A New Industry Buzz Word -- Clonal Selection

By Matthew Citriglia, MS on June 17, 2007

The wine industry is now big business with millions of dollars at stake. Boxes, market share, points of distribution, and category growth are daily buzzwords I must deal with as a wholesaler. Chemistry labs, Reverse Osmosis machines and companies like Equinox have homogenized wine to the point where it all tastes the same and gets the same ratings from the big named critics. There is one problem: consumers eventually crave variety. No one wants to listen to the same music or eat the same food day after day and educated consumers are looking for diversity. They want to know how this pinot different is from that pinot, and why they should spend the extra $20 on one cabernet verses another and which chardonnay is drier. Wineries are rushing back to their "roots," if you will: trying to justify their cost and establish what makes their wine different or unique from all the others. As wineries and grape growers have a renewed interest in talking about their wines and how they are expressed through the vineyard a new set of buzz words have emerged – CLONAL SELECTION.

What is a Clone?
To understand what a clone is, it is important to understand how grape vines are propagated. Vines can reproduce in one of two ways, sexual or asexual. Sexual reproduction would be planting a seed and allowing it to germinate and sprout into a vine. A seed harvested from a Pinot Noir vine and planted would produce a plant that shares characteristics of the two parent plants but would not be an exact replica. Example, I come from a big family with 4 brothers and 3 sisters and constantly run into people that I have never met before. They look at me and say "you're a Citriglia aren't you?" Although my siblings and I all resemble each other our personalities and interests vary dramatically. This dramatic diversity of personalities is exactly why wineries do not plant vineyards in this method.

The other way to propagate a vineyard is asexual or what is often called vegetative propagation. This is where a twig of a vine with a bud is cut from the "mother vine" and then either planted directly into the ground to sprout its own roots or, more commonly, grafted onto a specific rootstock. The newly planted or grafted vine is called a clone of the mother vine and is an exact replica. The terms "cuttings" or "budwood" are used to describe the plant material that was cut from the mother vine that will be replicated many times over. This method of cloning provides the winemaker/grower with uniformity in the vineyard which "technically" makes managing the vineyard easier.

Why Clonal Selection is Important?
Up until about 1970 most people thought that the importance of clonal selection was limited to viral resistance and yield and believed that fruit quality was a result of growing practices. Oregon learned the hard way that this is not true by selecting what were considered superior clones for producing Chardonnay and Pinot Noir in California and planted those vines in Oregon. Although they had limited success with these vines, ultimately Oregon made a deal with ENTAVE (Etablissement National Technique Pour l'Amelioration de la Viticulture) an arm of the French Agricultural department whose sole responsibility is to document, clean and certify grape clones in France. This partnership allowed Oregon growers to investigate and experiment with plant material that would grow best in their environment.

Today a winemaker/grower selects cuttings the way a chef would select spices for his kitchen. Although every clone will taste like the parent variety they will offer slightly different characteristics. Maybe one clone is fruitier while another retains more acidity. If one area of the vineyard does not drain well a clone that has a higher resistance to humidity may be selected and so on…. Clones have become highly specialized, and vineyard owners can select clones based on flavor profile, berry size, cluster shape, vine yields, vine vigor, bud break, and tolerances to heat, humidity and drought.

Clonal Variation or Selection
Even though a clone is a replica of a single vine there are three things that can impact its identity over time which in turn create clonal variation. This variation may be subtle or dramatic and may manifest itself in many ways such as berry size, vine vigor or even fruit flavor. The plant still resembles the parent clone but has its own style. Think of a band that plays a cover tune. Most people know that "Satisfaction" is a rock song written by the Rolling Stones yet whether it is played by Devo, Otis Redding or Vanilla Ice we clearly recognize the original song. Clonal variation is caused by three things:

--Spontaneous Mutation: this is where the vine's genetic material changes within a season. Although there are a variety of theories of why and how this happens, certain grape varieties are more prone to spontaneous mutation than others. The Pinot family is basically a family of mutations. I was walking through a young vineyard of Pinot Noir and stopped at a vine where half the vine had grayish-pink grapes and the other half had black grapes. The vineyard owner told me that of the 9 acre plot at least one vine a year suddenly changes into a different clone of Pinot.

--Vine Evolution or Adaptation: most vines are very stable but adaptable creatures. Over time they begin to adjust to the climate and soil conditions of a specific area. This slow evolution creates what some will call a second generation clone. As a vineyard owner walks through a section of older vines it becomes obvious that certain vines seem to grow better and live longer than others. The vigneron will then take cuttings of the best vines which can be used to propagate new vineyards or replant the current vineyard when the vines get too old.

