis and elsewhere have also worked with clonal selection - choosing a particular vine of, say, Chardonnay, that is more disease-resistant or otherwise desirable, and propagating it by grafting - no crossing necessary. Until now, California and other West Coast researchers have been more interested in these standard crosses, and California has no major commercial hybrid plantings right now.

A Harold Olmo hybrid, Rubired, is grown in a few areas to add color to hot climate wines. But that could change. Andrew Walker, professor of viticulture at UC Davis, says that the state’s winegrowers should start giving hybrids serious attention. Restrictions on fungicides and a move toward greener viticulture are making hybrids increasingly relevant. He says: „It’s almost a million acres of grapes in California, and they’re all potentially going to be impacted. And it’s not just California, it’s worldwide - not next week, but in 30 or 40 years down the road, when political and environmental pressures kick in” to end the use of copper, sulfur and other fungicides.

„Vinifera grapes have no resistance to powdery mildew,” Walker explained in an e-mail. That in turn requires extensive applications of fungicides, and he adds that Pierce’s disease - a fatal bacterium spread by the glassy-winged sharpshooter - „will have to be solved by hybrid varieties.” He has bred varieties with very high percentages of vinifera parentage that retain the resistance to Pierce’s disease found in Vitis arizonica, a native American vine species found in the Southwest and Mexico.

The first test wines will be made this fall. Phylloxera, a louse that attacks the vine’s root system, was the first vine disease to spur hybrid development. Another North American native, it made its way to Europe in the late 1800s and devastated the vineyards of most major wine regions. Native American grapevines are resistant to the pest, so French nurseries began creating hybrids in the hopes of saving their industry. The phylloxera problem was better addressed by grafting vinifera varieties onto resistant, American rootstocks - an alternative way of bringing American and European vine species together.

But hybrids have other potential uses. And it’s these qualities that explain the interest in hybrids once you leave the West Coast. Shorter growing seasons, harsh winters, humidity, disease - all make growing vinifera difficult in the Midwest or on the Eastern seaboard. Several native North American grape species like Vitis labrusca and Vitis riparia don’t mind the cold, shrug off the mildews that prosper in humidity, and ripen early; these are qualities Reisch would like to encourage in his experimental vines. John Brahm III owns Arbor Hill Winery in Naples, a small town in the Finger Lakes region of upstate New York. He points downhill toward Canandaigua Lake, where a neighbor’s vineyard sits. „He’s got Riesling, Chardonnay and Pinot Noir in there.

The lake’s about 700 feet in elevation, and his vineyard’s close enough to get some warming effects from the water. Our vineyards are farther uphill; I’d say the cutoff is around 1,000 feet. After that, you can’t grow vinifera and expect it to make it through the winter reliably.” Brahm has a number of hybrid grapes planted, but it’s his Traminette that’s gotten the most attention. Developed by Cornell, Traminette has many of the aromatic and textural traits of its vinifera parent, Gewurztraminer, but it also handles cold winters and most diseases well.

Brahm praises its ability to make quality wine in three different styles: dry, off-dry or dessert. He was quick to plant Traminette, but it’s not a purely local phenomenon; wineries in Missouri, Virginia, Michigan and elsewhere have also had success with it. And while Traminette spreads west, Eric Amberg, of Amberg Wine Cellars, is excited to have New York’s first plantings of Marquette, a hybrid developed at the University of Minnesota and released to the public for the first time last year. Many winegrowers are paying close attention to hybrid development, and some are even developing new varieties themselves.

The University of Minnesota’s program was actually reinvigorated in the late ‘60s by the successes of Elmer Swenson, a local Wisconsin farmer who had been breeding grapes on his own. But typically, grape breeding lends itself to academia, because it’s a long-term process. Last year, Cornell released three new hybrid varieties: Corot Noir and Noiret, both reds; and Valvin Muscat, a white; they were first bred in 1970, 1973 and 1962, respectively. It takes years of plantings, tastings and tests to determine the potential wine quality, adaptability and winter-hardiness of a new variety. Vintage variation, different environments and various growing techniques have to be accounted for.

A Cornell variety may be tried out in Geilweilerhof, Germany, at the University of Minnesota, or with a private winegrower to see how it does away from its birthplace. Early hybrids were accused of those foxy flavors, poor tannin structures and high acidity. Some opponents of hybrids said they were even toxic; subsequent research has found they are harmless to humans, but maybe dangerous to birds. Today, methyl anthranilate, a chemical common in Concord and some other hybrids, is actually used as a bird repellent. In the vineyard, many hybrid grapes are also prone to overcropping - too many grapes per vine, which results in diluted flavors and poor wine quality.

Girardet Wine Cellars in Southern Oregon has a reputation for its Baco Noir, a hybrid developed in France at the end of the 19th century. Michelle Biggs at Girardet says they have to work hard to keep the vines from growing too vigorously. On the plus side, she says, „It’s a tough, hardy grape, and its disease resistance is spectacular.” Cornell’s Reisch says there was one big flaw in many early hybrids: „They weren’t using quality vinifera grapes in the first place.” Another advantage to today’s hybrids is the high number of sources that contribute to their parentage.

While older hybrids were by and large straightforward crosses between two known varieties, contemporary hybrids have family trees that look like they could belong to Renaissance royalty, stretching back through seven or eight generations on both sides and including two, three or more species. That makes it easier to hide undesirable traits or bring out the characteristics you’re looking for. There have been some dead-ends as well. Peter Hemstad, professor at the University of Minnesota, recalls when the species Vitis amurensis was brought into the United States in the 1980s: Hailing from Siberia, it seemed like a sure answer to harsh winters.

„I investigated it pretty thoroughly, and I was not impressed at all,” he says. Compared with Vitis riparia, another Eastern United States grape species that typically grows on riverbanks, Hemstad says, „It was very susceptible to powdery mildew, and on its own rootstock, it’s completely susceptible to phylloxera” - two vine diseases winegrowers anywhere are concerned about. Breeders in Germany and Hungary continue to explore Vitis amurensis’ potential. (Read more)