--Viral Disease: The phylloxera out break in the late 1880's in Europe has had a dramatic world wide impact on vine health. Phylloxera is a louse that feeds on vine roots, but certain root stocks are resistant to it, so today all vines are grafted onto phylloxera-resistant root stock. Although grafting saved the vine from the deadly pest, the grafting union provides access for less lethal viral diseases. It may take years for a vine to show a viral infection and during that time it will genetically alter itself trying to fight off the organism. This genetic modification makes the vine slightly different than the mother vine. If a cutting is taken and cleaned, the new clone will be stronger and more resistant to the specific viral organism that attacked it.

Clones are not Crosses and Hybrids
These terms are often confused but refer to very different vines. A Cross is the breeding of a new grape variety by cross-pollinating two vines from the same species. Muller Thurgau and Pinotage are two well know crosses. Muller-Thurgau was created by crossing the Riesling vine with the Silvaner vine while Pinotage was a cross between the Pinot Noir vine and the Cinsault vine. These vines are all part of the same species – Vitus Vinifera. A Hybrid is the cross pollination between two different grape species like Vitus Vinifera with Vitus Labrusca. Chambourcin and Vidal Blanc are two popular hybrids.

Popular Clones
Many wineries are beginning to refer to clonal selection on the front and back labels of a wine. For example, Merryvale produces it's much sought after Beckstoffer Clone 6 Cabernet, while Morgan produces their 12 clone Pinot Noir referring to the number of different Pinot clones planted in their vineyards. Although this is good information to have, it does not really tell the customer what impact the clone has had on the wine style. That will take a little more investigation. Below are some common clones that you will find on front and back labels and what makes them unique.

Cabernet Clones:
California Clone 24 – Naturally low yielding vine with small clusters and small berries that produces hard and tannic wines in their youth with higher natural acidity. This clone is found in many old mountain vineyards such as Laurel Glen. Although difficult to tame, in the right hands it produces a wine that will age gracefully.

Beckstoffer Clone 6 – This clone produces very intense, small, thick-skinned berries which are high in anthocyanins.

California Clone 22 – Moderate yielding vine with moderate size berries and higher pH (This term refers to grape ripeness expressed as an acidic solution). A grape with high pH results in a less tart and more fruit driven style of cabernet. This is a popular clone where volume and immediate drinkability is important.

Chardonnay Clones:
California Clone 4 – This vine produces fewer clusters but with larger berries and a heavier cluster weight. The grapes are naturally higher in acidity and have highly soluble solids which provide very flavorful berries. J. Lohr grows this clone throughout Monterey.

UC Davis Clone 108 – A vigorous clone that ripens late with a high pH. The result is a wine lower in acid with a fat, ripe and round texture. This clone favors the warmer growing regions of California where volume is important.

Dijon Clone Family – The late bud break but early ripening times of this family of clones make them ideal for the cooler Oregon climate. Naturally low yielding with moderate berry weight, these vines produce wines with naturally higher acidity. D75, D76, D78, D95 are some of the more popular Dijon Clones you will find listed.

Pinot Noir Clones:
Clone 828 – Touted by Archery Summit, Morgan and Merry Edwards, this clone produces naturally low yields with small berries and a lower pH with more dense color pigmentation in the grape skin. This low pH results in a very tart wine while the dense pigmentation in the skin produces deeper colored Pinots.

Dijon Clone 115 – Provides ripe, high pH(low acid) fruit with small and tight clusters and high anthocyanins. It produces richly textured, flavorful wine that is more round and supple.

Pommard – This clone produces well-structured Pinot that is high in tannin and dark fruits and has a somewhat meaty, syrah-like character. This is Old School Pinot that is fading in favor of newer clones.

Although selecting the proper clones can improve wine quality and help capture site identity and provide complexity, there is no such thing as a "perfect" clone. No clone can overcome a winemakers/grower's inappropriate site selection or poor management decisions. It can not compensate for heavy handed winemaking or the harvesting of unbalanced grapes. If clonal selection is just being used as a buzz word to show they have something different consumers will see it as nothing but a marketing ploy. But if the winery is serious about harvesting balanced grapes where sugar and phenolic ripeness happen in harmony thus producing grapes with the proper pH, sugar and acid, clonal selection will help the winemaker create a truly distinctive wine that expresses Mother Nature in the glass.

Clonal Information from:
Vines.Org Encyclopedia
American Vineyard Foundation
J. Lohr Vineyard Development
Beckstoffer Vineyard Development
Morgan Winery
UC Davis Foundation Plant Material Services